Ultrasound in an in vitro fertilization program.

Ultrasound examinations of the preovulatory follicle were performed on 39 patients in 58 consecutive spontaneous cycles in which ovum aspiration for in vitro fertilization was planned. Examinations during the follicular phase helped to indicate when patients should be admitted for intensive monitoring of urinary luteinizing hormone (LH) levels and as a means of lateralizing the side of follicular development in those patients in whom one ovary was known to be inaccessible to laparoscopic aspiration. The technique was also of value in determining whether ovulation had occurred in those patients in whom the anticipated midcycle LH surge was not detected and as a routine measure prior to laparoscopy to ensure the continuing presence of the follicle.