PAPP-A as a promoter for fetal growth in relation to IGFBP-4 in obese and lean mothers

Abstract

PAPP-A and IGFBP-4 influence fetal growth by modulating the IGF system but the effect of both remains poorly understood. The objective of this thesis was to investigate the impact of PAPP-A and IGFBP-4 on fetal growth in normoglycemic obese and lean mothers. Hypothesis: Maternal PAPP-A and IGFBP-4 play an important role in obese and lean mothers in promoting fetal growth. A prospective study was conducted to achieve the objectives. Fetal biometrics were taken at the second and third trimesters and anthropometric measurements were taken immediately at birth. Maternal anthropometric measurements were obtained each trimester. First, second and third trimester blood samples were obtained from the mothers in both groups. ELISA was used to measure the serum levels of PAPP-A and IGFBP-4. Several outcome measures were used to compare the two groups. PAPP-A levels were correlated with maternal and fetal birth anthropometry and with fetal intrauterine growth trajectories. The results of the study revealed that lean mothers had higher levels of first trimester PAPP-A (p = 0.02) than obese mothers, but the two groups exhibited a significant increase in the PAPP-A throughout pregnancy (p = 0.001). In the lean mothers, PAPP-A correlated positively with the pondoral index (PI) (r = 0.5, p = 0.02) of the newborn. In the same group, there was a negative relationship between PAPP-A and waist circumference (w circu) (r = - 0.5, p = 0.02). In the obese mothers, PAPP-A correlated negatively with hip circumference (h circu) (r = 0.03, p = 0.04). These results suggest that PAPP-A and IGBP-4 have different dynamics in obese and lean pregnant women in relation to fetal growth and maternal anthropometry.