Amniiotic Band Syndrome Cleft lip/palate Congenital Limb defects Duodenal Atresia

Hydrocephalus Spina Bifida Patau Syndrome

Down Syndrome Achondroplasia Clubfoot

Gastroschisis Hypospadias Tracheoesophageal Fistula

Congenital Abnormalities in Babies

Some babies are born with certain abnormalities, which are present at the time of the birth of the baby. These are known as congenital abnormalities. These abnormalities are a result of problems, while the baby was developing in the fetus or because of complications during labor. These may be hereditary abnormalities. The causes of more than half of the congenital abnormalities in human are unknown. They are referred to as sporadic.

Amniotic Band SyndromeAmniotic band syndrome is caused when the amnion, the

inner layer of the placenta, breaks by chance. This causes amniotic fibrous bands to float in the amniotic fluid and potentially wrap around parts of the baby. Most commonly the bands will get entangled with the baby's arms, legs, fingers, and toes, although sometimes the bands can wrap around the baby's head or umbilical cord which can be life-threatening. The bands will partially constrict the blood flow in the affected appendage causing a deep groove in the baby's skin. Sometimes the constriction can be very severe causing amputation.Natural History

To explain the cause of ABS, there are two main theories.

The amniotic band theory is that ABS occurs due to a partial rupture of the amniotic sac. This rupture involves only the amnion; the chorion remains intact. Fibrous bands of the ruptured amnion float in the amniotic fluid and can encircle and trap some part of the fetus. Later, as the fetus grows but the bands do not, the bands become constricting. This constriction reduces blood circulation, hence causes congenital abnormalities. In some cases a complete "natural" amputation of a digit(s) or limb may occur before birth or the digit(s) or limbs may be necrotic (dead) and require surgical amputation following birth.

The vascular disruption theory: Because the constricting mechanism of the amniotic band theory does not explain the high incidence of cleft palate and other forms of cleft defects

occurring together with ABS, this co-occurrence suggests an "intrinsic" defect of the blood circulation.Diagnosis

Amniotic band syndrome is often difficult to detect before birth as the individual strands are small and hard to see on ultrasound. Often the bands are detected indirectly because of the constrictions and swelling upon limbs, digits, etc. Misdiagnosis is also common, so if there are any signs of amniotic bands, further detailed ultrasound tests should be done to assess the severity. 3D ultrasound and MRI can be used for more detailed and accurate diagnosis of bands and the resulting damage/danger to the fetus.Treatment

Treatment usually occurs after birth and where plastic and reconstructive surgery is considered to treat the resulting deformity. Plastic surgery ranges from simple to complex depending on the extent of the deformity. Physical and occupational therapy may be needed long term.

In rare cases, if diagnosed in utero, fetal surgery may be considered to save a limb which is in danger of amputation or other deformity. This typically would not be attempted if neither vital organs nor the umbilical cord are affected. This operation has been able to be successfully performed on foetuses as young as 22 weeks. The surgery took place at Melbourne's Monash Medical Centre in Australia and is believed to be the earliest surgery of its type, as surgeons usually hold off on operating until a mother is at least 28 weeks gestation. There are also several facilities in the United States that have performed successful amniotic band release surgery.Prognosis

The prognosis depends on the location and severity of the constricting bands. Every case is different and multiple bands may be entangled around the fetus.Bands which wrap around fingers and toes can result in syndactyly or amputations of the digits. In other instances, bands can wrap around limbs causing restriction of movement resulting in clubbed feet. In more severe cases, the bands can constrict the limb causing decreased blood supply and amputation. Amniotic bands can also sometimes attach to the face or neck causing deformities such as cleft lip and palate. If the bands become wrapped around the head or umbilical cord it can be life threatening for the fetus.

The number of cases of miscarriage that can be contributed to ABS is unknown, although it has been reported that it may be the cause of 178 in 10,000 miscarriages.

Cleft lip/palateA cleft lip is a narrow opening along the upper lip that can

extend all the way to the nostrils. The defect can be large or small, on one side of the face (unilateral) or both (bilateral). Oftentimes cleft lip is accompanied by cleft palate, a defect in the roof of the mouth or the soft tissues at the back of the mouth. Many cases of cleft lip present with other birth defects that may or may not be obvious.This is a very treatable condition and in most cases the cleft lip can be repaired with reconstructive surgery in early infancy, greatly improving the child's facial appearence.Causes

The development of the face is coordinated by complex morphogenetic events and rapid proliferative expansion, and is thus highly susceptible to environmental and genetic factors, rationalising the high incidence of facial malformations. During the first six to eight weeks of pregnancy, the shape of the embryo's head is formed. Five primitive tissue lobes grow:

a) one from the top of the head down towards the future upper lip; (Frontonasal Prominence)b-c) two from the cheeks, which meet the first lobe to form the upper lip; (Maxillar Prominence)

d-e) and just below, two additional lobes grow from each side, which form the chin and lower lip; (Mandibular Prominence)

If these tissues fail to meet, a gap appears where the tissues should have joined (fused). This may happen in any single joining site, or simultaneously in several or all of them. The resulting birth defect reflects the locations and severity of individual fusion failures (e.g., from a small lip or palate fissure up to a completely malformed face).The upper lip is formed earlier than the palate, from the first three lobes named a to c above. Formation of the palate is the last step in joining the five embryonic facial lobes, and involves the back portions of the lobes b and c. These back portions are called palatal shelves, which grow towards each other until they fuse in the middle. This process is very vulnerable to multiple toxic substances, environmental pollutants, and nutritional imbalance. The biologic mechanisms of mutual recognition of the two cabinets, and the way they are glued together, are quite complex and obscure despite intensive scientific research. Genetic factors contributing to cleft lip and cleft palate formation have been identified for some syndromic cases, but knowledge about genetic factors that contribute to the more common isolated cases of cleft lip/palate is still patchy.Syndromic cases: The Van der Woude

