Review article: Obesity in pregnancy

Maternal body mass index and adverse pregnancy outcomes: A ghanaian cohort study

OBJECTIVE

To examine the association between maternal weight at <17 weeks gestation and maternal and infant outcomes of pregnancy, delivery, and the postpartum period in pregnant Ghanaian women.

METHODS

A prospective cohort study of 1,000 women in Accra, Ghana (2012-2014), was conducted. Women were classified as having overweight (BMI 25-30) and obesity (BMI ≥ 30), and their obstetric and infant outcomes were analyzed using multivariate logistic regression.

RESULTS

The analysis included 824 women, average 28 years (SD 5.1); 313 (31.3%) had overweight and 169 (16.9%) obesity. Women with obesity had a two-fold increased risk for cesarean sections (RR 2.20, 95% CI 1.21-4.02) and more than a six-fold higher risk for pregnancy-induced hypertension (RR 6.17, 95% CI 2.90-13.13) and chronic hypertension (RR 6.00, 95% CI 1.40-25.76). Infants of women with overweight or obesity were more likely to be macrosomic (RR 2.37, 95% CI 1.13-4.97).

CONCLUSIONS

The global obesity epidemic has reached women in low- and middle-income countries (LMIC) with important adverse consequences for maternal and infant health. Antenatal care in LMIC will need to anticipate this potential expansion of complications, including the development of guidelines for optimal maternity care for pregnant women with overweight and obesity.

Convergence in insulin resistance between very severely obese and lean women at the end of pregnancy

AIMS

Disrupted intermediary metabolism may contribute to the adverse pregnancy outcomes in women with very severe obesity. Our aim was to study metabolism in such pregnancies.

METHODS

We recruited a longitudinal cohort of very severely obese (n = 190) and lean (n = 118) glucose-tolerant women for anthropometric and metabolic measurements at early, mid and late gestation and postpartum. In case-control studies of very severely obese and lean women we measured glucose and glycerol turnover during low- and high-dose hyperinsulinaemic-euglycaemic clamps (HEC) at early and late pregnancy and in non-pregnant women (each n = 6-9) and body fat distribution by MRI in late pregnancy (n = 10/group).

RESULTS

Although greater glucose, insulin, NEFA and insulin resistance (HOMA-IR), and greater weight and % fat mass (FM) was observed in very severely obese vs lean participants, the degree of worsening was attenuated in the very severely obese individuals with advancing gestation, with no difference in triacylglycerol (TG) concentrations between very severely obese and lean women at term. Enhanced glycerol production was observed in early pregnancy only in very severely obese individuals, with similar intrahepatic FM in very severely obese vs lean women by late gestation. Offspring from obese mothers were heavier (p = 0.04).

CONCLUSIONS/INTERPRETATION

Pregnancies complicated by obesity demonstrate attenuation in weight gain and insulin resistance compared with pregnancies in lean women. Increased glycerol production is confined to obese women in early pregnancy and obese and lean individuals have similar intrahepatic FM by term. When targeting maternal metabolism to treat adverse pregnancy outcomes, therapeutic intervention may be most effective applied early in pregnancy.

Placental fatty acid transport in maternal obesity

Pregestational obesity is a significant risk factor for adverse pregnancy outcomes. Maternal obesity is associated with a specific proinflammatory, endocrine and metabolic phenotype that may lead to higher supply of nutrients to the feto-placental unit and to excessive fetal fat accumulation. In particular, obesity may influence placental fatty acid (FA) transport in several ways, leading to increased diffusion driving force across the placenta, and to altered placental development, size and exchange surface area. Animal models show that maternal obesity is associated with increased expression of specific FA carriers and inflammatory signaling molecules in placental cotyledonary tissue, resulting in enhanced lipid transfer across the placenta, dislipidemia, fat accumulation and possibly altered development in fetuses. Cell culture experiments confirmed that inflammatory molecules, adipokines and FA, all significantly altered in obesity, are important regulators of placental lipid exchange. Expression studies in placentas of obese-diabetic women found a significant increase in FA binding protein-4 expression and in cellular triglyceride content, resulting in increased triglyceride cord blood concentrations. The expression and activity of carriers involved in placental lipid transport are influenced by the endocrine, inflammatory and metabolic milieu of obesity, and further studies are needed to elucidate the strong association between maternal obesity and fetal overgrowth.

Pre-Pregnancy BMI, Gestational Weight Gain, and the Risk of Hypertensive Disorders of Pregnancy: A Cohort Study in Wuhan, China

Background

Hypertensive disorders of pregnancy (HDP) are major causes of maternal death worldwide and the risk factors are not fully understood. Few studies have investigated the risk factors for HDP among Chinese women. A cohort study involving 84,656 women was conducted to investigate pre-pregnancy BMI, total gestational weight gain (GWG), and GWG during early pregnancy as risk factors for HDP among Chinese women.

Methods

The study was conducted between 2011–2013 in Wuhan, China, utilizing data from the Maternal and Children Healthcare Information Tracking System of Wuhan. A total of 84,656 women with a live singleton pregnancy were included. Multiple unconditional logistic regression was conducted to evaluate associations between putative risk factors and HDP.

Results

Women who were overweight or obese before pregnancy had an elevated risk of developing HDP (overweight: OR = 2.66, 95% CI = 2.32–3.05; obese: OR = 5.53, 95% CI = 4.28–7.13) compared to their normal weight counterparts. Women with total GWG above the Institute of Medicine (IOM) recommendation had an adjusted OR of 1.72 (95% CI = 1.54–1.93) for HDP compared to women who had GWG within the IOM recommendation. Women with gestational BMI gain >10 kg/m² during pregnancy had an adjusted OR of 3.35 (95% CI = 2.89–3.89) for HDP, compared to women with a gestational BMI gain <5 kg/m². The increased risk of HDP was also observed among women with higher early pregnancy (up to 18 weeks of pregnancy) GWG (>600g/wk: adjusted OR = 1.48, 95% CI = 1.19–1.84).

