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A Healthy A Healthy PregnancyPregnancy

Unit TwoUnit TwoPrenatal Prenatal

DevelopmentDevelopment

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Objectives:Objectives: To name the three To name the three

stages of Pregnancystages of Pregnancy Describe the prenatal Describe the prenatal

development during development during each of the three each of the three stages of Pregnancystages of Pregnancy

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Prenatal DevelopmentPrenatal Development Prenatal development is the Prenatal development is the

development of the baby during the development of the baby during the period before birth. period before birth.

Prenatal development is considered Prenatal development is considered in three stages:in three stages:

1.1. Period of the Period of the ZygoteZygote2.2. Period of the Period of the EmbryoEmbryo3.3. Period of the Period of the FetusFetus

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Period of the Period of the ZygoteZygote

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ConceptionConception Conception occurs with the union of the Conception occurs with the union of the OvumOvum

(a female cell or egg) and the (a female cell or egg) and the Sperm Sperm (male (male cell).cell).

This union is called the This union is called the Zygote or Zygote or fertilized fertilized eggegg

This stage begins at conception and lasts until This stage begins at conception and lasts until the zygote is implanted in the mother’s uterus. the zygote is implanted in the mother’s uterus.

The period of the Zygote lasts approximately The period of the Zygote lasts approximately two weeks (10-14 days)two weeks (10-14 days)

The zygote grows to be about the size of a The zygote grows to be about the size of a pinhead. Roots grow from the zygote into the pinhead. Roots grow from the zygote into the wall of the uterus where they can receive wall of the uterus where they can receive nutrients from the mother’s blood.nutrients from the mother’s blood.

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ConceptionConception

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EmbryoEmbryo The 2The 2ndnd stage of pregnancy is he period of the stage of pregnancy is he period of the

embryoembryo The embryo is the developing cluster of cells in the The embryo is the developing cluster of cells in the

uterus & lasts from about 2 weeks to 8 weeks after uterus & lasts from about 2 weeks to 8 weeks after conception conception

The embryo is attached to the mother by the The embryo is attached to the mother by the umbilical cordumbilical cord (20 inches long) which reaches (20 inches long) which reaches from the embryo’s stomach to the wall of the uterus. from the embryo’s stomach to the wall of the uterus.

The The umbilical cordumbilical cord contains arteries which carry contains arteries which carry the embryo’s waste products away from the embryo the embryo’s waste products away from the embryo to the mother’s blood system to be purified. It also to the mother’s blood system to be purified. It also brings oxygenated and nutrient-rich blood back to brings oxygenated and nutrient-rich blood back to the embryo to keep it alive. the embryo to keep it alive.

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Period of the EmbryoPeriod of the EmbryoFirst MonthFirst Month

•By the end of the first month, the embryo is about 1/10 of an inch long. The heart, which is no larger than a poppy seed, has begun beating.

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Period of the EmbryoPeriod of the Embryo The umbilical cord is connected to the The umbilical cord is connected to the

placentaplacenta. . The The placentaplacenta is an organ which serves as a is an organ which serves as a

medium for the exchange of nutrients and medium for the exchange of nutrients and waste between the mother and the fetus.waste between the mother and the fetus.

Throughout this period, the embryo is inside Throughout this period, the embryo is inside the the amniotic sacamniotic sac (a bag filled with watery (a bag filled with watery substance called amniotic fluid). The fluid will substance called amniotic fluid). The fluid will protect the developing baby against bumps, protect the developing baby against bumps, bruises and temperature changes. bruises and temperature changes.

During this period all of the organs that will be During this period all of the organs that will be present at birth are formed.present at birth are formed.

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Embryo -Two MonthsEmbryo -Two Months The embryo is about The embryo is about

1 inch long1 inch long and has and has distinct, slightly distinct, slightly webbed fingers. webbed fingers. VeinsVeins are clearly are clearly visible. The visible. The heartheart has has divided into right and divided into right and left chambers.left chambers.

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FetusFetus The third development period is called the The third development period is called the

period of the period of the fetusfetus. . This period extends from the end of the second This period extends from the end of the second

month of pregnancy until birth. During this month of pregnancy until birth. During this stage, the developing baby is referred to as a stage, the developing baby is referred to as a fetusfetus. .

The body parts, organs and systems which were The body parts, organs and systems which were formed during the embryo period will become formed during the embryo period will become much more developed and begin to function. much more developed and begin to function.

