Social Support During Pregnancy Modifies the Association Between Maternal Adverse Childhood Experiences and Infant Birth Size

Introduction Adverse childhood experiences (ACEs) can deleteriously affect health, including pregnancy and birth outcomes occurring later in life. Identification of modifiable factors during pregnancy that buffer the ill effects of adversity is warranted. Social support during pregnancy can promote better birth outcomes, yet it is unknown whether it could also mitigate perinatal risks stemming from ACEs. Thus, this study considers multiple forms of social support in pregnancy as modifiers of an ACEs and fetal growth association. Methods Data were collected from mother and infant pairs from an ongoing prospective birth cohort. Women enrolled around 27 weeks gestation and completed gold-standard assessments of ACEs and social support. Infant cephalization index scores [(head circumference /birthweight) × 100; a marker of asymmetric fetal growth] were derived. Multivariable regression models tested main effects and interaction between ACEs and social support in relation to infant cephalization. Results Higher levels of ACEs were associated with higher cephalization scores (β = 0.01, SE = 0.01, p < 0.05) whereas higher social support was associated with lower cephalization scores (β = − 0.03, SE = 0.01, p < 0.05). A significant interaction was observed showing a protective effect of social support among those with low (0 events) and moderate (1–3 events) ACEs but not among those with high ACEs (4 + events; p < 0.05). Tangible and emotional support, but not information support, contributed to the associations. Discussion Maternal ACEs can deleteriously affect birth size, yet social support during pregnancy provides some buffer from its enduring effects. Interventions designed to enhance pregnancy social support may not only improve maternal wellbeing, but may also safeguard infant health.