Fall in the heat-labile alkaline phosphatase isoenzyme levels during pregnancy in healthy Nigerians.

Estimation of heat-labile alkaline phosphatase isoenzyme in the serum of 45 healthy non-pregnant women and 98 women in the second and third trimesters of pregnancy revealed a statistically significant reduction of this isoenzyme during pregnancy. Variations in normal activity were also more marked in the pregnant women compared with the non-pregnant control subjects. Now that normal serum levels of the heat-labile alkaline phosphatase isoenzyme in pregnancy have been established it is possible to use estimations of the enzyme as part of the assessment of maternal liver function in pregnancy.