Risk of preterm delivery in relation to maternal low birth weight.
OBJECTIVE
We examined the relationship between maternal low birth weight and preterm delivery risk.


METHODS
Information concerning maternal birth weight was collected during in-person interviews. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI). Preterm delivery cases were studied in aggregate, in subgroups (spontaneous preterm labor, preterm premature rupture of membranes, medically induced preterm delivery, moderate preterm delivery [gestational age at delivery 34-36 weeks], and early preterm delivery [gestational age at delivery<34 weeks]).


RESULTS
After adjusting for confounders, women weighing<2,500 g at birth had a 1.54-fold increased risk of preterm delivery versus women weighing=2,500 g (95% CI 0.97-2.44). Maternal low birth weight was associated with a 2-fold increased risk of spontaneous preterm delivery (95% CI 1.03-3.89), but weakly associated with preterm premature rupture of membranes (OR=1.44; 95% CI 0.67-3.09) and medically induced preterm delivery (OR=1.10; 95% CI 0.43-2.82). Maternal low birth weight was more strongly associated with early preterm delivery (OR=1.94) than with moderate preterm delivery (OR=1.46). Women weighing<2,500 g at birth and who became obese (pre-pregnancy body mass index, =30 kg/m2) before pregnancy had a 3.65-fold increased risk of preterm delivery (95% CI 1.33-10.02) versus women weighing=2,500 g at birth and who were not obese prior to pregnancy (<30 kg/m2).


CONCLUSIONS
Results confirm earlier findings linking maternal low birth weight with future risk of preterm delivery.
De
Barna
B
Department of Epidemiology, Multidisciplinary International Research Training Program, University of Washington School of Public Health and Community Medicine, Seattle, WA 98195, USA.
Lin
Stephanie
S
Lohsoonthorn
Vitool
V
Williams
Michelle A
MA
D000328:Adult; D001835:Body Weight; D005260:Female; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D009035:Mothers; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology*; D012307:Risk Factors; D014861:Washington / Q000453:epidemiology