Objective: To determine if maternal circulating red blood cell (RBC) folate concentration in early pregnancy is associated with late gestation pregnancy complications including small for gestational age (SGA) infants, preeclampsia and preterm birth (PTB) in a socioeconomically disadvantaged population.
Method: This was a retrospective case control study, conducted at Lyell McEwin Health Service, South Australia, including 400 primiparous women. RBC folate and demographic data were collected at 10-12 weeks gestation. Pregnancy outcome data were obtained from patient case notes.
Results: Patients who were folate deficient were more likely to develop pregnancy complications, specifically SGA (OR 6.9, 95% CI 2-24.3) and PTB (OR 5.4 95% CI 1.4-21.2). Those who were folate insufficient were also at increased risk of SGA (OR 3.0, 95% CI 1.3-7.7). No association between folate and preeclampsia was found. Women who were supplementing with folic acid delivered infants who were 179 g heavier (5.5% increased birth weight, P = 0.003) and 4.5 days later, compared to those who did not supplement. Furthermore, low RBC folate was associated with cigarette smoking (P < 0.001).
Conclusions: Maternal RBC folate concentration in early pregnancy is associated with SGA and PTB, but not with preeclampsia.