The effect of low haematocrit on serum human placental lactogen values.

Serial determinations of serum human placental lactogen (HPL) levels in women with haematocrit values of 28 per cent or less between 18 and 30 weeks gestation have been compared with the controls who had haematocrit values of 35 per cent or more. The women with low haematocrit values were found to have significantly raised HPL levels throughout the period of study. The placenta was significantly heavier in the anaemic group (P less than 0.01) but there was no significant difference in birth weights of the infants. It would seem that caution should be exercised in using HPL values as an index of placental function in anaemic women.