Obesity and pregnancy: complications and cost

Association of maternal obesity before conception with poor lactation performance

The objective of this review is to evaluate the evidence for a link between maternal obesity and poor lactation performance. In nonhuman species, excess maternal fatness is deleterious for lactation and also for maternal health and survival. These effects occur during pregnancy and as milk production is beginning. They may result in poor growth and survival of the young. In women, there is a negative association between maternal obesity and the initiation as well as the continuation of breastfeeding. This appears to be derived from biological as well as sociocultural factors that are still poorly understood. Excessive gestational weight gain, complications of pregnancy and delivery, and the condition of the infant at birth may also contribute to this association. Given the increasingly high rates of obesity among women of reproductive age worldwide and the importance of breastfeeding for infant health, further study of this association is essential.

Fatores associados à ocorrência de cesárea e aborto em mulheres selecionadas em um centro de saúde no município do Rio de Janeiro, Brasil

OBJETIVOS: investigar fatores potencialmente associados à ocorrência de cesárea e aborto. MÉTODOS: foram analisados dados de uma coorte no pós-parto com 352 mulheres entre 15-45 anos. Os seguintes desfechos foram estudados: ocorrência de cesárea no último parto e ocorrência de aborto anterior à última gravidez. A análise estatística foi feita por meio de modelos de regressão logística multivariados e hierarquizados. RESULTADOS: as prevalências de cesárea e aborto foram de 36,3% e 34,0%, respectivamente. O modelo final revelou que as seguintes variáveis permaneceram estatisticamente associadas à ocorrência de cesárea: nível 1: cor de pele branca (OR=2,02; IC95%: 1,29-3,16); nível 2: ligadura (OR=19,68; IC95%: 5,77-67,15). As seguintes variáveis permane-ceram associadas à ocorrência de aborto: nível 1: idade >29 anos (OR=6,11; IC95%: 2,94-12,72), estado marital: vive em união (OR=4,22; IC95%: 2,03-8,78); solteira: (OR=3,70; IC95%: 1,59-8,61). CONCLUSÕES: a cor de pele branca e a prática de ligadura foram co-variáveis potencialmente associadas à ocorrência de cesárea, enquanto o estado marital em união ou solteira e a idade materna estiveram associadas à ocorrência de aborto, sendo maior a probabilidade para mulheres acima de 29 anos.

A lifestyle intervention of weight-gain restriction: diet and exercise in obese women with gestational diabetes mellitus

OBJECTIVE

This study assessed whether a weight-gain restriction regimen, with or without exercise, would impact glycemic control, pregnancy outcome, and total pregnancy weight gain in obese subjects with gestational diabetes mellitus (GDM). A total of 96 subjects with GDM met the inclusion criteria and were sequentially recruited, with 39 subjects self-enrolled in the exercise and diet (ED) group, and the remaining 57 subjects self-enrolled in the diet (D) group owing to contraindications or a lack of personal preference to exercise. All patients were provided a eucaloric or hypocaloric consistent carbohydrate meal plan and instructed in the self-monitoring of blood glucose. In addition, all ED subjects were prescribed an exercise routine equivalent to a 60% symptom-limited VO2 max. Subjects were followed at weekly or biweekly office visits. Results showed maternal weight and body mass index (35.2+/-7.2 (ED) vs. 33.5+/-9.2 (D)) at study entry as well as number of weeks into the study (7.7+/-5.7 (ED) vs. 9.4+/-4.7 (D)) were similar in both the ED and D groups. Weight gain per week was significantly lower in the ED group than in the D group (0.1+/-0.4 kg vs. 0.3+/-0.4 kg; p<0.05). Subjects (either ED or D) who gained weight had a higher percentage of macrosomic infants than those subjects who lost weight or had no weight change during pregnancy. Other pregnancy and fetal outcomes such as complications, gestational age at delivery, and rate of cesarean delivery were similar in both groups. Conclusions of this study were that caloric restriction and exercise result in limited weight gain in obese subjects with GDM, less macrosomic neonates, and no adverse pregnancy outcomes. Pregnancy is an ideal time for behaviour modification, and this intervention may also help promote long-term healthy lifestyle changes.

Obesity and pregnancy complications

Maternal obesity increases the risk of numerous complications of pregnancy, labor, and birth for both mother and neonate, including diabetes and hypertensive disorders. As more women enter pregnancy with a body mass index (BMI) indicative of overweight or obesity, providers of obstetric care should be aware of the implications of this increased BMI on perinatal outcomes as well as become familiar with management options.

A systematic review of maternal obesity and breastfeeding intention, initiation and duration

Background

Breastfeeding behaviour is multifactorial, and a wide range of socio-cultural and physiological variables impact on a woman's decision and ability to breastfeed successfully. An association has been reported between maternal obesity and low breastfeeding rates. This is of public health concern because obesity is rising in women of reproductive age and the apparent association with increased artificial feeding will lead to a greater risk of obesity in children. The aim of this paper is to examine the relationship between maternal overweight and obesity and breastfeeding intention and initiation and duration.

Methods

A systematic review was conducted in January and February 2007, using the following databases: Medline, CINAHL and the Australian Breastfeeding Association's Lactation Resource Centre. Studies which have examined maternal obesity and infant feeding intention, initiation, duration and delayed onset of lactation were tabulated and summarised.

Results

Studies have found that obese women plan to breastfeed for a shorter period than normal weight women and are less likely to initiate breastfeeding. Of the four studies that examined onset of lactation, three reported a significant relationship between obesity and delayed lactogenesis. Fifteen studies, conducted in the USA, Australia, Denmark, Kuwait and Russia, have examined maternal obesity and duration of breastfeeding. The majority of large studies found that obese women breastfed for a shorter duration than normal weight women, even after adjusting for possible confounding factors.

Conclusion

There is evidence from epidemiological studies that overweight and obese women are less likely to breastfeed than normal weight women. The reasons may be biological or they may be psychological, behavioral and/or cultural. We urgently need qualitative studies from women's perspective to help us understand women in this situation and their infant feeding decisions and behaviour.

Exercise in the prevention and treatment of maternal-fetal disease: a review of the literature

Evidence-based guidelines indicate that regular prenatal exercise is an important component of a healthy pregnancy. In addition to maintaining physical fitness, exercise may be beneficial in preventing or treating maternal-fetal diseases. Women who are the most physically active have the lowest prevalence of gestational diabetes (GDM), and prevention of GDM may decrease the incidence of obesity and type 2 diabetes in both mother and offspring. However, few studies have investigated the effectiveness of exercise in delaying or preventing GDM in at-risk women, and exercise prescriptions that optimize outcomes for women with GDM are lacking. Physically active women are also less likely to develop pre-eclampsia, and we have proposed the following 4 mechanisms that may explain this protective effect: enhanced placental growth and vascularity, reduced oxidative stress, reduced inflammation, and correction of disease-related endothelial dysfunction. Exercise may also prevent reproductive complications associated with maternal obesity. Obesity increases the risk of infertility and miscarriage, and weight loss programs that incorporate diet and exercise are a cost-effective fertility treatment that may also reduce the probability of obesity-related complications during pregnancy. Regular exercise following conception may prevent excessive gestational weight gain and reduce post-partum weight retention.

Pregnancy outcome in obese and morbidly obese gestational diabetic women

OBJECTIVE

We sought to determine whether pregnancy outcome differs between obese and morbidly obese GDM patients and to assess pregnancy outcome in association with mode of treatment and level of glycemic control.

