Anthropometric and Skin Fold Thickness Measurements of Newborns of Gestational Glucose Intolerant Mothers: Does it Indicate Disproportionate Fetal Growth?

Abstract

Studies have shown that gestational diabetes mellitus (GDM) causes disproportionate growth and increased adiposity in their newborns; however, the effect of gestational glucose intolerance (GGI), i.e., 2h plasma glucose (PG) between 120 and 139mg/dl in pregnancy on their newborns growth and adiposity is not well established. The objective of the present study is to evaluate the effect of GGI in pregnancy on anthropometry and adiposity of their newborns at birth in urban South Indian population. An observational study was conducted on 119 urban South Indian pregnant women and their newborns. PG levels 2h after ingestion of 75g glucose load were determined between 24 and 28weeks of gestation, and depending on their PG levels, these women were categorized into three different groups, (a) normal glucose tolerance (NGT)-2h PG < 120mg/dl, (b) GGI-2h PG between 120 and 139mg/dl and (c) GDM-2h PG > or = 140mg/dl. GDM mothers were treated with insulin and MNT advised. GGI mothers were advised MNT. These women were followed up till delivery. After delivery, their newborn's anthropometry like weight, length, head circumference (HC), chest circumference (CC), mid-arm circumference, abdominal circumference, bisacromial diameter and subscapular and triceps skin fold thicknesses (SFT) was measured within 72h of birth. Effect of GGI in pregnancy on newborn's anthropometry and SFT was analyzed and studied in comparison with newborns of other two categories. Further, the newborns were stratified into four groups according to their birth weight and newborns of GGI category were compared with newborns of other two categories of same weight. The triceps and subscapular skin fold thicknesses which are direct measurements of adiposity were significantly higher in newborns of GGI mothers compared to newborns of GDM and NGT mothers. GGI category newborns showed increased adiposity even when they were compared with newborns of GDM and NGT category of same weight. Also measurements which are likely to increase due to increased adiposity like bisacromial diameter, abdominal circumference, mid-arm circumference were significantly higher in GGI category newborns. On the other hand, measurements which indicate skeletal growth like length, HC, CC were similar in all three category newborns. This confirmed disproportionate growth and increased adiposity in newborns of GGI mothers.It should be noted here that the GDM mothers were on MNT andtreated with insulin, the dose of insulin was adjusted so as to mimick FastingPG and PostPrandial PG levels of NGT mothers. Gestational glucose intolerance during pregnancy does cause disproportionate growth (increased fat body mass but not skeletal mass) and increased adiposity in their newborns. This emphasizes the need for strict glycemic control (2h of PG level after 75 grams glucose load to < 120mg/dl and PPPG levels to < 120mg/dl) during pregnancy. Larger multicentered studies are recommended to confirm this association.