Conclusion

The results from this study show that maternal pre-pregnancy BMI, early GWG, and total GWG are positively associated with the risk of HDP. Weight control efforts before and during pregnancy may help to reduce the risk of HDP.

Dose-dependent biphasic leptin-induced proliferation is caused by non-specific IL-6/NF-κB pathway activation in human myometrial cells

BACKGROUND AND PURPOSE

Leptin, an adipokine synthesized by the placenta during pregnancy, has been proposed for the management of preterm labour (PTL), as it is able to prevent in vitro uterine contractility and remodelling associated with labour onset. Another common feature of labour onset is the phenotypic switch of myometrial smooth muscle cells from a proliferative to a hypertrophic state. As proliferative effects have been demonstrated for leptin in other tissues, we aimed to investigate its ability to induce myometrial proliferation and thus to maintain uterine quiescence.

EXPERIMENTAL APPROACH

We stimulated human primary myometrial smooth muscle cells with leptin in the presence or absence of receptor antagonists or signalling pathway inhibitors.

KEY RESULTS

Leptin induced myometrial cell proliferation in a biphasic manner. At 6.25 ng · mL(-1), leptin-induced proliferation was mediated by the leptin receptor and required the early activation of ERK1/2. At a concentration above 25 ng · mL(-1), leptin induced direct non-specific stimulation of the IL-6 receptor, leading to NF-κB activation, and exerted anti-proliferative effects. However, at 50 ng · mL(-1), leptin re-induces proliferation via IL-6 receptor stimulation that requires STAT3 and delayed ERK1/2 activation.

CONCLUSIONS AND IMPLICATIONS

These data bring new insights into leptin signalling-induced myometrial proliferation and its interrelationship with the IL-6/IL-6 receptor axis. In the light of our previous work, the present study emphasizes the potential value of leptin in the pharmacological management of PTL and it also strengthens the hypothesis that leptin might be a contributory factor in the parturition-related disorders observed in obese women.

The intrauterine and nursing period is a window of susceptibility for development of obesity and intestinal tumorigenesis by a high fat diet in Min/+ mice as adults

We studied how obesogenic conditions during various life periods affected obesity and intestinal tumorigenesis in adult C57BL/6J-Min (multiple intestinal neoplasia)/+ mice. The mice were given a 10% fat diet throughout life (negative control) or a 45% fat diet in utero, during nursing, during both in utero and nursing, during adult life, or during their whole life-span, and terminated at 11 weeks for tumorigenesis (Min/+) or 23 weeks for obesogenic effect (wild-type). Body weight at 11 weeks was increased after a 45% fat diet during nursing, during both in utero and nursing, and throughout life, but had normalized at 23 weeks. In the glucose tolerance test, the early exposure to a 45% fat diet in utero, during nursing, or during both in utero and nursing, did not affect blood glucose, whereas a 45% fat diet given to adults or throughout life did. However, a 45% fat diet during nursing or during in utero and nursing increased the number of small intestinal tumors. So did exposures to a 45% fat diet in adult life or throughout life, but without increasing the tumor numbers further. The intrauterine and nursing period is a window of susceptibility for dietary fat-induced obesity and intestinal tumor development.

Maternal obesity and occurrence of fetal macrosomia: a systematic review and meta-analysis

OBJECTIVE

To determine a precise estimate for the contribution of maternal obesity to macrosomia.

DATA SOURCES

The search strategy included database searches in 2011 of PubMed, Medline (In-Process & Other Non-Indexed Citations and Ovid Medline, 1950-2011), and EMBASE Classic + EMBASE. Appropriate search terms were used for each database. Reference lists of retrieved articles and review articles were cross-referenced.

METHODS OF STUDY SELECTION

All studies that examined the relationship between maternal obesity (BMI ≥30 kg/m(2)) (pregravid or at 1st prenatal visit) and fetal macrosomia (birth weight ≥4000 g, ≥4500 g, or ≥90th percentile) were considered for inclusion.

TABULATION, INTEGRATION, AND RESULTS

Data regarding the outcomes of interest and study quality were independently extracted by two reviewers. Results from the meta-analysis showed that maternal obesity is associated with fetal overgrowth, defined as birth weight ≥ 4000 g (OR 2.17, 95% CI 1.92, 2.45), birth weight ≥4500 g (OR 2.77,95% CI 2.22, 3.45), and birth weight ≥90% ile for gestational age (OR 2.42, 95% CI 2.16, 2.72).

CONCLUSION

Maternal obesity appears to play a significant role in the development of fetal overgrowth. There is a critical need for effective personal and public health initiatives designed to decrease prepregnancy weight and optimize gestational weight gain.

Fetal growth in relation to gestational weight gain in women with type 2 diabetes: an observational study

AIMS

To evaluate fetal growth in relation to gestational weight gain in women with Type 2 diabetes.

METHODS

A retrospective cohort study of 142 consecutive pregnancies in 28 women of normal weight, 39 overweight women and 75 obese women with Type 2 diabetes (pre-pregnancy BMI < 25, 25-29.9, ≥ 30 kg/m2, respectively). Gestational weight gain was categorized as excessive (exceeding the US Institute of Medicine recommendations) or as non-excessive (within or below the Institute of Medicine recommendations).