The fetus will begin will begin to resemble a The fetus will begin will begin to resemble a human being and features will increase in human being and features will increase in clarity. clarity.

During the fetal period the baby may increase in During the fetal period the baby may increase in length as much as twelve inches.length as much as twelve inches.

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Three Month FetusThree Month Fetus By now the fetus is By now the fetus is 2 2

1/2 to 3 inches long1/2 to 3 inches long and is fully formed. and is fully formed. He has begun He has begun swallowing and swallowing and kicking.kicking.

All All organsorgans and and musclesmuscles have formed have formed and are beginning to and are beginning to function.function.

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QuickeningQuickening The sensation of feeling life called The sensation of feeling life called

quickeningquickening, tells the mother that , tells the mother that she does have a live within her child she does have a live within her child

This happens sometimes between This happens sometimes between the fourth or fifth monthsthe fourth or fifth months

These fluttering movements are faint These fluttering movements are faint or infrequent a first but gradually or infrequent a first but gradually become sronger and more frequent.become sronger and more frequent.

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Fetus - Fourth MonthFetus - Fourth Month Your baby is covered Your baby is covered

with a layer of thick, with a layer of thick, downy hair called downy hair called lanugo.lanugo.

His heartbeat can be His heartbeat can be heard clearly. This is heard clearly. This is when you when you maymay feel feel your baby's first your baby's first kickkick

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Fetus- 4Fetus- 4thth Month Month

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FetusFetus Five Months Five Months A protective coating A protective coating

called called vernix vernix caseosacaseosa begins to begins to form on baby's skin. form on baby's skin.

By the end of this By the end of this month, your baby will month, your baby will be nearly 8 inches be nearly 8 inches long and weigh long and weigh almost a poundalmost a pound

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Fetus Six MonthsFetus Six Months EyebrowsEyebrows and and

eyelidseyelids are visible. are visible. Your baby's lungs are Your baby's lungs are

filled with filled with amniotic amniotic fluidfluid, and he has , and he has started breathing started breathing motions.motions.

If you If you talktalk or or singsing, he , he can hear you.can hear you.

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Six Month FetusSix Month Fetus

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Fetus Seven MonthsFetus Seven Months By the end of the By the end of the

seventh month, your seventh month, your baby weighs about baby weighs about 3 3 1/2 pounds1/2 pounds and is and is about about 12 inches long12 inches long. .

His body is well-formed.His body is well-formed. FingernailsFingernails cover his cover his

fingertipsfingertips

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FetusFetus Eight Months Eight Months Your baby is gaining Your baby is gaining

about about half a pound half a pound per weekper week, and layers , and layers of fat are piling on.of fat are piling on.

He has probably He has probably turned head-down in turned head-down in preparation for birth.preparation for birth.

He weighs between He weighs between 4 4 and 6 poundsand 6 pounds..

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8th Month Fetus8th Month Fetus

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Fetus Fetus Nine MonthsNine Months Your baby is a hefty Your baby is a hefty 6 6

to 9 poundsto 9 pounds and and measures between 19 measures between 19 and 22 inches. and 22 inches.

As he becomes more As he becomes more crowded, you may crowded, you may feel him move around feel him move around less.less.

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LighteningLightening Sometimes during the ninth month, Sometimes during the ninth month,

the beby’s weight seems to shift the beby’s weight seems to shift down and the mother feels more down and the mother feels more comfortable in her upper abdomen.comfortable in her upper abdomen.

This is called This is called LighteningLightening This means the baby has dropped This means the baby has dropped

into he birth canal and birth is not into he birth canal and birth is not far offfar off

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Weight Weight GainGain

The The recommended recommended weight gain for weight gain for the average the average woman during woman during pregnancy is pregnancy is 25-3025-30 pounds pounds and is and is distributed as distributed as follows:follows:

BabyBaby 7.5 lb7.5 lbPlacentaPlacenta 1.5 lb1.5 lbUterusUterus 2 lb2 lbAmniotic Amniotic FluidFluid

1.5 lb1.5 lb

Extra Extra Blood & Blood & Water Water RetentionRetention

4.5 lb4.5 lb

Breast Breast TissueTissue

3 lb3 lb

Maternal Maternal Stores of Stores of ProteinProtein

4 lb4 lb