To assess the association between first and second trimester gestational weight gain (GWG) and the risk of recurrent spontaneous preterm birth (sPTB).
We performed a retrospective cohort study of all live spontaneous preterm (24 weeks). Subjects were excluded for missing weight gain data in the subsequent pregnancy, multifetal gestation, pre-gestational diabetes or gastrointestinal disease. Clinical variables were abstracted from direct review of medical records from both pregnancies. Weight gain at 24-28 weeks in the subsequent pregnancy was evaluated in order to avoid the bias of greater total weight gains in subjects who went to term. Logistic regression, adjusting for pre-pregnancy BMI and the clinical variables which were significant in univariate analysis, was used to assess the association of mid-trimester gestational weight gain with recurrent preterm birth.
Of 166 included subjects, 48 (28.9%) had a recurrent sPTB. Subjects with recurrent sPTB were younger and had an earlier gestational age of index sPTB compared to those with a subsequent term delivery. GWG at 24-28 weeks was not associated with recurrence of sPTB (aOR 0.99, 95% CI 0.95-1.03). This remained non-significant when GWG was assessed as a binary variable dichotomized at the mean or quartile or when stratified by obesity. A post-hoc power analysis demonstrated sufficient power for a weight gain difference between groups of 5 pounds or more. Gestational age in the index pregnancy was the only variable significantly associated with recurrence of sPTB (aOR 1.29, 95% CI 1.11-1.49) in multivariate regression.
In women with a prior sPTB, there is no association between first and second trimester weight gain and the risk of recurrence.
© 2012 Mosby, Inc. Published by Elsevier Inc. All rights reserved.