Parental Smoking Linked to Increased Risk of Birth Defects in Offspring: Study Urges Quitting During Pregnancy

The evidence from the meta-analysis strengthens the argument that quitting smoking during pregnancy and the perinatal period can prevent these adverse health outcomes.

Kaijuan Wang, Henan Children's Hospital Zhengzhou Children's Hospital, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, China, and colleagues conducted a meta-analysis of case-control studies to evaluate the risk of birth defects in offspring in China linked to maternal active and passive smoking, as well as paternal smoking.

For this purpose, the researchers searched four electronic databases for relevant studies up to December 2023. They employed either a random-effect or fixed-effect model to calculate overall risk estimates and examine the association between parental smoking and the risk of birth defects during different stages of pregnancy. Subgroup and sensitivity analyses were conducted to identify potential sources of variation.

Based on the study, the researchers reported the following findings:

• The analysis included sixty-two studies with 137,574 cases and 8,770,837 controls.
• Maternal active smoking was significantly associated with an increased risk of birth defects (OR = 2.19).
• Maternal passive smoking was also linked to higher birth defect risk (OR = 2.59).
• Paternal active smoking was significantly associated with birth defect risk (OR = 1.47).
• Subgroup analysis revealed an increased risk of congenital heart disease in offspring due to paternal active smoking (OR = 2.97) and maternal active smoking (OR = 1.51).
• Sensitivity analysis confirmed the consistency of these findings.

The findings showed that maternal active and passive smoking, as well as paternal active smoking, increase the risk of birth defects in offspring. The researchers suggest that it is important to encourage parents to quit smoking during pregnancy and the perinatal period to reduce this risk.

"The meta-analysis reaffirms the harmful effects of smoking during pregnancy and highlights that both maternal and paternal smoking behaviors impact fetal development. Efforts to reduce smoking rates before conception and throughout the perinatal period are vital for improving birth outcomes and reducing the risk of congenital disorders in offspring," the researchers concluded.

Reference:

Han, J., Zhang, Y., Liu, Y., Liu, J., Zhang, Y., & Wang, K. (2024). Parental Smoking and the Risk of Birth Defects in Offspring in China: A Systematic Review and meta-Analysis. Birth Defects Research, 116(12), e2422. https://doi.org/10.1002/bdr2.2422