OBJECTIVE: To examine the association between interpregnancy interval and maternal-neonate health when matching women to their successive pregnancies to control for differences in maternal risk factors and compare these results with traditional unmatched designs. METHODS: We conducted a retrospective cohort study of 38,178 women with three or more deliveries (two or greater interpregnancy intervals) between 2000 and 2015 in British Columbia, Canada. We examined interpregnancy interval (0-5, 6-11, 12-17, 18-23 [reference], 24-59, and 60 months or greater) in relation to neonatal outcomes (preterm birth [less than 37 weeks of gestation], small-for-gestational-age birth [less than the 10th centile], use of neonatal intensive care, low birth weight [less than 2,500 g]) and maternal outcomes (gestational diabetes, beginning the subsequent pregnancy obese [body mass index 30 or greater], and preeclampsia-eclampsia). We used conditional logistic regression to compare interpregnancy intervals within the same mother and unconditional (unmatched) logistic regression to enable comparison with prior research. RESULTS: Analyses using the traditional unmatched design showed significantly increased risks associated with short interpregnancy intervals (eg, there were 232 preterm births [12.8%] in 0-5 months compared with 501 [8.2%] in the 18-23 months reference group; adjusted odds ratio [OR] for preterm birth 1.53, 95% confidence interval [CI] 1.35-1.73). However, these risks were eliminated in within-woman matched analyses (adjusted OR for preterm birth 0.85, 95% CI 0.71-1.02). Matched results indicated that short interpregnancy intervals were significantly associated with increased risk of gestational diabetes (adjusted OR 1.35, 95% CI 1.02-1.80 for 0-5 months) and beginning the subsequent pregnancy obese (adjusted OR 1.61, 95% CI 1.05-2.45 for 0-5 months and adjusted OR 1.43, 95% CI 1.10-1.87 for 6-11 months). CONCLUSION: Previously reported associations between short interpregnancy intervals and adverse neonatal outcomes may not be causal. However, short interpregnancy interval is associated with increased risk of gestational diabetes and beginning a subsequent pregnancy obese.
OBJECTIVE: To examine the association between interpregnancy interval and maternal-neonate health when matching women to their successive pregnancies to control for differences in maternal risk factors and compare these results with traditional unmatched designs. METHODS: We conducted a retrospective cohort study of 38,178 women with three or more deliveries (two or greater interpregnancy intervals) between 2000 and 2015 in British Columbia, Canada. We examined interpregnancy interval (0-5, 6-11, 12-17, 18-23 [reference], 24-59, and 60 months or greater) in relation to neonatal outcomes (preterm birth [less than 37 weeks of gestation], small-for-gestational-age birth [less than the 10th centile], use of neonatal intensive care, low birth weight [less than 2,500 g]) and maternal outcomes (gestational diabetes, beginning the subsequent pregnancy obese [body mass index 30 or greater], and preeclampsia-eclampsia). We used conditional logistic regression to compare interpregnancy intervals within the same mother and unconditional (unmatched) logistic regression to enable comparison with prior research. RESULTS: Analyses using the traditional unmatched design showed significantly increased risks associated with short interpregnancy intervals (eg, there were 232 preterm births [12.8%] in 0-5 months compared with 501 [8.2%] in the 18-23 months reference group; adjusted odds ratio [OR] for preterm birth 1.53, 95% confidence interval [CI] 1.35-1.73). However, these risks were eliminated in within-woman matched analyses (adjusted OR for preterm birth 0.85, 95% CI 0.71-1.02). Matched results indicated that short interpregnancy intervals were significantly associated with increased risk of gestational diabetes (adjusted OR 1.35, 95% CI 1.02-1.80 for 0-5 months) and beginning the subsequent pregnancy obese (adjusted OR 1.61, 95% CI 1.05-2.45 for 0-5 months and adjusted OR 1.43, 95% CI 1.10-1.87 for 6-11 months). CONCLUSION: Previously reported associations between short interpregnancy intervals and adverse neonatal outcomes may not be causal. However, short interpregnancy interval is associated with increased risk of gestational diabetes and beginning a subsequent pregnancy obese.
Authors: Annette K Regan; Stephen J Ball; Joshua L Warren; Eva Malacova; Cicely Marston; Natasha Nassar; Helen Leonard; Nicholas de Klerk; Gavin Pereira Journal: Am J Epidemiol Date: 2019-01-01 Impact factor: 4.897
Authors: Barbara Wilkinson; Mustafa Ascha; Emily Verbus; Mary Montague; Jane Morris; Brian Mercer; Kavita Shah Arora Journal: Contraception Date: 2018-09-05 Impact factor: 3.375
Authors: Mary Montague; Mustafa Ascha; Barbara Wilkinson; Emily Verbus; Jane Morris; Brian M Mercer; Kavita Shah Arora Journal: Obstet Gynecol Date: 2018-09 Impact factor: 7.661
Authors: Abigail Liberty; Kimberly Yee; Blair G Darney; Ana Lopez-Defede; Maria I Rodriguez Journal: Am J Obstet Gynecol Date: 2019-12-14 Impact factor: 8.661