Placental magnesium transport-related mRNA expression is not associated with serum magnesium in singletons and twins.

The mechanisms of placental magnesium (Mg) transport are unknown, especially in twins. We cross-sectionally investigated the association of Mg transport-related protein mRNA expression with serum Mg, placental Mg concentration (p[Mg]), and placenta weight in singleton and twin placentas from 67 mothers. Maternal and cord blood serum Mg were not associated with placental mRNA expression. TRPM6 and TRPM7 mRNAs were positively associated with placental weight in twins while TRPM7 mRNA was positively associated with p[Mg] in singletons. In placentas of relatively healthy women, TRPM6 and TRPM7 may regulate p[Mg] and growth, rather than serum Mg, especially in twin placentas.