ABSTRACT
The mother can deliver nutrients to the fetus only through the placenta during pregnancy. Folic acid plays an important role in placenta development and fetal growth, and is involved in cell division, embryogenesis and fetal growth. The ability of transplacental folic acid is one of the limiting steps of folate application. Folic acid and its active forms arrive at the fetus by three transporters: folic acid receptor, reduced folic acid carrier and proton coupled folic acid transporter. The expression and transport capacity of transporters were changed significantly with pregnancy complications such as hypertension, fetal growth restriction and premature delivery. Antiepileptic drugs, progesterone, antihypertensive drugs, drug abuse, and heavy metals can alter the transport of folic acid and across the placental barrier of other drugs by regulating the placental folate transporter.