Obstetrics & Gynecology:
Original Research: Lead Article
Maternal Morbid Obesity and the Risk of Adverse Pregnancy Outcome
Cedergren, Marie I. MD, PhD
From the Division of Obstetrics and Gynecology, Department of Molecular and Clinical Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
Received August 25, 2003. Received in revised form October 9, 2003. Accepted October 17, 2003.
Supported by the Ostergotland County Council. The authors thank the National Board of Health and Social Welfare, Stockholm, for access to the health registers.
Address reprint requests to: Dr. Marie Cedergren, Department of Obstetrics and Gynecology, University Hospital, SE-581 85 Linköping, Sweden; e-mail: email@example.com.
OBJECTIVE: To evaluate whether morbidly obese women have an increased risk of pregnancy complications and adverse perinatal outcomes.
METHODS: In a prospective population-based cohort study, 3,480 women with morbid obesity, defined as a body mass index (BMI) more than 40, and 12,698 women with a BMI between 35.1 and 40 were compared with normal-weight women (BMI 19.8–26). The perinatal outcome of singletons born to women without insulin-dependent diabetes mellitus was evaluated after suitable adjustments.
RESULTS: In the group of morbidly obese mothers (BMI greater than 40) as compared with the normal-weight mothers, there was an increased risk of the following outcomes (adjusted odds ratio; 95% confidence interval): preeclampsia (4.82; 4.04, 5.74), antepartum stillbirth (2.79; 1.94, 4.02), cesarean delivery (2.69; 2.49, 2.90), instrumental delivery (1.34; 1.16, 1.56), shoulder dystocia (3.14; 1.86, 5.31), meconium aspiration (2.85; 1.60, 5.07), fetal distress (2.52; 2.12, 2.99), early neonatal death (3.41; 2.07, 5.63), and large-for-gestational age (3.82; 3.50, 4.16). The associations were similar for women with BMIs between 35.1 and 40 but to a lesser degree.
CONCLUSION: Maternal morbid obesity in early pregnancy is strongly associated with a number of pregnancy complications and perinatal conditions.
LEVEL OF EVIDENCE: II-2
Today, obesity is a worldwide individual and public health issue because it contributes to the development of several chronic diseases. The rate of obesity in the general population is increasing dramatically. Obesity among fertile women is reaching epidemic proportions.1 In Sweden, the prevalence of overweight women in their fertile years doubled during 1980–1997.2 The number of women suffering from morbid obesity has also markedly increased in this country during the last decade.
It is already commonly known that maternal overweight and obesity are associated with adverse pregnancy outcome, such as maternal hypertension, preeclampsia, gestational diabetes, more frequent cesarean delivery, delivery of large-for-gestational-age (LGA) infants, and stillbirths.3–8 There are obvious signs in a few studies that pregnancies in morbidly obese women show even more complications and adverse outcomes,9–11 although low patient numbers limit their statistical power.
The objective of this study was to thoroughly assess, in a large prospective data set from the Swedish medical health register, whether morbid obesity, defined by a body mass index (BMI) 35.1–40 or BMI greater than 40, was associated with an increased risk of adverse perinatal outcome and if so to quantify this risk after adjustment for conceivable confounders.
MATERIALS AND METHODS
The local ethics committee approved this study. The study population consisted of 972,806 pregnancies delivered in Sweden January 1, 1992, through December 31, 2001. In 805,275 (82.8%) cases, information on maternal height and weight in early pregnancy was available. The women were identified by using the Swedish Medical Birth Registry. Medical data on almost all (98–99%) deliveries in Sweden are listed in the register, which also includes stillbirths after 28 weeks of gestation. The register contains a large number of items concerning pregnancy, delivery, and pediatric neonatal examination. It is based on a copy of the standardized medical record forms completed at the maternity health care centers, at the start of prenatal care, usually in gestational weeks 10–12, records from the delivery units, and the pediatric examination of the newborn. The system is identical throughout the country. A description and validation of the register content is available.12,13 The midwife records maternal weight and height on a standardized form at the first visit at the maternity health care center. Ninety percent of the women present themselves to this antenatal clinic during the first trimester of their pregnancy.