Syndrome is caused by a specific variation in the gene IRF6 that increases the occurrence of these deformities threefold. Another syndrome, Siderius X-linked mental retardation, is caused by mutations in the PHF8 gene (OMIM 300263); in addition to cleft lip and/or palate, symptoms include facial dysmorphism and mild mental retardation. In some cases, cleft palate is caused by syndromes which also cause other

problems. Stickler's Syndrome can cause cleft lip and palate, joint pain, and myopia. Loeys-Dietz syndrome can cause cleft palate or bifid uvula, hypertelorism, and aortic aneurysm. Cleft lip/palate may be present in many different chromosome disorders including Patau Syndrome (trisomy 13).Non-syndromic cases: Many genes associated with syndromic cases of cleft lip/palate (see above) have been identified to contribute to the incidence of isolated cases of cleft lip/palate. This includes in particular sequence variants in the genes IRF6, PVRL1 and MSX1. The understanding of the genetic complexities involved in the morphogenesis of the midface, including molecular and cellular processes, has been greatly aided by research on animal models, including of the genes BMP4, SHH, SHOX2, FGF10 and MSX1. If a person is born with a cleft, the chances of that person

having a child with a cleft, given no other obvious factor, rises to 1 in 14. Many clefts run in families, even though in some cases there does not seem to be an identifiable syndrome present, possibly because of the current incomplete genetic understanding of midfacial development.

Environmental influences may also cause, or interact with genetics to produce, orofacial clefting. An example for how environmental factors might be linked to genetics comes from research on mutations in the gene PHF8 that cause cleft lip/palate (see above). It was found that PHF8 encodes for a histone lysine demethylase, and is involved in epigenetic regulation. The catalytic activity of PHF8 depends on molecular oxygen, a fact considered important with respect to reports on increased incidence of cleft lip/palate in mice that have been exposed to hypoxia early during pregnancy. In humans, fetal cleft lip and other congenital abnormalities have also been linked to maternal hypoxia, as caused by e.g. maternal smoking, maternal alcohol abuse or some forms of maternal hypertension treatment. Other environmental factors that have been studied include: seasonal causes (such as pesticide exposure); maternal diet and vitamin intake; retinoids - which are members of the vitamin A

family; anticonvulsant drugs; alcohol; cigarette use; nitrate compounds; organic solvents; parental exposure to lead; and illegal drugs (cocaine, crack cocaine, heroin, etc).

Current research continues to investigate the extent to which Folic acid can reduce the incidence of clefting.

Congenital Limb DefectsCongenital limb defects is a term used to describe any

number of defects affecting the upper or lower limb. These defects may range in severity from mild to severe. In some cases, such as syndactyly of the toes, the defects is often left alone and the baby will grow up with no problems. Other cases may require surgery or possibly a prosthesis (artificial limb).Some common classifications of limb defects are:Phocomelia - The limbs are smaller or much shorter than normal.Polydactyly - Extra toes or fingers.Syndactyly - Commonly seen as "webbed" toes or fingers.Absent radius - The radius, one of the bones in the forearm, is small or missing altogether causing the forearm to shorten and curve.CausesThe cause of congenital limb defects is unknown. However, risk factors that may increase the likelihood of a congenital limb defect include the following:

conditions affecting the baby in the uterus during development

exposures by the mother to chemicals or viruses while pregnant

specific medications

Classification complete absence of the limb failure of the portion of the limb to separate

(commonly seen in fingers or toes) duplication (commonly seen as extra fingers or

toes)

overgrowth, the limb is much larger than the normal limb

undergrowth, the limb is much smaller than the normal limb

congenital constriction band syndrome - early rupture of the amnion (inner membranes that cover the fetus in utero and contains the amnionic fluid) resulting in bands that may become entangled in the extremities of the fetus, causing immobilization, constrictions of the limbs, amputations, and other deformities.

TreatmentSpecific treatment for congenital limb defects will

be determined by your child's physician based on: your child's age, overall health, and medical

history the extent of the condition

the type of condition

your child's tolerance for specific medications, procedures, or therapies

expectations for the course of the condition

your opinion or preference

The overall goal for treatment of congenital limb defects is to provide the child with a limb that has proper function and appearance. Treatment goals can vary for each child. Some goals may include the following:

promoting normal development discovering sense of independence encouraging self-care improving cosmetic appearance adaptation

There are no standardized treatment protocols for congenital limb defects. Treatment options may include:

prosthetics (artificial limbs) orthotics (splints or braces) surgery rehabilitation (physical or occupational therapy)

Duodenal AtresiaDuodenal atresia is a defect in which the duodenum, the

first part of the small intestine, has not developed correctly. Part of the duodenum is sealed shut and food and liquids cannot pass. This condition is often associated with other congenital defects. Surgical intervention is required to correct the duodenal blockage and allow the baby to digest food normally.

