Interpregnancy interval and perinatal outcomes across Latin America from 1990 to 2009: a large multi-country study

Objective: To determine the relationship of interpregnancy interval with maternal and offspring outcomes.

Design: Retrospective study with data from the Perinatal Information System database of the Latin American Centre for Perinatology and Human Development, Uruguay.

Setting: Latin America, 1990-2009.

Population: A cohort of 894 476 women delivering singleton infants.

Methods: During 1990-2009 the Perinatal Information System database of the Latin American Centre for Perinatology identified 894 476 women with defined interpregnancy intervals: i.e. the time elapsed between the date of the previous delivery and the first day of the last normal menstrual period for the index pregnancy. Using the interval 12-23 months as the reference category, multiple logistic regression estimated adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs) of the association between various interval lengths and maternal and offspring outcomes.

Main outcome measures: Maternal death, pre-eclampsia, eclampsia, puerperal infection, fetal death, neonatal death, preterm birth, and low birthweight.

Results: In the reference interval there was 0.05% maternal death, 1.00% postpartum haemorrhage, 2.80% pre-eclampsia, 0.15% eclampsia, 0.28% puerperal infection, 3.45% fetal death, 0.68% neonatal death, 12.33% preterm birth, and 9.73% low birthweight. Longer intervals had increased odds of pre-eclampsia (>72 months), fetal death (>108-119 months), and low birthweight (96-107 months). Short intervals of <12 months had increased odds of pre-eclampsia (aOR 0.80; 95% CI 0.76-0.85), neonatal death (aOR 1.18; 95% CI 1.08-1.28), and preterm birth (aOR 1.16; 95% CI 1.11-1.21). Statistically, the interval had no relationship with maternal death, eclampsia, and puerperal infection.

Conclusions: A short interpregnancy interval of <12 months is associated with pre-eclampsia, neonatal mortality, and preterm birth, but not with other maternal or offspring outcomes. Longer intervals of >72 months are associated with pre-eclampsia, fetal death, and low birthweight, but not with other maternal or offspring outcomes.

Tweetable abstract: A short interpregnancy interval of <12 months is associated with neonatal mortality and preterm birth.