Time interval between FSH priming and aspiration of immature human oocytes for in-vitro maturation: a prospective randomized study.

This prospective randomized controlled study was performed to examine the influence of coasting for 2 days versus 3 days following a fixed daily dose of FSH for 3 days. The outcome was 2-fold. In the first experiment (n = 50 cycles), the incidence of apoptosis in granulosa cells was compared. In the second experiment (n = 28 cycles), the rates of maturation, fertilization, cleavage, pregnancy and implantation were compared. In addition, clinical pregnancy rate per aspiration was registered. Granulosa cells were collected from follicular aspirates and pooled for each patient. The APOPTAG Detection Kit was used for staining of the granulosa cells and detection of apoptosis. Oocytes were matured in vitro for 28-30 h before intracytoplasmic sperm injection. The incidence of apoptosis in granulosa cells did not differ between granulosa cells obtained after 2 days coasting (n = 25 cycles) compared with granulosa cells obtained after 3 days coasting (n = 25 cycles) (26.2 versus 26.2%). When oocytes obtained after coasting for 2 days (n = 12 cycles) were compared with oocytes obtained after coasting for 3 days (n = 16 cycles), no significant difference was found between rates of maturation (63 versus 65%), fertilization (60 versus 68%), cleavage (86 versus 92%) or implantation [5/12; 42 versus 1/12 (8%)]. A higher clinical pregnancy rate per aspiration [5/16 (31%) versus 1/12 (8%)] was obtained after coasting for 3 days compared with coasting for 2 days. The difference was not significant. This randomized study showed no difference in apoptosis of granulosa cells and no difference in developmental competence of oocytes obtained after coasting for 3 days compared with 2 days coasting.