CARATTERIZZAZIONE DI PARAMETRI BIOMETRICI PLACENTARI E FETALI IN GRAVIDANZE DI DONNE OBESE

Abstract

Title: Placental and Fetal Biometry in Obese Pregnant Women. Introduction: Placental biometry at birth has been shown to predict chronic disease in later life. Maternal obesity is a risk factor for adverse pregnancy outcomes, possibly because it is characterized by intrauterine low-grade inflammation. Barker’s hypothesis underlined that the maternal endocrine and nutritional environment can affect fetal metabolism thus the intrauterine environment of an obese woman might establish a pathologic fetal status via placental inflammation, compromising placental function and altering fetal growth and development. Herein we investigated the placental characteristics in singleton pregnancies of overweight (OW), obese (OB) and normal weight (NW) women. Sex specific differences in fetal and neonatal morbidity and mortality are well documented. Differences in birthweight are also recognised, with males generally larger than females at birth and placental weight and F/P weight ratio higher in males compared to females. Sex specific adaptation of the placenta to an external insult may be crucial for the differences in fetal growth and survival. While the effect of fetal sex on placental development and growth has been studying in depth, sex differences in the context of overnutrition still need to be evaluated. Thus we studied placental biometry and function in male/female fetuses of OW, OB and NW women. Methods: A total of 699 women were enrolled at delivery: 536 were NW (18 25 kg/m2), 115 were OW (25BMI<30 kg/m2) and 48 were OB (BMI≥ 30 kg/m2). This study was performed at the Dept of Clinical Sciences, Unit of Obstetrics and Gynecology, L. Sacco Hospital, University of Milan, Italy. Only singleton pregnancies delivering both by cesarean section and vaginal delivery were enrolled. Exclusion criteria were maternal syndromes, placenta previa, obstetrical complications (preeclampsia, gestational hypertension, gestational diabetes, intrauterine growth retardation, placental abruption), adverse neonatal outcomes, glucose tolerant test positive. Pregnancies carrying fetuses with abnormal karyotype, malformations and infections were also excluded from the study. Gestational age, maternal data (age, height, BMI, weight gain, hemoglobin -Hb and glucose), fetal data (weight, length, ponderal index and gas analysis at birth) and placental data (weight, larger -D- and smaller -d- diameters) were collected. Placental area was calculated as D x d x π/4. Assuming a constant density, placental thickness was estimated as: weight/area. We expressed placental efficiency using the fetoplacental weight ratio (F/P), calculated as birth weight divided by the placental weight. Results: maternal, fetal and placental characteristics in NW vs OW and OB Fetal weights were significantly higher in the OW and OB groups (3435,00±392,11 gr and 3477,00 ±434,21 gr vs 3344,00±385,71 gr; p<0,05). In the OW group only, placental weights (461,69±93,48 gr vs 434,24±92,47 gr; p<0,01) were higher and the thickness (1,72±0,37 cm vs…