Educational attainment and offspring birth weight: A bidirectional Mendelian randomization study.

Area of Science:

• Genetics
• Epidemiology
• Public Health

Background:

• Previous studies show mixed results on the association between educational attainment (EA) and offspring birth weight (BW).
• Confounding factors often limit traditional epidemiological studies.
• Causal inference is needed to clarify this relationship.

Purpose of the Study:

• To investigate the causal association between parental educational attainment (EA) and offspring birth weight (BW).
• To differentiate the effects of maternal and paternal EA on offspring BW.
• To identify potential confounders in the EA-BW relationship.

Main Methods:

• Two-sample bidirectional Mendelian randomization (MR) analysis.
• Utilized summary statistics from large Genome-Wide Association Studies (GWAS) for EA and BW.
• Employed inverse-variance weighted (IVW) and other MR methods, with sensitivity analyses and multivariable MR for confounder assessment.

Main Results:

• Female EA showed a positive causal effect on offspring BW (0.24 SD increase per 1 SD increase in female EA).
• Male EA also demonstrated a positive causal effect on offspring BW (0.21 SD increase per 1 SD increase in male EA).
• The association for male EA was attenuated after adjusting for BMI and alcohol consumption, suggesting confounding.

Conclusions:

• Female educational attainment has a direct positive causal impact on offspring birth weight.
• The association between male educational attainment and offspring birth weight may be influenced by lifestyle factors like BMI and alcohol intake.
• Maternal education is a significant factor influencing offspring birth weight, independent of certain lifestyle confounders.