By Abdul El-Sayed
Marriage is an important predictor of health. Married people live longer, and married mothers are less likely to deliver prematurely. Once born, their babies are generally healthier, and are less likely prone to infant mortality than those born to unmarried mothers.
Yet relationships are changing — and marriage is no different. Larry Bumpass, a sociologist who studies marriage at the University of Wisconsin notes that marriage has changed dramatically over the past several decades, arguing that marriage has undergone a “decline in significance” as marital norms that shape the way that couples relate with one another have changed, and both men and women have become more individualistic in their goals and desires. What’s more, young people are increasingly choosing against marriage, as the proportion of unmarried heterosexuals aged 30-44 cohabiting with a partner has doubled since the mid-1990s.
It makes sense, then, that if marriage has deteriorated, the social goods that substantiate the health advantage for married people may also break down — things like social, emotional, and financial support shared between partners in a couple.
In a study published in Public Health Reports we considered how the relationship between marriage and premature births has changed with time. As the graph below shows, the likelihood of prematurity increased among married women and decreased among unmarried women who delivered babies with time in the state of Michigan between 1989 and 2006.
While some of this observed effect may be due to changes in marital norms, as the old adage goes, “correlation doesn’t equal causation,” and there’s another wrinkle to the story.
Married women are also richer and have better access to obstetrical care than their unmarried counterparts, on average. As technologies have improved that allow us to deliver sick babies earlier than ever before, it’s possible that the effect we observed in the study could be explained by a higher rate of clinically-indicated premature births among married women compared to unmarried women, given the difference in access to these life-saving technologies between them.
What’s more, other researchers have noted an increase in elective cesarean section deliveries. Married women, owing to their economic advantage, may also be more likely to have elective c-sections that fall just before the period in which a baby is no longer considered premature.
Rather than one explanation or the other, it’s likely that these findings represent all three underlying trends — our observations are likely to be partly attributable to changing marital norms, as well as to elective and clinically indicated delivery among richer, married women.
Where does the science go from here? To parse out the main driver of this changing relationship between maternal marriage and infant health, we’re now conducting a study to see if we observe the same change over time in the relationship between marriage and infant mortality — an outcome much less likely to be explained by maternal or physician choice.
Figure adapted from published article: El-Sayed AM, Galea S. Changes in the Relationship Between Marriage and Preterm Birth, 1989-2006. Public Health Reports. 2011: 126: 717-725.
Image Credit: Thinkstock.com
Edited by Karestan Koenen.
Article originally posted on the2x2project.org, an online publication sponsored by the Department of Epidemiology at Columbia University. 2×2 aims to inform the health conversation through timely and effective communication of emerging public health science.