[The betamethasone test in the diagnosis of placental insufficiency]

A trial to evaluate a functional test of the fetoplacental unit by measuring the extent of suppression of maternal estriol serum levels by glucocorticoids is described. 21 women between the 30th and 40th week of gestation received 4 mg betamethason intravenous injection at 8.30 a.m. Blood samples were collected immediately before betamethason application and at 1.00 p.m., 4.00 p.m., 8 p.m. o'clock and at 8.30 a.m. on the next day. Estriol (E3), cortisol, dehydroepiandrosterone sulfate (DHEA-S) and human placental lactogen (HPL) were determined from serum samples by radioimmunologic methods. Patients were divided into 3 groups: severe placental insufficiency (group I, n = 6) described by growth retardation of the fetus of more than 2 weeks, normal gestations (group II, n = 8) and slight growth retardation (group III, n = 7). After temporary suppression in groups II and III, E3, DHEA-S and cortisol levels showed a significant increase the day after betamethason. In group I an increase of these parameters was observed 2 to 5 days after betamethason. These results show that a low intravenous dosage of betamethason and collection of blood samples for E3 assays in intervals of 12 hours can be used as a functional test of the fetoplacental unit.