Body mass index (kg/m2) was calculated from maternal weight and height data. Obese women were defined by a BMI greater than 29. Within this group, two subgroups of morbidly obese women were studied: BMI 35.1–40 and BMI greater than 40. The definition of morbid obesity may vary; therefore, we decided to evaluate the 2 groups separately. Obese women were compared with normal-weight women (BMI 19.8–26).
The unit of analysis was delivery. The possible impact of the fact that a woman may have more than one delivery during the study period was checked by only including the first delivery of each woman during the study period.
Primary outcomes were, antenatally, the occurrence of preeclampsia, abruptio placenta, placenta previa, and stillbirths after 28 weeks of gestation among singleton pregnancies. Around-term variables evaluated were the rate of cesarean delivery, labor inductions, pre- and postterm delivery, instrumental delivery, anal sphincter injury, shoulder dystocia, postpartum hemorrhage, and epidural anesthesia. Small-for-gestational age infants were defined as those with birth weights more than 2 standard deviations below the mean birth weight for gestational age according to a Swedish reference curve,14 and LGA infants were those with birth weight above 2 standard deviations. Estimated gestational age was in most cases based on second-trimester ultrasound screening.
Neonatal outcomes studied were as follows: meconium aspiration, fetal distress, low Apgar score (less than 7 at 5 minutes), and early neonatal death (less than 7 days after birth). The outcome variables are registered in the Swedish Medical Birth Registry by using the International Classification of Diseases. Women with insulin-dependent diabetes mellitus were excluded.
Maternal age, parity, smoking, and year of birth were thought to be potential confounding factors and were included as covariates in the adjusted analyses. Maternal education, as a marker of socioeconomic status, was also added (information only available for the years 1992–1995). Preexisting hypertension and gestational diabetes were not included as confounders in this analysis for 2 reasons. First, a true confounder affects both the exposure and the outcome. Exposure in this study was prepregnancy massive obesity. Second, our purpose was to address the outcome, not necessarily the path.
Adjusted odds ratios (ORs) were determined by using Mantel-Haenszel technique.15 The morbidly obese groups, BMI 35–40 and BMI greater than 40, were each compared with normal-weight women (BMI 19.8–26). Estimates of 95% confidence intervals (95% CI) were made with a test-based method, based on the Mantel-Haenszel χ2 (Miettinen OS. Simple interval estimation of risk ratio [letter]. Am J Epidemiol 1974;100:515–6).
The majority of the women in the study population were of European Caucasian origin, 1% were born in South America, 1.4% were Asian, and 1% came from Sub-Saharan Africa. Maternal BMI could be calculated for 82.8% of all births registered during the study period. In this group, 1.6% (12,698 of 805,275) had a BMI between 35.1 and 40 and 0.4% (3,480 of 805,275) had a BMI greater than 40. Morbidly obese women, defined as having a BMI greater than 35, represented 2% of all pregnant women with a known BMI in this work.
The morbidly obese women were compared with normal-weight women with respect to maternal age, parity, maternal smoking in early pregnancy, and the number of multiple pregnancies (Table 1). The women who were obese were slightly older, more often multiparous, and smokers. Multiple pregnancies occurred equally often across BMI strata.
The following comparisons were restricted to singleton deliveries. Antenatal complications are presented in Table 2. The risk of preeclampsia among the morbidly obese women was increased almost 5-fold. The corresponding OR for women with BMIs between 35.1 and 40 was 3.90. Being morbidly obese carried an almost 3-fold increase in risk of antepartum stillbirths relative to normal-weight women, adjusted OR 2.79 (95% CI 1.94, 4.02). Abruptio placenta occurred equally often among normal-weight women and morbidly obese women. There was a decreased risk of placenta previa in the morbidly obese group, even more pronounced among the heaviest mothers.
