Pregnancy cohort
The study population consisted of participants who enrolled in the “Interdisciplinary Group for Advanced Research in BirtH outcomes- DBT India Initiative (Garbh-Ini)”. Ethical approval was obtained from “Institutional Ethics committee Gurgaon Civil Hospital and Safdarjung Hospital” and “Institutional Ethics Committee (Human Research), Translational Health Science and Technology Institute”. The pregnant mothers visiting the antennal clinic at Gurgaon Civil Hospital were approached for enrolment in the Garbh-Ini cohort. Garbh-Ini is a unique pregnancy cohort, started in 2015 at the “Civil Hospital, Gurugram, Haryana, India” with the ultimate objective to determine the clinical, epidemiological, genetic, epigenetic, proteomic and microbial correlates of preterm birth. Women who give a written informed consent are enrolled at <20 weeks of gestation and are followed up at regular intervals till delivery and once post-partum. Detailed clinical and epidemiological information from pregnant women, growing fetus and from the newborn are being documented. Different biospecimens (maternal blood, urine, saliva, high vaginal fluid, cord blood and placenta) are being collected according to the study protocols. The objectives and methodology of Garbh-Ini are published elsewhere18. The stored maternal sera samples of women (delivering SGA or AGA neonate) in the Garbh-Ini program were used to accomplish the objective of this study.
Definitions
SGA was defined as birthweight less than 10th centile for a specific gestational age and sex. The neonates were categorized as SGA or AGA on the basis of their weight at birth, sex and completed gestational age in weeks using Fenton Growth Chart19.