The effects of patient obesity in gynaecologicalpracticeL.M. Irvine* and R.W. Shaww

*Consultant Obstetrician & Gynaecologist,Watford General Hospital,Vicarage Road,WatfordWD18OHB,UKwProfessor, Academic Division of Obstetrics & Gynaecology,Derby City General Hospital,Clinical Sciences Building,Uttoxeter Road,Derby DE22 3NE,UK

Summary Obesity is an increasing problem in the developed world, is more com-moninwomenthanmen andaffectsgynaecologicalpracticeinthreeways.Ithas adirecteffect intermsof increasedriskof polycysticovarian syndromeproblemswithovulationinduction, and endometrial carcinoma. It has an indirect effect in terms of diff|culty inpelvic examination and imaging techniques.Obesity also leads to technical diff|culties atsurgery and an increase inmorbidity andmortalitypost-operatively.�c 2003 Elsevier Science Ltd.Allrights reserved.

KEYWORDSobesity; gynaecologicalpathology; diagnosis;treatment; morbidity

INTRODUCTIONObesity has longbeenknown to have severe health com-plications; Hippocrates commented on the fact thatstout individuals died before thin individuals. The word‘obesity’ is from the Latin word ‘obesum’, which means‘on account of having being eaten’.

Over the last 20 years in the developed world, therehas been a signif|cant increase in the number of indivi-dualswhohavebeenclassif|ed as obese.Thehighest rateshave been reported in the USA followed by Europe andthe UK. In Great Britain, rates of obesity have at leastdoubled between 1980 and 1993, with 13% of males and16% of females being classif|ed as obese, and we havethe third highest rate of increase.The incidence of obe-sity is set to rise by 5% per year.This has a huge effect onwomen’s health and has profound resource implications.Obesity is consistently higher in women compared withmen and its incidence increases with age. Both of theseconfound the problemwith an increasingly aged popula-tion with a longer life expectancy for women. Themechanismby which obesity occurs is due to amismatchof energy input to energyexpenditure.The dramatic risein levels of obesity is thought to be due to an increase incalorif|c intake (especially high-fat diets) coupled with adecrease in physical activity.

Obesity is such a major health issue that it has adisease code: E66 (World Health Organization 1997).It is a complex problem with many interacting varia-bles, including a genetic component, racial variation,environmental factors and an inverse relationship withsocial class. In theUK, Smith reported that12% of Class1

comparedwith 21% of Class 4 peoplewere obese. Itmaybe that obesity results in lower social class.

In the past, there has been no agreed measure ofobesity.Weight is used in some studies of obesity and isdef|ned as a weight of over 90kg. The problem of usingweight alone is that for a given weight, the taller theindividual the less obese they are. To circumvent thisproblem, themeasurementof skin folds at variouspointsof the body have been used. It has also been suggestedthat being weighed in water gives an accurate measureof adipose tissue. These methods are cumbersome andare notwidelyused in clinical practice. A simple scientif|cmeans of quantifying obesity has been developed withthe calculation of body mass index (BMI). This gives aratio in terms of weight and height, and is calculated bythe formula:

BMI ¼ Weight in kilograms=Height in metres2

To simplify the calculation of BMI, charts have beendrawn up relating weight in kilos or stones to height infeet and inches ormetres.

Using arbitrary ranges of BMI, various conditions havebeen described from underweight, through healthy tooverweight, obese and very obese. Most workers havetaken a BMI of between 31and 41 for obese and441 forvery obese (Table1).

GENERALHEALTHISSUESASSOCIATEDWITHOBESITYObesity is a well-known risk factor in the developmentof a multiplicity of health problems. These tend to beeithermetabolic or degenerative, and lead to a great dealof morbidity and even mortality. There is a relationship

Correspondence to: RWS. Tel.: +44(0) 1332 625 633; E-mail: Robert.shaw@nottingham.ac.uk.

Current Obstetrics & Gynaecology (2003) 13,179--184�c 2003 Elsevier Science Ltd. All rights reserved.doi:10.1016/S0957-5847(03)00005-2

between increasing BMI and death rates from all causes;from a BMI of 25 to 40, there is a 2.5-fold increase inmortality. Hypertension is the most common complica-tion of obesity.

Obesity is also well recognized as a risk factor in thedevelopment of diabetes; eitherType I (early onset insu-lin-dependent diabetes) or Type II (maturity-onset). Inwomen aged between 30 and 64 years who developedType II diabetes, 61% of all cases had a BMI of 29 or above.Death from ischaemic heart disease in women is alsorelated to obesity; women with a BMI429 have athree-fold increase in death comparedwithwomenwitha BMIo21.