METHODS

A cohort study of 4,830 patients with gestational diabetes (GDM), treated in the same center using the same diabetic protocol, was performed. Obesity was defined as prepregnancy BMI >30 and <35 kg/m(2); morbid obesity was defined as prepregnancy BMI >or=35 kg/m(2). Well-controlled GDM was defined as mean blood glucose <105 mg/dl. Pregnancy outcome measures included the rates of large for gestational age (LGA) and macrosomic babies, metabolic complications, the need for NICU admission and/or respiratory support, rate of shoulder dystocia, and the rate of cesarean section.

RESULTS

Among the GDM patients, the rates of obesity and morbid obesity were 15.7% (760 out of 4830, BMI: 32.4+/-1.6 kg/m(2)) and 11.6% (559 out of 4830, BMI: 42.6+/-2.2 kg/m(2)), respectively. No differences were found with regard to maternal age, ethnicity, gestational age at delivery or oral glucose tolerance test (OGTT) results. Moreover, similar rates of cesarean section, fetal macrosomia, shoulder dystocia, composite outcome, and metabolic complications were noted. Insulin treatment was initiated for 62% of the obese and 73% of the morbidly obese GDM patients (P<0.002). Similar rates of obese and morbidly obese patients achieved desired levels of glycemic control (63% versus 61%, respectively). In both obese and morbidly obese patients who achieved a desired level of glycemic control (<105 mg/dl), no difference was found in pregnancy outcome except that both neonatal metabolic complications and composite outcomes were more prevalent in diet-treated subjects in comparison to insulin-treated GDM patients.

CONCLUSION

In obese women with GDM, pregnancy outcome is compromised regardless of the level of obesity or treatment modality.

The combined effect of maternal smoking and obesity on the risk of preeclampsia

AIMS

Cigarette smoking during pregnancy is associated with a lower risk of preeclampsia, whereas obesity increases the risk of preeclampsia. We sought to assess the combined effect of smoking and obesity on the risk of preeclampsia.

METHODS

We conducted a population-based cohort study of 129,674 women who delivered singleton infants during 2000-2001. Data for cigarette use, pre-pregnancy body mass index (BMI), preeclampsia, and potential confounders were obtained from birth certificate files. Mantel-Haenszel stratified analysis and logistic regression were used to analyze the data.

RESULTS

The preeclampsia risk was 3.1, 4.5, 7.6 and 8.8% for normal weight (BMI 18.5-24.9), overweight (25.0-29.9), obese (30.0-39.9) and morbidly obese (>or=40.0 kg/m2) women, respectively, who smoked cigarettes while pregnant. The preeclampsia risk was 3.9, 6.2, 9.0 and 12.3% for the same groups of women, respectively, who did not smoke during their pregnancy. Compared to non-smokers, the relative risk of preeclampsia for women who smoked cigarettes was 0.78 (95% confidence interval 0.73-0.83) before and after adjusting for pre-pregnancy BMI and other factors associated with preeclampsia.

CONCLUSION

The risk of preeclampsia is lower for women who smoke cigarettes while pregnant regardless of their pre-pregnancy BMI.

The use of customised versus population-based birthweight standards in predicting perinatal mortality

OBJECTIVE

The objective of this study was to critically examine potential artifacts and biases underlying the use of 'customised' standards of birthweight for gestational age (GA).

DESIGN

Population-based cohort study.

SETTING

Sweden.

POPULATION

A total of 782,303 singletons > or =28 weeks of gestation born in 1992-2001 to Nordic mothers with complete data on birthweight; GA; and maternal age, parity, height, and pre-pregnancy weight.

METHODS

We compared perinatal mortality in four groups of infants based on the following classification of small for gestational age (SGA): non-SGA based on either population-based or customised standards (the reference group), SGA based on the population-based standard only, SGA based on the customised standard only, and SGA according to both standards. We used graphical methods to compare GA-specific birthweight cutoffs for SGA using the two standards and also used logistic regression to control for differences in GA and maternal pre-pregnancy body mass index (BMI) in the four groups.

MAIN OUTCOME MEASURES

Perinatal mortality, including stillbirth and neonatal death.

RESULTS

Customisation led to a large artifactual increase in the proportion of SGA infants born preterm. Adjustment for differences in GA and maternal BMI markedly reduced the excess risk among infants classified as SGA by customised standards only.

CONCLUSION

The large increase in perinatal mortality risk among infants classified as SGA based on customised standards is largely an artifact due to inclusion of more preterm births.

Obesity in pregnancy: a study of the impact of maternal obesity on NHS maternity services

OBJECTIVE

To gain a detailed understanding of healthcare professionals' perceptions of the impact that caring for obese pregnant women has on maternity services.

DESIGN

Qualitative interview study using purposeful sampling and face-to-face interviews.

SETTING

Sixteen maternity units in NHS Trusts in the North East Government Office Region of England, UK.

SAMPLE

Thirty-three maternity and obstetric healthcare professionals with personal experience of managing the care of obese pregnant women.

METHODS

Semi-structured interviews with healthcare professionals representing each maternity unit in the region. Transcripts were analysed using systematic content analysis.

MAIN OUTCOME MEASURES

Views on the impact maternal obesity has on maternity services, the facilities required to care for obese mothers in pregnancy, and existing services directed towards maternal obesity.

RESULTS

Five dominant themes relating to service delivery emerged; booking appointments, equipment, care requirements, complications and restrictions, and current and future management of care. Many of the issues identified were associated with managing the care of obese women in pregnancy safely, resources and cost issues to be able to do this, multidisciplinary care requirements because of coexisting morbidities when the mother is obese, and restricted care options and patient choice.

CONCLUSIONS

Healthcare professionals in the North East of England feel that maternal obesity has a major impact on services and resource, on the health of both the mother and child, and on the psychological wellbeing of the mother.

A comparison of complications of pregnancy and delivery in morbidly obese and non-obese women

Morbid obesity in pregnancy is a growing problem and is having an impact on morbidity, mortality as well as significantly increasing antenatal and intra-partum costs of pregnancy care. The incidence of morbid obesity in pregnancy in our unit was 7.5% during the study period and this was associated with statistically significant increased maternal and perinatal morbidity. It also led to increased costs because of multidisciplinary management of the pregnancies, increased investigations and hospital stay when compared with normal weight pregnant women. Looking after morbidly obese pregnant women is an expensive undertaking, as the cost of the care of one morbidly obese pregnant woman and her baby is several times that of the normal weight woman. Health planners need to factor in these costs which are set to escalate given the predicted increase in the obese population in the UK.

Consequences of food energy excess and positive energy balance

This paper discusses possible consequences of energy excess throughout the life cycle. Firstly we consider the effects of foods on hunger, satiety and satiation. Also, the changes in food availability and consumption in relation to changes in social and economic determinants of energy excess. The relationship between physical activity and energy intake (EI) is also considered. Secondly we explore the definition of energy excess and the metabolic effects of macronutrients (mainly in relation to fuel partitioning oxidation/storage) on energy balance. The cellular and molecular regulation determined by specific genes involved in lipogenesis, fuel partitioning and/or in energy dissipation are explored. Thirdly, we examine the main consequences induced by energy excess and positive energy balance, starting with the alterations in glucose utilisation (insulin resistance) leading to type 2 diabetes and the linkage of energy excess with other non-communicable diseases (NCDs). Biological, social and psychological consequences during perinatal, childhood and adolescence periods are specifically analysed. Fourthly, the transition from energy deficit to excess, under the optic of a developing country is analysed with country examples drawn from Latin America. The possible role of supplementary food programmes in determining positive energy balance is discussed especially in relation to pre-school and school feeding programmes. Fifthly, we deal with the economic costs of energy excess and obesity related diseases. Finally, some areas where further research is needed are described; biological and genetic determinants of individual and population energy requirements, foods and food preparations as actually consumed, consumer education and research needs on social determinants of energy imbalances.

Grossesse des patientes obèses: quels risques faut-il craindre?

