First trimester maternal weight influences foeto-placental growth [abstract]

ABSTRACT

OBJECTIVE: To examine the effect of maternal weight on foetoplacental growth. METHODS: Seven hundred and twelve women attending their first antenatal clinic visit at the University Hospital of the West Indies, Kingston, Jamaica, were invited to join a perspective study. Maternal anthropometry and blood pressure were performed. Abdominal ultrasound was performed at 14, 17, 20, 25, 30, and 35 weeks of gestation to determine placental and foetal growth. Placental volume was measured at the first 3 visits and foetal biparietal diameter, femoral lenght, and head and abdominal circumfrence were measured at all 6 visits. Two groups of women were created based on their first trimester weight (<55kg and o55kg) for comparison. A ratio of placental volume to foetal abdominal circumference was created and the rate of growth examined between 14 to 17 and 17 to 20 weeks' gestation. RESULTS: Women with lower maternal weight in the first trimester had significantly smaller placental volumes at 17 and 20 weeks' gestation (p<0.03 and P<0.0001, respectivley). Lighter women had foetuses with a smaller head circumference and femoral length noted at 35 weeks gestation (p<0.01 and p<0.03, respectively). A significant relation with with foetal abdominal circumferences was seen as early as 25 weeks' gestation. The rate of foeto-placental growth when first examined at 14 weeks was similar between the two groups of women. However, in the lighter women, relative growth of placenta between 14 to 17 and 17 to 20 weeks' gestation was less than in the heavier women, suggesting poorer relative placental growth in lighter mothers. CONCLUSION: Maternal weight is an important contributor to foeto-placental growth. Lighter women are more likely to have poorer placental growth and hence smaller foetuses. (AU)