The prognostic value of human placental lactogen (HPL) levels in threatened abortion.

The value of a single HPL estimation in serum was assessed in 337 patients with a threatened abortion between 7 and 27 weeks gestation. Serial assays were subsequently performed on 75 of these. A scheme is proposed whereby an HPL result can be given a "favourable", "equivocal" or "unfavourable" prognosis according to its level. Using this scheme a correct prognosis was obtained in 86 per cent of cases between 9 and 19 weeks gestation while an incorrect prognosis was obtained in 3 per cent of cases. There appeared to be little prognostic value after 19 weeks gestation though prior to 9 weeks the results were sufficiently promising to suggest that a more sensitive assay would be useful.