Cesarean delivery was more common in morbidly obese women (Table 3). The frequency was almost 3 times as high for morbidly obese women as it was for women of normal BMI. The risk of instrumental delivery was increased 18% in women with a BMI between 35.1 and 40 and increased 34% in women with a BMI greater than 40. When the analyses were restricted to only the first delivery of each woman during the study period, no significant change in OR was obtained. Shoulder dystocia occurred 3 times more often among the morbidly obese women.
Massive obesity was associated with both early and late deliveries. Compared with normal-weight women, morbidly obese women were more likely to be induced, even after deduction of preeclampsia patients: the adjusted OR 2.38 (95% CI 2.17, 2.60).
The prevalence of LGA infants was almost 4 times as high among morbidly obese women than among women with normal BMI (Table 4). The risk was also increased for having a small-for-gestational-age infant among the morbidly obese (greater than 40), although after removing women with preeclampsia, this increased risk was no longer statistically significant: adjusted OR 1.23 (95% CI 0.94, 1.60).
Neonatal outcome data are presented in Table 5. There was a more than 2-fold risk increase for fetal distress and low Apgar scores among infants of the morbidly obese women. Meconium aspiration occurred more often in infants of morbidly obese women than in women with normal BMI values: adjusted OR 2.85 (95% CI 1.60, 5.07). This variable was studied only when a vaginal delivery had been performed. The risk seems to be the same among women with a BMI between 35.1 and 40. For the years 1992–1995, information on maternal education was available. Adjustment for this factor reduced the estimated ORs only marginally.
A comparison also was made between women with a known BMI and those with an unknown BMI (17.3%) in our sample concerning the above-described variables. There were no differences in ORs. Those with unknown BMI seem to be a random sample of all pregnancies and therefore do not give a selection bias.
In this large population-based cohort study, a strong association exists between maternal morbid obesity in early pregnancy and a number of threatening complications during pregnancy, delivery, and in the neonatal period. This association has been pointed out in earlier studies, although low numbers of cases limited their statistical power.
Perlow et al10 determined in the late 1980s the impact of massive obesity (weight more than 300 pounds = more than 136 kg) on perinatal outcome. The study included 111 women who fulfilled this definition. They found an increased risk for overall cesarean delivery (OR 2.9), Apgar score at 5 minutes less than 7 (OR 3.0), birth weight more than 4,500 g (OR 8.1), and intrauterine growth restriction (OR 9.3). More recently, in a study from the United Arab Emirates concerning 188 morbidly obese women, BMIs greater than 40 were presented.9 An increased risk for cesarean delivery (OR 2.3) and birth weight above 4,000 g (OR 3.9) was described.
When it comes to relatively rare complications, such as shoulder dystocia and stillbirth, sufficient patient numbers concerning the morbidly obese women have not previously been available. In a recent report from Sweden, the risk of stillbirth was doubled among obese women (BMI greater than 30).7 Our findings indicate an almost 3-fold increased risk of antepartum stillbirth in the group of morbidly obese women. Whatever mechanism is behind the association between maternal obesity and stillbirth, it seems to be influenced by the degree of obesity.
Massive obesity seems to be protective from placenta previa. The information on this condition comes to the register from the delivery units and therefore it is unlikely that the decreased risk is due to undetected cases by ultrasound among the massively obese.
In a large study from London, no increased risk of instrumental delivery was seen among women with a BMI greater than 30.3 That is in contrast with our findings because we found a slightly increased risk specifically for the massively obese women. Anal sphincter lacerations were surprisingly not over-represented in the group of morbidly obese women despite the increased prevalence of LGA infants, instrumental deliveries, and the use of epidural anesthesia. All of these are factors well documented to be associated with an increased risk of perineal lacerations.16,17 A possible explanation is that midline episiotomy is not practiced at all in Sweden. There were increased numbers of labor inductions. From a clinical point of view, this is relevant and warrants further evaluation, such as the reasons for induction of labor, which is beyond the scope of this study.