The most common degenerative disease associatedwith obesity is that of osteoarthritis which may furtherdecrease mobility and may increase the chance ofdeveloping a deep venous thrombosis or pulmonaryembolus after gynaecological surgery.

BODYWEIGHTANDONSETOFMENSTRUATIONThe association between body weight and age at me-narche has formed part of the basis for the explanationof the secular trend towards earlier menarche noted inthe UK and other developed countries over the last 100years due to improvednutritional status. Studies indicatethat pubertal development and body weight are intrinsi-cally linked, and a critical weight of at least 45kg is pre-sent in the majority of girls before menses occur.However, the mechanism for this relationship has notbeen def|ned conclusively.

Insulin has been suggested as a modulator of the tem-po of pubertal development through regulation of insu-lin-like growth-factor-binding protein-1(IGFBP-1) andsex-hormone-binding globulin (SHBG). States of exces-sive calorie intake and obesity are known to be asso-ciated with increased serum levels of insulin. If excessivenutritional intake persists during childhood, hyperinsuli-naemia would persist and could result in lower levels ofIGFBP-1 and reduced SHBG concentrations. The conse-quences of these changes would be enhanced insulin-likegrowth factor 1 (IGF-1) and increased sex steroid bioa-

vailability.The conversewouldbe true in states of under-nutrition.

It is unclear whether hyperinsulinaemia in childhood isa result of obesity or if it is the cause of obesity, butthe worrying increase in the proportion of obesechildren entering their early teens couldhavemajor con-sequences on reproductive function in girls in futureyears.

LEPTINThe discovery of leptin in1994 made a considerable con-tribution to the understanding of obesity. Leptin is theprimary product of the ob gene and is a 167 amino acidpeptidemade exclusively in adipose tissue. It seems likelythat leptin plays a central role in energy production andreproduction. Leptin is secreted by fat cells in responseto insulin and glucocorticoids. It is transported by a pro-tein, which appears to be in the extracellular domain ofthe leptin receptor.Leptin receptors havebeen reportedatmany sites butmost importantly in the hypothalamus,choroid plexus and ovary.

Leptin decreases the intake of food and stimulatesthermogenesis. It also appears to inhibit hypothalamicneuropeptide-Y, which is an inhibitor of GnRHpulsatility,thus allowing increased levels of circulating luteinizinghormone (LH) to occur (Fig.1).

Leptin appears to serve as the signal from thebody fatto the brainwith regard to adequacy of fat stores for re-production. Thus menstruation and ovulation will onlyoccur if fat stores are adequate to support an ensuingpregnancy.Obesity, on the other hand, is associatedwithhigh circulating concentrations of leptin and this in turnmight be a mechanism for hypersecretion of LH foundin approximately 40% of women with polycystic ovarysyndome (PCOS).

POLYCYSTICOVARYSYNDROMEHigh-resolution ultrasound, particularly transvaginal ul-trasound, has helped make more accurate estimates ofthe prevalence of polycystic ovaries possible. Whilstpolycystic ovaries canbe detectedin normal-weightovu-lating women, these do not have the associated meta-bolic abnormalities found in women with PCOS whotend to have increasing BMI and associated menstrualirregularities. Polycystic ovaries appear to have theirorigins during adolescence and are thought to be asso-ciated with increased weight gain during puberty. Thepolycystic ovary gene(s) has not yet been identif|ed. Inaddition, the effects of environmental influences such asweight changes and circulating hormone concentrations,and the age at which they occur, exercise and diet haveyet to be determined.

Table 1 World HealthOrganizationclassif|cationof normaland abnormalbodyweights using bodymass index (BMI)

BMI

18.5--24.9 Ideal BMI25--29.9 Class1overweight30--39 Class 2 overweight440 Class 3 overweight

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Obesitymay well be important in the pathogenesis ofPCOS.Obesity leads to hyperinsulinaemia, which causesboth hyperandrogenaemia and raised IGF-1 levels.Theseaugment ovarian response to gonadotrophins, particu-larly LH, which stimulates theca cells to produce moreandrostenedione.

Peripheral conversion of androstenedione to testos-terone and reduced liver synthesis of SHBG result inhigher levels of free androgens.

Free androgens can manifest themselves through animpact on the hair follicles and resultant acne and hirsut-ism. It is known that obesity is not a prerequisite for thepresence of polycystic ovaries, but weight gain at a laterdate may well result in women with polycystic ovarieshaving a potential to develop more of the metabolicfeatures of PCOS.

