WEDNESDAY, May 16, 2018 (HealthDay News) -- Poor prenatal growth and higher postnatal anger have indirect effects on infant reactivity and regulation (RR), according to a study published in the March/April issue of Child Development.
Pamela Schuetze, Ph.D., from Buffalo State College and University at Buffalo in New York, and colleagues examined pathways from maternal tobacco, marijuana, stress, and anger in pregnancy to infant RR at 9 months of infant age in a low-income, diverse sample, beginning in the first trimester of pregnancy. Fetal growth and postnatal stress/anger were examined as potential mediators, while infant sex was assessed as a moderator. A total of 247 dyads were included, with 173 substance-exposed infants.
The researchers identified no significant direct effects of prenatal risk on RR, with no moderation by sex. Significant indirect effects were seen on RR via poor fetal growth and elevated postnatal anger.
"The study adds to the sparse literature on joint effects of tobacco and marijuana, and highlights the role of fetal growth and maternal anger as important pathways from prenatal risk to infant RR," the authors write.