The advantage of register studies is that the large number of individuals available for evaluation gives higher statistical power and makes it possible to demonstrate associations with low-prevalence pregnancy outcome variables. The drawback is the sometimes-low validity of information.
Exposure information (weight and height) was recorded in early pregnancy and therefore prospective regarding the pregnancy outcome variables. Recall bias was thus avoided. Exposure information could be retrieved for 82.8% of all births registered during the study period. We evaluated the group of women with missing data on weight and height and no ORs concerning the outcome variables studied were increased compared with women with known BMI. The possibility of selection bias of extremely obese women in the group of women with missing data is thus less probable.
A number of potential confounding factors associated with maternal obesity were adjusted for in this study, such as maternal age, parity, and smoking in early pregnancy. A putative confounding factor, not stratified for in this study, is socioeconomic level that could have affected the results, but smoking during pregnancy is strongly correlated with socioeconomic level in Sweden.18 For part of the material, maternal education was added as a confounder. This reduced the estimated ORs marginally.
We did not exclude women with gestational diabetes diagnosed in late pregnancy. It is possible that our sample includes women with undetected or unreported non–insulin-dependent diabetes, which could explain the results, but these conditions can be regarded as intermediaries. The same is true for the inclusion of women with chronic hypertension. The purpose of this study was to evaluate the pregnancy outcome in the group of morbidly obese women and not to identify the mechanisms behind the associations. Earlier studies also found that stratifying for a number of potential factors that could influence the outcome did not substantially change the risk estimates.3
It is possible that a multiple-testing problem exists. Most effects found are strong and highly statistically significant, but some are moderate and show marginal statistical significance and may be the result of multiple testing, for example, the increased risk for postpartum bleeding.
Another problem concerning studies in this field is the definition of obesity and even more difficult the definition of morbid obesity. Different values for defining obesity were used in different studies, which make it difficult to compare risk estimates. To facilitate such comparisons, we present risk estimates for both women with BMIs between 35.1 and 40 and women with BMIs greater than 40. There seems to be overall slightly higher risk estimates in the group with BMIs greater than 40 as compared with the group with BMIs between 35.1 and 40, although ratios are not statistically significantly different.
This large study points out a strong association between maternal morbid obesity in early pregnancy and a number of threatening complications during pregnancy, delivery, and in the neonatal period. The importance of these findings could be examined from different views. It implicates the need of prepregnancy advice and counseling to young women and could be a convincing argument for weight reduction in this group. Pregnancies among morbidly obese women must be classified as high-risk pregnancies, and appropriate antenatal care should be provided. In addition, massive obesity among women of child-bearing age is associated with a number of health risks later in life.
Pregnancy is a life event in which women are inclined to behavioral changes. Is it possible that with appropriate management before and during pregnancy, the gestational weight gain could be reduced and maybe even contribute to persistent behavioral changes concerning nutrition and physical exercise postpartum?
