The Association Between Pregnancy Complications and Subsequent Interpregnancy Interval: a Nationwide Register-Based Quantile Logistic Regression Analysis

Abstract

There is a limited number of studies examining the influence of birth complications on the length of the subsequent interpregnancy interval (IPI). This study aimed to study the association between different pregnancy complications at first pregnancy and subsequent IPI. All women with their first and second pregnancies were gathered from the National Medical Birth Register for years 2004–2018. A logistic regression model was used to assess the association between the pregnancy complication (gestational hypertension, gestational diabetes (GDM), preterm birth, perinatal mortality, shoulder dystocia) in the first pregnancy and subsequent length of the IPI. IPIs with a length in the lower quartal were considered short IPIs, and length in the upper quartal as long IPIs. Adjusted odds ratios (aOR) with 95% CIs were compared between the groups. A total of 52,709 women with short IPI, 105,604 women with normal IPI, and 52,889 women with long IPI were included. Women with gestational hypertension had higher odds for long IPI (aOR 1.12, CI 1.06–1.19), GDM had higher odds for short IPI (aOR 1.09, CI 1.09–1.13), preterm delivery had higher odds for short and long IPI (aOR 1.12, CI 1.07–1.17 for both), and perinatal mortality had higher odds for short IPI (aOR 8.05, CI 6.97–9.32) and lower odds for long IPI (aOR 1.13, CI 0.93–1.38). Women with gestational hypertension and preterm birth had higher odds for long IPI, and women with diagnosed GDM and perinatal mortality had higher odds for short IPI. We found no evidence of a difference in the length of the IPI for women with shoulder dystocia. More research on the reasons behind the subsequent long and short IPI is warranted.