A husband's optimism and confidence may play a crucial, if often unseen, role in helping babies arrive healthy and on time.
A new study from University of California Merced psychology researchers found that when married fathers reported higher levels of resilience — a quality that includes traits such as optimism, self-esteem, and perceived social support — their partners showed lower levels of inflammation during pregnancy and carried their babies longer.
"This is one of the first studies to show that a father's inner strengths, such as his optimism and ability to cope with challenges, can ripple through the family in measurable, biological ways," said Professor Jennifer Hahn-Holbrook , a co-author.
The findings were published in the journal Biopsychosocial Science and Medicine.
The research team, led by Ph.D. student Kavya Swaminathan , analyzed data from 217 mother-father pairs who participated in the Community Child Health Network study across five sites in the U.S.
Mothers provided blood samples during pregnancy that were analyzed for C-reactive protein, a marker of inflammation associated with an increased risk of preterm birth. Both parents also completed surveys assessing resilience-related traits such as optimism, self-esteem and social support.
Preterm birth, defined as delivery before 37 weeks, is a leading cause of infant mortality and lifelong health complications, including heart disease and developmental disorders. High maternal inflammation is a well-established risk factor. The UC Merced study indicates one reason why some mothers may be biologically protected: their partners' emotional resources.
In married couples in this study, higher paternal resilience was associated with lower maternal inflammation, which in turn predicted a longer gestation period. Every day in the womb is better for fetal health and development. Among unmarried or cohabiting couples, that connection was not seen.
"This study is exciting because it highlights how the people surrounding a pregnant woman can shape her biology in ways that affect both her health and her baby's," Swaminathan said.
The study does not prove cause and effect, but offers strong evidence that emotional and social strength in the father can have physical consequences for mothers and babies.
"Fathers who feel confident and supported might engage in more positive daily behaviors, such as cooking healthy meals, offering encouragement and reducing stress at home," said Hahn-Holbrook, a Health Sciences Research Institute faculty member. "Emotional connections may also play a role, since couples tend to coregulate their moods and even their immune systems."
The study draws on the biopsychosocial model, which examines how emotional and social factors interact with biological factors to shape health. Previous research has shown that chronic stress can increase inflammation during pregnancy. The UC Merced study flips the lens to examine how positive psychological resources can protect against it.
Others involved in the study included UCLA Professor Christine Dunkel Schetter, one of several primary investigators, along with UC Merced psychology Professor Haiyan Liu and Stony Brook University Professor Christine Guardino.
Funding for the study came from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and the National Institute of Nursing Research.