RESULTS

Excessive and non-excessive gestational weight gain were seen in 61 (43%) and 81 women (57%) with a median (range) gestational weight gain of 14.3 (9-32) vs. 7.0 (-5-16) kg (P < 0.001), respectively. Infants of women with excessive gestational weight gain were characterized by higher birth weight (3712 vs. 3258 g; P = 0.001), birth weight z-score (1.14 vs. -0.01, P = 0.001) and prevalence of large-for-gestational-age infants (48 vs. 20%; P < 0.001). In normal weight, overweight and obese women with non-excessive gestational weight gain, the median weight gain in the first half of pregnancy was 371, 114 and 81 g/week, and in the second half of pregnancy 483, 427 and 439 g/week, respectively. In multiple linear regression analysis, gestational weight gain was associated with a higher infant birth weight z-score independent of pre-pregnancy BMI, smoking, HbA1c and insulin dose at last visit, ethnicity and parity [β=0.1 (95% CI 0.06-0.14), P < 0.001].

CONCLUSIONS

Infant birth weight was almost 0.5 kg higher in women with Type 2 diabetes and excessive gestational weight gain than in women with Type 2 diabetes and non-excessive weight gain.

Female obesity and infertility

Infertility affects one in seven couples, and its rate is on the increase. Ovulatory defects and unexplained causes account for >50% of infertile aetiologies. It is postulated that a significant proportion of these cases are either directly or indirectly related to obesity. The prevalence of overweight and obese men and women has topped 50% in some developed countries. Obesity is on the increase worldwide; in turn, the consequences in terms of the associated morbidity and mortality have also been increasing. Obesity is associated with various reproductive sequelae including anovulation, subfertility and infertility, increased risk of miscarriage and poor neonatal and maternal pregnancy outcomes. Thus, the combination of infertility and obesity poses some very real challenges in terms of both the short- and long-term management of these patients. The mechanism with which obesity impacts female reproductive function is summarised in this review.

Reducing morbidity and mortality among pregnant obese

Obesity is increasing; in the UK, almost 20% of pregnant women have a body mass index (BMI) of ≥30 kg/m(2). Obese mothers have increased risks of pregnancy complications including miscarriage, congenital anomaly, gestational diabetes, pre-eclampsia, macrosomia, induction of labour, caesarean section, anaesthetic and surgical complications, post-partum haemorrhage, infection and venous thromboembolism. Complications tend to be greater in those with the highest BMIs. In recent triennia, obesity (27-29%) was over-represented in maternal mortality figures. Strategies to reduce morbidity and mortality include calculating BMI at booking visit to identify obese mothers and plan their antenatal care and delivery. This should include nutritional and lifestyle advice, screening for gestational diabetes and pre-eclampsia, thromboembolism risk assessment, antenatal anaesthetic review if BMI is ≥ 40 kg/m(2), ensuring availability of robust theatre tables and other equipment and involving senior doctors, especially in the labour ward. Afterwards, continuing weight reduction should be encouraged to reduce future pregnancy and health risks.

Preconception care: nutritional risks and interventions

INTRODUCTION

There is increasingly a double burden of under-nutrition and obesity in women of reproductive age. Preconception underweight or overweight, short stature and micronutrient deficiencies all contribute to excess maternal and fetal complications during pregnancy.

METHODS

A systematic review and meta-analysis of the evidence was conducted to ascertain the possible impact of preconception care for adolescents, women and couples of reproductive age on maternal, newborn and child health (MNCH) outcomes. A comprehensive strategy was used to search electronic reference libraries, and both observational and clinical controlled trials were included. Cross-referencing and a separate search strategy for each preconception risk and intervention ensured wider study capture.

RESULTS

Maternal pre-pregnancy weight is a significant factor in the preconception period with underweight contributing to a 32% higher risk of preterm birth, and obesity more than doubling the risk for preeclampsia, gestational diabetes. Overweight women are more likely to undergo a Cesarean delivery, and their newborns have higher chances of being born with a neural tube or congenital heart defect. Among nutrition-specific interventions, preconception folic acid supplementation has the strongest evidence of effect, preventing 69% of recurrent neural tube defects. Multiple micronutrient supplementation shows promise to reduce the rates of congenital anomalies and risk of preeclampsia. Although over 40% of women worldwide are anemic in the preconception period, only one study has shown a risk for low birth weight.

CONCLUSION

All women, but especially those who become pregnant in adolescence or have closely-spaced pregnancies (inter-pregnancy interval less than six months), require nutritional assessment and appropriate intervention in the preconception period with an emphasis on optimizing maternal body mass index and micronutrient reserves. Increasing coverage of nutrition-specific and nutrition-sensitive strategies (such as food fortification; integration of nutrition initiatives with other maternal and child health interventions; and community based platforms) is necessary among adolescent girls and women of reproductive age. The effectiveness of interventions will need to be simultaneously monitored, and form the basis for the development of improved delivery strategies and new nutritional interventions.

Obesity and pregnancy: a transversal study from a low-risk maternity

BACKGROUND

Obesity is a public health problem and is increasing in all populations, including pregnant women. It influences maternal and neonatal outcomes; however, data are scarce in developing countries. We aimed to compare perinatal results between obese and non-obese pregnant women in a low-risk maternity.

METHODS

Transversal study of 1,779 40-week-pregnancies from 2005 to 2009 that completed a standard questionnaire with sociodemographic, obstetrical and neonatal variables and performed an ultrasound with amniotic fluid index (AFI) measurement and foetal vitality (FBP, non-stress test). They were analysed about their association with obesity on pregnancy.