HydrocephalusHydrocephalus is a condition in which there is excessive

fluid accumulation in the brain. Cerebral spinal fluid is what surrounds the brain and spinal cord and cushions them. When there is too much cerebral spinal fluid it can build up in the ventricles, or spaces, in the brain. This can cause pressure on the tissues of the brain as well as cause the baby's head to enlarge.Hydrocephalus is most often treated with a surgically placed shunt. The shunt diverts the cerebral spinal fluid away from the brain and to another part of the body where the fluid can be safely and effectively absorbed.Early Symptoms Eyes that appear to gaze downward Irritability Seizures Separated sutures Sleepiness Vomiting

ClassificationHydrocephalus can be caused by impaired cerebrospinal

fluid (CSF) flow, reabsorption, or excessive CSF production. The most common cause of hydrocephalus is CSF

flow obstruction, hindering the free passage of cerebrospinal fluid through the ventricular system and subarachnoid space (e.g.,stenosis of the cerebral aqueduct or obstruction of the interventricular foramina - foramina of Monro secondary to tumors, hemorrhages, infections or  congenital malformations).

Hydrocephalus can also be caused by overproduction of cerebrospinal fluid (relative obstruction) (e.g., papilloma of choroid plexus).Based on its underlying mechanisms, hydrocephalus can be

classified into communicating and non-communicating (obstructive). Both forms can be either congenital or acquired.Treatment

Hydrocephalus treatment is surgical. It involves the placement of a ventricular catheter (a tube made of silastic), into the cerebral ventricles to bypass the flow obstruction/malfunctioningarachnoidal granulations and drain the excess fluid into other body cavities, from where it can be resorbed. Most shunts drain the fluid into the peritoneal cavity (ventriculo-peritoneal shunt), but alternative sites include the right atrium (ventriculo-atrial shunt), pleural cavity (ventriculo-pleural shunt), and gallbladder. A shunt system can also be placed in the lumbar space of the spine and have the CSF redirected to the peritoneal cavity (Lumbar-peritoneal shunt). An alternative treatment for obstructive hydrocephalus in selected patients is theendoscopic third ventriculostomy (ETV), whereby a surgically created opening in the floor of the third ventricle allows the CSF to flow directly to the basal cisterns, thereby shortcutting any obstruction, as in aqueductal stenosis. This may or may not be appropriate based on individual anatomy.

Spina Bifida

Spina bifida is a condition which affects the vertebrae, or backbones, and sometimes the spinal cord. 70% of spina bifida cases are preventable by taking adequate amounts of folate vitamin during pregnancy.

There are several forms of spina bifida. The mildest form is occulta, where the only visible evidence is a tuft of hair on the back. The next two forms are spina bifida with meningocele and spina bifida with meningomyelocele. In these two cases a cyst-like sac protrudes from the back, in the first case only containing cerebral spinal fluid, but in meningomyelocele, the cyst contains part of the spinal cord.

In the most severe form, spina bifida with myeloschiscis, the cyst is open and the spinal cord is exposed to the outside elements. 

The defect usually can be repaired at birth if it is small and isolated. Experimental surgery is also being done now while the baby is still in the womb.ClassificationSpina bifida occulta

Occulta is Latin for "hidden." This is one of the mildest forms of spina bifida.

In occulta, the outer part of some of the vertebrae are not completely closed. The split in the vertebrae is so small that the spinal cord does not protrude. The skin at the site of the lesion may be normal, or it may have some hair growing from it; there may be a dimple in the skin, alipoma, a dermal sinus or a birthmark.

Many people with the mildest form of this type of spina bifida do not even know they have it, as the condition is asymptomatic in most cases. A systematic review of radiographic research studies found no relationship between spina bifida occulta and back pain. More recent studies not included in the review support the negative findings. However, other studies suggest spina bifida occulta is not always harmless. One study found that among patients with back pain, severity is worse if spina bifida occulta is present.

Spina bifida cysticaIn spina bifida cystica, a cyst protrudes through the

defect in the vertebral arch. These conditions can be diagnosed in utero on the basis of elevated levels of alpha-fetoprotein, after amniocentesis, and by ultrasound imaging. Spina bifida cystica may result in hydrocephalus and neurological deficits.Meningocele

The least common form of spina bifida is a posterior meningocele (or meningeal cyst).In a posterior meningocele, the vertebrae develop normally, however the meninges are forced into the gaps between the vertebrae. As the nervous system remains undamaged, individuals with meningocele are unlikely to suffer long-term health problems, although there are reports of tethered cord. Causes of meningocele include teratoma and other tumors of thesacrococcyx and of the presacral space, and Currarino syndrome, Bony defect with outpouching of meninges. Myelomeningocele

In this, the most serious and common form, the unfused portion of the spinal column allows the spinal cord to protrude through an opening. The meningeal membranes that cover the spinal cord form a sac enclosing the spinal elements. Spina bifida with myeloschisis is the most severe form of spina bifida cystica. In this defect, the involved area is represented by a flattened, plate-like mass of nervous tissue with no overlying membrane. The exposure of these nerves and tissues make the baby more prone to life-threatening infections.

The protruded portion of the spinal cord and the nerves which originate at that level of the cord are damaged or not properly developed. As a result, there is usually some degree of paralysis and loss of sensation below the level of the spinal cord defect. Thus, the higher the level of the defect the more severe the associated nerve dysfunction and resultant paralysis. People may have ambulatory problems, loss of sensation, deformities of the hips, knees or feet and loss of muscle tone. Depending on the location of the lesion, intense pain may occur originating in the lower back, and continuing down the leg to the back of the knee.

