Moving during early pregnancy may increase preterm birth risk

(Reuters Health) - Moving to a new home during the first three months of pregnancy may add stresses that increase a woman’s risk of having a premature birth, low birth weight and a baby that’s small for its gestational age, suggests a U.S. study.

Women who are considering moving while pregnant could work with their healthcare providers to make plans to move and ensure the proper support is in place, the report’s authors advise in the Journal of Epidemiology & Community Health.

“Moving is pretty common during pregnancy, and it makes sense because it’s a time in people’s lives to think about expanding to a larger house or finding a new place to raise a child,” said Julia Bond of the University of Washington School of Public Health in Seattle, who led the new research.

Previous studies estimate that up to a quarter of pregnant women in the U.S. move, she added.

“Don’t panic and think you can’t move,” Bond told Reuters Health by phone. “It’s simply worth talking about potential stressors with your doctor.”

The researchers analyzed Washington State birth certificate data from 2007-2014 to assess whether 28,000 women who moved during the first trimester of their pregnancies had a higher risk of low birthweight, preterm birth and smaller-sized infants, as compared with 112,000 women who did not move.

The study team defined preterm birth as less than 37 weeks gestation and low birthweight as less than 2500 grams, or about 5.5 pounds. Babies in the bottom 10% in size for their gestational age were considered small.

After adjusting for other factors that could influence these outcomes, such as maternal age, marital status, education, income, race and health insurance, researchers found moving was still associated with increased risks.

Among women who moved, there was a 9.1% risk of preterm birth, compared with 6.4% for those who didn’t move. Similarly, when women moved, the risk of low birthweight was 6.4% and small size 9.8%, compared with 4.5% and 8.7%, respectively, among women who didn’t move.

Although moving was tied to preterm births and low birthweight in all socioeconomic strata, women who moved during their first trimester were more likely to be in their teens or 20s, to lack a high school degree, to live in an area with a median household income below $40,000 and to lack prenatal care, and they were less likely to be married.

“If anything, this identifies moving as an exposure worth investigating, but there are many unanswered questions,” Bond said. “There may be no downside to moving if you have movers and family to help, for instance, but I can imagine it would be a huge stressor if you were evicted.”

The study wasn’t designed to prove that moving influences birth outcomes. One limitation is that researchers were unable to tell whether women moved into more or less desirable locations, the authors note. Also, they only included live births, so they couldn’t study whether moving affects pregnancy loss or stillbirth.

Overall, moving may affect pregnancy due to the physical strain, disruptions to social support, inability to obtain regular healthcare, or the psychosocial stress of moving itself, the authors write.

Other stressors before a child’s birth, such as job loss or a death in the family, could also affect childhood health and outcomes, said Annette Evans of Cardiff University in the UK, who wasn’t involved in the study.

“Residential moves may indicate a more chaotic lifestyle,” she said by email. “If possible, try to minimize the stress experienced when moving house in early pregnancy.”

SOURCE: Journal of Epidemiology & Community Health, online July 30, 2019.