RESULTS

When compared with non-obese women, the group of obese patients had higher systolic (118.1 vs 109.2 mmHg; p < 0.01) and diastolic (76.6 vs 70.4 mmHg; p < 0.01) pressure levels, AFI (12.52 vs. 9.61 cm; p = 0.02), presence of meconium on labour (20.52 vs. 14.67%; p = 0.02), birthweight (3602 vs. 3437 g; p < 0.01) and caesarean section (39.74 vs. 29.98%, p < 0.01).

CONCLUSIONS

Labour induction before 40 weeks in the antenatal period associated with foetal weight estimation should be considered as a recommendation for decreasing high percentages of caesarean delivery found in obese women.

Excess nutrient supply in early life and its later metabolic consequences

Suboptimal nutrition in early life, both in utero and during infancy, is linked to increased risk of adult obesity and its associated adverse metabolic health problems. Excess nutrient supply during early life can lead to metabolic programming in the offspring. Such overnutrition can occur in the offspring of obese mothers, the offspring of mothers who gain excess weight during gestation, infants of diabetic mothers and infants who undergo rapid growth, particularly weight gain, during early infancy. Postnatal overnutrition is particularly detrimental for infants who are born small for gestational age, who are overfed to attain 'catch-up growth'. Potential mechanisms underlying metabolic programming that results from excess nutrition during early life include resetting of hypothalamic energy sensing and appetite regulation, altered adipose tissue insulin sensitivity and impaired brown adipose tissue function. More detailed understanding of the mechanisms involved in metabolic programming could enable the development of therapeutic strategies for ameliorating its ill effects. Research in this field could potentially identify optimal and appropriate preventative interventions for a burgeoning population at risk of increased mortality and morbidity from obesity and its concomitant metabolic conditions.

The effect of pre-existing maternal obesity and diabetes on placental mitochondrial content and electron transport chain activity

INTRODUCTION

Mitochondria dysfunction has been extensively implicated in the progression of these metabolic disorders, their role in placental tissue of diabetic and/or obese pregnant women is yet to be investigated. The aim of this study was to determine the effect of pre-existing type 1 and type 2 diabetes mellitus (DM), and pre-existing maternal obesity on placental mitochondrial function as assessed by mitochondrial content, electron transport chain (ETC) complex activities and oxidative stress.

METHODS

Human placenta was obtained at the time of term Caesarean section from (i) non-obese (n = 19) and obese (n = 23) normal glucose tolerant (NGT) pregnant women; (ii) women with type 1 DM (n = 14) and BMI-matched NGT women (n = 14); and (iii) women with type 2 DM (n = 11) and BMI-matched NGT women (n = 11). The following endpoints were assessed: placental mitochondrial content by citrate synthase activity and mitochondrial DNA (mtDNA content); mitochondrial respiratory chain activity (complexes I, II, II & III, III and IV), and mitochondrial ROS (as assessed by mitochondrial hydrogen peroxide (H2O2) levels).

RESULTS

When compared to placenta from NGT non-obese women, there was significantly lower mitochondrial DNA (mtDNA) content and electron transport chain complex I activity, and significantly higher mitochondrial H2O2 levels in placenta from NGT obese women (P < 0.05). Placental tissue from type 1 DM women showed significant reductions in ETC complex I, II & III, and III activity and increased H2O2 levels when compared to BMI-matched NGT women (P < 0.05). Type 2 DM women only exhibited significantly reduced ETC complex II & III activity when compared to BMI-matched NGT women (P < 0.05).

DISCUSSION AND CONCLUSIONS

Women with pre-existing obesity or diabetes have decreased placental mitochondrial respiratory chain enzyme activities which may have detrimental consequences on placental function and therefore fetal growth and development.

Searching for the definition of macrosomia through an outcome-based approach

Background

Macrosomia has been defined in various ways by obstetricians and researchers. The purpose of the present study was to search for a definition of macrosomia through an outcome-based approach.

Methods

In a study of 30,831,694 singleton term live births and 38,053 stillbirths in the U.S. Linked Birth-Infant Death Cohort datasets (1995–2004), we compared the occurrence of stillbirth, neonatal death, and 5-min Apgar score less than four in subgroups of birthweight (4000–4099 g, 4100–4199 g, 4200–4299 g, 4300–4399 g, 4400–4499 g, 4500–4999 g vs. reference group 3500–4000 g) and birthweight percentile for gestational age (90^th–94^th percentile, 95^th-96^th, and ≥97^th percentile, vs. reference group 75^th–90^th percentile).

Results

There was no significant increase in adverse perinatal outcomes until birthweight exceeded the 97^th percentile. Weight-specific odds ratios (ORs) elevated substantially to 2 when birthweight exceeded 4500 g in Whites. In Blacks and Hispanics, the aORs exceeded 2 for 5-min Apgar less than four when birthweight exceeded 4300 g. For vaginal deliveries, the aORs of perinatal morbidity and mortality were larger for most of the subgroups, but the patterns remained the same.

Conclusions

A birthweight greater than 4500 g in Whites, or 4300 g in Blacks and Hispanics regardless of gestational age is the optimal threshold to define macrosomia. A birthweight greater than the 97^th percentile for a given gestational age, irrespective of race is also reasonable to define macrosomia. The former may be more clinically useful and simpler to apply.

