Ylöstalo P, Rönnberg L, Jouppila P
Fertil Steril. 1979 Jun;31(6):651-5. doi: 10.1016/s0015-0282(16)44055-0.
Ultrasonic monitoring of ovarian follicles and estimation of serum estradiol were carried out in 12 patients with clomiphene therapy, in 5 patients with gonadotropin therapy, and in 7 normal controls. The average diameter of preovulatory follicles in normal controls was 12,8 mm; in ovulation induction groups it was 2 to 4 mm greater. The level of serum estradiol was also higher in ovulation induction groups than in normal controls. The combined use of these two methods is recommended: ultrasonic monitoring to minimize the risk of multiple pregnancies and estrogen level monitoring to minimize the risk of hyperstimulation. Ultrasound is also safe and practical in following the size of hyperstimulated ovaries.