OBJECTIVE

To evaluate the deleterious effects of maternal obesity on obstetrical complications and neonatal outcomes.

PATIENTS AND METHODS

Historical cohort study including all patients delivered in our maternity between 1st January 2002 and 31st December 2004. Intra uterine death and fetal loss before 22 weeks were excluded. Women were categorized by the Body Mass Index: less than 25, between 25 and 30, and more than 30. Maternal data, obstetrical complications, labor and its complications, and neonatal outcomes were studied.

RESULTS

During these 3 years, 23.5% (1336/5686) of patients were overweight and 7.5% (425/5686) were obese. Obstetrical pathologies (gestational diabetes mellitus, hypertension, preeclampsia and fetal macrosomia) and labour induction were more significantly frequent in obese patients (P < 0.01). We noted twice more caesarean sections during labour in obese patients. The rate of artificial placental delivery was significantly higher in obese patients (P < 0.01). Obese patients with prior caesarean sections had a rate of vaginal delivery significantly lower than non obese patients with prior C-sections (23.6 vs 43.8%; P < 0.01). Mean children birth weight was significantly higher in obese patients (3305 vs 3181 g; P < 0.01) with no impact on Apgar score.

DISCUSSION AND CONCLUSION

Our study confirms that obesity is responsible for major obstetrical complications, for what should no doubt be considered as high risk pregnancies. Our practices must take these complications into account by ensuring an adapted and early management in order to improve maternal and neonatal issues.

Developmental programming of obesity in mammals

Converging lines of evidence from epidemiological studies and animal models now indicate that the origins of obesity and related metabolic disorders lie not only in the interaction between genes and traditional adult risk factors, such as unbalanced diet and physical inactivity, but also in the interplay between genes and the embryonic, fetal and early postnatal environment. Whilst studies in man initially focused on the relationship between low birth weight and risk of adult obesity and metabolic syndrome, evidence is also growing to suggest that increased birth weight and/or adiposity at birth can also lead to increased risk for childhood and adult obesity. Hence, there appears to be increased risk of obesity at both ends of the birth weight spectrum. Animal models, including both under- and overnutrition in pregnancy and lactation lend increasing support to the developmental origins of obesity. This review focuses upon the influence of the maternal nutritional and hormonal environment in pregnancy in permanently programming appetite and energy expenditure and the hormonal, neuronal and autocrine mechanisms that contribute to the maintenance of energy balance in the offspring. We discuss the potential maternal programming 'vectors' and the molecular mechanisms that may lead to persistent pathophysiological changes resulting in subsequent disease. The perinatal environment, which appears to programme subsequent obesity, provides a potential therapeutic target, and work in this field will readily translate into improved interventional strategies to stem the growing epidemic of obesity, a disease which, once manifest, has proven particularly resistant to treatment.

Assessment and Management of Obesity

Obesity is a serious medical condition that significantly impacts the health of pregnant and nonpregnant women. Although obstetrician-gynecologists have reported that they are knowledgeable of the health risks associated with obesity, they have also reported that their knowledge of weight assessment and management is inadequate. The purpose of this article is to review the proper procedures for assessing and managing obesity. By properly assessing obesity and constructing individualized weight management plans for those affected, obstetrician-gynecologists can help reduce the prevalence of obesity in women of childbearing ages.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to explain the impact of obesity on the health of nonpregnant and pregnant women, summarize the methods of distinguishing overweight from obesity, and recall the proper weight management programs for and assessments of obesity in women.

Maternal nutrition during pregnancy and health of the offspring

The ability of mother to provide nutrients and oxygen for her baby is a critical factor for fetal health and its survival. Failure in supplying the adequate amount of nutrients to meet fetal demand can lead to fetal malnutrition. The fetus responds and adapts to undernutrition but by doing so it permanently alters the structure and function of the body. Maternal overnutrition also has long-lasting and detrimental effects on the health of the offspring. There is growing evidence that maternal nutrition can induce epigenetic modifications of the fetal genome. Only relatively recently has evidence from epidemiological and animal studies emerged suggesting that fetal responses to the intrauterine environment may underlie the prevalence of many chronic diseases of adulthood including Type 2 (non-insulin-dependent) diabetes. It is now of crucial importance to gain the understanding of the molecular mechanisms underlying the relationship between fetal alterations to the intra-uterine environment and their long-term effects on the health of an individual.

Maternal obesity, metabolism, and pregnancy outcomes

About one third of all pregnant women in the United States are obese. Maternal obesity at conception alters gestational metabolic adjustments and affects placental, embryonic, and fetal growth and development. Neural tube defects and other developmental anomalies are more common in infants born to obese women; these defects have been linked to poor glycemic control. Preeclampsia, a gestational disorder occurring more frequently in obese women, appears to be due to a subclinical inflammatory state that impairs early placentation and development of its blood supply. Fetal growth and development during the last half of pregnancy depends on maternal metabolic adjustments dictated by placental hormones and the subsequent oxygen and nutrient supply. Maternal obesity affects these metabolic adjustments as well. Basal metabolic rates are significantly higher in obese women, and maternal fat gain is lower, possibly in response to altered leptin function. The usual increase in insulin resistance seen in late pregnancy is enhanced in obese mothers, causing marked postprandial increases in glucose, lipids, and amino acids and excessive fetal exposure to fuel sources, which in turn increases fetal size, fat stores, and risk for disease postnatally. Impaired glucose tolerance, gestational diabetes, and hyperlipidemia are more common among obese mothers. To date, little attention has been given to the role of diet among obese women in preventing these problems. However, studies of women with impaired glucose tolerance show that replacing refined carbohydrates and saturated fat with complex, low-glycemic carbohydrates and polyunsaturated fatty acids improves metabolic homeostasis and pregnancy outcomes. Thus, current dietary guidelines regarding the amount and type of carbohydrates and fat for nonpregnant women seem appropriate for pregnant women as well.

Pre-pregnancy body mass index and pregnancy outcomes

OBJECTIVE

To determine the effect of maternal pre-pregnancy BMI on pregnancy outcomes.

METHODS

Pregnancy cohort recruited pregnancies between 16 and 18 weeks. BMI evaluated underweight, BMI<18.5, normal, BMI 18.5-25, overweight BMI 25-30, and obese BMI>30 women.

RESULTS

Pre-pregnancy BMI classified 331 women as underweight (11.7%), 1982 normal (69.9%), 326 overweight (11.5%), and 188 as obese (6.6%). Obese women were more likely to develop gestational diabetes (p<0.001), hypertension (p<0.001), preeclampsia (p<0.001), need labor induction (p<0.001), cesarean delivery for fetal distress (p<0.001), postpartum hemorrhage (p=0.003), need neonatal resuscitation (p=0.001) and deliver hypoglycemic infants (p=0.007). Being underweight is correlated with fetal growth restriction (p=0.001).

CONCLUSION

Pre-pregnancy obesity is a risk factor for gestational diabetes, preeclampsia, labor induction, cesarean for fetal distress, postpartum hemorrhage and neonatal hypoglycemic and need for resuscitation. Being underweight is risk factor for fetal growth restriction.