Whether weight restriction and reduction can pre-vent the developmentof PCOS awaits appropriate trials.This would need to commence at the early stages ofpuberty.

OVULATIONINDUCTIONOverweight women per se have a higher incidence ofmenstrual disturbance, ovulation disorders and infertil-ity. During ovulation-induction regimens, obese womentend to have lower success rates.

The most common drug prescribed to induce ovula-tion is clomiphene citrate.The dose of clomiphenecitraterequired to achieve ovulation is positively correlatedwith body weight, and non-responders are more likelyto be obese. This may reflect the fact that many obesewomenwho require clomiphene citrate to induce ovula-tion because they have markedly irregular (oligomenor-rhoeic) cycles have PCOS. Obese PCOS women alsorespond poorly to pulsatile GnRH therapy.

The dose of exogenous gonadotrophins needed toinduce ovulation has also been found to be increasedby up to 50% in womenwith a BMIp25 comparedwithwomen of normalweight.

If pregnancy is achieved, pregnancycomplications suchas early miscarriage, gestational diabetes, pregnancy-induced hypertension and macrosomia are morecommon in obesewomen.

As outlinedpreviously, excessivebody fat is associatedwith insulin resistance, hyperinsulinaemia, high serumIGF levels and higher LH concentrations. An increasedwaist:hip ratio, indicating body fat deposition,appears to have a more important effect than bodyweight alone.

Weight loss should be encouraged in all such womenprior to ovulation induction since moderate weightloss (at least 5%) may restore regular menses or at leastimprove sensitivity to various ovulation-inductiontherapies.

Hypothalamus

GnRH

LEPTIN INSULIN

PITUITARY

ADIPOSE TISSUE

INSULIN

Sex

OESTROGEN

LEPTIN

PANCREAS

LH FSH

−

OVARY OVARY

steroidsSex steroids

+ /−

+ /−

+ + +

+ +

+

+

Figure1 Relationshipsbetweeninsulin, leptin, pituitaryandovary. Insulin stimulatesleptin secretion, enhancespituitaryresponse toGnRH and promotes ovarian steroidogenesis.Leptin stimulates hypothalamus and inhibits ovarian oestrogen and progesterone pro-duction.Leptin and insulinpotentiate the secretion of each other.

OBESITYINGYNAECOLOGICALPRACTICE 181

OTHERGYNAECOLOGICALCONDITIONSASSOCIATEDWITHOBESITY

Endometrial carcinoma

Themost common association between obesity and sig-nif|cantgynaecologicalpathology is endometrial carcino-ma.The mechanism for this is thought to be changes inoestrogen metabolism resulting in high circulating levelsof oestrogens, particularly oestrone from peripheralconversion in fat tissues, which may result in thedevelopment of cystic endometrial hyperplasia.

Susceptible individuals may then go on to develop aty-pical endometrial hyperplasia or overt adenocarcinomaof the endometrium.

Ovarian cancer

Although obesity per se is not a risk factor for the devel-opment of ovarian cancer, it may make the diagnosismore diff|cult. Most women with advanced ovarian can-cer present with abdominal distension. In obesewomen,they may not have noticed distension, and thus presentwith more advanced disease. In addition, current diag-nostic techniques using ultrasoundmay bemore diff|cultto perform and interpret (see below).

DIAGNOSTICPROBLEMSASSOCIATEDWITHOBESITY

Clinical assessment

Clinical examination in obese patients can be diff|cult.Palpation of the abdomen may not reveal even largemasses due to the layer of adipose tissue. Peritonismwith guarding and rebound tenderness may not bedemonstrated to the same extent, even in the presenceof a haemoperitoneum from a leaking ectopic pregnancy,or ruptured corpus luteum or haemorrhagic ovariancyst. Bimanual examination may also be extremelydiff|cult.

Vaginal examination

Pelvic examination is a notoriously inaccurate means ofassessing uterine size or adnexal masses. In a study of140 women who underwent examination under anaes-thesia prior to laparoscopy or laparotomy, the overallsensitivity for left and right adnexal masses was 0.23--0.136 and 0.15--2.8, respectively. Although obesity wasnot def|ned in this study, it was concluded that obesitynoticeably reduced the detection of adnexal masses oneither side.

Speculum examination may also be diff|cult withproblems visualizing the cervix, due to increasedvaginal length and also prolapse of the vaginal sidewall.

Ultrasound scanning

Themost commonlyused imaging technique in gynaeco-logical practice is ultrasound. Transabdominal scanningwas developed initially and, in obese patients, this is limi-ted in resolution due to the depth of tissue before thepelvic organs can be visualized.