Shoulder dystocia: risk factors, predictability, and preventability

Shoulder dystocia remains an unpredictable obstetric emergency, striking fear in the hearts of obstetricians both novice and experienced. While outcomes that lead to permanent injury are rare, almost all obstetricians with enough years of practice have participated in a birth with a severe shoulder dystocia and are at least aware of cases that have resulted in significant neurologic injury or even neonatal death. This is despite many years of research trying to understand the risk factors associated with it, all in an attempt primarily to characterize when the risk is high enough to avoid vaginal delivery altogether and prevent a shoulder dystocia, whose attendant morbidities are estimated to be at a rate as high as 16-48%. The study of shoulder dystocia remains challenging due to its generally retrospective nature, as well as dependence on proper identification and documentation. As a result, the prediction of shoulder dystocia remains elusive, and the cost of trying to prevent one by performing a cesarean delivery remains high. While ultimately it is the injury that is the key concern, rather than the shoulder dystocia itself, it is in the presence of an identified shoulder dystocia that occurrence of injury is most common. The majority of shoulder dystocia cases occur without major risk factors. Moreover, even the best antenatal predictors have a low positive predictive value. Shoulder dystocia therefore cannot be reliably predicted, and the only preventative measure is cesarean delivery.

Too heavy, too late: investigating perinatal health outcomes in immigrants residing in Spain. A cross-sectional study (2009-2011)

BACKGROUND

Studies have shown that immigrants residing in Spain have lower risks of delivering low birthweight (LBW) and preterm babies despite their socioeconomic disadvantages (the healthy migrant paradox). However, less is known about other important perinatal outcomes derived from birth weight and gestational age such as macrosomia and post-term birth. This paper aims to compare the main indicators related to birth weight and gestational age (LBW, macrosomia, preterm and post-term) for immigrants and Spaniards.

METHODS

Cross-sectional study based on the Spanish vital statistics for years 2009-2011. Multinomial regression models were performed to obtain crude and adjusted ORs and their 95% CIs.

RESULTS

After adjusting for known confounders, compared with Spaniards, most immigrant groups show lower or not significantly different risks of delivering LBW (OR between 0.65 and 0.87) or, more exceptionally, preterm babies (between 0.75 and 0.93). However, most of them also show higher risks of delivering macrosomic (OR between 1.21 and 2.58) and post-term babies (OR between 1.11 and 1.50). Mothers from sub-Saharan Africa show a higher risk in all perinatal outcomes studied.

CONCLUSIONS

The immigrant health paradox should be carefully assessed in comprehensive terms. Together with a predominantly lower risk of LBW, most immigrants have a higher risk of macrosomia, post-term and preterm births. These results have policy-making implications since studying the right tail of the birth weight and gestational age distributions implies considering a different set of risk factors.

The impact of maternal obesity on intrapartum outcomes in otherwise low risk women: secondary analysis of the Birthplace national prospective cohort study

OBJECTIVES

To evaluate the impact of maternal BMI on intrapartum interventions and adverse outcomes that may influence choice of planned birth setting in healthy women without additional risk factors.

DESIGN

Prospective cohort study.

SETTING

Stratified random sample of English obstetric units.

SAMPLE

17,230 women without medical or obstetric risk factors other than obesity.

METHODS

Multivariable log Poisson regression was used to evaluate the effect of BMI on risk of intrapartum interventions and adverse maternal and perinatal outcomes adjusted for maternal characteristics.

MAIN OUTCOME MEASURES

Maternal intervention or adverse outcomes requiring obstetric care (composite of: augmentation, instrumental delivery, intrapartum caesarean section, general anaesthesia, blood transfusion, 3rd/4th degree perineal tear); neonatal unit admission or perinatal death.

RESULTS

In otherwise healthy women, obesity was associated with an increased risk of augmentation, intrapartum caesarean section and some adverse maternal outcomes but when interventions and outcomes requiring obstetric care were considered together, the magnitude of the increased risk was modest (adjusted RR 1.12, 95% CI 1.02-1.23, for BMI > 35 kg/m(2) relative to low risk women of normal weight). Nulliparous low risk women of normal weight had higher absolute risks and were more likely to require obstetric intervention or care than otherwise healthy multiparous women with BMI > 35 kg/m(2) (maternal composite outcome: 53% versus 21%). The perinatal composite outcome exhibited a similar pattern.

CONCLUSIONS

Otherwise healthy multiparous obese women may have lower intrapartum risks than previously appreciated. BMI should be considered in conjunction with parity when assessing the potential risks associated with birth in non-obstetric unit settings.

Is ethnicity a risk factor for developing preeclampsia? An analysis of the prevalence of preeclampsia in China

Preeclampsia is a major complication of pregnancy. Risk factors for preeclampsia include population and regional ethnicity. Chinese women living outside the Chinese mainland have a lower prevalence of preeclampsia than resident Caucasians. We performed a retrospective study to identify potential factors that may be associated with developing preeclampsia in China. A total of 67,746 pregnant women were included in this study from 2002 to 2011. Data included maternal age, maternal body mass index (BMI), age at marriage, parity, gestation and blood pressure at diagnosis, proteinuria, and birth weight. In the study period, 1301 (1.92%) nulliparous women developed preeclampsia. The prevalence of mild or severe preeclampsia was 1.42% or 0.49%, respectively. The average BMI was 21.61 kg m(-2). On the basis of the WHO BMI classification, 78.8% of women were of normal BMI, 18.3% were overweight and 2.9% were obese. A total of 37.8% of preeclamptic women had lived with the same partner for less than 1 year, which was significantly higher than those healthy pregnant women who did not develop preeclampsia (24.2%). The prevalence of preeclampsia in China is low compared with Caucasians, and the contribution to this lower prevalence may be dependent on BMI or lifestyle including period of cohabitation with the partner. Our data suggest that Chinese ethnicity may be a factor responsible for the low risk of developing preeclampsia in the populations studied.

Maternal obesity and fetal deaths: results from the Brazilian cross-sectional Demographic Health Survey, 2006

BACKGROUND

Obesity is highly related to negative reproductive health outcomes, but its relationship with spontaneous abortion and stillbirth remains to be understood, especially in transitioning economies. This study aimed to examine the relationship between obesity and spontaneous abortions and stillbirths in a representative sample of the Brazilian population.

