SMOOTHED BREAST-FEEDING DURATIONS AND WAITING TIME TO CONCEPTION

Breastfeeding beyond the resumption of mother's menstruation plays a s ignificant role in the proximate determinants of fertility. Breastfeed ing and postpartum amenorrhoea data collected from retrospective surve ys usually exhibit digit preferences. Here, these heaping errors were smoothed by B-spline and used in multivariate models of risk of concep tion to investigate the contraceptive effect of breastfeeding. The dat a used come from a 1987 Indian survey. Results show that lactation, af ter mother's menses resume, reduces the risk of conception. Heaping in breastfeeding data attenuates this relationship. When adjustment is m ade, breastfeeding reduced the rate of conception by 47 per cent; the reduction, with adjusted data, was 63 per cent.