Zero-waiting time to conception in human reproduction: Failure of survival models and determinants by logistic regression models

Some mothers have no menses between two consecutive live births leading to the duration of waiting time to conception to be zero resulting into the fecundability cannot be estimated with survival models. The phenomenon had first ever been termed as ”zero-waiting time to conception” in 2010. In this study, it was to explore the determinants of zero-waiting time to conception of women in the tribal dominated populations in Manipur, the internationally border with Myanmar. A cross-sectional community base study was conducted during July, 2014 to June, 2015 taking 1278 eligible mothers who were having at least two live births under cluster sampling technique. Some important independent variables of the phenomenon could be detected by using binary logistic regressions. With a prevalence rate of 32 per thousand, some of the determinants were observed to be age at marriage, age at delivery, and parity each at P<0.01 and tribal/non-tribal differential and infant mortality (P<0.05). The findings might be baseline information for future researchers in maternal and child health development in India particularly in North East India.