Maternal serum activin A and inhibin A in trisomy 18 pregnancies at 10-14 weeks.

ABSTRACT

In 45 cases of trisomy 18 and 493 control pregnancies at 10-14 weeks of gestation, maternal serum inhibin A, total activin A, free beta-hCG and PAPP-A were measured. In the trisomy 18 pregnancies the median values were 0.74 MoM for inhibin A, 1.23 MoM for activin A, 0.38 MoM for free beta-hCG and 0.16 MoM for PAPP-A. The degree of deviation from normal in the levels of inhibin and activin is small in comparison with free beta-hCG and PAPP-A and they are therefore unlikely to be of value in improving the sensitivity of 90% for a 1% false-positive rate achieved by screening with fetal nuchal translucency and maternal serum free beta-hCG and PAPP-A.