Specific role of maternal weight change in the first trimester of pregnancy on birth size.
The specific role of weight change in the first weeks of gestation in fetal growth has not been fully explored in humans. Our aims were to investigate: (1) the specific association between weight change in the first trimester of pregnancy (WCT1) and size at birth in term pregnancies; and (2) the role of placental weight in this relationship. From 2002 women included in the French EDEN study, 1744 mother-child pairs reached term, had pre-pregnancy weight available and at least five measures of weight in pregnancy. We extrapolated women's weight at each week of gestation with a three-degree polynomial model and estimated weight change during each trimester of gestation. We used a multivariate linear model to investigate the associations between WCT1 and birth size after taking into account potential confounders (age, parity, BMI, tobacco use, educational level, length of gestation, newborn gender, weight change after the first trimester and centre of study). Then, we performed path analysis to investigate whether the relation between WCT1 and birth size could be mediated by placental weight. After taking into account weight gain in later gestation, WCT1 was positively associated with birthweight. Results of path analysis showed that there was no direct association between WCT1 and birth size, but that this association was mediated by placental weight. Weight change during the first weeks of pregnancy may impact on fetal growth independently of weight change later in pregnancy through its effects on placental growth and function.
INSERM, CESP Centre for Research in Epidemiology and Populations Health, U1018 Team 10 'Lifelong Epidemiology of Obesity, Diabetes and Chronic Renal Disease', Villejuif, France Univ Paris-Sud 11, UMRS 1018, Villejuif, France Regional Maternity, University of Nancy, Nancy, France INSERM, UMRS 953, Epidemiological Research on Perinatal Health and Women's and Children's Health, Villejuif, France UPMC Univ Paris 06, F-75005, Paris, France.
Ibrahima
I
Diouf
Jérémie
J
Botton
Marie Aline
MA
Charles
Olivier
O
Morel
Anne
A
Forhan
Monique
M
Kaminski
Barbara
B
Heude
D000328:Adult; D001724:Birth Weight; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D047109:Fetal Development; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D016014:Linear Models; D008297:Male; D009034:Mother-Child Relations; D015999:Multivariate Analysis; D009929:Organ Size; D010929:Placentation; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D015430:Weight Gain; D055815:Young Adult