Couples in the Control group did not receive the Family Foundations Coparenting Program.

Couples randomly assigned to the Intervention Group received the Family Foundations Coparenting Program.

Family Foundations, a program for adult couples expecting their first child, is designed to help them establish positive parenting skills and adjust to the physical, social, and emotional challenges of parenthood. Program topics include coping with postpartum depression and stress, creating a caring environment, and developing the child's social and emotional competence.

Family Foundations is delivered to groups of couples through four prenatal and four postnatal classes of 2 hours each. Prenatal classes are started during the fifth or sixth month of pregnancy, and the postnatal classes end when the children are 6 months old.

Family Foundations is delivered in a community setting by childbirth educators who have received 3 days of training from Family Foundations staff.

We assessed coparenting relationship quality with the 31-item Coparenting Scale, which was created based on prior work (e.g., Abidin & Brunner, 1995; Cordova, 2001; Frank, Olmstead, Wagner,& Laub, 1991; Margolin et al., 2001; McHale, 1997). The overall score represents an average of items covering theoretically important domains: coparental agreement, support,undermining, and exposure of the child to conflict.

Aggressive parenting was measured using Parent-Child Conflict Tactics Scales (Straus et al., 1998).

We assessed parent and child cardiovascular disease risk via inflammatory (C-reactive protein, Interleukin-6) and metabolic (total cholesterol, glycated hemoglobin, body mass index, blood pressure) outcomes previously linked to cardiovascular disease risk (e.g., Danesh et al., 2004; Goran et al., 2003; Ortega et al., 2016; Fuchs et al., 2020).