Perinatal substance use may affect how strongly moms feel for infants

Substance use during pregnancy and postpartum may impact parts of the brain associated with "affective empathy," the emotional response experienced as a result of others' emotions, a new Yale-led study finds.

“Moms who use substances deserve support and help,” says Li Yan McCurdy, PhD, postdoctoral fellow in Yale’s Department of Radiology & Biomedical Imaging and first author of the study. “Being able to identify these similarities and differences is important for helping us find ways to support these moms in caregiving.” Among women participating in the study who had used substances in the perinatal period, the most common was nicotine (70%), followed by alcohol (30%), cannabis (20%) and cocaine (20%).

Researchers performed fuctional magnetic resonance imaging (fMRI) scans while mothers looked at images of happy and sad infants (theirs or others') and listened to sounds of infants crying. After the scan, mothers were asked to provide a "think" rating and a "feel" rating for each cue, identifying how happy or sad the infant looked or sounded as well as how strongly the cue made the mother feel.

The team found mothers who had used substances during pregnancy or postpartum reported feeling less intensely in response to the infants, especially to sad cues. fMRI scans also showed brain regions associated with affective empathy were less activated in this group. However, there was no significant difference in affective empathy ratings when the cue was an image of the participant's own smiling infant. “It seems there’s something quite unique about seeing your own happy baby that makes moms who use substances feel equally happy compared to moms who don’t,” McCurdy says. “In terms of developing interventions, perhaps seeing your smiling baby can be a source of reward and motivation.”

The team hopes its results will help inform efforts to support mothers struggling with addiction. "We hope that advances in our understanding of how substance use impacts brain and psychological processes will help us find new ways to support women during the perinatal period and reduce stigma for mothers with addiction," says Helena Rutherford, PhD, Associate Professor in the Yale Child Study Center and senior author of the study.