BACKGROUND: This study compares embryo quality, fertilisation rate and pregnancy rates after ICSI related with the quality of oocytes achieved after r-FSH stimulation. METHODS: We evaluated 955 oocytes from patients following r-FSH and 643 oocytes from patients stimulated with ultrapure urinary FSH. The oocytes were divided into: a) normal oocytes; b) ooctyes with extra cytoplasmatic abnormalities (dark zona pellucida, wide perivitelline space); c) oocytes with cytoplasmatic abnormalities (dark cytoplasm, granular cytoplasm, retractile body), d) oocytes with shape abnormalities; e) oocytes with double abnormalities; f) oocytes with triple abnormalities. The embryos were divided into: A) even and homogeneous blastomeres without fragmentation; B) even and homogeneous blastomeres with <20% fragmentation; C) uneven and non-homogeneous blastomeres with 20-50% fragmentation; D) uneven and non homogeneous blastomere with >50% fragmentation. RESULTS: 40.9% of oocytes from patients treated with r-FSH have a normal morphology vs 35.2% of control groups (p<0.04). Abnormalities have a similar frequency in the two groups, except for the presence of three combined abnormalities (7.7 vs 5.4%; p<0.04). Fertilisation rate, cleavage rate, oocyte quality and pregnancy rate do not appear to be influenced by oocyte morphology and the type of FSH used for stimulation. CONCLUSIONS: The administration of r-FSH allows a large number of oocytes to be rescued, with a high incidence of normal morphology. The fertilisation rate and the quality of embryos obtained from oocytes with structural abnormalities are similar to those observed in morphologically normal oocytes. Even the probability of pregnancy is similar in the two groups.
BACKGROUND: This study compares embryo quality, fertilisation rate and pregnancy rates after ICSI related with the quality of oocytes achieved after r-FSH stimulation. METHODS: We evaluated 955 oocytes from patients following r-FSH and 643 oocytes from patients stimulated with ultrapure urinary FSH. The oocytes were divided into: a) normal oocytes; b) ooctyes with extra cytoplasmatic abnormalities (dark zona pellucida, wide perivitelline space); c) oocytes with cytoplasmatic abnormalities (dark cytoplasm, granular cytoplasm, retractile body), d) oocytes with shape abnormalities; e) oocytes with double abnormalities; f) oocytes with triple abnormalities. The embryos were divided into: A) even and homogeneous blastomeres without fragmentation; B) even and homogeneous blastomeres with <20% fragmentation; C) uneven and non-homogeneous blastomeres with 20-50% fragmentation; D) uneven and non homogeneous blastomere with >50% fragmentation. RESULTS: 40.9% of oocytes from patients treated with r-FSH have a normal morphology vs 35.2% of control groups (p<0.04). Abnormalities have a similar frequency in the two groups, except for the presence of three combined abnormalities (7.7 vs 5.4%; p<0.04). Fertilisation rate, cleavage rate, oocyte quality and pregnancy rate do not appear to be influenced by oocyte morphology and the type of FSH used for stimulation. CONCLUSIONS: The administration of r-FSH allows a large number of oocytes to be rescued, with a high incidence of normal morphology. The fertilisation rate and the quality of embryos obtained from oocytes with structural abnormalities are similar to those observed in morphologically normal oocytes. Even the probability of pregnancy is similar in the two groups.