Inhibin A serum levels in proteinuric and nonproteinuric pregnancy-induced hypertension: evidence for placental involvement in gestational hypertension?

OBJECTIVES: To evaluate the serum levels of inhibin A in pregnant women with different types of hypertension.
METHODS: A case-control study, including 60 cases (20 women with preeclampsia, 20 with mild gestational hypertension, and 20 with chronic hypertension), and 60 gestational-age- and parity-matched controls. Inhibin A was measured in duplicate by enzyme-linked immunosorbent assay in serum samples frozen at -80 degrees C.
RESULTS: As compared to controls, inhibin A levels were significantly elevated in women with preeclampsia ¿2.32 standard deviation (SD) 1.4¿ versus 0.50 (0.29) ng/mL, p < 0.001) and gestational hypertension [1.09 (0.73) versus 0.55 (0.29) ng/mL, p < 0.05], but not in the group of chronic hypertension [0.88 (0.69) versus 0.54 (0.39) ng/mL, p = 0.08]. Overlap in inhibin A values between cases and controls was observed in 20% (4/20) of women with preeclampsia and 55% (11/20) with gestational hypertension.
CONCLUSIONS: Increased serum inhibin A may indicate that a proportion of mild nonproteinuric hypertension cases are associated with placental involvement.