Maternal history of adoption or foster care placement in childhood: a risk factor for preterm birth

The objective of the study was to assess the impact of maternal history of adoption or foster care placement in childhood on the risk for preterm birth (PTB), controlling for other known risk factors for PTB.

Participants were 302 pregnant women from a low-income, diverse sample drawn from 2 intensive prospective studies of maternal mood and behavior and fetal and infant development. Gestational age was determined by best obstetric estimate. Maternal history of adoption or foster care placement prior to age 18 years was determined by maternal report. Other maternal characteristics, including maternal medical conditions, psychosocial characteristics, and health behaviors, were measured during the second and third trimesters of pregnancy.

The odds of delivering preterm (gestational age <37 weeks) were approximately 4 times greater among women with a history of childhood adoption or foster care placement compared with women who were never placed out of the home during childhood. This association remained significant after adjusting for other known risk factors for PTB including maternal medical conditions, psychosocial characteristics, and negative health behaviors in pregnancy.

Findings suggest that a history of adoption/foster care placement is an important risk factor for PTB and may be comparable with other established risk factors for PTB including prior history of PTB, body mass index, African-American race, and advanced maternal age. More studies are needed to understand why women with placement histories may be at increased risk to deliver preterm.