Pregnant women who commute long distances to work every day risk having babies born premature and underweight, according to a new study published in Economics & Human Biology.
Researchers from Lehigh University and the University of Wisconsin-Madison noted that while a growing body of research has linked long commutes with making workers more depressed, obese and sleep-deprived (not to mention being associated with high blood pressure, neck and back pain, and higher rates of divorce), there haven’t been empirical studies to examine what lengthy trips to work and back during pregnancy might do to a developing fetus.
So the team analyzed New Jersey birth records between 2014 and 2015, as Garden State workers have some of the longest commutes in the country (about 31 minutes each way), according to the Census Bureau, compared to the average American’s 26.6-minute trip to the office. The researchers looked at the birth records for New Jersey women who traveled between 50 and 100 miles to their jobs each day, which they deduced by measuring the distance between the mothers’ home addresses and their places of employment. Census data defines “long-distance commuters” as the approximately 2.2 million workers traveling 50 miles or more between work and home, and “extreme commuters” as the approximately 1.7 million workers who spend 90 minutes or more traveling each way (so at least three hours round-trip.) Some 600,000 “mega commuters” travel 90 minutes and 50 miles each way, as well.
The researchers found that for expectant mothers who travel 50 miles to work or more, for every 10 miles that they traveled, their probability of having a low-weight baby increased by 14% compared to the national average, and the fetal growth of their baby in utero slowed by 43%. They were also more likely to have preterm births (earlier than 37 weeks into the pregnancy).
The researchers suggested that the chronic stress stemming from the long commute could be affecting the developing fetus. Previous studies have shown that maternal stress during pregnancy can lead to preterm birth, low birth weight and birth defects, and longer commutes are associated with more stress.
Also see: More than 1 in 5 workers have quit their jobs over a bad commute, but this new tool could fix that
But the new report also found many of the pregnant women who were long-distance commuters went to fewer prenatal doctor appointments; perhaps because they didn’t have time after working and commuting all day to go for regular checkups. For those making a 50-mile or more schlep to work, every 10-mile increase in travel distance was associated with a 2.5% decrease in the number of prenatal visits. Many health-care providers recommend that pregnant women make their first prenatal visit about 11 weeks into their pregnancies (within the first trimester), but 15% of the moms-to-be who were also long-distance commuters in this study didn’t get their first checkup until later, and almost 4% put off their prenatal visits until their third trimester — or did not have any prenatal visits, at all.
“The finding that low birth weight might be associated with a source of stress like long-distance commuting is somewhat expected, since chronic strain has been found to be linked to adverse birth outcomes,” said Muzhe Yang, Associate Professor of Economics at Lehigh University and co-author of the study, in a statement. “However, it was surprising to find an association with under-use of prenatal care among pregnant women commuting long-distance.”
Co-author Yang Wang, assistant professor of public affairs at the University of Wisconsin-Madison, added that, “Those who are in greater need of prenatal care because of the potential adverse effects of stress triggered by long commutes are under-using prenatal care, which could lead to even worse birth outcomes.”
They wrote that they hope their study can lead to public policy proposals to expand maternity leave to include prenatal appointments while working women are still pregnant, so that they can take time off for checkups that are vital to their own health and their babies’ health. Yet only five U.S. states and the District of Columbia offer paid family leave, and just 15% of private industry, state- and local-government workers have access to paid family leave. Among the women who do get maternity leave, it lasts only 10 weeks on average, and a quarter of new moms go back to work within two weeks of giving birth.
See: This is what happens when you pay women to take maternity leave
“The findings highlight a subpopulation of pregnant women who are likely in greater need of prenatal maternity leave to facilitate prenatal visits,” added Yang. “Having the needed time off during the prenatal period can be particularly important for pregnant women who are long commuters.”