Many individuals with spina bifida will have an associated abnormality of the cerebellum, called the Arnold Chiari II malformation. In affected individuals the back portion of the brain is displaced from the back of the skull down into the upper neck. In approximately 90 percent of the people with myelomeningocele, hydrocephalus will also occur because the displaced cerebellum interferes with the normal flow of cerebrospinal fluid.The myelomeningocele (or perhaps the scarring due to surgery) tethers the spinal cord. In some individuals this causes significant traction on the spinal cord and can lead to a worsening of the paralysis, scoliosis, back pain, or worsening bowel and/or bladder function.Signs and Symptoms

Children with spina bifida often have hydrocephalus, which consists of excessive accumulation of cerebrospinal fluid in the ventricles of the brain.

According to the Spina Bifida Association of America (SBAA), over 73 percent of people with spina bifida develop an allergy to latex, ranging from mild to life-threatening. The common use of latex in medical facilities makes this a particularly serious concern. The most common approach to avoid developing an allergy is to avoid contact with latex-containing products such as examination gloves, condoms, catheters, and many of the products used by dentists. Prevention

There is no single cause of spina bifida nor any known way to prevent it entirely. However, dietary supplementation with folic acid has been shown to be helpful in preventing spina bifida (see above). Sources of folic acid include whole grains, fortified breakfast cereals, dried beans, leaf vegetables and fruits.

Folate fortification of enriched grain products has been mandatory in the United States since 1998. The U.S. Food and Drug Administration, Public Health Agency of Canada and UK recommended amount of folic acid for women of childbearing age and women planning to become pregnant is at least 0.4 mg/day of folic acid from at least three months

beforeconception, and continued for the first 12 weeks of pregnancy. Women who have already had a baby with spina bifida or other type of neural tube defect, or are taking anticonvulsantmedication should take a higher dose of 4–5 mg/day. Certain mutations in the gene VANGL1 are implicated as a risk factor for spina bifida: these mutations have been linked with spina bifida in some families with a history of spina bifida. Pregnancy screening

Neural tube defects can usually be detected during pregnancy by testing the mother's blood (AFP screening) or a detailed fetal ultrasound. Spina bifida may be associated with other malformations as in dysmorphic syndromes, often resulting in spontaneous miscarriage. However, in the majority of cases spina bifida is an isolated malformation.

Genetic counseling and further genetic testing, such as amniocentesis, may be offered during the pregnancy as some neural tube defects are associated with genetic disorders such astrisomy 18. Ultrasound screening for spina bifida is partly responsible for the decline in new cases, because many pregnancies are terminated out of fear that a newborn might have a poor future quality of life. With modern medical care, the quality of life of patients has greatly improved. Treatment

There is no known cure for nerve damage due to spina bifida. To prevent further damage of the nervous tissue and to prevent infection, pediatric neurosurgeons operate to close the opening on the back. During the operation for spina bifida cystica, the spinal cord and its nerve roots are put back inside the spine and covered with meninges. In addition, a shunt may be surgically installed to provide a continuous drain for the cerebrospinal fluid produced in the brain, as happens with hydrocephalus. Shunts most commonly drain into the abdomen. However, if spina bifida is detected during pregnancy, then open fetal surgery can be performed.

Most individuals with myelomeningocele will need periodic evaluations by specialists including orthopedists to check on their bones and muscles, neurosurgeons to evaluate the brain and spinal cord and urologists for the kidneys and

bladder. Such care is best begun immediately after birth. Most affected individuals will require braces, crutches, walkers or wheelchairs to maximize their mobility. As a general rule, the higher the level of the spina bifida defect the more severe the paralysis, but paralysis does not always occur. Thus, those with low levels may need only short leg braces while those with higher levels do best with a wheelchair, and some may be able to walk unaided. Many will need to manage their urinary system with a program of catheterization. Most will also require some sort of bowel management program, though some may be virtually unaffected.

Patau Syndrome (Trisomy 13) Trisomies occur when there is a triplet of a specific

chromosome instead of the normal number of 2. The most common trisomy is trisomy 21 or Down syndrome. In Patau syndrome there is an extra chromosome 13 resulting in multiple and often severe physical and mental abnormalities. Some physical characteristics are flattened facial features, malformed and low-set ears, cleft lip and/or palate, prominent heels, and genital malformations. Often there are problems with the nervous system, including forebrain development, spinal cord development, mental retardation, and seizures. Vision and eye problems are common, as well as respiratory and heart defects. Approximately 45% of Patau syndrome babies die within the first month of life, while the number increases to 70% in the first 6 months.Causes

Most cases of Patau's syndrome result from trisomy 13, which means each cell in the body has three copies of chromosome 13 instead of the usual two copies. A small percentage of cases occur when only some of the body's cells have an extra copy, resulting in a mixed population of cells with a differing number of chromosomes; such cases are called mosaic Patau.

Patau syndrome can also occur when part of chromosome 13 becomes attached to another chromosome (translocated) before or at conception. Affected people have two copies of chromosome 13, plus extra material from chromosome 13 attached to another chromosome. With a translocation, the person has a partial trisomy for chromosome 13 and often the physical signs of the syndrome differ from the typical Patau syndrome.

Most cases of Patau syndrome are not inherited, but occur as random events during the formation of reproductive cells (eggs and sperm). An error in cell division called non-disjunctioncan result in reproductive cells with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of the chromosome. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 13 in each of the body's cells. Mosaic Patau syndrome is also not inherited. It occurs as a random error during cell division early in fetal development.

