• The influence of maternal body composition on birth weight.

      Farah, Nadine; Stuart, Bernard; Donnelly, Valerie; Kennelly, Mairead M; Turner, Michael J; UCD Centre for Human Reproduction, Coombe Women and Infants University Hospital, , Dublin, Ireland. nadine.farah@ucd.ie (2012-02-01)
      OBJECTIVE: To identify the maternal body composition parameters that independently influence birth weight. STUDY DESIGN: A longitudinal prospective observational study in a large university teaching hospital. One hundred and eighty-four non-diabetic caucasian women with a singleton pregnancy were studied. In early pregnancy maternal weight and height were measured digitally in a standardised way and the body mass index (BMI) was calculated. At 28 and 37 weeks' gestation maternal body composition was assessed using segmental multifrequency bioelectrical impedance analysis. At delivery the baby was weighed and the clinical details were recorded. RESULTS: Of the women studied, 29.2% were overweight and 34.8% were obese. Birth weight did not correlate with maternal weight or BMI in early pregnancy. Birth weight correlated with gestational weight gain (GWG) before the third trimester (r=0.163, p=0.027), but not with GWG in the third trimester. Birth weight correlated with maternal fat-free mass, and not fat mass at 28 and 37 weeks gestation. Birth weight did not correlate with increases in maternal fat and fat-free masses between 28 and 37 weeks. CONCLUSIONS: Contrary to previous reports, we found that early pregnancy maternal BMI in a non-diabetic population does not influence birth weight. Interestingly, it was the GWG before the third trimester and not the GWG in the third trimester that influenced birth weight. Our findings have implications for the design of future intervention studies aimed at optimising gestational weight gain and birth weight. CONDENSATION: Maternal fat-free mass and gestational weight gain both influence birth weight.
    • Maternal leptin and body composition in the first trimester of pregnancy.

      Fattah, Chro; Barry, Sinead; O'connor, Norah; Farah, Nadine; Stuart, Bernard; Turner, Michael J; UCD Centre for Human Reproduction, Coombe Women and Infants University Hospital, , Dublin, Ireland. (2012-02-01)
      BACKGROUND: Leptin is produced mainly by adipocytes. Levels are increased in women with obesity and during pregnancy. Increased levels are also associated with pregnancy complications such as, pre-eclampsia and gestational diabetes mellitus. OBJECTIVE: We studied what component of body composition correlated best with maternal leptin in the first trimester of pregnancy and, whether maternal leptin correlated better with visceral fat rather than fat distributed elsewhere. SUBJECTS AND METHODS: Women were recruited in the first trimester. Maternal adiposity was measured using body mass index and advanced bioelectrical impedance analysis. Maternal leptin was measured using an enzyme-linked immunosorbent assay technique. RESULTS: Of the 100 subjects studied, the mean leptin concentration was 37.7 ng/ml (range: 2.1-132.8). Leptin levels did not correlate with gestational age in the first trimester, maternal age, parity or birth weight. Serum leptin correlated positively with maternal weight and body mass index, and with the different parameters of body composition. On multiple regression analysis, serum leptin correlated with visceral fat but not fat distributed elsewhere. CONCLUSIONS: Visceral fat is the main determinant of circulating maternal leptin in the first trimester of pregnancy. This raises the possibility that maternal leptin in early pregnancy may be a marker for the development of metabolic syndrome, including diabetes mellitus.