164-LB: Association of Maternal Insulin Sensitivity during Gestation and Neonatal Size

Background: Decrease in insulin sensitivity in late gestation is thought to promote fetal growth in humans. Methods: Cohorts with serial glucose and insulin measurements during pregnancy were included in this study. These include two Indian (n=248), a Mexican (n=115), two European (n=326) and an American (n=32) cohort. HOMA-S was correlated with neonatal weight. Results: Indian mothers were short & thin (153.7 cm, 48.8 kg and 20.2 kg/m2) and gained 5.9 kg between first and third trimesters, babies were 2720g. Mexican mothers were short (156cm, 63 kg and BMI 25.1kg/m2) and gained 7.5 kg, babies were 2955g. European mothers were tall and obese (168.0 cm, 95.5 kg and 33.7 kg/m2), gained 7.4 kg and babies were 3640g. In Indian mothers, FPG progressively decreased with increasing gestation with a small (15%) increase in insulin concentrations, HOMA-S remained stable. In Mexican and European mothers FPG remained stable, insulin increased (>50%) and HOMA-S decreased (>30%). American mothers showed the classic increase in HOMA-S in early pregnancy and a fall in late gestation (Figure 1). In Indian and Mexican mothers HOMA-S was not associated with offspring birth weight while in European cohorts, it was inversely associated. Conclusion: Chronic maternal undernutrition (stunting) and failure to reduce insulin sensitivity in late gestation may contribute to poor fetal growth in India and Mexico. Mechanistic studies are warranted. Disclosure S. Deshpande-joshi: None. O. Perichart-perera: Other Relationship; Self; IFA CELTICS, Nestle. M. Van poppel: None. C. A. Vinter: None. D. M. Jensen: None. G. Desoye: None. P. Catalano: None. C. S. Yajnik: None. H. Damle: None. M. K. Deshmukh: None. D. Bhat: None. N. S. Memane: None. A. A. Bhalerao: None. R. Ladkat: None. P. Tiwari: None. S. R. Otiv: None.