Patau syndrome due to a translocation can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 13 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 13. Although they do not have signs of Patau syndrome, people who carry this type of balanced translocation are at an increased risk of having children with the condition.Clinical Manifestations

Of those fetuses that do survive to gestation and subsequent birth, common abnormalites include: Nervous system

mental & motor challenged microcephaly holoprosencephaly (failure of the forebrain to

divide properly). structural eye defects,

including microphthalmia, Peters anomaly, cataract, iris and/or fundus (coloboma), retinal dysplasia or retinal

detachment, sensory nystagmus, cortical visual loss, and optic nerve hypoplasia

meningomyelocele (a spinal defect) Musculoskeletal and cutaneous

polydactyly (extra digits) low-set ears prominent heel deformed feet known as rocker-bottom feet omphalocele (abdominal defect) abnormal palm pattern overlapping of fingers over thumb cutis aplasia (missing portion of the skin/hair) cleft palate

Urogenital abnormal genitalia kidney defects

Other heart defects (ventricular septal defect) single umbilical artery

TreatmentMedical management of children with Trisomy 13 is

planned on a case-by-case basis and depends on the individual circumstances of the patient. Treatment of Patau syndrome focuses on the particular physical problems with which each child is born. Many infants have difficulty surviving the first few days or weeks due to severe neurological problems or complex heart defects. Surgery may be necessary to repair heart defects or cleft lip and cleft palate. Physical, occupational, and speech therapy will help individuals with Patau syndrome reach their full developmental potential.

Down Syndrome (Trisomy 21) Down syndrome is a chromosomal disorder which

causes physical and intellectual delays in development and occurs when there are 3 chromosome 21's, resulting in 47 total chromosomes instead of the normal 46. The most common

clinical features are short neck and flat face, upward slanting eyes, low muscle tone and a single crease across the palm of the hand. Congenital heart defects accompany Down syndrome in about 40% of the cases. Vision and hearing problems are also common.Cause

Normally, at the time of conception a baby inherits genetic information from its parents in the form of 46 chromosomes: 23 from the mother and 23 from the father. In most cases of Down syndrome, a child gets an extra chromosome 21 — for a total of 47 chromosomes instead of 46. It's this extra genetic material that causes the physical features and developmental delays associated with DS.

Although no one knows for sure why DS occurs and there's no way to prevent the chromosomal error that causes it, scientists do know that women age 35 and older have a significantly higher risk of having a child with the condition. At age 30, for example, a woman has about a 1 in 900 chance of conceiving a child with DS. Those odds increase to about 1 in 350 by age 35. By 40 the risk rises to about 1 in 100.Medical Problems Associated With DS

While some kids with DS have no significant health problems, others may experience a host of medical issues that require extra care. For example, almost half of all children born with DS will have a congenital heart defect.

Kids with Down syndrome are also at an increased risk of developing pulmonary hypertension, a serious condition that can lead to irreversible damage to the lungs. All infants with Down syndrome should be evaluated by a pediatric cardiologist.

Approximately half of all kids with DS also have problems with hearing and vision. Hearing loss can be related to fluid buildup in the inner ear or to structural problems of the ear itself. Vision problems commonly include amblyopia (lazy eye), near- or farsightedness, and an increased risk of cataracts. Regular evaluations by an audiologist and an ophthalmologist are necessary to detect and correct any problems before they affect language and learning skills.Prenatal Screening and Diagnosis

Two types of prenatal tests are used to detect Down syndrome in a fetus: screening tests and diagnostic tests. Screening tests estimate the risk that a fetus has DS; diagnostic tests can tell whether the fetus actually has the condition.

Screening tests are cost-effective and easy to perform. But because they can't give a definitive answer as to whether a baby has DS, these tests are used to help parents decide whether to have more diagnostic tests.

Diagnostic tests are about 99% accurate in detecting Down syndrome and other chromosomal abnormalities. However, because they're performed inside the uterus, they are associated with a risk of miscarriage and other complications.

For this reason, invasive diagnostic testing previously was generally recommended only for women age 35 or older, those with a family history of genetic defects, or those who've had an abnormal result on a screening test.

However, the American College of Obstetrics and Gynecology (ACOG) now recommends that all pregnant women be offered screening with the option for invasive diagnostic testing for Down syndrome, regardless of age.

If you're unsure about which test, if any, is right for you, your doctor or a genetic counselor can help you sort through the pros and cons of each.Screening tests include: Nuchal translucency testing. This test, performed

between 11 and 14 weeks of pregnancy, uses ultrasound to measure the clear space in the folds of tissue behind a developing baby's neck. (Babies with DS and other chromosomal abnormalities tend to accumulate fluid there, making the space appear larger.) This measurement, taken together with the mother's age and the baby's gestational age, can be used to calculate the odds that the baby has DS. Nuchal translucency testing is usually performed along with a maternal blood test.

The triple screen or quadruple screen (also called the multiple marker test). These tests measure the quantities of normal substances in the mother's blood. As the names imply, triple screen tests for three markers and quadruple screen includes one additional marker and is more

accurate. These tests are typically offered between 15 and 18 weeks of pregnancy.

Integrated screen. This uses results from first trimester screening tests (with or without nuchal translucency) and blood tests with second trimester quad screen to come up with the most accurate screening results.

A genetic ultrasound. A detailed ultrasound is often performed at 18 to 20 weeks in conjunction with the blood tests, and it checks the fetus for some of the physical traits abnormalities associated with Down syndrome.

