Women who received letrozole had more cumulative live births than those who received clomiphene ( 103 of 374 [ 27.5 % ] vs. 72 of 376 [ 19.1 % ] , P = 0.007 ; rate ratio for live birth , 1.44 ; 95 % confidence interval , 1.10 to 1.87 ) without significant differences in overall congenital anomalies , though there were four major congenital anomalies in the letrozole group versus one in the clomiphene group ( P = 0.65 ) .