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Labor and delivery management of the morbidly obese parturient
Anesthesia and Analgesia, ():
Journal of Perinatal MedicineMaternal obesity and complications during pregnancyJournal of Perinatal Medicine
American Journal of Obstetrics and GynecologyOverweight and obese in gestational diabetes: The impact on pregnancy outcomeAmerican Journal of Obstetrics and Gynecology
Maternal and Child Health JournalPopulation-based assessment of the risk of primary cesarean delivery due to excess prepregnancy weight among nulliparous women delivering term infantsMaternal and Child Health Journal
Birth Defects Research Part A-Clinical and Molecular TeratologyTeratology public affairs committee position paper: Maternal obesity and pregnancyBirth Defects Research Part A-Clinical and Molecular Teratology
Applied Physiology Nutrition and Metabolism-Physiologie Appliquee Nutrition Et MetabolismeExercise in the prevention and treatment of maternal-fetal disease: a review of the literatureApplied Physiology Nutrition and Metabolism-Physiologie Appliquee Nutrition Et Metabolisme
Deutsche Medizinische WochenschriftTelemetric monitoring of blood pressure and body weight during pregnancyDeutsche Medizinische Wochenschrift
Obesity ReviewsMaternal obesity and risk of cesarean delivery: a meta-analysisObesity Reviews
Annals of EpidemiologyUse of spline regression in an analysis of maternal prepregnancy body mass index and adverse birth outcomes: Does it tell us more than we already know?Annals of Epidemiology
Jognn-Journal of Obstetric Gynecologic and Neonatal NursingEffects of obesity on pregnancyJognn-Journal of Obstetric Gynecologic and Neonatal Nursing
ObesityMaternal obesity: A problem for both mother and childObesity
Archives of Gynecology and ObstetricsPrepregnancy body mass index and adverse pregnancy outcomesArchives of Gynecology and Obstetrics
Fertility and SterilityObesity and reproduction: an educational bulletinFertility and Sterility
International Journal of Gynecology & ObstetricsEffect of bariatric surgery on pregnancy outcomeInternational Journal of Gynecology & Obstetrics
Iranian Red Crescent Medical Journal
Prepregnancy Body Mass Index and Gestational Weight Gain and Their Association with Some Pregnancy Outcomes
Iranian Red Crescent Medical Journal, 10(4):
Journal of Human Nutrition and DieteticsIdentification of 'hot spots' of obesity and being underweight in early pregnancy in LiverpoolJournal of Human Nutrition and Dietetics
Plos OneSevere Obesity in Young Women and Reproductive Health: The Danish National Birth CohortPlos One
Hypertension in PregnancyObesity and the Hypertensive Disorders of PregnancyHypertension in Pregnancy
Human Reproduction UpdateBrain imaging studies of appetite in the context of obesity and the menstrual cycleHuman Reproduction Update
Recent Advances in Prenatal Genetic Diagnosis
Perinatal outcomes regarding to the risk factors and the efficacy of the treatment of diabetes
Recent Advances in Prenatal Genetic Diagnosis, ():
International Journal of ObesityBurden of disease attributable to obesity and overweight in KoreaInternational Journal of Obesity
Medical Clinics of North AmericaImprovement in infertility and pregnancy outcomes after weight loss surgeryMedical Clinics of North America
Journal of Maternal-Fetal & Neonatal MedicineThe effect of low body mass index on the development of gestational hypertension and preeclampsiaJournal of Maternal-Fetal & Neonatal Medicine
Acta Obstetricia Et Gynecologica ScandinavicaSnoring, witnessed sleep apnoeas and pregnancy-induced hypertensionActa Obstetricia Et Gynecologica Scandinavica
West Indian Medical Journal
Obstetrical and neonatal outcomes in obese women
West Indian Medical Journal, 56(5):
Agro Food Industry Hi-Tech
The relationship between pregnancy and obesity: a call for further research
Agro Food Industry Hi-Tech, 18(1):
Gynecologie Obstetrique & FertilitePregnancy in obese patients: which risks is it necessary to fear?Gynecologie Obstetrique & Fertilite
