Serum inhibin A levels in pregnant women with systemic lupus erythematosusor antiphospholipid syndrome

Maternal serum inhibin a levels are increased on average in pregnancies aff ected by Down syndrome (DS). However, some reports have found increased ser um levels in women with pre-eclamptic toxaemia as well. In the current stud y, maternal serum inhibin A was retrospectively measured in a series of 32 serum samples from pregnant women previously diagnosed as having either sys temic lupus erythematosus (SLE) or primary antiphospholipid syndrome (APS). For comparison, normal medians were calculated from 57 unaffected control pregnancies together with a total Of 854 samples tested at 13-19 weeks of g estation as part of the routine antenatal DS screening. All results were ex pressed in multiples of the gestation specific normal medians (MoM). A cubi c regression formula was fitted, weighting for the number of women tested a t each gestation. The median MoM value in the 16 cases of SLE and the 16 ca ses of primary APS is 0.60 (95%, confidence interval 0.40-0.91) and 0.8& (9 5% confidence interval 0.66-1.17), respectively. For primary APS this was n ot statistically significant, whereas the SLE patients had a highly statist ically significant reduction of serum inhibin a (p<0.002, Wilcoxon Rank sum Test, 2 tailed). Six pregnancies in the SLE group had a complicated obstet ric outcome, i.e, missed abortion, placental abruption, exacerbation of the underlying disease which necessitated delivery, and severe postpartum haem orrhage. In 85% of this subgroup, serum inhibin A levels were below the nor mal 10th centile. The current data suggest that serum inhibin A is dea ease d on average in SLE patients. Those preliminary results might have various obstetric implications such as antenatal DS screening of SLE patients, iden tification of pregnant women at risk of developing SLE, who have presented for routine DS screening and for monitoring SLE patients throughout their p regnancy. Copyright (C) 2000 John Wiley & Sons, Ltd.