To circumvent this problem transvaginal scanning wasdeveloped in the late 1990s. This is the preferred ultra-sound technique in obesewomen, as the tip of the probegoes closer to the pelvic organs and resolution isincreased. Even with vaginal scanning, it may be morediff|cult to measure both ovarian size or endometrialthickness in obese patients, with decreased sensitivity ofup to 30%.

SURGICALTREATMENTSANDCOMPLICATIONSASSOCIATEDWITHOBESITYSurgery can be technically more diff|cult in obese wo-men.Thismaybe inpartdue to the layerof adipose tissuewhich makes access to the pelvis more diff|cult than inthose with a normal BMI. In addition, previous pelvicsurgery is a well-known risk factor for the developmentof complications in subsequent surgery. Women ofBMI 434 have been reported to have an approxi-mately three-fold increase in the rate of Caesareansection compared with matched controls with a normalBMI.

Previous surgery is a risk factor in terms of intra-operative technical diff|culties, longer surgical time andthe development of post-operative complications includ-ing deep vein thrombosis andwound infection.

Obese women are more likely to have had a failedlaparoscopy, necessitating laparotomy. Overall, obesewomen are more likely to have a midline incision, whichmakes subsequent attempted laparoscopymore diff|cult,and increases the risk of bowel perforation.

The risks can be subdivided into intra-operativeproblems associated with the method of surgery, andearly and late post-operative complications.

Laparoscopic surgery

With laparoscopic surgery, obesity is associated with ahigher rate of failed instrumentation, trauma tobowel and vascular injury. It may also prove diff|cult forthe anaesthetist to ventilate a patient in a steepTrendelenburg position due to excessive weight on thethorax.

Despite these issues, in a small study def|ning ‘massiveobesity’ as a BMI X40, it was found that apart fromdiff|culties in exposure of the surgical f|eld, there wereno conversions to laparotomy and the post-operative

182 CURRENTOBSTETRICS & GYNAECOLOGY

course was uneventful. It was concluded from this smallstudy that patients who are massively obese couldbenef|t most from laparoscopic surgery compared withlaparotomy for procedures which could be undertakenby either route.

To help reduce the problems experienced at laparo-scopy, a consensus viewdocument suggested that the ab-domen should be elevated by traction before insertionof the Verres needle (BSGE Consensus Document onLaparoscopy 2001). A pneumoperitoneum should be in-duced to a pressure rise of no more than 25mmHg,rather than a f|xed volume of CO2 being instilled. Thisseparates the back of the abdominal wall from the greatvessels, and thusminimizes the risk of a type I injury (themost serious).

In obese patients, abdominal elevation can be diff|cultand smaller volumes of CO2 are introduced to achieve apressure of 25mmHg, due to the weight of the anteriorabdominal wall.

To further aid successful entry techniques, longerinstruments, Verres needles and trochars are recom-mended.

Open surgery

Atopen surgery in patientswith increased BMI, access tothe pelvis becomes more diff|cult. In particular, this is aproblem with the Pfannenstiel incision, where the pan-nus may need to be retracted manually by an assistantthroughout the operation. Some surgeons would optfor a midline incision in the extremely obese woman, forease of access and a decrease in post-operative woundinfection. However, there may be a higher incidence of‘burst abdomen’ or incisional hernia when the midlineincision is used. Obese women have a high incidenceof intra-operative complications due to diff|cult accessor distorted anatomy, major intra-operative bleedingincluding trauma to the uterus or bladder, and diff|culthaemostasis especially the vaginal vault. Conversionto subtotal hysterectomy may avoid some of theseproblems provided there are no absolute contradictions(presence of CIN, micro--invasive Ca etc.).

Late complications of surgery

Late complications of surgery include increasedlikelihood of the development of wound infection. Thismay be reduced by the use of staples for skin closure,the use of intravenous prophylactic antibiotics, meticu-lous haemostasis and insertion of drains to the rectussheath.

Other complications include chest infections due toreduced mobility, which can be reduced with an activeprogramme of physiotherapy post-operatively.

One of the potentially serious post-operative com-plications is deepvein thrombosis, whichmay lead topul-

monary embolism which may prove fatal. Both of thesecomplications are more common in women with an in-creased BMI. The risks can be reduced with the use ofintermittent calf compression systems during surgery,and thrombo-embolic deterrent stockings post-opera-tively. Subcutaneous heparin preparations, which mayneed to be used in higher doses than in women with anormal BMI, should also be prescribed for 5 days in allobese patients. Early mobilization will help reduce therisk of developing a deep venous thrombosis.

