Fatal hydrops fetalis caused by anti-D in a mother with partial D.

Background: Rare cases of hemolytic disease of the newborn occur in women with genetic variants of the D antigen. A partial D variant might be suspected when typing for the D antigen shows weaker-than-normal reactions (weak D). Historically, patients with a weak D phenotype have not been considered candidates for Rh immune globulin prophylaxis.

Pharmacokinetics of ionized versus total magnesium in subjects with preterm labor and preeclampsia.

Objective: Intravenous magnesium sulfate is widely used in obstetrics for the treatment of both preterm labor and preeclampsia. Although therapeutic levels of total magnesium have been proposed, the levels remain controversial. Because the active form of magnesium is the free or ionized form, it is essential to determine whether ionized magnesium and total magnesium levels are highly correlated in vivo.