Diagnostic tests include: Chorionic villus sampling (CVS). CVS involves taking a

tiny sample of the placenta, either through the cervix or through a needle inserted in the abdomen. The advantage of this test is that it can be performed during the first trimester, between 8 and 12 weeks. The disadvantage is that it carries a slightly greater risk of miscarriage as compared with amniocentesis and has other complications.

Amniocentesis. This test, performed between 15 and 20 weeks of pregnancy, involves the removal of a small amount of amniotic fluid through a needle inserted in the abdomen. The cells can then be analyzed for the presence of chromosomal abnormalities. Amniocentesis carries a small risk of complications, such as preterm labor and miscarriage.

Percutaneous umbilical blood sampling (PUBS). Usually performed after 20 weeks, this test uses a needle to retrieve a small sample of blood from the umbilical cord. It carries risks similar to those associated with amniocentesis.

After a baby is born, if the doctor suspects DS based on the infant's physical characteristics, a karyotype — a blood or tissue sample stained to show chromosomes grouped by size, number, and shape — can be performed to verify the diagnosis.

AchondroplasiaAchondroplasia, a form of dwarfism, is a bone growth

abnormality. This disorder is considered a short-limb dysplasia

which means that people with achondroplasia have an average-sized torso with small arms and legs. It can be caused by a spontaneous gene mutation or it can be inherited from a parent who has achondroplasia.People with achondroplasia have relatively short upper arms and upper legs. They also may have shortened hands and stubby fingers, a large head with a prominent forehead and a flattened bridge of the nose, and sometimes reduced muscle tone. Usually the average full-grown height for someone with this disorder is around 4 feet.Causes

Achondroplasia is one of a group of disorders called chondrodystrophies or osteochondrodysplasias.

Achondroplasia may be inherited as an autosomal dominant trait, which means that if a child gets the defective gene from one parent, the child will have the disorder. If one parent has achondroplasia, the infant has a 50% chance of inheriting the disorder. If both parents have the condition, the infant's chances of being affected increase to 75%.

However, most cases appear as spontaneous mutations. This means that two parents without achondroplasia may give birth to a baby with the condition.SymptomsThe typical appearance of achondroplastic dwarfism can be seen at birth. Symptoms may include:

Abnormal hand appearance with persistent space between the long and ring fingers

Bowed legs Decreased muscle tone Disproportionately large head-to-body size difference Prominent forehead (frontal bossing) Shortened arms and legs (especially the upper arm and

thigh) Short stature (significantly below the average height for a

person of the same age and sex) Spinal stenosis Spine curvatures called kyphosis and lordosis

Exams and TestsDuring pregnancy, a prenatal ultrasound may show

excessive amniotic fluid surrounding the unborn infant.Examination of the infant after birth shows increased

front-to-back head size. There may be signs of hydrocephalus ("water on the brain").

X-rays of the long bones can reveal achondroplasia in the newborn.Treatment

There is no specific treatment for achondroplasia. Related abnormalities, including spinal stenosis and spinal cord compression, should be treated when they cause problems.Prognosis

People with achondroplasia seldom reach 5 feet in height. Intelligence is in the normal range. Infants who receives the abnormal gene from both parents do not often live beyond a few months.Prevention

Genetic counseling may be helpful for prospective parents when one or both have achondroplasia. However, because achondroplasia most often develops spontaneously, prevention is not always possible.

Clubfoot Clubfoot refers to a condition in which the baby's foot is turned inward and downward at birth. It can be mild or severe, and can affect one or both feet. In many cases, the defect can be corrected using casts on the childs's feet and legs. Some cases may require surgery; however, the outcome is usually excellent and the child will go on to live a normal healthy life. Deformities

The deformities affecting joints of the foot occur at three joints of the foot to varying degrees. They are Inversion at subtalar joint Adduction at talonavicular joint and Equinus at ankle joint

The deformities can be remembered using the mnemonic, "InAdEquate" for Inversion, Adduction and Equinus.Causes

There are different causes for clubfoot depending on what classification it is given. Structural TEV is caused by genetic factors such as Edwards syndrome, a genetic defect with three copies of chromosome 18. Growth arrests at roughly 9 weeks and compartment syndrome of the affected limb are also causes of Structural TEV. Genetic influences increase dramatically with family history. It was previously assumed that postural TEV could be caused by external influences in the final trimester such as intrauterine compression fromoligohydramnios or from amniotic band syndrome. However, this is countered by findings that TEV does not occur more frequently than usual when the intrauterine space is restricted.Breech presentation is also another known cause.TEV occurs with some frequency in Ehlers Danlos Syndrome and some other connective tissue disorders. TEV may be associated with other birth defects such as spina bifida cystica.Treatment

Clubfoot is treated with manipulation by podiatrists, physiotherapists, orthopedic surgeons, specialist Ponseti nurses, or orthotists by providing braces to hold the feet in orthodox positions, serial casting, or splints called knee ankle foot orthoses (KAFO). Other orthotic options include Dennis-Brown bars with straight last boots, ankle foot orthoses and/or custom foot orthoses (CFO). In North America, manipulation is followed by serial casting, most often by the Ponseti Method. Foot manipulations usually begin within two weeks of birth. Even with successful treatment, when only one side is affected, that foot may be smaller than the other, and often that calf, as well.

