Excess folate and odds of twins

High blood levels of the vitamin folate appear to increase the risk of a twin birth after women are impregnated through in vitro fertilization (IVF) or other assisted reproduction techniques. Folate, a B vitamin found in green leafy vegetables, cereals and liver, is essential for fetal growth. Women are advised to take folic acid supplements, a synthetic compound of folate, before becoming pregnant and during the early months of pregnancy, to curb the risk of defects such as spina bifida, a defect of the spine.The goal of doctors who perform IVF is to increase the rate of successful pregnancies, so they usually implant more than one embryo. However, this practice leads to an increased risk of multiple births, which in turn raises the risk of death and illness for both the mothers and the infants. Researchers from the Aberdeen University, UK, prospectively evaluated outcomes for 602 women undergoing fertility treatment. In the IVF group, 32 percent of attempts resulted in a fetus with a heartbeat, and 29 percent in live births. There were 93 singleton pregnancies and 37 twin pregnancies. Younger women were more likely to have twins. The rate of twins was also associated with higher levels of folate. However, folate concentrations were unrelated to the likelihood of successful pregnancies. The researchers advise doctors to recommend women undergoing assisted reproduction that they should not exceed the recommended doses of folic acid.