Review article: Obesity, waist-hip ratio and hunter-gatherers

Obesity is a rapidly growing global problem. It is not simply the result of eating too much, and not all types of obesity have the same significance. Obesity is in part genetic, and one particularly important genetic type of obesity is the tendency to 'truncal obesity',-that is, a raised waist-to-hip ratio. Such obesity is powerfully associated not only with a tendency to diabetes, but also to cardiovascular disease, ('Syndrome X'). Interestingly, this is the type of obesity seen in every hunter-gatherer (HG) population around the globe. Such people are intolerant of carbohydrate, especially refined carbohydrate, especially in the excessive amounts typically consumed in affluent societies. In such pure HG communities, rates of diabetes can be as high as 50%, when the 'Western' lifestyle is adopted. Many of us, however, share some of their genes and their carbohydrate intolerance-perhaps as many as 20 or 30% of the world's population. Pregnancy can uncover this characteristic, and obesity and glucose intolerance in pregnancy are rapidly burgeoning problems. Quite contrary to the common nutritional dogma of encouraging regular carbohydrates, it is suggested that pregnant women with a high waist-to-hip ratio should be strongly advised to adhere to a low-glycaemic-index diet. Additionally, many dietary interventions, some of them derived from observation of HG populations, are of proven benefit in reducing the expression of glucose intolerance and may well help in tackling the obesity epidemic.

Diet around conception and during pregnancy--effects on fetal and neonatal outcomes

Substrate supply to the fetus is a major regulator of prenatal growth. Maternal nutrition influences the availability of nutrients for transfer to the fetus. Animal experiments demonstrate that restriction of maternal protein or energy intake can retard fetal growth. Effects of maternal nutrition vary with the type and timing of the restriction and the species studied. Maternal undernutrition before conception and/or in early pregnancy can alter fetal physiology in late gestation, and influence postnatal function, often without measurable effects on birth size. In contrast, to date, observational and intervention studies in humans provide limited support for a major role of maternal nutrition in determining birth size, except where women are quite malnourished. However, recent studies report associations between newborn size and the balance of macronutrients in women's diets in Western settings. Associations between maternal dietary composition and adult blood pressure of the offspring are also reported in human populations. Most studies in women have focused on dietary content or supplementation during mid-late pregnancy. Further investigation of how maternal dietary composition, before conception and throughout pregnancy, affects fetal physiology and health of the baby will increase the understanding of how maternal diet and nutritional status influence fetal, neonatal and longer-term outcomes.

Achieving safe motherhood: Applying a life course and multiple determinants perinatal health framework in public health

Safe motherhood has begun to be identified as a priority for the health of American women. We argue that safe motherhood can be achieved through application of a life course and multiple determinants framework. This framework, with its focus on the preconception period, poses a dilemma in that it links together periods of life and domains of activities that have traditionally not been linked with maternal health. The interests of women and children have often been juxtaposed in the making of policy. Further, the domains of women's health, maternal and child health, and family planning have often clashed over policy priorities and funds. This framework shows that the research literature now links them inextricably to better health outcomes, albeit indirectly; there are no intervention studies that have demonstrated the empirical efficacy of this approach. Thus, although this framework creates a strong rationale for the linkages described, it also demands attention to a set of implementation strategies that will overcome existing barriers. Through a focus on one maternal factor, obesity, we discuss how a range of strategies grounded in the framework can be undertaken to address maternal morbidity and mortality. We then examine selected strategies at each level of the multiple determinants life course framework and emphasize how public policies and public and private sector professional practice can be reexamined to improve outcomes for women in all time periods and aspects of reproductive potential, which in turn might enhance outcomes for their offspring, both at birth and beyond. Our intent is to influence how policy makers, public health professionals, clinicians, and researchers approach safe motherhood.

Pregnancy and Obesity: A Review and Agenda for Future Research

At present, more than 60% of American women of childbearing age are either overweight or obese. As the obesity epidemic in the United States and many other countries continues to grow unchecked, there is greater interest in the relationship between obesity and other major health issues. This paper reviews the literature on the relationship between obesity and pregnancy. We begin with a discussion of the relationship between excess body weight and fertility and then turn to the relationship between maternal body weight and pregnancy-related complications. The role of pregnancy as a possible risk factor for the development of obesity is noted. The studies investigating the efficacy of behavioral interventions to control excessive weight gain during pregnancy or help women lose weight after childbirth are then reviewed. The paper concludes with an agenda for future research examining the relationship between obesity and pregnancy.

Pregnancy outcomes of First Nations women in relation to pregravid weight and pregnancy weight gain

OBJECTIVE

To determine the effect of pregravid weight and pregnancy weight gain on pregnancy outcomes in Cree women.

METHODS

We reviewed maternal and infant outcomes of the first pregnancy in Cree women living in James Bay, Quebec, from 1994 to 2000. We examined data from women who had a full-term singleton birth and a maternal pregravid body mass index (BMI) > or = 18.5 kg/m2 and whose weight had been recorded in the first trimester and within one month prior to delivery. Weight in the first trimester was used to estimate pregravid BMI.

RESULTS

Data were available for 603 women. At the beginning of pregnancy, 23.1% of the women had normal weight (BMI 18.5-24.9 kg/m2), 27.9% were overweight (BMI 25-29.9 kg/m2), and 49.1% were obese (BMI > or = 30 kg/m2). Nearly one-half of the women gained excessive weight in pregnancy. Adverse outcomes were less common in women with a normal pregravid BMI than in women with a pregravid BMI in the overweight or obese range. Obese women with excessive weight gain had a higher prevalence of preeclampsia (14.9%) than obese women with low (3.7%) or acceptable (6.3%) weight gain; however, obese women with excessive weight gain had a lower prevalence of gestational diabetes mellitus.

CONCLUSION

Interventions must be developed to prevent pregravid obesity and excessive weight gain in pregnancy in Cree women to improve maternal and fetal outcomes.

Relations between high ponderal index at birth, feeding practices and body mass index in infancy

OBJECTIVE

We compared feeding practices between infants of high ponderal index (PI) at birth (PI above the 90th percentile) and normal PI at birth (PI between 10th and 90th percentiles), and examined how birth size and infant feeding practices were related to body mass index (BMI) at 12 months.

DESIGN

In a cohort of 3000 infants invited to participate in a national Norwegian dietary survey, 1825 participated both at 6 and 12 months of age, and the present study included those born full term and with a PI (weight/length3) at birth > or =10th percentile (n=1441). Data on feeding practices were collected by food-frequency questionnaires, and anthropometrical data were measured by health-care personnel.

RESULTS

A lower proportion of infants born with high PI were exclusively breastfed for at least 4 months compared with infants born with normal PI (37 and 47%, respectively; P=0.03). Earlier introduction of solid foods and higher consumption of some foods were also observed among infants of high PI. In a multivariate analysis, adjusted mean BMI (kg/m2) at 12 months was higher for infants of high PI at birth than for infants of normal PI (17.6 and 17.0, respectively; P<0.001) and higher for infants exclusively breastfed <3 months than for infants exclusively breastfed > or =3 months (17.5 and 17.2, respectively; P=0.001).

CONCLUSIONS

High PI at birth was associated with a shorter duration of exclusive breastfeeding. Furthermore, high PI at birth and short-term exclusive breastfeeding were both associated with higher BMI at 12 months.

Maternal caffeine consumption and fetal death: a case-control study in Uruguay

The objective of this study was to examine the association between caffeine intake during pregnancy and fetal mortality in Montevideo, the capital city of Uruguay, taking into account several potential confounding factors. A population-based case-control study was conducted between 1 August 2002 and 31 December 2003. A total of 382 cases and 792 controls were recruited. Cases consisted of women hospitalised with a medically confirmed diagnosis of spontaneous antepartum fetal death, in all maternity hospitals during the study period. Antepartum fetal death was defined as a fetal death in which the attending doctor certified that the death occurred prior to the onset of labour. Fetal deaths were included if they were of at least 20 weeks' gestational age or weighed >350 g. Controls were women who had a live, vigorous and term adequate-for-gestational-age newborn. Multiple gestations and fetuses/newborns with evident congenital malformations were excluded. Only a small proportion of the mothers (8.1% of the cases and 9.5% of the controls) did not consume caffeine during pregnancy. Among consumers, mate drinking was the most frequent source of caffeine in both cases and controls. After controlling for mother's and her partner's education, history of abortions and/or fetal deaths, vomiting/nausea during the first trimester of gestation and attendance for prenatal care, the category of mean caffeine intake of > or = 300 mg/day showed a significantly increased risk of fetal death (OR 2.33 [1.23; 4.41]) compared with no caffeine consumption during pregnancy. The study also found that less-educated women, mothers who did not attend for prenatal care and women with a history of abortions and fetal death were at an increased risk of fetal death. As mate drinking is highly consumed among pregnant women in Uruguay, the association found with fetal death makes it a preventable risk factor.