METHODS

Cross-sectional study using secondary data of Brazilian women of reproductive age (15-45 years old) from the National Demographic and Health Survey in 2006. Obesity was measured by body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHR). Logistic regression modeling of the survey data was used to evaluate the relationship between obesity and the study outcomes.

RESULTS

The three obesity markers used were found to be strongly and positively associated with spontaneous abortion and stillbirth occurrence. In the adjusted models, there was strong evidence that for each unit increase in BMI (OR = 1.05; 95%CI: 1.02-1.08) and WHR (OR = 1.32; 95%CI: 1.03-1.69), the odds of having a spontaneous abortion was higher. In addition, compared to those of optimal weight, obese women were more likely to have negative outcomes. Maternal age, parity, skin color, educational level and household income were important covariates for adjustment. A sensitivity analysis among women who had only one pregnancy was also performed and showed similar results.

CONCLUSION

Obesity is potentially associated with an increased risk of spontaneous abortion and stillbirth in a representative sample of the Brazilian population. These findings are in accordance with previous studies and thus reinforce the need for obstetric care providers to counsel obese reproductive-age women regarding the risks, complications and importance of weight loss and weight control prior to pregnancy.

Maternal obesity in early pregnancy and risk of adverse outcomes

Objectives

To assess the role of the health consequences of maternal overweight and obesity at the start of pregnancy on gestational pathologies, delivery and newborn characteristics.

Methods

A cohort of pregnant women (n = 6.558) having delivered at the Maternal & Child University Hospital of Gran Canaria (HUMIGC) in 2008 has been studied. Outcomes were compared using multivariate analyses controlling for confounding variables.

Results

Compared to normoweight, overweight and obese women have greater risks of gestational diabetes mellitus (RR = 2.13 (95% CI: 1.52–2.98) and (RR = 2.85 (95% CI: 2.01–4.04), gestational hypertension (RR = 2.01 (95% CI: 1.27–3.19) and (RR = 4.79 (95% CI: 3.13–7.32) and preeclampsia (RR = 3.16 (95% CI: 1.12–8.91) and (RR = 8.80 (95% CI: 3.46–22.40). Obese women have also more frequently oligodramnios (RR = 2.02 (95% CI: 1.25–3.27), polyhydramnios. (RR = 1.76 (95% CI: 1.03–2.99), tearing (RR = 1.24 (95% CI: 1.05–1.46) and a lower risk of induced deliveries (RR = 0.83 (95% CI: 0.72–0.95). Both groups have more frequently caesarean section (RR = 1.36 (95% CI: 1.14–1.63) and (RR = 1.84 (95% CI: 1.53–2.22) and manual placenta extraction (RR = 1.65 (95% CI: 1.28–2.11) and (RR = 1.77 (95% CI: 1.35–2.33). Newborns from overweight and obese women have higher weight (p<0.001) and a greater risk of being macrosomic (RR = 2.00 (95% CI: 1.56–2.56) and (RR = 2.74 (95% CI: 2.12–3.54). Finally, neonates from obese mother have a higher risk of being admitted to special care units (RR = 1.34 (95% CI: 1.01–1.77). Apgar 1 min was significantly higher in newborns from normoweight mothers: 8.65 (95% CI: 8.62–8.69) than from overweight: 8.56 (95% CI: 8.50–8.61) or obese mothers: 8.48 (95% CI: 8.41–8.54).

Conclusion

Obesity and overweight status at the beginning of pregnancy increase the adverse outcomes of the pregnancy. It is important to promote the normalization of bodyweight in those women who intend to get pregnant and to provide appropriate advice to the obese women of the risks of obesity at the start of the pregnancy.

An update on diabetic women obstetrical outcomes linked to preconception and pregnancy glycemic profile: a systematic literature review

Women with type 2 diabetes were less likely to have diabetes related complications than women with type 1. Women with type 1 diabetes had a high prepregnancy care and showed a worse glycemic control than women with type 2 both in the preconception period and during pregnancy. Obstetrical outcomes showed that preeclampsia and stillbirth rate is almost doubled in type 1 patients while perinatal deaths and SGA importantly increased in type 2 diabetes. In modern obstetrical care it is mandatory to maintain glucose levels as close to normal as possible particularly in diabetic population. HbA1C no higher than 6% before pregnancy and during the first trimester seems to decrease the risk of adverse obstetrical outcomes. Both the preconceptional counseling and glycemic profile optimization represent a fundamental step to improve pregnancy outcomes in women with preexisting diabetes. A systematic approach to family planning and the availability of preconception care for all diabetic women who desire pregnancy could be an essential step for diabetic management program.

Relationship between body mass index and women’s body image, self-esteem and eating behaviours in pregnancy: A cross-cultural study

This study examined the relationship between self-esteem, restrained eating, body image and body mass index during pregnancy. A total of 110 pregnant Israeli and UK women completed the Rosenberg Self-Esteem Questionnaire, the Dutch Eating Behaviour Questionnaire, scales to assess body image and demographics. Body mass index was calculated from antenatal records. Regression modelling determined the relationship between variables, countries and body mass index categories. High correlations were found between body image and body mass index with significantly higher body dissatisfaction for Israeli women. Self-esteem scores for pregnant women were similar to those reported for non-pregnant women. Poorer body image and higher prevalence of restrained eating were found in healthy weight Israeli women.

Impact of restricted maternal weight gain on fetal growth and perinatal morbidity in obese women with type 2 diabetes

OBJECTIVE

Since January 2008, obese women with type 2 diabetes were advised to gain 0-5 kg during pregnancy. The aim with this study was to evaluate fetal growth and perinatal morbidity in relation to gestational weight gain in these women.

