THE ABNORMALLY LARGE FOLLICLE DURING CONTROLLED OVARIAN HYPERSTIMULATION - MANAGEMENT AND OUTCOME OF THE CYCLE

Objective: To investigate if the presence of an abnormally large folli cle during controlled ovarian hyperstimulation (COH) under pituitary s uppression has any effect on the outcome of the cycle. Design: Prospec tive, observational. Setting: The reproductive endocrinology unit of a university hospital. Patients: One hundred fifty patients undergoing COH for assisted reproductive techniques during a 6-month period (Augu st 1990 to January 1991). Interventions: Transvaginal follicular aspir ation and IVF-uterine ET. Results: A total of 19 cycles had abnormally large follicles identified on day 8 of the stimulation cycle after no rmal baseline ultrasound. Gonadotropins were continued and hCG injecti on was indicated when two or more follicles of the main cohort achieve d a diameter of 20 to 22 mm. Twenty preovulatory oocytes were retrieve d from 22 large follicles. Two were transferred for GIFT and 18 were i nseminated in vitro, resulting in a 72.0% fertilization rate. The mean number of oocytes retrieved per patient was 10.9, 71.4% of which were mature with a fertilization rate of 67.7%. All these figures were com parable with the results obtained in the 131 patients of the control g roup undergoing IVF. No evidence of premature luteinization was observ ed in the study group, based on plasma P levels (X0.83 ng/mL [conversi on factor to SI unit, 3.180], range 0.31 to 1.40 ng/mL). The clinical pregnancy rate for the group with abnormally large follicles did not d iffer from the control group (27.8% versus 28.2%, respectively). Concl usions: The presence of an abnormally large follicle during COH under pituitary suppression does not affect the outcome of the cycle. Moreov er, under these conditions, continuous gonadotropin stimulation of a f ollicle to diameters considerably larger than the standard ones does n ot have a detrimental effect on the oocyte contained in it, suggesting that oocyte aging is an independent process from follicular growth on ce LH surge is prevented.