ESPE Abstracts

Introduction: Placental hormones can control the transfer of maternal nutrients to the fetus and modulate fetal and neonatal growth. Data about the interaction between maternal, placental and fetal IGF1/IGFBP in relation to newborn size is not clear,

Aim: To review research paper published in Pubmed, Google scholar, Research gate, and Scopus in the past 20 years on the relation between maternal, placental and fetal/infantile/ IGF1/IGFBP-1 in relation to birth size in pregnancies associated with maternal obesity. 28 research papers were selected and reviewed (n= 1902).

Results: In 47 women, serum IGF-I during pregnancy was positively correlated and IGFBP-1 was negatively correlated with maternal body weight and fat-free body weight respectively before and during pregnancy. In 289 women, who were pregnant with a single fetus, between 24- and 29-week gestational age (GA), maternal IGF-I levels were mainly determined by body weight, placental growth hormone (PGH), and insulin, while IGFBP-1 concentrations were negatively determined by body weight, insulin, and IGF-I. In a pregnancy cohort (n= 307), maternal plasma IGF-1 concentrations increased by an average of 55.4% between 24–28 and 32–35 weeks of gestation. The maternal IGF-I correlated with birth weight and placental weight. Each SD increase in maternal IGF-I level at 24–28 weeks was associated with a 75-g increase in birth weight, a 20-g increase in placental weight, and 1.91-fold higher odds of macrosomia. Maternal and fetal IGF-I levels were significantly higher in GDM vs nondiabetic pregnancies. In 23 Swedish non-diabetic pregnant women, birth weights (range, 3025-4235 g) were positively correlated to maternal BMI and the activity of placental insulin/IGF-I and mTOR signaling was positively correlated to birth weight. One study reported that the Circulating IGF-I, basal membrane GLUT1 expression and glucose transporter activity was correlated with birth weight, in non- diabetic women. In 27 obese pregnant women, birthweight was positively correlated with maternal body mass index, umbilical vein glucose and insulin. Umbilical vein glucose levels were positively correlated with placental weight and maternal BMI. Women entering pregnancy obese had higher circulating concentrations of IGF-1 and insulin, and more pronounced insulin resistance, compared with pregnant women with normal BMI. A positive correlation of IGF-1 levels with FBG was detected in obese women.

Conclusion: In obese mothers or who had gain excessive weight during pregnancy, the occurrence of higher maternal IGF1 can increase the size of the placenta, stimulating mTOR signaling, contributing to fetal overgrowth.