Low intraovarian vascular resistance: a marker for severe ovarian hyperstimulation syndrome

OBJECTIVE

To assess intraovarian blood flow in relation to the severity of ovarian hyperstimulation syndrome (OHSS) after controlled ovarian hyperstimulation.

DESIGN

A prospective study.

SETTING

Monash IVF, Clayton, Victoria, Australia.

PATIENT(S)

Thirty patients with OHSS after embryo or gamete transfer who also had sonographic evidence of ascites.

MAIN OUTCOME MEASURE(S)

The resistance to blood flow within the ovaries of 11 patients with severe OHSS and 19 patients with mild OHSS was measured by using transabdominal ultrasonography with color flow and pulsed Doppler imaging.

RESULT(S)

The pulsatility index (PI), resistance index (RI), and the S-D ratio, all measures of downstream vascular impedance, were significantly lower in those patients with severe OHSS. In cases with RI < 0.48, more than two thirds of the patients had a pleural effusion, whereas patients with either PI < 0.75 or S-D < 1.92 had pleural effusion in over one half of the cases. It was notable that blood flow velocity did not differ significantly between the two groups despite the changes in vascular impedance.

CONCLUSION(S)

There appears to be a close correlation between the severity of OHSS and the resistance to blood flow within the stimulated ovaries. Measurement of intraovarian vascular resistance before gamete transfer or ET in patients undergoing controlled ovarian hyperstimulation may help in predicting those patients at particular risk of developing severe OHSS.

A simple technique to quantify human sperm-zona pellucida binding assays

A simplified method for assessing the degree of sperm-zona pellucida binding was developed. The zonae pellucidae of salt-stored, failed-fertilized human oocytes were each inseminated with between 1 x 10(5) and 1 x 10(6) motile spermatozoa/ml, prepared by a direct swim-up method from 11 individuals with normal sperm counts, as defined by the World Health Organization. Following 4 h of incubation at 37 degrees C in humidified air, the zonae pellucidae were 'washed' by vigorous pipetting to remove any loosely attached spermatozoa. The zonae were then placed individually in microwells and dissolved by exposure to acidified (pH < 2.0) medium to form a fluid monolayer. The slides were sealed and the number of spermatozoa in the monolayer counted by each of three observers within 24 h. There was good agreement in the counts between the different observers, with a mean coefficient of variation of only 7.4% and a range of 1.8-16.7%. It was notable that the highest coefficients of variation occurred at the extremes of sperm numbers and that the results were stable overnight. The method is also able to identify observer bias within this variation, indicating the potential for improvements in assay performance. The technique reported has the advantage over current sperm-zona pellucida binding assays of allowing the determination of the precise number of spermatozoa bound to a zona pellucida while producing a slide which remains stable overnight.

Spermatozoa selected by a discontinuous Percoll density gradient exhibit better motion characteristics, more hyperactivation, and longer survival than direct swim-up

OBJECTIVE

To determine if a discontinuous Percoll density gradient selects spermatozoa with different motion characteristics than direct swim-up.

DESIGN

Controlled prospective study of the effect of two preparation techniques on spermatozoa from normal semen samples using computer-aided sperm analysis (CASA).

SETTING

The Fertility laboratory, Queen Charlotte's Hospital, London, United Kingdom.

PATIENTS

Eighteen male patients.

INTERVENTIONS

Semen samples were divided into two equal parts. The first part was prepared by a direct swim-up whereas the other half was subjected to a three-layer discontinuous Percoll density gradient centrifugation. The separated samples were then examined at 30 minutes and 3, 6, and 24 hours by CASA.

RESULTS

Although swim-up selected a higher proportion of motile spermatozoa, Percoll produced a greater yield of motile cells. Straight line velocity was similar for both methods throughout study. In contrast, spermatozoa isolated by Percoll exhibited a significantly higher curvilinear velocity and amplitude of lateral head displacement, which lasted for > or = 6 hours. These changes were accompanied by a significant reduction in linearity of progression. The most dramatic effect of Percoll was to produce significantly greater numbers of spermatozoa expressing hyperactivation. After both swim-up and Percoll there was a decline in progressive motility over the 24 hours, although this was only significant for swim-up.

