Serum and amniotic fluid lactic dehydrogenase in pregnant women

No significant differences were found when the serum and amniotic fluid total lactic dehydrogenase (LDH) and LDH isoenzymes in women with newborn infants involved by Rh hemolytic disease were compared with women with uninvolved infants. During the twenty-fourth to thirty-second weeks of gestation, the serum LDH 1 level was higher and the serum LDH 3 level was lower than levels of the nonpregnant control subjects. Serum LDH 3 levels were lower than those of the nonpregnant control subjects during the thirty-third to forty-second weeks of pregnancy. It was noted that there was an increase in amniotic fluid LDH 5 with increasing gestational age.