Extensive surgery of the soft tissue or bone is not usually necessary to treat clubfoot; however, there are two minimal surgeries that may be required:

1. Tenotomy (needed in 80% of cases) is a release (clipping) of the Achilles tendon - minor surgery- local anesthesia

2. Anterior Tibial Tendon Transfer (needed in 20% of cases) - where the tendon is moved from the first ray (toe) to the third ray in order to release the inward traction on the foot.

Of course, each case is different, but in most cases extensive surgery is not needed to treat clubfoot. Extensive surgery may lead to scar tissue developing inside the child's foot. The scarring may result in functional, growth and aesthetic problems in the foot because the scarred tissue will interfere with the normal development of the appendage. A child who has extensive surgery may require on average two additional surgeries to correct the issues presented above.

In stretching and casting therapy the doctor changes the cast multiple times over a few weeks, gradually stretching tendons until the foot is in the correct position of external rotation. The heel cord is released (percutaneous tenotomy) and another cast is put on, which is removed after three weeks. To avoid relapse a corrective brace is worn for a gradually reducing time until it is only at night up to four years of age.

GastroschisisGastroschisis occurs when the intestines are displaced

outside of the abdomen through a defect in the abdominal wall. This condition is very similiar to an omphalocele, which is when the intestines are displaced out  and into the umbilical cord. These conditions can be surgically repaired at birth. As long as the bowel is not damaged, the outcome for the surgery is very good.  Causes

Gastroschisis is a type of hernia. Hernia means "rupture.” Babies with this condition have a hole in the abdominal wall, usually on the right side of the umbilical cord. The child's intestines usually stick out (protrude) through the hole.

The condition looks similar to an omphalocele. An omphalocele, however, is a birth defect in which the infant's intestine or other abdominal organs stick out of the belly button area and are covered with a membrane.

Other related birth defects are rare in patients with gastroschisis.Exams and Tests

Physical examination of the infant is enough for the health care provider to diagnose gastroschisis. The baby will have problems with movement and absorption in the gut, because the unprotected intestine is exposed to irritating amniotic fluid.

The mother may have shown signs of too much amniotic fluid (polyhydramnios). A prenatal ultrasound often identifies the gastroschisis.Treatment

If gastroschisis is found before birth, the mother will need special monitoring to make sure her unborn baby remains healthy. Plans should be made for careful delivery and immediate management of the problem after birth.

Treatment for gastroschisis is surgery to repair the defect. A surgeon will put the bowel back into the abdomen and close the defect, if possible. If the abdominal cavity is too small, a mesh sack is stitched around the borders of the defect and the edges of the defect are pulled up. Over time, the herniated intestine falls back into the abdominal cavity, and the defect can be closed.

Other treatments for the baby include nutrients by IV and antibiotics to prevent infection. The baby's temperature must be carefully controlled, because the exposed intestine allows a lot of body heat to escape.Prognosis

The child has a good chance of recovering if the abdominal cavity is large enough. A very small abdominal cavity may result in complications that require additional surgery.

HypospadiasHypospadias is an abnormality in the development of the

urethra, the tube that carries urine, in the penis. Normally the urethra extends the full length of the penis and its opening is at the glans or tip of the penis. With hypospadias, however, the opening can be anywhere along a line running down the

underside of the penis called the urethral groove. In the majority of the cases, first degree hypospadias, the opening is on the glans and these cases are the least severe. In the more severe cases the opening is on the shaft (second degree) or perineum (third degree), and can often involve other complications. Hypospadias is almost always surgically corrected in infancy.

Tracheoesophageal fistula A fistula is a tube. The esophagus is a tube that goes to

the stomach and the trachea is a tube that goes to the lungs. Normally these two tubes do not connect but when a baby has a tracheoesophageal fistula, there is a tube connecting the two. This can cause problems with feeding and even breathing in newborns and needs to be corrected.Causes

Although no definite cause exists for congenital TEFs, an association with trisomies 18, 21, and 13 has been reported.

Causes of acquired TEFs include iatrogenic injury, blunt chest or neck trauma, prolonged mechanical ventilation via endotracheal or tracheostomy tube, and excessive tube cuff pressure in patients ventilated for lung disease. Spigel et al investigated the development of TEFs in patients with small-cell and non-small-cell lung cancer. They reported their findings from 2 small, independent phase II clinical trials in which patients were administered bevacizumab combined with chemotherapy and radiation.3 Both trials were closed early for safety reasons. However, the data suggested an association between the use of bevacizumab and chemoradiotherapy and a relatively high incidence of TEFs in the settings of small-cell and non-small-cell lung cancer.

Clinical PresentationTracheoesophageal fistula is suggested in a newborn by

copious salivation associated with choking, coughing, vomiting, and cyanosis coincident with the onset of feeding. A fistula may also be a the cause of polyhydramnios while in utero.Treatment

It is surgically corrected, with resection of any fistula and anastomosis of any discontinuous segments. Surgical repair is associated with complications, including Stricture, due to gastric acid erosion of the shortened

esophagus. Leak of contents at the point of anastomosis. Recurrence of fistula.

Edwards Syndrome (Trisomy 18)  Trisomies occur when there is a triplet of a specific

chromosome instead of the normal number of 2. The most common trisomy is trisomy 21 or Down syndrome. In Edwards syndrome, or trisomy 18, there are 3 chromosome 18's. Patients with trisomy 18 can range from mildly to severely affected. Some characteristics of this syndrome are clenched hands, shield chest with short sternum, short neck, and small jaw. Heart defects are typical of trisomy 18, including ventricular septal defects, atrial septal defects, and coarctation of the aorta. Also common are omphaloceles (when a portion of the intestinal tract is located outside of the body) and kidney problems.Causes Trisomy 18. Majority of Edward's syndrome falls in this category. In a situation, where all cells of individual contains additional chromosome 18, is known as trisomy 18.Symptoms

Growth Deficiency, Abnormal skull shape and facial features, Clenched hands, Rocker bottom feet, Cardiac and renal abnormalities

TreatmentsThere is no specific and known treatment for Edward's Syndrome. The symptoms caused by Edward's syndrome are also manageable up to some extent.