The evolution of human fatness and susceptibility to obesity: an ethological approach

Human susceptibility to obesity is an unusual phenomenon amongst animals. An evolutionary analysis, identifying factors favouring the capacity for fat deposition, may aid in the development of preventive public health strategies. This article considers the proximate causes, ontogeny, fitness value and evolutionary history of human fat deposition. Proximate causes include diet composition, physical activity level, feeding behaviour, endocrine and genetic factors, psychological traits, and exposure to broader environmental factors. Fat deposition peaks during late gestation and early infancy, and again during adolescence in females. As in other species, human fat stores not only buffer malnutrition, but also regulate reproduction and immune function, and are subject to sexual selection. Nevertheless, our characteristic ontogenetic pattern of fat deposition, along with relatively high fatness in adulthood, contrasts with the phenotype of other mammals occupying the tropical savannah environment in which hominids evolved. The increased value of energy stores in our species can be attributed to factors increasing either uncertainty in energy availability, or vulnerability to that uncertainty. Early hominid evolution was characterised by adaptation to a more seasonal environment, when selection would have favoured general thriftiness. The evolution of the large expensive brain in the genus Homo then favoured increased energy stores in the reproducing female, and in the offspring in early life. More recently, the introduction of agriculture has had three significant effects: exposure to regular famine; adaptation to a variety of local niches favouring population-specific adaptations; and the development of social hierarchies which predispose to differential exposure to environmental pressures. Thus, humans have persistently encountered greater energy stress than that experienced by their closest living relatives during recent evolution. The capacity to accumulate fat has therefore been a major adaptive feature of our species, but is now increasingly maladaptive in the modern environment where fluctuations in energy supply have been minimised, and productivity is dependent on mechanisation rather than physical effort. Alterations to the obesogenic environment are predicted to play a key role in reducing the prevalence of obesity.

The prevalence and impact of overweight and obesity in an Australian obstetric population

OBJECTIVE

To assess the prevalence and impact of overweight and obesity in an Australian obstetric population.

DESIGN, SETTING AND PARTICIPANTS

The Mater Mother's Hospital (MMH), South Brisbane, is an urban tertiary referral maternity hospital. We reviewed data for the 18 401 women who were booked for antenatal care at the MMH, delivered between January 1998 and December 2002, and had a singleton pregnancy. Of those women, 14 230 had an estimated pre-pregnancy body mass index (BMI) noted in their record; 2978 women with BMI < or = 20 kg/m2 were excluded from further study; the remaining 11 252 women were divided into four categories: "normal" (BMI 20.01-25 kg/m(2)), "overweight" (BMI 25.01-30 kg/m(2)), "obese" (BMI 30.01-40 kg/m(2)) and "morbidly obese" (BMI > 40 kg/m(2)).

MAIN OUTCOME MEASURES

Prevalence of overweight and obesity in an obstetric population; maternal, peripartum and neonatal outcomes associated with raised BMI.

RESULTS

Of the 14 230 women, 6443 (45%) were of normal weight, and 4809 (34%) were overweight, obese or morbidly obese. Overweight, obese and morbidly obese women were at increased risk of adverse outcomes (figures represent adjusted odds ratio [AOR] [95% CI]): hypertensive disorders of pregnancy (overweight 1.74 [1.45-2.15], obese 3.00 [2.40-3.74], morbidly obese 4.87 [3.27-7.24]); gestational diabetes (overweight 1.78 [1.25-2.52], obese 2.95 [2.05-4.25], morbidly obese 7.44 [4.42-12.54]); hospital admission longer than 5 days (overweight 1.36 [1.13-1.63], obese 1.49 [1.21-1.86], morbidly obese 3.18 [2.19-4.61]); and caesarean section (overweight 1.50 [1.36-1.66], obese 2.02 [1.79-2.29], morbidly obese 2.54 [1.94-3.32]). Neonates born to obese and morbidly obese women had an increased risk of birth defects (obese 1.58 [1.02-2.46], morbidly obese 3.41 [1.67-6.94]); and hypoglycaemia (obese 2.57 [1.39-4.78], morbidly obese 7.14 [3.04-16.74]). Neonates born to morbidly obese women were at increased risk of admission to intensive care (2.77 [1.81-4.25]); premature delivery (< 34 weeks' gestation) (2.13 [1.13-4.01]); and jaundice (1.44 [1.09-1.89]).

CONCLUSIONS

Overweight and obesity are common in pregnant women. Increasing BMI is associated with maternal and neonatal outcomes that may increase the costs of obstetric care. To assist in planning health service delivery, we believe that BMI should be routinely recorded on perinatal data collection sheets.

Teratology public affairs committee position paper: Maternal obesity and pregnancy

Compared to normal-weight women, obese women have an increased risk of infertility and pregnancy complications. The most consistently described pregnancy complications are hypertensive disorders, gestational diabetes mellitus, thromboembolic events, and cesarean section. Fetal and neonatal complications may include congenital malformations, macrosomia, and shoulder dystocia. The literature suggests that women with a body mass index (BMI) >or=30 have approximately double the risk of having a child with a neural tube defect (NTD) compared to normal-weight women, and the increased risk associated with higher maternal body weight does not appear to be modified by folic acid supplementation. The Public Affairs Committee of the Teratology Society supports the public health initiatives identified by the U.S. Food and Drug Administration in 2004 and the research initiatives identified by the National Institutes of Health in 2004. The Public Affairs Committee recommends that clinicians counsel women about appropriate caloric intake and exercise and that health-care providers educate parents about appropriate childhood nutrition. Breast-feeding should be encouraged based on evidence of a protective effect against childhood obesity, as well as other health advantages.

Obesity and obstetric anaesthesia

The prevalence of obesity continues to increase despite preventive strategies. Obese parturients are at increased risk of having either concurrent medical problems or superimposed antenatal diseases such as pre-eclampsia and gestational diabetes. Moreover, they have a tendency to labour abnormally contributing to increased instrumental delivery and Caesarean section. Obesity is a risk factor for anaesthesia related maternal mortality. Morbidly obese women must be considered as high-risk and deserve an anaesthetic consultation during their antenatal care. The significant difficulty in administering epidural analgesia should not preclude their use in labour. A more liberalised use of regional techniques may be a means to further reduce anaesthesia-related maternal mortality in the obese population. The mother's life should not be jeopardised to save a compromised fetus. Prophylactic placement of an epidural catheter when not contraindicated in labouring morbidly obese women would potentially decrease anaesthetic and perinatal complications associated with attempts at emergency provision of regional or general anaesthesia. Early mobilisation, aggressive chest physiotherapy and adequate pain control are essential components of effective postoperative care.

Increasing prepregnancy body mass index: analysis of trends and contributing variables

OBJECTIVE

In the United States, obesity has increased steadily. As obesity in pregnancy is a high-risk obstetric situation, important questions are whether there has been a trend toward higher prepregnancy body mass indexes (BMIs) in women who have become pregnant and if there are subgroups at risk. The objective of this study was to analyze the shifts, if any, in the prepregnancy BMIs in women who delivered.

STUDY DESIGN

Analysis of the birth certificate data collected in a regional perinatal data system of all live born deliveries (79,022 cases) occurring in a contiguous 8-county area in upstate New York from 1999 to 2003.

