Norah O'Connor

Maternal weight and body composition in the first trimester of pregnancy

Objective. Previous studies on weight gain in pregnancy suggested that maternal weight on average increased by 0.5–2.0 kg in the first trimester of pregnancy. This study examined whether mean maternal weight or body composition changes in the first trimester of pregnancy. Design. Prospective observational study. Population. We studied 1,000 Caucasian women booking for antenatal care in the first trimester of pregnancy. Setting. Large university teaching hospital. Methods. Maternal height and weight were measured digitally in a standardized way and Body Mass Index (BMI) was calculated. Maternal body composition was measured using segmental multifrequency Bioelectrical Impedance Analysis (BIA). Sonographic examination confirmed the gestational age and a normal ongoing singleton pregnancy in all subjects. Main outcome measures. Maternal weight, maternal body composition. Results. The mean BMI was 25.7 kg/m2 and 19.0% of the women were in the obese category (≥30.0 kg/m2). Cross‐sectional analysis by gestational age showed that there was no change in mean maternal weight, BMI, total body water, fat mass, fat‐free mass or bone mass before 14 weeks gestation. Conclusions. Contrary to previous reports, mean maternal weight and mean body composition values remain unchanged in the first trimester of pregnancy. This has implications for guidelines on maternal weight gain during pregnancy. We also recommend that calculation of BMI in pregnancy and gestational weight gain should be based on accurate early pregnancy measurements, and not on self‐reported or prepregnancy measurements.

The measurement of maternal adiposity.

Summary The issue of maternal obesity has become a major public health problem. Internationally, the diagnosis of obesity is based on body mass index (BMI) that is, weight in kg/height in m2. While epidemiological associations have been shown between different BMI categories and adverse clinical outcomes, there is also a growing realisation that BMI has significant limitations. In this review, we assess current methods to measure body fat and, in particular, their application in pregnant women.

Body Mass Index and spontaneous miscarriage

OBJECTIVE We compared the incidence of spontaneous miscarriage in women categorised as obese, based on a Body Mass Index (BMI) >29.9 kg/m(2), with women in other BMI categories. STUDY DESIGN In a prospective observational study conducted in a university teaching hospital, women were enrolled at their convenience in the first trimester after a sonogram confirmed an ongoing singleton pregnancy with fetal heart activity present. Maternal height and weight were measured digitally and BMI calculated. Maternal body composition was measured by advanced bioelectrical impedance analysis. RESULTS In 1200 women, the overall miscarriage rate was 2.8% (n=33). The mean gestational age at enrolment was 9.9 weeks. In the obese category (n=217), the miscarriage rate was 2.3% compared with 3.3% in the overweight category (n=329), and 2.3% in the normal BMI group (n=621). There was no difference in the mean body composition parameters, particularly fat mass parameters, between those women who miscarried and those who did not. CONCLUSIONS In women with sonographic evidence of fetal heart activity in the first trimester, the rate of spontaneous miscarriage is low and is not increased in women with BMI>29.9 kg/m(2) compared to women in the normal BMI category.

Polycystic ovary syndrome and the peripheral blood white cell count

This retrospective cross-sectional study examined if the white cell count (WCC) is increased in women with polycystic ovary syndrome (PCOS) and if so, is it due to PCOS or to the associated obesity? Body mass index (BMI) was calculated and body composition was measured using bioelectrical impedance analysis. Of the 113 women studied, 36 had PCOS and 77 did not. The mean WCC was higher in the PCOS group compared with the non-PCOS group (8.9 × 109/l vs 7.4 × 109/l p = 0.002). This increase was due to a higher neutrophil count (5.6 × 109/l vs 4.3 × 109/l; p = 0.003). There was a leucocytosis (WCC >11 × 109/l) present in 19% of the PCOS group compared with 1% in the non-PCOS group (p < 0.001). The neutrophil count was abnormally high (>7.7 × 109/l) in 14% of the PCOS group compared with 4% in the non-PCOS group (p < 0.001). On regression analysis, however, the only independent variable which explained both the increased WCC and the increased neutrophil count was PCOS. We found that PCOS is associated with an increased WCC due to increased neutrophils, which supports the evidence that PCOS is associated with low-grade inflammation. The increase appears to be due to the underlying PCOS, and not to the increased adiposity associated with PCOS.

Comparison in maternal body composition between Caucasian Irish and Indian women

The use of body mass index (BMI) for the diagnosis of obesity has limitations, especially when comparing ethnic groups with different body proportions. The aim of this prospective study was to compare maternal body composition in early pregnancy between Caucasian Irish and Indian women. A total of 81 Indian women and 81 Irish Caucasian women were matched for age, parity and BMI. Maternal weight and height were measured, and body composition analysed using bioelectrical impedance. The Irish women were taller and weighed more than the Indian women (p < 0.001). At any given BMI, the Indian women had a higher total body fat percentage, visceral fat level and high fat percentage than the Irish women (p = 0.024, 0.001 and 0.001, respectively). Our findings suggest that lower BMI cut-offs should be used for screening for gestational diabetes mellitus in Indian women attending our antenatal services.