THE EFFECT OF GLUCOCORTICOID THERAPY ON FETAL LUNG MATURITY INDEXES IN HYPERTENSIVE PREGNANCIES

Objective: To assess fetal lung maturity tests in hypertensive pregnan cies and to examine the effect of glucocorticoid therapy. Methods: In a cohort study involving 68 pregnant women with hypertension, 34 recei ved antenatal betamethasone before amniocentesis and 34 did not. Contr ols were 68 women with uncomplicated pregnancies, matched for gestatio nal age at amniocentesis and fetal gender. Amniotic fluid (AF) samples were analyzed by lamellar body count, planimetric and stechiometric l ecithin-sphingomyelin ratio (L/S), and presence of phosphatidylglycero l. Results: Fetal lung maturity, as determined by lamellar body counts and by planimetric L/S, was lower in hypertensive pregnancies not tre ated with steroids than in controls (19,600 +/- 14,500 versus 39,800 /- 22,700, P < .009, and 1.9 +/- 0.6 versus 3.9 +/- 1.8, P < .01, resp ectively). In the period of 24 to 33 weeks' gestation, the percentage of untreated pregnancies with mature lamellar body counts and mature L /S was significantly lower than that of controls (13% versus 33%, P < .001; 6% versus 40%, P < .002 and P < .003, respectively). In contrast , in patients treated with betamethasone, the percentage of cases with mature indices for both tests was not significantly different from th at of controls, but was higher than that of untreated hypertensive pat ients (40% versus 13%, P < .001; 33% versus 6%, P < .001). Phosphatidy lglycerol did not differ among groups. From 34 to 38 weeks, no differe nce was found in the percentage of mature cases for lamellar bodies in pregnant women with hypertension not treated with steroids in compari son with controls (68% versus 84%), nor between cases treated and cont rols (74% versus 84%). In the same period, no difference in L/S values was found among groups, and the percentage of cases positive for phos phatidylglycerol was lower in hypertensive pregnancies than in control s (47% versus 95%, P < .001) and was not affected by steroid treatment (37% versus 95%, P < .001). Conclusion: Fetal lung maturity, as refle cted in AF tests, is delayed in hypertensive pregnant patients, and st eroids increase all lung maturity indices except phosphatidylglycerol between 24 and 33 weeks' gestation. (Obstet Gynecol 1998;92:220-5. (C) 1998 by The American College of Obstetricians and Gynecologists.)