RESULTS

From 1999 to 2003, there was an overall increase in the mean prepregnancy BMI of the total delivery population (P < .01). There was a relative 11% increase in the Institute of Medicine (IOM) overweight (P < .01) and a relative 8% increase in the obese (P < .01) categories. There was an increase in the numbers of women in the IOM overweight or obese categories in these subgroups (P < .05): age (all subgroups), ethnicity (white and black), education (all subgroups), insurance type (all subgroups), previous live births (all subgroups), urbanization status (all subgroups), median family income of ZIP code area (all subgroups), and smoking (both smokers and nonsmokers).

CONCLUSION

There was a significant increase toward higher prepregnancy BMIs across multiple subgroups. Our study demonstrates that increased prepregnancy BMI is an issue that spans almost the entire spectrum of subgroups of patients who delivered.

Metformin revisited: re-evaluation of its properties and role in the pharmacopoeia of modern antidiabetic agents

BACKGROUND

The usefulness of metformin as an oral antidiabetic agent is widely accepted. However, several other classes of oral antidiabetic agents have been recently introduced, raising the need to evaluate the role of metformin as initial therapy and in combination with these newer drugs for treatment of type 2 diabetes mellitus (DM).

METHODS

Synthesis of information was preceded by a comprehensive review of the English language literature using Medline. We also reviewed bibliographies of relevant articles. The studies most pertinent to the mechanism of action, efficacy, toxicity and administration of metformin were selected for citation in this review.

RESULTS

Metformin acts by increasing tissue sensitivity to insulin, principally in the liver. Beneficial properties of metformin include weight reduction, favourable effects on the lipid profile and the fibrinolytic pathway, and improvement of ovarian function in some insulin-resistant women. It does not cause hyperinsulinaemia or hypoglycaemia. Metformin is effective as monotherapy and, in combination with both insulin secretagogues and thiazolidinediones (TZDs), may obviate the need for insulin treatment. Several fixed-dose combination pills containing metformin and other agents are available. A protocol for the initiation of therapy with contemporary oral agents for type 2 DM is presented, with emphasis on the continuing central role of metformin.

CONCLUSIONS

Metformin remains a safe and effective agent for the therapy of patients with type 2 DM. It is useful as monotherapy or in combination regimens with the newer insulin secretagogues, TZDs or insulin. It is still in most circumstances the agent of choice for initial therapy of the typical obese patient with type 2 DM and mild to moderate hyperglycaemia.

Risk factors for adverse perinatal outcomes in imprisoned pregnant women: a systematic review

Background

Imprisoned pregnant women constitute an important obstetric group about whom relatively little is known. This systematic review was conducted to identify the risk factors associated with adverse pregnancy outcome present in this group of women.

Methods

The review was conducted according to a prespecified protocol. Studies of any design were included if they described information on any of the pre-specified risk factors. We calculated the results as summary percentages or odds ratios where data was available on both cases and population controls.

Results

The search strategy identified 27 relevant papers of which 13 met the inclusion criteria, involving 1504 imprisoned pregnant women and 4571 population control women. Imprisoned women are more likely to be single, from an ethnic minority, and not to have completed high school. They are more likely to have a medical problem which could affect the pregnancy outcome and yet less likely to receive adequate antenatal care. They are also more likely to smoke, drink alcohol to excess and take illegal drugs.

Conclusion

Imprisoned women are clearly a high risk obstetric group. These findings have important implications for the provision of care to this important group of women.

Gestational weight gain and pregnancy outcomes in 481 obese glucose-tolerant women

OBJECTIVE

To investigate the effect of gestational weight gain in obese glucose-tolerant women.

RESEARCH DESIGN AND METHODS

We performed a historical cohort study of 481 women with prepregnancy BMI > or = 30 kg/m2 and a normal 2-h 75-g oral glucose tolerance test (OGTT) during the third trimester (according to World Health Organization criteria). Data on OGTT results and clinical outcomes were collected from medical records. Four groups were defined according to weight gain: group 1, <5.0 kg (n = 93); group 2, 5.0-9.9 kg (n = 134); group 3, 10.0-14.9 kg (n = 132); and group 4, > or = 15.0 kg (n = 122).

RESULTS

Birth weight increased significantly with increasing weight gain (mean grams +/- SD): group 1, 3,456 +/- 620; group 2, 3,624 +/- 675; group 3, 3,757 +/- 582; and group 4, 3,784 +/- 597 (P < 0.001). The birth weight in group 1 was similar to that of the background population of primarily normal-weight women (3,478 g). In multivariate analyses, increasing weight gain was associated with significantly higher rates of hypertension (OR 4.8 [95% CI for group 4 vs. group 1: 1.7-13.1]), cesarean section (3.5 [1.6-7.8]), induction of labor (3.7 [1.7-8.0]), and large-for-gestational-age infants (4.7 [2.0-11.0]). There was no difference in rates of small-for-gestational-age infants. Significant predictors for birth weight (determined by multiple linear regression) were gestational weight gain, 2-h OGTT result, pre-gestational BMI, maternal age, gestational age, and smoking.

CONCLUSIONS

Increasing weight gain in obese women is associated with increasing pregnancy complications. Our data suggest that minimal gestational weight gain might normalize birth weight. Prospective studies should be performed to clarify the safety of recommending limited gestational weight gain.

Long-term effect of maternal obesity on pancreatic beta cells of offspring: reduced beta cell adaptation to high glucose and high-fat diet challenges in adult female mouse offspring

AIM/HYPOTHESIS

Obesity is a global problem with high risks of cardiovascular diseases, stroke and type 2 diabetes. It is well known that maternal obesity affects offspring by inducing malformation, functional abnormalities in many organs and cells, and by increased risk of obesity and type 2 diabetes. However, little is known about abnormalities induced by maternal obesity in pancreatic beta cells of offspring.

METHODS

We used mouse mothers with the Agouti yellow modification on a C57BL/6 background as a maternal model of normoglycaemic obesity, and produced Agouti-negative offspring. Half of the offspring were fed a high-fat diet. Offspring glucose tolerance was tested at different ages, and animals were killed at 50 weeks of age for islet function analysis.

RESULTS

Maternal obesity impaired glucose tolerance in female offspring fed a high-fat diet, and significantly reduced insulin secretion at 50 weeks of age in female offspring that had been fed a normal diet and high-fat diet. Insulin secretion and glucose potentiation from these islets were significantly reduced. Islet protein, DNA and insulin contents were increased while glyceraldehyde-3-phosphate dehydrogenase and transketolase activities were reduced in female offspring.

CONCLUSIONS/INTERPRETATION

Our results indicate that maternal obesity has a long-term effect on the beta cells of female, but not of male, offspring, and leads to increased risk of gestational diabetes and type 2 diabetes in the offspring's later lives.

Impaired maternal glucose homeostasis during pregnancy is associated with low status of long-chain polyunsaturated fatty acids (LCP) and essential fatty acids (EFA) in the fetus

Low status of long-chain polyunsaturated fatty acids (LCP) and essential fatty acids (EFA) in the fetus is associated with less favorable neonatal neurological condition. A 'relative', rather than 'absolute' EFA deficiency might explain this finding. A relative EFA deficiency may derive from impaired maternal glucose homeostasis. We measured fatty acids in umbilical vessels of infants born to 7 mothers with (gestational) diabetes mellitus and of 258 infants born to healthy mothers. Umbilical veins of infants of diabetic mothers had higher omega7 and omega9 fatty acids and DHA deficiency index and lower 20:4omega6 and EFA index. Their umbilical arteries had higher omega7 and omega9 fatty acids, and lower 20:4omega6, LCP and EFA index. We conclude that children born to mothers with poor glucose homeostasis have lower EFA and LCP status, which is consistent with a 'relative deficiency' deriving from augmented de novo fatty acid synthesis from the abundant glucose.

