Maternal Serum Antioxidants in Mid Pregnancy and Risk of Preterm Delivery and Small for Gestational Age Birth: Results from a Prospective Pregnancy Cohort.

Preterm delivery (PTD) and poor fetal growth are major contributors to neonatal mortality and morbidity that can extend from birth onward. Although overt maternal nutrient deficiencies are associated with adverse pregnancy outcomes, such deficiencies are rare in developed countries. However, some evidence suggests that even within the normal range, higher levels of antioxidant nutrients are protective against adverse pregnancy outcomes. Using data from the prospective Pregnancy Outcomes and Community Health (POUCH) Study ( = 301 preterm;  = 246 term), we examined associations between maternal blood levels of selected antioxidants and pregnancy outcomes. Serum collected at 16-27 weeks' gestation was analyzed for carotenoids, retinol, and α- and γ-tocopherol. Using weighted polytomous regression, these nutrient concentrations were assessed in relation to (1) PTD (<37 weeks gestation) overall and grouped as spontaneous or medically indicated; and (2) small for gestational age (SGA) defined as birthweight-for-gestational age <10th percentile of a national reference population. Women with total serum carotenoids in the upper quartile (Q4) had significantly lower odds of medically indicated PTD compared with women in the lower quartiles (Q1-Q3) even after adjustment for maternal characteristics (aOR = 0.4; 95% CI: 0.2-0.9). Odds ratios for SGA were consistently ≤0.5 among women with any of the serum nutrients in Q4 as compared with Q1-Q3, but final models did not reach statistical significance. Results support the possibility that high maternal serum antioxidants and/or the larger dietary or lifestyle pattern they represent may play a protective role in preventing adverse pregnancy outcomes.