Inter-pregnancy interval and long-term neurological morbidity of the offspring.

PURPOSE

The purpose of our study was to evaluate the effect of IPI on long-term neurological morbidity of the offspring.

METHODS

In this retrospective cohort study, 144,397 singleton infants born to multiparous mothers, between the years 1991 and 2014 in a tertiary medical center, were evaluated for different perinatal outcomes and were followed until 18 years of age for long-term neurological morbidity according to three IPI groups: Short IPI (< 6 months), long IPI (> 60 months) and intermediate IPI (6-60 months). We used a Kaplan-Meier survival curve to compare cumulative incidence of long-term neurological morbidity, and a Cox regression analysis to control for confounders such as gestational age, birth weight and maternal age.

RESULTS

Offspring born to mothers with long IPI had higher rates of neurological morbidity (3.62% among offspring born after long IPI vs. 3.18% and 3.19% among offspring born after short and intermediate IPI, respectively, p = 0.041). The cumulative incidence of long-term neurological morbidity was significantly higher in the long IPI group (Kaplan-Meier log-rank test p < 0.001). Being born after a long IPI was found to be an independent risk factor for long-term neurological morbidity of the offspring (adjusted hazard ratio 1.2; 95% confidence interval 1.1-1.4; p < 0.001).

CONCLUSION

Long IPI is independently associated with an increased risk of long-term neurological morbidity of the offspring.