RESEARCH DESIGN AND METHODS

A retrospective cohort comprised the records of 58 singleton pregnancies in obese women (BMI ≥30 kg/m(2)) with type 2 diabetes giving birth between 2008 and 2011. Birth weight was evaluated by SD z score to adjust for gestational age and sex.

RESULTS

Seventeen women (29%) gained ≤5 kg, and the remaining 41 gained >5 kg. The median (range) gestational weight gains were 3.7 kg (-4.7 to 5 kg) and 12.1 kg (5.5-25.5 kg), respectively. Prepregnancy BMI was 33.5 kg/m(2) (30-53 kg/m(2)) vs. 36.8 kg/m(2) (30-48 kg/m(2)), P = 0.037, and median HbA1c was 6.7% at first visit in both groups and decreased to 5.7 and 6.0%, P = 0.620, in late pregnancy, respectively. Gestational weight gain ≤5 kg was associated with lower birth weight z score (P = 0.008), lower rates of large-for-gestational-age (LGA) infants (12 vs. 39%, P = 0.041), delivery closer to term (268 vs. 262 days, P = 0.039), and less perinatal morbidity (35 vs. 71%, P = 0.024) compared with pregnancies with maternal weight gain >5 kg.

CONCLUSIONS

In this pilot study in obese women with type 2 diabetes, maternal gestational weight gain ≤5 kg was associated with a more proportionate birth weight and less perinatal morbidity.

Neonatal outcomes in obese mothers: a population-based analysis

Background

If it is well known that obesity increases morbidity for both mother and fetus and is associated with a variety of adverse reproductive outcomes, then few studies have assessed the relation between obesity and neonatal outcomes. This is the aim of the present study after taking into account type of labor and delivery, as well as social, medical and hospital characteristics in a population-based analysis.

Methods

This study used 2009 data from the Belgian birth register data pertaining to the regions of Brussels and Wallonia and included 38,675 consecutive births. Odds ratio and 95% confidence intervals for admission to neonatal intensive care unit, Apgar score, and perinatal mortality were calculated by logistic regression analyses adjusting for medical, social and hospital characteristics using obesity as the primary independent variable. The impact of analyzing all delivery sites together was tested using mixed-effect analyses.

Results

The adjusted odds ratio for neonatal intensive care unit admission was higher for obese mothers by 38% compared to non-obese mothers (95% confidence interval (CI): 1.22-1.56), and by 45% (CI: 1.21-1.73) and 34% (CI: 1.10-1.63) after spontaneous and induced labour respectively. The adjusted odds ratio was 1.18 (CI: 0.86-1.63) after caesarean section. The adjusted odds ratio for 1 minute Apgar score inferior to 7 was higher for obese mothers by 31% compared to non-obese mothers (CI: 1.15-1.49) and by 26% (CI: 1.04-1.52) and 38% (CI: 1.12-1.69) after spontaneous and induced labour respectively. The adjusted odds ratio was 1.50 (CI: 0.96-2.36) after caesarean section. The adjusted odds ratio for perinatal mortality was 1.36 (CI: 0.75-2.45) for obese mothers compared to non-obese mothers.

Conclusions

Neonatal admission to intensive care and low Apgar scores were more likely to occur in infants from obese mothers, both after spontaneous and induced labor.

Improving breastfeeding rates in an "at risk" population

A new public health frontier challenging maternity care is addressing the sub-optimal breastfeeding rates of women who are obese. Despite the World Health Organisation's recommendation that breastfeeding is initiated within the first hour of birth and continued exclusively for six months, less than half of infants and young children globally are optimally breastfed. While initiation rates of exclusive breastfeeding immediately after birth are as high as 90 percent in Australia, this rate dramatically declines in the first few weeks postpartum, with only approximately 15 percent of infants exclusively breastfed to five months of age (less than 6 months). The aim of this paper was to highlight difficulties obese women have breastfeeding and highlight implications for research and practice.

[Could we perform quality second trimester ultrasound among obese pregnant women?]

OBJECTIVE

To compare the quality of second trimester ultrasound images and their anatomical quality scores among obese women and those with a normal body mass index (BMI).

MATERIALS AND METHODS

This prospective study, which took place from 2009 to 2011, included every obese pregnant woman (prepregnancy BMI greater than 30 kg/m(2)) who had an ultrasound examination at 20 to 24 weeks in our hospital and a control group with a normal BMI (20-24.9kg/m(2)) who had the same examination. A single operator evaluated the quality of all images, reviewing the standardized ultrasound planes - three biometric and six anatomical - required by French guidelines and scoring the quality of the six anatomical images. Each image was assessed according to 4-6 criteria, each worth one point. We sought excellent quality, defined as the frequency of maximum points for a given image.

RESULTS

The obese group included 223 women and the control group 60. The completion rate for each image was at least 95 % in the control group and 90 % in the obese group, except for diaphragm and right outflow tract images. Overall, the excellence rate varied from 35 % to 92 % in the normal BMI group and 18 % to 58 % in the obese group and was significantly lower in the latter for all images except abdominal circumference (P=0.26) and the spine (P=0.06). Anatomical quality scores were also significantly lower in the obese group (22.3 vs. 27.2 ; P=0.001).

CONCLUSION

Image quality and global anatomical scores in second trimester ultrasound scans were significantly lower among obese than normal-weight women.

Adiposity-related inflammation: effects of pregnancy

In the nonpregnant population, there is extensive evidence of a systemic low-grade inflammatory status in relation to excess adipose tissue. Less is known about the relation during pregnancy.

OBJECTIVE

Our main objective was therefore to explore the effect of pregnancy on adiposity-related systemic inflammation.

