Large-for-gestational-age births: maternal characteristics, risk factors and perinatal outcomes from a decade-long cohort

Abstract

Background: Objectives were to describe the clinical profile and identify risk factors for large-for-gestational-age (LGA) births, defined by GROW customized birth-weight centile, comparing LGA with appropriately grown (AGA) births at a tertiary perinatal referral network in India.

Methods: This retrospective hospital-based study analysed 80,630 singleton births, live and stillborn, at 28 weeks gestation or more, to booked mothers between January 2013-December 2023, comprising 10,391 LGA and 70,239 AGA births. Multifetal pregnancies were excluded. Small-for-gestational-age births (<10^th centile; n=9,842) were excluded and LGA were compared with AGA. Univariable and multivariable logistic regression identified independent risk factors.

Results: In this analysis 1 in 9 babies were LGA, and they were delivered by caesarean section far more often (62.7% vs 43.7%). LGA proportion was higher in diabetics than non-diabetic mothers (17.5% vs 11.2%). In the adjusted model (n=80,630; 10,391 events), independent risk factors for LGA were diabetes (adjusted odds ratio [aOR] 1.60), preterm birth (1.50), short stature (1.30), multiparity (1.16), assisted conception (1.12), obesity (1.09), advanced maternal age (1.08) and male baby (1.06). LGA birth was associated with higher odds of shoulder dystocia (aOR 4.54), birth injury (3.29), caesarean (2.07), neonatal hypoglycemia (1.46) and postpartum haemorrhage (1.29).

Conclusions: When contrasted with AGA, LGA was driven chiefly by maternal diabetes, with an association with preterm birth. The inverse association with hypertensive/placental disease persisted but was attenuated, indicating that part of the apparent “protective” effect seen against a non-LGA comparator is contributed by small-for-gestational-age births. LGA carries substantially higher caesarean rate and warrants anticipatory intrapartum planning.