hPL deficiency with normal estriol levels in a normal pregnancy.

The third published case of human placental lactogen (hPL) deficiency in a normal pregnancy is reported. The results of the 3 cases are discussed. In all cases, estriol levels were normal and hPL levels were either unmeasurable or below 1 microgram/ml. The placenta showed no obvious abnormalities. Growth hormone and prolactin determinations did not contribute to the understanding of the deficiency; neither did the glucose levels in the maternal blood. All 3 infants were male.