VALIDITY IN NULLIPARAS OF INCREASED BETA-HUMAN CHORIONIC-GONADOTROPINAT MIDTERM FOR PREDICTING PREGNANCY-INDUCED HYPERTENSION COMPLICATED WITH PROTEINURIA AND INTRAUTERINE GROWTH-RETARDATION

The objective of the present study was to investigate whether increase d beta-human chorionic gonadotrophin (beta HCG) plasma concentrations in an unselected population of nulliparas could predict the occurrence of complicated pregnancy-induced hypertension (PIH). The design was t hat of a prospective population study. It was conducted at the obstetr ic departments of Amiens-University Hospital and Creil General Hospita l on 434 consecutive nulliparas with singleton pregnancies after natur al fertilization who accepted the systematic offer of trisomy 21 scree ning but for whom this disorder was finally eliminated. Measurement of plasma concentration of beta HCG (ELISA method) was carried out betwe en 14 and 20 weeks (mean: 17 weeks) of amenorrhea, and measurement of blood pressure and proteinuria (>300 mg/24 h or Albustix ++) during th e first, second and third term and 2-3 months after the delivery, as w ell as measurement of birth weight for determination of small for gest ational age (SGA) babies. 37 women developed PIH, 10 without other com plication, 16 with proteinuria (5 of which with SGA babies) and 11 wit h SGA babies. Furthermore 2 patients presented abruptio placentae with out PIH. 395 women did not develop PIH including 389 normotensive wome n and 6 chronic hypertensive patients without superimposed toxemia. On ly 1 was diabetic. None had chronic renal disease. Mean (+/- SD) level s of beta HCG were higher in PM than in controls: 46,805 +/- 19,068 ve rsus 23,479 +/- 13,463 IU. A pathological threshold was chosen as the mean for the whole population + 1 SD: 25,613 + 15,479 = 41,082 IU. Ele vated levels (above this value) were significantly associated with iso lated PIH or PIH complicated with proteinuria and/or with SGA babies. The positive predictive value of this criterion was respectively 11, 1 5 and 12% for each of these complications. The relative risk (and 95% confidence limit) of women with elevated beta HCG for each of these co mplications was 20 (6-79), 11 (4-43) and 22 (7-93). Elevated plasma be ta HCG found around 17 weeks of amenorrhea predicts PIH complicated wi th either proteinuria or SGA babies with a positive predictive value c omparable to that of the best and earliest test proposed up to now to select nulliparas at high risk of preeclampsia, namely the abnormaliti es of the Doppler waveforms of the uterine arteries. Since this test i s simpler to perform, it represents the most convenient method to scre en a population of nulliparas for evaluation of the benefits of low-do se aspirin.