[Plasma beta chorionic gonadotropin between 14 and 20 weeks of amenorrhea: a sign of pregnancy-related hypertension].
A defect of placenta maturation has been described in hypertension of pregnancy. Plasma beta chorionic gonadotropins (beta HCG) of placental origin rise at the onset of pregnancy and reach a peak between 9 and 10 weeks of amenorrhoea. As we were making systematic assays between 14 and 20 weeks in a trisomy detection programme, we looked for differences in plasma beta HCG levels between women with pregnancy-induced arterial hypertension and pregnant women with normal blood pressure. We also studied the predictive value of such assays. Pregnancy-induced hypertension was found in 6 women in a population of 89 nulliparas and in 12 women in a population of 163 multiparas. beta HCG levels were significantly higher in women who later developed hypertension among both nulliparas (52,833 +/- 19,538 IU vs 24,499 +/- 16,485 IU) and multiparas (50,558 +/- 23,597 IU vs 20,911 +/- 11,677 IU). In nulliparas, taking 43,000 IU as threshold of pathology we found that the predictive value of beta HCG was higher than that of other tests which had gone through controlled studies (sensitivity 67 percent, specificity 91.6 percent, positive predictive value 36 percent, negative predictive value 97.4 percent, relative risk 5.4). In multiparas, taking 38,000 as threshold and combining this marker with obstetrical history it was possible to predict the occurrence of hypertension more precisely than with other markers which had gone through controlled studies (sensitivity 66.7 percent, specificity 98 percent, positive predictive value 61.4 percent, negative predictive value 97.3 percent, relative risk 8.4).