Independent association between leptin and blood pressure during third trimester in normal and gestational diabetic pregnancies

OBJECTIVE

To assess the relationship between plasma leptin concentration during third trimester of pregnancy and blood pressure, independent of body mass index at examination and other potential confounders.

STUDY DESIGN

A cross-sectional study was performed including 95 women (61 non-diabetic women, 34 women with gestational diabetes (GD)) in their third trimester of pregnancy. The relationship between plasma leptin and blood pressure was investigated using multiple linear regression analysis.

RESULTS

Independent of body mass index (BMI), leptin was positively correlated to systolic (P = 0.024) and diastolic blood pressure (P = 0.002). Stepwise linear regression identified leptin as the only variable independently associated with systolic blood pressure (P = 0.003), while leptin (P < 0.001) and age (P = 0.024) were the only variables independently correlated to diastolic blood pressure.

CONCLUSIONS

This study reports for the first time that, independent of BMI at examination, presence of GD or other confounders, plasma leptin is positively correlated with blood pressure in pregnant women.

Obesity-Related Complications in Danish Single Cephalic Term Pregnancies

OBJECTIVE

Our objective was to investigate the relationship between prepregnancy and obstetric body mass index (BMI) as well as fetal complications in a large, unselected cohort of Danish women with single cephalic pregnancies.

METHODS

A cohort of 8,092 women from the Copenhagen First Trimester Study with a registered prepregnancy BMI and a single cephalic term delivery were stratified into 3 BMI groups: normal weight (BMI < 25 kg/m(2)), overweight (BMI 25-29.9 kg/m(2)), and obese (BMI >/= 30 kg/m(2)). The effects of BMI and parity on the outcome were analyzed using multivariate logistic regression analyses.

RESULTS

Overweight women had an odds ratio (OR) of 3.4 for diabetes, 1.9 for hypertension, 1.7 for preeclampsia, and 1.5 for cesarean delivery. The corresponding figures for obese women were 15.3, 4.8, 2.7, and 1.7, respectively. No relationship was found between BMI and vacuum extraction. Obese women had an increased risk of delivering macrosomic but also low birth weight children. No differences existed among the 3 weight groups with regard to neonatal morbidity estimated by Apgar score, umbilical cord pH, or admittance to a neonatal intensive care unit. Nulliparous women had an increased incidence of preeclampsia (OR 2.8), hypertension (OR 1.9), emergency cesarean delivery (OR 3.4), vacuum extraction (OR 5.6), and perineal rupture (OR 1.7) but a lower frequency of elective cesarean delivery (OR 0.25).

CONCLUSION

The rate of complications during pregnancy and delivery increases with an increasing prepregnancy BMI in women with single cephalic term pregnancies, particularly in nulliparous women.

Maternal prepregnant body mass index, duration of breastfeeding, and timing of complementary food introduction are associated with infant weight gain

BACKGROUND

Women who are overweight or obese before pregnancy breastfeed for shorter durations than do normal-weight women. These shorter durations may place infants of overweight and obese women at risk of not receiving the benefits of breastfeeding, which may include a reduced risk of overweight later in life.

OBJECTIVE

We examined how maternal prepregnant body mass index (BMI; in kg/m2) and infant feeding pattern are associated with infant weight gain.

DESIGN

In this prospective, observational study, we used multiple regression analyses adjusted for potential confounding factors to examine these associations among 3768 mother-infant dyads from the Danish National Birth Cohort.

RESULTS

In multiple regression analyses, increasing maternal prepregnant BMI, decreasing durations of breastfeeding, and earlier complementary food introduction were associated with increased infant weight gain. An interaction was identified for short durations of breastfeeding (<20 wk). Earlier complementary food introduction (<16 wk) was associated with greater infant weight gain; however, the timing of complementary food introduction did not increase infant weight gain at longer durations of breastfeeding (> or =20 wk). In this sample, prepregnant obesity (BMI > or = 30.0), short durations of breastfeeding, and earlier introduction of complementary food were associated with 0.7 kg of additional weight gain during infancy.

CONCLUSIONS

Infant weight gain is associated with maternal prepregnant BMI and with an interaction between the duration of breastfeeding and the timing of complementary food introduction. Future investigations of the effects of breastfeeding on infant weight gain should account for all of these factors.

Development of overweight associated with childbearing depends on smoking habit: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

OBJECTIVE

To prospectively evaluate whether childbearing leads to development of overweight in women and to evaluate the role of other known risk factors.

RESEARCH METHODS AND PROCEDURES

A prospective, multicenter observational study, the Coronary Artery Risk Development in Young Adults (CARDIA) Study from 1986 to 1996, examined subjects at baseline and in follow-up years 2, 5, 7, and 10. Included were 998 (328 black and 670 white) nulliparous women, age 18-30 years, who were not overweight at baseline. Relative odds for incident overweight (BMI > or = 25 kg/m2) associated with parity change (0, 1, or 2+) and risk factors were estimated using discrete-time survival models adjusted for baseline and time-dependent covariates.

RESULTS

Parity change-association with development of overweight depended on smoking habit (interaction, p < 0.001). In multivariate adjusted models, 1 and 2+ births vs. 0, respectively, were associated with increased risk for development of overweight among never smokers [odds ratio (OR) = 2.66; 95% confidence interval (CI): 1.80, 3.93, and 2.10, 95% CI: 1.24, 3.56] and decreased risk among current smokers (OR = 0.41; 95% CI: 0.17, 0.96, and 0.36, 95% CI: 0.08, 1.65). Risk was increased for black vs. white race (OR = 3.49; 95% CI: 2.59, 4.69), frequent weight cycling (OR = 1.45; 95% CI: 1.03, 2.04), and high school education or less (OR = 2.21; 95% CI: 1.50, 3.26) and was decreased for highest physical activity quartile (OR = 0.62; 95% CI: 0.43, 0.90).

DISCUSSION

Childbearing contributes to development of overweight in nonsmokers but not in smokers, where development of overweight is less likely in women who bear children. Race, education, and behaviors are important factors in development of overweight in young women.

Determination of Maternal Body Composition in Pregnancy and Its Relevance to Perinatal Outcomes

Three models and 10 specific methods for determining maternal body composition are discussed and their perinatal relevance reviewed. English language publications (1950 to January 2004) were searched electronically and by hand. Search terms included "body composition," "human," " pregnancy," "obesity," "adiposity," "regional," "2-, 3-, 4-component," "truncal," "peripheral," "central," "visceral" along with specific techniques and outcomes listed subsequently. Three models of body composition are described: 2-component being fat and fat-free mass; 3-component being fat, water, and protein; and 4-component being fat, water, protein, and osseous mineral. Ten techniques of body composition assessment are described: 1) anthropometric techniques including skinfold thicknesses and waist-hip ratio; 2) total body water (isotopically labeled); 3) hydrodensitometry (underwater weighing); 4) air-displacement plethysmography; 5) bio-impedance analysis (BIA); 6) total body potassium (TBK); 7) dual-energy x-ray absorptiometry (DEXA); 8) computed tomography (CT); 9) magnetic resonance imaging (MRI); and 10) ultrasound (USS). Most methods estimate total adiposity. Regional fat distribution-central (truncal) compared with peripheral (limb) or visceral compared with subcutaneous-is important because of regional variation in adipocyte metabolism. Skinfolds, DEXA, CT, MRI, or USS can distinguish central from peripheral fat. CT, MRI, or USS can further subdivide central fat into visceral and subcutaneous. Perinatal outcomes examined in relation to body composition include pregnancy duration, birth weight, congenital anomalies, gestational diabetes, gestational hypertension, and the fetal origins of adult disease. A few studies suggest that central compared with peripheral fat correlates better with birth weight, gestational carbohydrate intolerance, and hypertension. Means of accurately assessing maternal body composition remain cumbersome and impractical, but may more accurately predict perinatal outcomes than traditional assessments such as maternal weight.

