New Home and Newly Pregnant? Could Be Risky to Baby – MedPage Today
Women who moved during the first three months of pregnancy had a higher risk of low birth weight infants and preterm delivery, according to a population-based cohort study.
After adjusting for multiple confounders, women who relocated to a new home during the first trimester had an increased risk of low birth weight infants (adjusted risk ratio [RR] 1.37, 95% CI 1.29-1.45) and delivering before 37 weeks gestation (RR 1.42, 95% CI 1.36-1.49) compared to women who did not move during the first trimester, reported Julia Bond, MPH, of the University of Washington in Seattle, and colleagues, writing in the Journal of Epidemiology and Community Health.
“We were seeing that women who had these markers of lower socioeconomic status were more likely to move in our sample, so we really thought that accounting for those would attenuate for the association in a pretty marked way.” Bond told MedPage Today in an interview. “But we didn’t really see that.”
Previous studies suggested that psychosocial stress in the first trimester more strongly impacts birth outcomes than stress experienced during later stages of pregnancy, researchers wrote. Bond said separately that analyzing one type of stressful event in isolation, such as moving residences, may help us understand how women are affected by specific experiences during their pregnancy.
“We were really interested in peripartum stressful experiences in general,” Bond said. “But, looking at moving specifically, that is something that hasn’t really been done.”
Researchers obtained data from Washington state birth certificates, which include length of time at current residence. The study defined women that moved during the first trimester using gestational age and duration of current residence at birth.
The study included singleton births from 2007 to 2014 among women older than age 18. Teen pregnancies were excluded from analysis, as they may have additional stresses and increased risk of low birth weight and preterm delivery, the authors said.
Researchers adjusted for maternal age, marital status, parity, race, and smoking status. They also used median household income from the census tract of residence and insurance provider for the birth as proxies of socioeconomic status.
The sample was comprised of around 28,000 women that moved during the first trimester and about 112,000 randomly selected women that did not move during the first trimester. Women who moved residences during their first trimester were more likely to be in their teens or 20s, to have not completed high school, to live in a census tract with a median household income less than $40,000, and to be nulliparous. This cohort was also more likely to smoke during pregnancy, and were less likely to be married.
Overall, of the women that moved, the prevalence of low birth weight infants was 6.4% compared to 4.5% of women who did not move. The prevalence of preterm birth was 6.4% among women that did not move versus 9.1% of women that moved during the first trimester. While the prevalence of small for gestational age infants was 9.8% among movers compared to 8.7% among non-movers, the association was non-significant after adjusting for confounders, the authors said.
Limitations of this study include potential misclassification of the data, obtained from birth certificates where women reported their own length of residence. In addition, researchers were unable to determine motivations behind residential moves, which may impact the stress a woman may experience.
Whether a woman was forced to move or was excited about moving may make a difference on the impact the event has on her pregnancy, Bond said, adding that, “I’m hoping that future research will delve more deeply into moving.”
While it is too early to make clinical recommendations, Bond noted that this research has a few key takeaways.
“What we do know is that moving during pregnancy is pretty common,” she said. “So, it may just warrant an extra conversation between a pregnant person and their care team, just to make sure it’s on the radar.”
The authors reported no conflicts of interest.