Maternal apolipoprotein E genotype as a potential risk factor for poor birth outcomes: The Bogalusa Heart Study

OBJECTIVE: To assess the association between apolipoprotein E (apoE) genotype and preterm birth (PTB) and small for gestational age (SGA). STUDY DESIGN: ApoE phenotyping was performed on 680 women linked to 1 065 births. Allele frequencies were compared and PTB and SGA risk was estimated using log-binomial regression. RESULTS: The ε2 allele was more common in SGA births (p < 0.01). SGA risk was increased among ε2 carriers compared to genotype ε3/ε3, though associations were attenuated following adjustment for maternal age, education, race, smoking, and prenatal visits. Stronger associations were observed for term SGA (first birth: aRR = 1.78, 95% CI 1.06 – 2.98; any birth: aRR = 1.52, 95% CI 0.96 – 2.40) and among whites specifically (first: aRR = 2.88, 95% CI 1.45 – 5.69; any: aRR = 2.75, 95% CI 1.46 – 5.22). CONCLUSIONS: Associations between maternal apoE genotype and SGA may represent decreased fetal growth in women with lower circulating cholesterol levels.