International Journal of Gynecology & ObstetricsMaternal obesity and neonatal congenital cardiovascular defectsInternational Journal of Gynecology & Obstetrics
American Journal of Clinical NutritionBreastfeeding reduces postpartum weight retentionAmerican Journal of Clinical Nutrition
Bjog-An International Journal of Obstetrics and GynaecologyBody composition by dual-energy X-ray absorptiometry in women with previous pre-eclampsia or small-for-gestational-age offspringBjog-An International Journal of Obstetrics and Gynaecology
Endocrine ReviewsEvidence-Based and Potential Benefits of Metformin in the Polycystic Ovary Syndrome: A Comprehensive ReviewEndocrine Reviews
American Journal of Obstetrics and GynecologyUric acid concentrations are associated with insulin resistance and birthweight in normotensive pregnant womenAmerican Journal of Obstetrics and Gynecology
Journal of Adolescent HealthJoint Effect of Obesity and Teenage Pregnancy on the Risk of Preeclampsia: A Population-Based StudyJournal of Adolescent Health
Human Reproduction UpdateNutrition and reproduction in womenHuman Reproduction Update
American Journal of Obstetrics and GynecologyShared and disparate components of the pathophysiologies of fetal growth restriction and preeclampsiaAmerican Journal of Obstetrics and Gynecology
American Journal of Obstetrics and GynecologyObstetric outcomes in overweight and obese adolescentsAmerican Journal of Obstetrics and Gynecology
American Journal of Public HealthMaternal obesity in early pregnancy and risk of spontaneous and elective preterm deliveries: A retrospective cohort studyAmerican Journal of Public Health
New England Journal of Medicine
Clomiphene, metformin, or both for infertility in the polycystic ovary syndrome
New England Journal of Medicine, 356(6):
Trends in pre-pregnancy obesity in nine states, 1993-2003
Trends in Endocrinology and MetabolismObesity: a risk factor for preeclampsiaTrends in Endocrinology and Metabolism
Acta Obstetricia Et Gynecologica ScandinavicaMaternal body mass index at delivery and risk of caesarean due to dystocia in low risk pregnanciesActa Obstetricia Et Gynecologica Scandinavica
MidwiferyConsumer satisfaction with a weight-gain intervention programme for obese pregnant womenMidwifery
Human ReproductionExtreme obesity and risk of placental abruptionHuman Reproduction
Salud I Ciencia
Could the viscous cycle of obesity be restricted?
Salud I Ciencia, 17(1):
British Medical JournalSexuality and obesity, a gender perspective: results from French national random probability survey of sexual behavioursBritish Medical Journal
American Journal of PerinatologyMaternal obesity: Can pregnancy weight gain modify risk of selected adverse pregnancy outcomes?American Journal of Perinatology
American Journal of Obstetrics and GynecologyAntithrombotic therapy and pregnancy: consensus report and recommendations for prevention and treatment of venous thromboembolism and adverse pregnancy outcomesAmerican Journal of Obstetrics and Gynecology
American Journal of Obstetrics and GynecologyEarly pregnancy lipid concentrations and spontaneous preterm birthAmerican Journal of Obstetrics and Gynecology
Journal of Maternal-Fetal & Neonatal MedicineObesity and diabetes: A recipe for obstetric complicationsJournal of Maternal-Fetal & Neonatal Medicine
ThoraxIs maternal asthma a life or death issue for the baby?Thorax
Journal of the National Medical Association
Perinatal Outcomes in Nutritionally Monitored Obese Pregnant Women: A Randomized Clinical Trial
Journal of the National Medical Association, 101(6):
MaturitasObesity in older mothers, gestational weight gain, and risk for preterm phenotypes estimatesMaturitas
Acta Obstetricia Et Gynecologica ScandinavicaMaternal and anthropomorphic risk factors for shoulder dystociaActa Obstetricia Et Gynecologica Scandinavica
Jognn-Journal of Obstetric Gynecologic and Neonatal NursingCaring for obese pregnant womenJognn-Journal of Obstetric Gynecologic and Neonatal Nursing