It is thought that increased length of surgical timeand delay inmobilization are important causes. Anothercause may be increased synthesis of plasminogen acti-vator inhibitor in adipose tissue in obese patients and,if legs are in stirrups, compression of knee and calfvessels.

ANAESTHETICCONSIDERATIONSAn increased BMI is associated with a number of anaes-thetic problems and complications. These can be sub-divided into medical complications (hypertension,ischaemic heart disease and diabetes) and mechanicalproblems with obese patients such as diff|cult venousaccess and diff|culty with tracheal intubation due toadipose tissue in the neck and limitedneck/cervical spinemovements.

Anaesthetic problems are also related to the type ofsurgery undertaken.When laparoscopic surgery is per-formed, it may be impossible for the patient to breathspontaneously due to the pressure from the abdomenon the thoracic cavity. Itmay also be diff|cult to ventilatea patient evenwith high ventilation pressures. As laparo-scopy is more diff|cult in obese women, the operatingtime is increased, thus increasing the time spent undergeneral anaesthesia.

In terms of post-operative analgesia, the sitingof an epidural block is often much more diff|cult thanin those women with a normal BMI. An increasedBMI will also increase the dosages of post-operativenarcotics required to achieve adequate pain relief -- animportant factor for trainees to be aware of when pre-scribing.

CEPODThe conf|dential inquiries into peri-operative deaths(CEPOD) makes only one reference to patient weight:in approximately 30% of patients, there was no recordof pre-operative weight. This does not, however, meanthat obesity does not play a major role in post-operativemortality.

In anaesthetic practice, patients aregradedin terms ofASA (American Society of Anaesthesiologists) scoreranging from Grade1 (patient well) through to Grade 5

OBESITYINGYNAECOLOGICALPRACTICE 183

(death almost inevitable).Grade 2 ismild systemic diseaseand Grade 3 is disease limiting full life.

As obesity is a recognized cause of Type II diabetes,ischaemic heart disease, hypertension and chronic lungdisease, obesity will have a direct effect on increasingpatients’ ASA scores. In the CEPOD report, there is acorrelation between increased ASA scoring and post-operativemortality.

OBESITYINGYNAECOLOGY* Effect on onset/resumption of menstruation.* Reduces the success of ovulation-induction regimes.* Has a direct effect on the development of endo-

metrial hyperplasia and potential for endometrialcancer.

* Makes clinical examination and diagnosis morediff|cult; pelvic masses, cervical cancer and ectopicpregnancy.

* Makes investigations more diff|cult (transvaginal andtransabdominal scanning).

* Makes surgery more complex both at laparoscopyand at laparotomy.

ACKNOWLEDGEMENTSWewould like to thankMrsMarie Hunt for the prepara-tion of this manuscript.We would also like to acknowl-edge the help of the library at the Royal College ofObstetricians and Gynaecologists. This work has beenfunded in part by the Watford Gynaecology ResearchFund.

FURTHERREADING

Garry R. A consensus document concerning laparoscopic entry

techniques: Middlesbrough, 19--20 March 1999. Gynaecol Endosc

1999; 8: 403--406.

Padilla LA, Radosevich DM, Milad MP. Accuracy of the pelvic

examination in detecting adnexal masses. Obstet Gynaecol 2000;

96: 593--598.

Raiga J, Barakat P, Diemunch P, Calmelet P, Brettes JP. Laparoscopic

surgery and ‘‘massive’’ obesity. J Gynecol Obstet Biol Reprod 2000;

29: 154--160.

WHO. Physical Status: the Use and Interpretation of Anthropometry.

WHO Technical Report. Geneva: WHO, 1995.

Zhang Y, Proenca R, Maffei M, Barone M, Leopold L, Friedman JM.

Positional Cloning of the Mouse Obese Gene and its Human

Homologue. Nature 1994; 372; 425--432.

CEPOD report 2000--2001.

Shaw RW, Soutter WP, Stanton SL (eds). Gynaecology, 3rd edn.

Edinburgh: Churchill Livingstone, 2002.

PRACTICEPOINTS

* Body weight is an important factor controllingonset of menses at puberty

* Obesity increases the incidence of endometrialcancer

* Polycystic ovary syndrome is more prevalent inobesewomen

* Clinical examinationmay bemore diff|cult* Imaging techniques may be less sensitive and

specif|c than inwomenwith a normal BMI* Surgical procedures may be more diff|cult and be

associatedwith increasedmorbidity* Ovulation-inductionregimesmaybe less successful

unless weight loss occurs

184 CURRENTOBSTETRICS & GYNAECOLOGY