DESIGN AND METHODS

This study is a longitudinal cohort study of 240 pregnant women of Scandinavian heritage at Oslo University hospital-Rikshospitalet, Norway from 2002 to 2005. The inflammatory markers (C-reactive protein [CRP], Interleukin-6 [IL-6], monocyte chemoattractant protein 1 [MCP-1], IL1-Ra, tumor necrosis factor receptor II, and IL-10) were measured at four timepoints during pregnancy and analyzed by enzyme immuno-assay. The women were categorized based on BMI at inclusion (BMI <25, 25-30, and >30 kg/m(2)). Data were analyzed by Friedman-test, Wilcoxon signed rank test, or Kruskal-Wallis test as appropriate.

RESULTS

Maternal adiposity was associated with significantly higher circulatory levels of several inflammatory markers (CRP, MCP-1, IL-6, and IL-1Ra). However, this proinflammatory upregulation was not evident toward the end of pregnancy, as levels of CRP, MCP-1, and IL-6 were not any longer significantly different between the BMI categories.

CONCLUSIONS

Although normal pregnancy exhibits proinflammatory features, this does not seem to have additive or synergistic effects on the inflammation associated with adiposity. On the contrary, we found that the BMI-dependent increase in proinflammatory markers was not evident at the end of pregnancy.

The effect of body mass index on the outcome of pregnancy in women with recurrent miscarriage

Background:

Maternal obesity is associated with menstrual disorders, infertility and sporadic miscarriages. Recurrent miscarriage (RM) affects at least 1% of couples trying to conceive. In over 50% of cases, the cause of the loss of pregnancy remains unexplained. The aim of this study was to determine the relationship between maternal Body Mass Index (BMI) and future outcomes of pregnancy in couples with “unexplained” RM.

Methods and Results:

All couples referred to the specialist recurrent miscarriage clinic at St. Mary's Hospital, London, were investigated for an underlying cause. Those with unexplained RM were eligible. Demographic and clinical data were retrieved from a computerised database and medical records. The World Health Organisation (WHO) classification of BMI was used. Univariate analysis demonstrated that BMI, maternal age, number of previous miscarriages and ethnicity were significantly associated with pregnancy outcome. Logistic regression demonstrated that maternal obesity (BMI ≥ 30 kg/m²) significantly increased the risk of miscarriage in couples with unexplained RM (OR 1.73; 95% CI 1.06 – 2.83). Asian women with a BMI similar to Caucasian women had a higher risk of a further miscarriage (OR 2.87, 95% CI, 1.52 – 5.39).

Conclusions:

Maternal obesity is an independent factor associated with an increased risk of miscarriage in couples with RM. All women with RM should have their BMI recorded at their first clinic visit. The potential effect of weight loss on the outcome of subsequent pregnancies should be assessed in future studies. The increased risk of miscarriage in Asian women needs to be explored further.

[Medical care organization in analgesia, anaesthesia and intensive care in maternity units: results from the National Perinatal Surveys in 2003 and 2010]

OBJECTIVE

The equipment and practices in obstetric analgesia, anaesthesia and intensive care, as well as their evolution between 2003 and 2010 in metropolitan France, were described.

POPULATION AND METHODS

Data were derived from two representative samples of births in 2003 and 2010, based on all births in France during one week. The sample included 534 maternity units and 14,903 births in 2010 and 618 maternity units and 14,737 births in 2003.

RESULTS

The caesarean operating room was adjacent or inside the labour ward in 66% of maternity units in 2010 vs 56% in 2003. An anaesthetist was appointed permanently to the labour ward in 38.9% of maternity units in 2010 vs 21.5% in 2003. Locoregional analgesia or anaesthesia rate increased significantly: 81.5% in 2010 compared to 74.9% in 2003. Almost all operative vaginal deliveries were performed under epidural anesthesia in 2010. Patient controlled epidural analgesia (PCEA) was available in 58% of the units in 2010 but only 34.2% of women had PCEA. Newborn's resuscitations were performed mainly by paediatricians in 2010, but 11.4% of children were resuscitated by an anaesthetist in level 1 maternity units.

CONCLUSION

The conditions required to ensure anaesthetic care safety in maternity units has improved since 2003. Improvements in quality of care are still possible.

Head circumference of infants born to mothers with different educational levels; the Generation R Study

OBJECTIVE

Head circumference (HC) reflect growth and development of the brain in early childhood. It is unknown whether socioeconomic differences in HC are present in early childhood. Therefore, we investigated the association between socioeconomic position (SEP) and HC in early childhood, and potential underlying factors.

METHODS

The study focused on Dutch children born between April 2002 and January 2006 who participated in The Generation R Study, a population-based prospective cohort study in Rotterdam, The Netherlands. Maternal educational level was used as indicator of SEP. HC measures were concentrated around 1, 3, 6 and 11 months. Associations and explanatory factors were investigated using linear regression analysis, adjusted for potential mediators.

RESULTS

The study included 3383 children. At 1, 3 and 6 months of age, children of mothers with a low education had a smaller HC than those with a high education (difference at 1 month: -0.42 SD; 95% CI: -0.54,-0.30; at 3 months: -0.27 SD; 95% CI -0.40,-0.15; and at 6 months: -0.13 SD; 95% CI -0.24,-0.02). Child's length and weight could only partially explain the smaller HC at 1 and 3 months of age. At 6 months, birth weight, gestational age and parental height explained the HC differences. At 11 months, no HC differences were found.

CONCLUSION

Educational inequalities in HC in the first 6 months of life can be mainly explained by pregnancy-related factors, such as birth weight and gestational age. These findings further support public health policies to prevent negative birth outcomes in lower socioeconomic groups.