Bjog-An International Journal of Obstetrics and GynaecologyThe risk of unexplained antepartum stillbirth in second pregnancies following caesarean section in the first pregnancyBjog-An International Journal of Obstetrics and Gynaecology
Australian & New Zealand Journal of Obstetrics & GynaecologyObesity - More than non-communicable diseasesAustralian & New Zealand Journal of Obstetrics & Gynaecology
American Journal of Clinical Nutrition
Combined associations of prepregnancy body mass index and gestational weight gain with the outcome of pregnancy
American Journal of Clinical Nutrition, 87(6):
American Journal of Obstetrics and GynecologyLate recognition of pregnancy as a predictor of adverse birth outcomesAmerican Journal of Obstetrics and Gynecology
Human ReproductionShould access to fertility treatment be determined by female body mass index?Human Reproduction
Critical Care ClinicsAirway problems in pregnancyCritical Care Clinics
Gynecologic and Obstetric InvestigationObesity and Clomiphene Challenge Test as predictors of outcome of in vitro fertilization and intracytoplasmic sperm injectionGynecologic and Obstetric Investigation
Bjog-An International Journal of Obstetrics and GynaecologyOutcome of pregnancy in a woman with an increased body mass indexBjog-An International Journal of Obstetrics and Gynaecology
Fetal Diagnosis and TherapyOmphalocoele-exstrophy-imperforate anus-spinal defects complex in dizygotic twinsFetal Diagnosis and Therapy
Gynecologic and Obstetric InvestigationEffect of weight loss by bariatric surgery on the risk of miscarriageGynecologic and Obstetric Investigation
Public Health Reports
Maternal obesity and risk of infant death based on Florida birth records for 2004
Public Health Reports, 123(4):
American Journal of Obstetrics and GynecologyPregnancy: a "teachable moment" for weight control and obesity preventionAmerican Journal of Obstetrics and Gynecology
Monatsschrift KinderheilkundePrenatal prevention of childhood obesityMonatsschrift Kinderheilkunde
ContraceptionFamily planning for obese women: challenges and opportunitiesContraception
Bjog-An International Journal of Obstetrics and GynaecologyPoor uterine contractility in obese womenBjog-An International Journal of Obstetrics and Gynaecology
International Journal of Gynecology & ObstetricsObstetric outcome following laparoscopic adjustable gastric bandingInternational Journal of Gynecology & Obstetrics
Acta Obstetricia Et Gynecologica ScandinavicaPre-pregnancy body mass index and weight gain during pregnancy in relation to preterm delivery subtypesActa Obstetricia Et Gynecologica Scandinavica
American Journal of EpidemiologyObesity subtypes and risk of spontaneous versus medically indicated preterm births in singletons and twinsAmerican Journal of Epidemiology
International Journal of Obstetric AnesthesiaMaternal obesity and anaesthesiaInternational Journal of Obstetric Anesthesia
Journal of Maternal-Fetal & Neonatal MedicineMaternal BMI and preterm birth: A systematic review of the literature with meta-analysisJournal of Maternal-Fetal & Neonatal Medicine
ObesityMaternal Obesity and Breast-feeding Practices Among White and Black WomenObesity
Reproductive SciencesMaternal Obesity and its Relationship With Spontaneous and Oxytocin-Induced Contractility of Human Myometrium In VitroReproductive Sciences
Cochrane Database of Systematic ReviewsIntrapartum interventions for preventing shoulder dystociaCochrane Database of Systematic Reviews
European Journal of Obstetrics Gynecology and Reproductive BiologyMaternal morbidity associated with obstetrical maneuvers in shoulder dystociaEuropean Journal of Obstetrics Gynecology and Reproductive Biology
Journal of Reproductive Medicine
Cesarean birth in the morbidly obese woman - A report of 3 cases
Journal of Reproductive Medicine, 52(3):
Journal of Maternal-Fetal & Neonatal MedicineThe impact of maternal age, body mass index and maternal weight gain on the glucose challenge test in pregnancyJournal of Maternal-Fetal & Neonatal Medicine
Reproductive SciencesContractility and calcium signaling of human myometrium are profoundly affected by cholesterol manipulation: Implications for labor?Reproductive Sciences
