Ovarian hyperstimulation syndrome (OHSS) is a rare iatrogenic complication of ovarian stimulation occurring during the luteal phase or during early pregnancy. Fortunately, the reported prevalence of the severe form of OHSS is small, ranging from 0.5 to 5%. Nevertheless, as this is an iatrogenic complication of a non-vital treatment with a potentially fatal outcome, the syndrome remains a serious problem for specialists dealing with infertility. The aim of this literature review was to determine whether it is possible to identify patients at risk, and which preventive method should be applied when an exaggerated ovarian response occurs. Data pertaining to the epidemiology and prevention of OHSS in women were searched using Medline, Current Contents and PubMed, and are summarized. Preventive strategies attempt either to limit the dose or concentration of hCG or to find a way to induce luteolysis without inducing a detrimental effect on endometrial and oocyte quality. The following particular preventive strategies were reviewed: cancelling the cycle; coasting; early unilateral ovarian follicular aspiration (EUFA); modifying the methods of ovulation triggering; administration of glucocorticoids, macromolecules and progesterone; cryopreservation of all embryos; and electrocautery or laser vaporization of one or both ovaries.

The ovarian hyperstimulation syndrome (OHSS) is a rare iatrogenic complication of ovarian stimulation occurring during the luteal phase or during early pregnancy. This complication is unusual as it is not the consequence of a treatment which is vital or mandatory for the patient's health. Nevertheless, it can be accompanied by severe morbidity and may even be fatal. Data pertaining to the clinical course and consequences of OHSS in women and its treatment were searched using Medline, Current Contents and PubMed. To date, only a few studies have collected a large number of cases of OHSS. The clinical course of OHSS may involve, according to its severity and the occurrence of pregnancy, electrolytic imbalance, neurohormonal and haemodynamic changes, pulmonary manifestations, liver dysfunction, hypoglobulinaemia, febrile morbidity, thromboembolic phenomena, neurological manifestations and adnexal torsion. Treatment of the acute phase relies only on an empirical and symptomatic approach. The general approach will be adapted to the levels of severity. Specific approaches such as paracentesis, pleural puncture, surgical approach of OHSS and specific medication during OHSS were evaluated sporadically. More adequate treatment methods would require a better understanding of the underlying pathophysiological mechanisms, to promote an aetiological therapeutic approach. Properly conducted studies, including large numbers of patients are required in order to determine the best method of prevention and management.

The multicentric study regroups 128 cases of the ovarian hyperstimulation syndrome (OHSS) in in-vitro fertilization (IVF) and 256 selected controls. Values of serum oestradiol obtained from different laboratories were found to be normally distributed after logarithmic transformation. Comparative study of clinical and biological characteristics indicates that among OHSS patients (i) mean age was lower; (ii) tubal indications for IVF were less frequent; (iii) polycystic ovary-like conditions (i.e. hyperandrogenism, anovulation, luteinizing hormone/follicle stimulating hormone ratio > 2) were more frequent. OHSS patients displayed ovarian hypersensitivity reflected by higher oestradiol peak concentrations in response to lower dosage of human menopausal gonadotrophin and by a steeper slope of oestradiol increment during stimulation. In these patients, the collection of greater numbers of fertilizable oocytes allowed replacement of more embryos with a good vitality score. Ongoing pregnancy rate was found to be higher among the OHSS patients. The following complications were recorded among OHSS cases: abdominal fluid at echographic examination or clinical ascites (86.7 and 71.1%, respectively); pleural and pericardial effusion (21 and 3%, respectively); haemoconcentration (71.1%); electrolytic disorders (6.2%). Although significantly different between groups, clinical and biological parameters under study showed considerable overlap of their distributions in control and OHSS cases. Therefore, these data must be submitted to discriminant analysis in order to derive a formula predictive of the risk of OHSS.

The aim of this study was to determine whether the presence of a hydrosalpinx influences in-vitro fertilization (IVF) prognosis. Comparisons were made between 69 IVF cycles in 37 patients carrying hydrosalpinges (hydrosalpinx group) and 67 IVF cycles in 41 patients without tubes or surgically sterilized (control group). Twenty-two patients carrying hydrosalpinges underwent salpingectomy or salpingoplasty (operated group); they then underwent 42 IVF trials which were compared with the two former groups. In the hydrosalpinx group, pregnancy rates by oocyte retrieval were 10.1% for clinical and ongoing pregnancies. In the control group, the corresponding pregnancy rates were 23.0 and 21.3% respectively. The implantation rate per embryo was 4.2% for clinical and ongoing pregnancies in the hydrosalpinx group and 11.0 and 10.4% respectively in the control group. The operated group had pregnancy rates of 38.1% for clinical pregnancies and 31.0% for ongoing pregnancies, with implantation rates of 17.4 (clinical) and 14.8% (ongoing) respectively. Pregnancy and implantation rates were statistically lower in the hydrosalpinx group as compared with controls and with the operated group. The differences between control and operated groups were not significant. In conclusion, the presence of a hydrosalpinx is thus associated with poor prognosis in IVF treatment. Surgical correction of such lesions appears to restore high success rates.

The aim of this work was to evaluate the relationship between follicular size at the time of oocyte retrieval, and the subsequent oocyte competence to be fertilized and to develop in vitro. All the obtained oocytes were classified according to the corresponding volume of aspirated follicular fluid. Aspirated volume of follicular fluid <2 ml corresponded to a follicular diameter <16 mm and constituted the small size group. Volume of follicular fluid from 2 to 6 ml corresponded to a diameter from 16 to 23 mm and constituted the medium size group. The large size group contained follicles with diameter >23 mm and corresponded to an aspirated volume of follicular fluid of >6 ml. A progressive and significant increase in the rates of oocytes with a first polar body was observed from the small size group to the other groups and from the medium to the large size group: 75.3, 85.9 and 95.3% respectively. After classical in-vitro fertilization (IVF), significantly better rates of fertilization and development were obtained in the medium size group compared to the two other groups. Moreover, a positive relationship was observed between follicular diameter and rates of embryos scored as 'good' when oocytes were fertilized by intracytoplasmic sperm injection (ICSI). These results demonstrated that follicular size is positively related to the oocyte ability to be fertilized and to develop. Although oocytes from small follicles gave lower percentages of development probably due to partial oocyte incompetence, they allowed an increase in the total number of embryos scored as 'good'.