Vicky O'Dwyer

Correlation Between Birth Weight and Maternal Body Composition

OBJECTIVE: To estimate which maternal body composition parameters measured using multifrequency segmental bioelectric impedance analysis in the first trimester of pregnancy are predictors of increased birth weight. METHODS: Nondiabetic women were recruited after ultrasonographic confirmation of an ongoing singleton pregnancy in the first trimester. Maternal body composition was measured using bioelectric impedance analysis. Multivariable linear regression analysis was performed to identify the strongest predictors of birth weight, with multiple logistic regression analysis performed to assess predictors of birth weight greater than 4 kg. RESULTS: Data were analyzed for 2,618 women, of whom 49.6% (n=1,075) were primigravid and 16.5% (n=432) were obese based on a body mass index (BMI) of 30 or higher. In univariable analysis, maternal age, BMI, parity, gestational age at delivery, smoking, fat mass, and fat-free mass all correlated significantly with birth weight. In multivariable regression analysis, fat-free mass remained a significant predictor of birth weight (model R2=0.254, standardized &bgr;=0.237; P<.001), but no relationship was found between maternal fat mass and birth weight. After adjustment for confounding variables, women in the highest fat-free mass quartile had an adjusted odds ratio of 3.64 (95% confidence interval 2.34–5.68) for a birth weight more than 4 kg compared with those in the lowest quartile. CONCLUSIONS: Based on direct measurements of body composition, birth weight correlated positively with maternal fat-free mass and not adiposity. These findings suggest that, in nondiabetic women, interventions intended to reduce fat mass during pregnancy may not prevent large-for-gestational-age neonates and revised guidelines for gestational weight gain in obese women may not prevent large-for-gestational-age neonates. LEVEL OF EVIDENCE: III

Maternal mortality and the rising cesarean rate

To review maternal mortality in a large stand‐alone maternity hospital in a European city and to determine whether the increased cesarean rate was associated with an increase in maternal deaths.

Maternal obesity and pre-pregnancy folic acid supplementation.

Objective: The purpose of this nested cohort study was to compare the rate of pre-pregnancy supplementation in obese women with that of women with a normal BMI. Methods: Pregnant women were enrolled at their convenience in a large university hospital. Weight and height were measured in the first trimester and BMI categorised. Results: Of the 288 women, 35.1% were in the normal, 29.5% in the overweight and 35.4% in the obese BMI categories. Only 45.1% (n = 46) of the obese women took pre-pregnancy folic acid compared with 60.4% (n = 61) of women with a normal BMI (p < 0.03). The lower incidence of folic acid supplementation in obese women was associated with an unplanned pregnancy in 36.3% of women compared with 22.8% in the normal BMI category (p < 0.04). Conclusions: Obese women should take folate supplements whether they are planning to conceive or not.

Maternal obesity and induction of labor

To review induction of labor analyzed by body mass index (BMI) category in primigravidas and multigravidas.

Influence of maternal glycemia on intrauterine fetal adiposity distribution after a normal oral glucose tolerance test at 28 weeks gestation.

Objective. To examine the relationship between maternal glucose levels and intrauterine fetal adiposity distribution in women with a normal oral glucose tolerance test (OGTT) at 28 weeks gestation. Study Design. We recruited 231 women with a singleton pregnancy. At 28 and 37 weeks gestation, sonographic measurements of fetal body composition were performed. Multiple regression analysis was used to study the influence of different maternal variables on fetal adiposity distribution. Results. Maternal glucose levels correlated with the fetal abdominal subcutaneous tissue measurements (r = 0.2; P = 0.014) and with birth weight (r = 0.1; P = 0.04). Maternal glucose levels did not correlate with the fetal mid-thigh muscle thickness and mid-thigh subcutaneous tissue measurements. Conclusion. We found that in nondiabetic women maternal glucose levels not only influence fetal adiposity and birth weight, but also influence the distribution of fetal adiposity. This supports previous evidence that maternal glycemia is a key determinant of intrauterine fetal programming.

Maternal obesity and inpatient medication usage

What is already known about this subject •  Maternal obesity is associated with an increased use of healthcare resources including medication costs in an outpatient setting.

Caesarean Section and Maternal Obesity

In developed countries in women of reproductive age an increase in obesity levels has been widely reported with an associated increase in maternal obesity (Yu et al, 2006, Heslehurst et al, 2008, Huda et al, 2010). Obesity in pregnancy is associated with an increased incidence of medical complications including gestational diabetes mellitus, pre-eclampsia and venous thromboembolism (Huda et al, 2010). As a result, in part, obesity is associated with a higher incidence of obstetric interventions such as caesarean section, as well as an increase in pregnancy complications including haemorrhage, infection and congenital malformations (Yu et al, 2006, Heslehurst, 2008). The World Health Organization criteria define a Body Mass Index (BMI) 29.9 as obese. Obesity can be further subcategorised into class one obese which is 30.0-34.9, class two 35.0-39.9 and class three >40.0.

Dyspnoea at Term in an Obese Mother

Peripartum cardiomyopathy is a serious, potentially life-threatening heart disease of uncertain aetiology in previously healthy women. We report a morbidly obese woman who presented with peripartum shortness of breath. We discuss the differential diagnosis of dyspnoea in pregnancy and highlight the complexity of care of the morbidly obese woman.

Vaginal birth after caesarean section (VBAC) and maternal obesity

Objective The purpose of this study was to examine the influence of obesity on vaginal birth after caesarean section, when body mass index (BMI) was based on the accurate measurement rather than self-reporting of maternal weight and height. Study design We enrolled women at their convenience after a sonogram confirmed an ongoing singleton pregnancy in the first trimester. Weight and height were measured digitally and BMI calculated. Clinical and demographic details were recorded prospectively. Results Out of 2300 women enrolled, 2209 subsequently delivered in the hospital a baby weighing 500 g or more. There were 50.5% (n=1161) primigravidas and 49.5% (n=1139) multigravidas. There were 188 women who had a previous delivery by caesarean section. The overall VBAC success rate in labour was 66.9%. Of the women that attempted a vaginal birth after previous caesarean section the success rate was 63.2% in Class 1 obese women and 80.0% in Class 2–3 obese women compared with 71.4% in women in the normal BMI category. Conclusion Our study showed that successful VBAC rates after one previous caesarean section are similar in obese (BMI>29.9 kg/m2) and non-obese women.

Mode of delivery in obese primigravidas analysed by visceral fat (VF) measurement in early pregnancy

Objective The purpose of the study was to examine the relationship between mode of delivery in primigravidas and visceral fat measured in early pregnancy. Study design We enrolled women at their convenience between July 2008 and April 2010 after a sonogram confirmed they had an ongoing singleton pregnancy in the first trimester. Visceral fat was measured using bioelectrical impedence analysis (Tanita 180, Tokyo). Clinical and demographic details were recorded at the first antenatal visit and at delivery. Visceral fat centiles had previously been derived for a white European population.1 Results Out of 1008 primigravidas enrolled, 973 subsequently delivered in the hospital a baby weighing 500 g or more. In women with a visceral fat >7, there was an increase in the mean age, mean birth weight and rate of induction of labour (p=0.01). There was a higher rate of emergency caesarean section in women with a visceral fat measurement >7 compared to women with a visceral fat measurement ≤7 (p=0.01). This was due to higher rates of fetal distress (p=0.01) in labour. Conclusion Our study showed an association between increased caesarean section rates and maternal obesity based on the visceral fat measurement in the first trimester.