Article Text
Abstract
Objective Pregnant teenagers are susceptible to folate deficiency which is associated with an increased risk of delivering small-for-gestational-age infants. Folate is vital for DNA synthesis and DNA methylation. Little is known about the placenta in teenage pregnancy or the impact of folate deficiency. It is hypothesised that folate deficiency is detrimental to placental development and function in teenage pregnancy.
Methods Teenagers (n=37) and adults (n=15) were recruited from 28 weeks gestation and their red cell folate status assessed. Placentas were collected from 16 teenagers, including 6 folate-deficient teenagers and 10 folate-adequate teenagers. Cell proliferation and apoptosis was evaluated immunohistochemically in fixed placental samples. Amino acid uptake via the system A transporter was assessed as a marker of placental function.
Results Significantly more teenagers (38%) were folate deficient compared to the adults (0%) (p<0.01). There was an increased rate of apoptosis in placentas from folate-deficient teenagers compared to folate-adequate teenagers (p<0.05). No difference in cell proliferation was seen. Folate-deficient teenagers had lower placental system A transport activity compared to those with adequate folate status (p<0.05).
Conclusion Folate deficiency adversely affects placental development and function in teenage pregnancy. This may contribute to their susceptibility to poor pregnancy outcome. How folate deficiency causes these effects is unknown, but it may be due to aberrant DNA synthesis or altered methylation status of key placental genes. Further research is needed in folate deficiency in teenage pregnancy and the effect of confounding factors such as smoking.