The influence of obesity and diabetes on the risk of cesarean delivery

OBJECTIVE

To determine the influence of pregravid obesity and diabetes on cesarean delivery (CD) risk.

STUDY DESIGN

Women with singleton pregnancies of 23 weeks or more estimated gestational age who were undergoing a trial of labor January 1997 through June 2001 were categorized by pregravid body mass index (underweight [<19.8 kg/m 2 ], normal [19.8-25 kg/m 2 ], overweight [25.1-30 kg/m2], obese [>30 kg/m2]). Diabetes (DM) was divided into categories of gestational, treated with diet modification (A1GDM) or insulin (A2GDM), and pregestational (PDM). Prior CDs were excluded. CD rates for each group were compared in univariate analyses stratified by estimated gestational age (term, preterm, total). Other variables examined included DM, macrosomia (birth weight 4500 g or more), induction, and parity. Multiple regression included significant variables to predict the influence of diabetes and obesity on CD risk.

RESULTS

Records for 12,303 deliveries were evaluated (obese: 2828 [22.9%]; overweight: 2605 [21.2%]; A1GDM: 270 [2.2%]; A2GDM: 93 [0.8%]; PDM: 126 [1%]). Obese and overweight subjects had a higher risk for CD, compared with normal subjects (13.8% and 10.4% versus 7.7%, P < .0001 for each). Other CD risk factors were macrosomia (25% versus 9.4%), nulliparity (16.5% versus 4.7%), induction (17.4% versus 8.3%), diabetes (A1GDM: 16.7% versus 9.4%; A2GDM: 24.7% versus 9.5%; PDM: 34.9% versus 9.3%) and black race (10.7% versus 8.8%) ( P < .0001 for each). In multiple regression models including term deliveries, obesity and PDM were independent CD risk factors ([adjusted OR overweight: 1.5, P < .0001; adjusted OR PDM: 2.9, P = .01]; [adjusted OR obese: 2.4, P < .0001, PDM: 2.9, P = .0002]).

CONCLUSION

Pregravid obesity and diabetes independently increase the risk for CD. Given the disparate prevalence of obesity and diabetes in the United States, body habitus has a significantly larger impact on CD risk.

The influence of obesity and diabetes on the prevalence of macrosomia

OBJECTIVE

This study was undertaken to determine the relative contribution of abnormal pregravid maternal body habitus and diabetes on the prevalence of large-for-gestational-age infants.

STUDY DESIGN

Maternal and neonatal records for singleton term (> or =37 weeks' estimated gestational age) deliveries January 1997 through June 2001 were reviewed. Subjects were characterized by pregravid body mass index (BMI), divided into underweight (BMI <19.8 kg/m2), normal (BMI 19.8-25 kg/m2), overweight (BMI 25.1-30 kg/m2), and obese (BMI >30 kg/m2) subgroups. Diabetes was classified as gestational, treated with diet alone (A1GDM), or with insulin (A2GDM), and pregestaional diabetes (PDM). Newborn weight greater than the 90th percentile for gestational age, based on published local birth weight data, defined large for gestational age (LGA). The risk of LGA delivery for underweight, overweight, and obese women were compared with that of women with normal pregravid BMI. Multiple regression models, including parity, newborn sex, BMI, race, and diabetes, were constructed to examine the relative effect of abnormal BMI and diabetes on the risk of the delivery of an LGA infant.

RESULTS

Complete data for 12,950 deliveries were included (1,640 [13.0%] underweight, 2,991 [23.7%] overweight, and 2,928 [23.2%] obese). LGA delivery affected 11.8% of the study sample; 303 (2.3%) of subjects had A1GDM, whereas 94 (0.7%) had A2GDM, and 133 (1.6%) had PDM. Compared with normal BMI subjects, obese women were at elevated risk for LGA delivery (16.8% vs 10.5%; P < .0001) as were overweight women (12.3% vs 10.5%; P = .01). Diabetes was also a risk factor for LGA delivery (A1GDM: [29.4% vs 11.4%]; A2GDM: [29.8% vs 11.7%]; PDM: [38.3% vs 11.6%]; P < .0001 for each). Other risk factors for LGA delivery included parity (13.2% vs 9.5%; P < .0001), and male gender (14.3% vs 9.3%; P < .0001). Black race and low pregravid BMI were associated with a lower risk of LGA delivery (9.0% vs 13.7%; P < .0001) and (6.4% vs 10.5%; P = .006), respectively. Multiple regression revealed the independent influence of pregravid obesity and PDM, increasing the risk of LGA delivery (BMI >30kg/m 2 [Adjusted odds ratio (AOR) = 1.6]), and PDM (AOR = 4.4).

CONCLUSION

Obesity and pregestational diabetes are independently associated an increased risk of LGA delivery. The impact of abnormal body habitus on birth weight grows as BMI increases. Diabetes has the greatest affect on the normal and underweight population. With the increasing prevalence and relative frequency of overweight and obese women in pregnancy compared with diabetes (46.7% vs 4.1%), abnormal maternal body habitus exhibits the strongest influence on the prevalence of LGA delivery in our population.

The impact of maternal obesity and weight gain on vaginal birth after cesarean section success

OBJECTIVE

This study was undertaken to determine the impact of maternal obesity on success of a trial of labor (vaginal birth after cesarean section [VBAC]) after a single low transverse cesarean delivery.

STUDY DESIGN

Individual charts of women with low transverse cesarean delivery in their first viable pregnancy who underwent a VBAC in their second viable pregnancy at our urban tertiary care institution were reviewed. Maternal body mass index (BMI) was classified as underweight (<19.8 kg/m2), normal (19.8-24.9 kg/m2), overweight (25-29.9 kg/m2), or obese (> or =30 kg/m2). Clinical characteristics and labor outcomes were assessed. Factors potentially affecting VBAC success were analyzed by univariate analysis. Logistic regressions were performed to determine the impact of maternal pregravid BMI on VBAC success after controlling for confounding factors.

RESULTS

Of 510 women attempting a trial of labor, 337 (66%) were successful and 173 (34%) failed VBAC. Decreased VBAC success was seen in obese (54.6%) but not overweight (65.5%) women compared with women of normal BMI (70.5%), P = .003 and .36, respectively. Underweight women had more VBAC success than women of normal BMI (84.7% vs 70.5%, P = .04). Controlling for other factors, the association between increasing pregravid BMI and BMI > or =30 kg/m 2 with decreased VBAC success persisted, P = .03 and .006, respectively. Normal BMI women who became overweight before the second pregnancy had decreased VBAC success compared with those whose BMI remained normal (56.6% vs 74.2%, P = .006). However, overweight women who decreased their BMI to normal before the second pregnancy did not significantly improve VBAC success (64.0% vs 58.4%, P = .67).

CONCLUSION

Increasing pregravid BMI and weight gain between pregnancies reduce VBAC success after a single low transverse cesarean delivery.

Effects of obesity on women's reproduction and complications during pregnancy

Obesity is increasing rapidly among women all over the world, and more women in fertile ages become overweight and obese. Among all other problems, women who are obese have higher rates of amenorrhoea and infertility. Obese women have a higher risk of complications during pregnancy such as hypertensive diagnoses and gestational diabetes, and delivery complications such as higher rates of caesarean sections and prolonged time of delivery. The aim of this article is to review the consequences of being obese during the reproductive life of a woman.