Annual Review of NutritionAssociation of maternal obesity before conception with poor lactation performanceAnnual Review of Nutrition
Bjog-An International Journal of Obstetrics and GynaecologyWeight gain restriction for obese pregnant women: a case-control intervention studyBjog-An International Journal of Obstetrics and Gynaecology
Acta Obstetricia Et Gynecologica ScandinavicaDietary and lifestyle interventions to limit weight gain during pregnancy for obese or overweight women: A systematic reviewActa Obstetricia Et Gynecologica Scandinavica
American Journal of EpidemiologyInteractions between smoking and weight in pregnancies complicated by preeclampsia and small-for-gestational-age birthAmerican Journal of Epidemiology
Obesity ReviewsThe impact of maternal BMI status on pregnancy outcomes with immediate short-term obstetric resource implications: a meta-analysisObesity Reviews
Archives of Gynecology and ObstetricsThe effect of body mass index value during labor on pregnancy outcomes in Turkish population (obesity and pregnancy outcomes)Archives of Gynecology and Obstetrics
Journal of the National Medical Association
The Superobese Mother and Ethnic Disparities in Preterm Birth
Journal of the National Medical Association, 101():
American Journal of PerinatologyThe Association of Prepregnancy Body Mass Index with Pregnancy Outcomes in Triplet GestationsAmerican Journal of Perinatology
Seminars in Fetal & Neonatal MedicineObstetric management of obesity in pregnancySeminars in Fetal & Neonatal Medicine
Seminars in Fetal & Neonatal MedicineSetting maternity care standards for women with obesity in pregnancySeminars in Fetal & Neonatal Medicine
Womens Health IssuesPRECONCEPTION PREDICTORS OF WEIGHT GAIN DURING PREGNANCY Prospective Findings from the Central Pennsylvania Women's Health StudyWomens Health Issues
Clinical Obstetrics and GynecologyNutrition and PregnancyClinical Obstetrics and Gynecology
Current Opinion in Obstetrics and GynecologyObesity and reproduction: impact and interventionsCurrent Opinion in Obstetrics and Gynecology
EpidemiologyMaternal Obesity and the Risk of Infant Death in the United StatesEpidemiology
Obstetrics & GynecologyObesity-Related Complications in Danish Single Cephalic Term PregnanciesObstetrics & Gynecology
Obstetrics & GynecologyExtreme Obesity in Pregnancy in the United KingdomObstetrics & Gynecology
Obstetrics & GynecologyObstetric Outcomes After In Vitro Fertilization in Obese and Morbidly Obese WomenObstetrics & Gynecology
Obstetrics & GynecologyExtreme Obesity and Risk of Stillbirth Among Black and White GravidasObstetrics & Gynecology
Obstetrics & GynecologyOptimal Gestational Weight Gain for Body Mass Index CategoriesObstetrics & Gynecology
Obstetrics & GynecologyMaternal Obesity and Neonatal Mortality According to Subtypes of Preterm BirthObstetrics & Gynecology
Obstetrics & GynecologyMaternal Outcomes in Pregnancies Complicated by ObesityObstetrics & Gynecology
The Journal of Perinatal & Neonatal NursingObesity as a Complication of Pregnancy and LaborThe Journal of Perinatal & Neonatal Nursing
The Journal of Perinatal & Neonatal NursingBest Practices in Perinatal Nursing: Improving Outcomes for Obese and Morbidly Obese Women During the Intrapartum and Postpartum PeriodsThe Journal of Perinatal & Neonatal Nursing
MCN: The American Journal of Maternal/Child NursingCaring for the Extremely Obese Woman During Pregnancy and BirthMCN: The American Journal of Maternal/Child Nursing
MCN: The American Journal of Maternal/Child NursingLATE Preterm Birth: A New Nursing IssueMCN: The American Journal of Maternal/Child Nursing
Obstetrical & Gynecological SurveyObesity and PregnancyObstetrical & Gynecological Survey
Obstetrical & Gynecological SurveyAre All Brachial Plexus Injuries Caused by Shoulder Dystocia?Obstetrical & Gynecological Survey
The EndocrinologistCase Report: Exenatide Use During PregnancyThe Endocrinologist
© 2004 The American College of Obstetricians and Gynecologists