( 2 ) The pregnancy outcome of two group : the premature birth rate , low birth weight rate and cesarean section rate of 9 % ( 3/32 ) , 9 % ( 3/32 ) and 69 % ( 22/32 ) in sildenafil group were significantly lower than 16 % ( 5/32 ) , 19 % ( 6/32 ) and 81 % ( 26/32 ) in control group ( P < 0.05 ) .