Abstract:
We examined whether high doses of folic acid and iron supplementation in
early-to-mid pregnancy affect the risk of preterm birth, low birth
weight, and small for gestational age neonates, in the mother-child
cohort in Crete, Greece (Rhea study).
We included 1,279 women with singleton pregnancies with complete data on
supplements use in early-to-mid pregnancy and birth outcomes.
Anthropometric measurements at birth were obtained from medical records.
Red blood cell folate concentrations in cord blood were measured in a
subsample of the study population (n = 58).
Sixty-six percent of the study participants reported high doses of
supplemental folic acid use (5 mg/day), while 21 % reported excessive
doses of folic acid use (> 5 mg/day) in early-to-mid pregnancy. Daily
intake of 5-mg supplemental folic acid was associated with a 31 %
decrease in the risk of preterm birth (RR, 0.69; 95 % CI, 0.44, 0.99),
60 % decrease in the risk of delivering a low birth weight neonate (RR,
0.40; 95 % CI, 0.21, 0.76), and 66 % decrease in the risk of
delivering a small for gestational age (SGA) neonate (RR, 0.34; 95 %
CI, 0.16, 0.73). Daily doses of iron supplementation more than 100 mg
were associated with a twofold increased risk for SGA neonates (RR,
2.14; 95 % CI, 0.99, 5.97).
These findings suggest that high daily doses of supplementary folic acid
in early-to-mid pregnancy may be protective for preterm birth, low birth
weight, and small for gestational age neonates, while high daily doses
of supplementary iron may be harmful for fetal growth.
Authors:
Papadopoulou, Eleni
Stratakis, Nikolaos
Roumeliotaki, Theano and
Sarri, Katerina
Merlo, Domenic F.
Kogevinas, Manolis
Chatzi,
Leda
