THE EFFECT OF LOW-DOSE ASPIRIN ON PREGNANCIES COMPLICATED BY ELEVATEDHUMAN CHORIONIC-GONADOTROPIN LEVELS

OBJECTIVE: Our purpose was to determine whether elevated second-trimes ter human chorionic gonadotropin levels identify women likely to benef it from low-dose aspirin therapy. STUDY DESIGN: We evaluated second-tr imester human chorionic gonadotropin levels obtained from healthy null iparous women before screening for participation in a double-blind ran domized trial of aspirin therapy: 262 women took 60 mg of aspirin dail y and 420 did not. RESULTS: Among women who did not take aspirin, thos e with human chorionic gonadotropin levels greater than or equal to 2. 0 multiples of the median had a significantly lower mean birth weight (2859 vs 3159 gm, p = 0.04) than did those with normal human chorionic gonadotropin levels. All women who took aspirin had a higher mean bir th weight than women who did not, but women with human chorionic gonad otropin levels greater than or equal to 2.0 multiples of the median ha d the greatest increase (416.2 gm higher in those with human chorionic gonadotropin levels greater than or equal to 2.0 multiples of the med ian, p = 0.02; 96 gm higher in those with human chorionic gonadotropin levels <2.0 multiples of the median, p = 0.04). Regression analysis s uggested that the higher birth weight was partly explained by a higher gestational age at delivery and partly by increased weight independen t of gestational age. CONCLUSIONS: Aspirin therapy increased birth wei ght in all women, especially in women with high human chorionic gonado tropin levels, partly by increasing gestational age at delivery. This observation needs to be confirmed by further studies.