Figure 2. Associations in each study and pooled across studies for maternal and paternal pregnancy smoking and offspring congenital heart disease (CHD).

Maternal first‐trimester smoking was prioritized and used where possible. A, Odds ratios (ORs) of any CHD for maternal smoking during pregnancy (top) and paternal smoking (bottom). B, ORs of any CHD after removing those with a chromosomal/genetic defect from the study population. C and D, ORs of nonsevere CHD and severe CHD, respectively. All results are adjusted for confounders (depending on cohort: maternal and paternal age, education, ethnicity, alcohol, maternal parity, and offspring sex) as well as the other parent's smoking. These analyses are from the LifeCycle project, a consortium that brings birth cohorts together and harmonizes individual‐level data for their use in research.¹³ All LifeCycle studies with eligible data were included in this study. More information on each can be found as follows: ABCD (The Amsterdam Born Children and Their Development Study),¹⁵ ALSPAC (Avon Longitudinal Study of Parents and Children),¹⁶, ¹⁷ BASELINE (Cork Scope Baseline Study),¹⁸ BiB (Born in Bradford) study,¹⁹ DNBC (Danish National Birth Cohort) study,²⁰ MoBa (Norwegian Mother, Father and Child Cohort Study),²¹, ²² and NINFEA (Nascita e Infanzia: gli Effetti dell'Ambiente [Birth and Childhood: Effects of the Environment]) study.²³, ²⁴