In a prospective randomized study, we analysed 125 patients at risk of ovarian hyperstimulation syndrome (OHSS), selected in the period between January 1996 and July 1997. All the patients had blood oestradiol concentration >/=1500 pg/ml on the day of human chorionic gonadotrophin (HCG) administration and >/=15 oocytes were collected. The patients were matched in two groups: group A, control group (n = 67), had fresh embryo transfers; group B (n = 58) had cryopreservation of all obtained pronucleate embryos. Pregnancy, live birth rates and the incidence of OHSS were compared between the two groups. There were no significant differences in terms of pregnancies per patient (46.3 versus 48.3%) and live birth rates (38. 8 versus 39.6%). No cases of OHSS occurred in group B, while four patients developed the syndrome in group A. The implantation rate was slightly but not significantly lower in group B (chi2 = 1.03). These results suggest that elective cryopreservation of all zygotes might prevent the risk of OHSS in patients undergoing IVF treatment. In contrast to what has been reported by other authors, our results show that the elective cryopreservation of zygotes does not affect pregnancy and live birth rates.

Purpose This study was designed to examine the effect of bacterial contamination on in vitro fertilization treatment outcomes. Method In a prospective clinical trial, 152 patients aged 23-38 years, mean 33.3±4.6, undergoing IVF treatment were selected for this study. During embryo transfer, separate samples were collected for microbial examination from the following sites: the fundus of the vagina, the cervix, the embryo culture medium prior and post-embryo transfer, the tip of the catheter, and the external sheet. All the samples were separately cultured to identify any bacteria or yeast present. Results Pregnancy rates in patients testing positive for Entrobacteriaceae (22.2% versus 51%) and Staphylococcus species (17.6% versus 44%) were significantly lower than those in the negative culture group ( p< 0.001). The pregnancy rates do not seem to be affected by the other isolated microorganisms.Conclusion This study shows that the presence of vaginalcervical microbial contamination at the time of embryo transfer is associated with significantly decreased pregnancy rates.

The aim of this study was to examine the safety and the efficiency of a 'non-contact' UV laser to assist hatching through zona opening of human embryos. Between January and November 1995 we performed zona drilling for assisted hatching using a new laser system (PALM UV Laser microbeam), operating in a 'non-contact' mode to create a hole in the zona pellucida of human embryos. In a randomized study, laser zona opening was applied on embryos from two groups of patients with repeated in-vitro fertilization (IVF) failures (two to four attempts): group A was composed of 107 patients who received mixed embryos (216 laser-treated and 223 not treated) and group B of 72 patients who received 218 laser-treated embryos only. Both groups were compared with a control group of 98 patients whose embryos were not laser treated (n = 407) (group C). The mean ages of all groups (38.1, 38.2 and 37.8 years respectively) and the number of IVF attempts (two to four attempts) were similar. The resulting clinical pregnancies were 39 (36.4%) in group A, 32 (44.4%) in group B and 19 (19.3%) in group C. The implantation rates/embryo were 9.3% in A, 16% in B and 5.1% in the control group. In total, 17 normal babies have been delivered (10 in group A and seven in group B). These results show that laser zona drilling increased the pregnancy and implantation rates in all the treated patients. The increase was slight but significant in patients of group A (P < 0.01 and P < 0.02), it was even higher in the patients of group B (P < 0.05).

Between July 1995 and May 1996, 36 patients with non-obstructive azoospermia of secretory origin underwent intracytoplasmic injection of spermatids. A previous histological biopsy was performed on all patients: 15 had spermatogenic arrest, a further 13 had Sertoli cell-only syndrome, and the remaining eight had post-cryptorchidism tubal atrophy. The ejaculate was duly examined and a complete absence of spermatozoa and spermatids was confirmed, with only bacteria and debris being found. Testicular sperm extraction (TESE) was then performed. In 19 out of 36 cases round spermatids only were found, while elongated spermatids were found in the remaining 17. Both round and elongated spermatids were isolated and used for injection. A total of 135 oocytes at metaphase II were recovered from 19 partners and injected with round spermatids, while 123 mature oocytes from 17 partners were injected with elongated spermatids. The number of oocytes fertilized, as judged by the presence of two pronuclei, was 75 (55.5%) and 71 (57.7%) respectively. By 34 h after injection, the number of embryos which had cleaved to the 2-cell stage was 56 (74.6%) with round spermatids and 55 (77.4%) with elongated spermatids. All cleaved embryos were transferred into the uterus of the partners. Clinical pregnancies were established in two cases of round spermatid cycles (10.5%) (both are still ongoing), and three cases of elongated spermatid cycles (17.6%) (two are still ongoing; one was lost after 8 weeks of gestation). Chromosomal analysis showed that all fetuses had a normal karyotype (three male and one female) with no chromosomal abnormalities.

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