Edward's syndrome may cause breathing and feeding difficulties and if proper assistance is offered to these

babies, some of the babies may overcome these initial difficulties.

Some children may have heart problem and difficulty in gaining weight.

A perfect nutritional diet may be suitable for these children.

The survival rate of infants having Edward's syndrome is extremely low.

Almost half the babies die before birth and a large percentage of infant's dies within one year of birth.

Most of the deaths are caused by heart abnormalities and apnea.

There are some reported cases of children living above 10 years of age.

Turner SyndromeTurner syndrome is a genetic defect in which one of the

two sex chromosomes is missing or defective. This disease affects 1 in 2500 live female births each year. The characteristics of Turner syndrome are multiple and vary widely from patient to patient. Most all individuals affected by this syndrome have short stature, usually growing to an adult height of around 4 feet 8 inches. Other common characteristics in appearance are a short, often webbed neck and low-set ears. Hands and feet may be swollen or puffy at birth and there may be the presence of colored spots on the skin. The loss of ovarian function is common early in childhood, meaning they will not enter puberty at the normal age, if ever. Some girls may have some breast development and begin menstruating but they normally cease development and menstruation within a few years. There are some heart defects that may occur along with Turner syndrome, such as coarctation of the aorta and bicuspid aortic valve. Osteoporosis is a common development with Turner syndrome patients, as well as type II diabetes and kidney problems.

Other Effects Turner Syndrome Can HaveA number of other health problems occur more often in

girls with Turner syndrome, including kidney problems, high blood pressure, heart problems, overweight, hearing difficulties, diabetes, andthyroid problems. Some girls with the condition may experience learning difficulties, particularly in math. Many have a difficult time with tasks that require skills such as map reading or visual organization.

In addition to short stature and lack of sexual development, some of the other physical features commonly seen in girls with Turner syndrome are: a "webbed" neck (extra folds of skin extending from the

tops of the shoulders to the sides of the neck) a low hairline at the back of the neck drooping of the eyelids differently shaped ears that are set lower on the sides of

the head than usual abnormal bone development (especially the bones of the

hands and elbows) a larger than usual number of moles on the skin edema or extra fluid in the hands and feet

Because Turner syndrome can affect how a girl looks and develops, some girls may have problems with body image or self-esteem.

People with TS are all different. Some may have many physical differences and symptoms, whereas others experience only a few medical problems. With early and appropriate medical care and ongoing support, most people with TS can lead normal, healthy, and productive lives.Diagnosing Turner Syndrome

Girls with Turner syndrome are usually diagnosed either at birth or around the time they might be expected to go through puberty. If a baby girl has some of the signs of Turner syndrome, a doctor will usually order a special blood test called a karyotype. The test counts the number of chromosomes and can identify any that are abnormally shaped or have missing pieces. In some cases, there are no recognizable signs that a girl has the condition until she reaches the age at which she would normally go through puberty.

If the karyotype blood test reveals that a girl has Turner syndrome, her doctor may order additional tests to check for problems with the kidneys, heart, hearing, and other problems that are often associated with Turner syndrome.Treating Turner Syndrome

Because Turner syndrome is a condition that is caused by a chromosomal abnormality, there's no specific cure. However, scientists have developed a number of treatments that can help correct some of the problems associated with the condition — such as growth problems — and researchers are constantly looking into new forms of treatment.

Growth hormone treatment can improve growth and influence a girl's final adult height. In fact, in many cases, the treatment can help many girls with Turner syndrome reach a final height in the average range, especially if treatment is started early enough in childhood.

Another treatment for Turner syndrome is estrogen replacement, which helps the girl develop the physical changes of puberty, including breast development and menstrual periods. This treatment is often started when a girl reaches about age 12 or 13.

And a technique called in vitro fertilization can make it possible for some women with Turner syndrome to become pregnant. A donor egg can be used to create an embryo, which is then put into the uterus (womb) of the woman with Turner syndrome. With proper supportive care, the woman can carry the

pregnancy to term and deliver a baby through the normal birth process.Living With Turner SyndromeAlthough people with Turner syndrome may have certain learning difficulties, the majority are able to attend regular school and classes and are generally able to:

write well learn well by hearing memorize information as well as others develop good language skills

If you have Turner syndrome, you know that it can affect you in several ways. But it's only a small part of your total physical, emotional, and intellectual self.

Here are some suggestions that can help you cope: Join a support group for girls with Turner syndrome. Ask

your doctor or parents for more information or for help finding a Turner Syndrome Society chapter in your area.

Stay active in sports or hobbies that you enjoy. Consider doing volunteer work. Helping other people can

boost your self-esteem and your confidence, too. Consider talking to a professional therapist. A qualified

counselor or other mental health professional can help you build your self-esteem and address your concerns about living with Turner syndrome. Discuss this with your parents if you think you might need help.

Keep a journal or diary in which you can record your thoughts and feelings about the challenges you're dealing with.

Talk to your parents or school counselor if you are having problems at school.