CONCLUSIONS

In normal semen, a discontinuous Percoll density gradient selects spermatozoa with better motion characteristics, more hyperactivation, and improved longevity compared with direct swim-up. In view of the relationship between sperm motion characteristics and fertilizing ability, we conclude that the three-layer discontinuous Percoll density gradient be adopted as the preferred method for the preparation of spermatozoa for assisted reproduction.

The variable effects of 2'-deoxyadenosine on human sperm motility and hyperactivation in vitro

The response of human sperm motility and hyperactivation to the stimulant 2'-deoxyadenosine (2'-DEA) was studied in vitro using computer-assisted sperm motion analysis. A total of 20 randomly selected individuals with normal sperm counts as defined by the World Health Organization were chosen and their migration-separated spermatozoa exposed to a range (0.1-10.0 mM) of concentrations of 2'-DEA. The straight line velocity (VSL) was increased above control values only at 0.1 mM, while the curvilinear velocity (VCL) and lateral head displacement (ALH) were increased significantly at all concentrations. Linearity of progression (LIN), on the other hand, declined with increasing concentration of 2'-DEA. These changes were related to a significant increase in the number of spermatozoa exhibiting hyperactive-like motion. There was, however, considerable intra-individual variability in the response to 2'-DEA. In some individuals VCL and ALH exhibited little or no response to 2'-DEA, whilst in others an increase above the control of 50-55% occurred. The maximum response for VCL and ALH occurred at 2.5 mM 2'-DEA. Individuals showed greater variability in the percentage of spermatozoa exhibiting hyperactivity in response to 2'-DEA, with increases ranging from 76 to 948% of the control value, although the maximum response was also most commonly seen at 2.5 mM 2'-DEA. The diversity of response to 2'-DEA emphasizes the importance of tailoring doses to the individual rather than employing one concentration for all. Further tests on a subgroup of the individuals examined the longevity of spermatozoa in response to 24 h of continued exposure to 2'-DEA.(ABSTRACT TRUNCATED AT 250 WORDS)

Variability of human sperm response to immediate and prolonged exposure to pentoxifylline

Pentoxifylline improves some motility characteristics of human spermatozoa, but the variability of response to this drug has not been clearly defined. We used computer-assisted sperm motion analysis to examine the in-vitro response of spermatozoa to pentoxifylline. Individuals (n = 31) with normal sperm counts were randomly selected and their spermatozoa exposed to different concentrations of pentoxifylline. Further tests on a subgroup of individuals examined the longevity of spermatozoa in response to this agent. Straight line velocity (VSL) was only improved at 0.1 mM and the major effect of the drug was on curvilinear velocity (VCL) and lateral head displacement (ALH). Prolonged exposure to pentoxifylline enhanced sperm motion only at 0.1 mM. Higher concentrations produced dose-dependent detrimental effects on all the motion characteristics. There was considerable inter-individual variability in both VCL and ALH response ranging from little or no detectable response to a 40% increase above control value. The maximum response was most commonly seen at a concentration of 2 mM pentoxifylline.

Fetal outcome in mothers with impaired glucose tolerance in pregnancy

A 75 g oral glucose tolerance test was carried out on 953 pregnant women who were identified on the basis of clinical risk factors. The tests were analysed by the WHO criteria: 826 were normal, 120 showed impaired glucose tolerance, and 7 identified diabetes. A number of obstetric and perinatal outcome measures were compared between the groups with normal and impaired glucose tolerance, and also with 135 women who had pre-existing Type 1 diabetes and delivered during the study period. There was no significant difference in the incidence of antenatal complications between mothers with normal and impaired glucose tolerance. There was a higher rate of induced labour (p < 0.05) and caesarean section (p < 0.01) in the impaired glucose tolerance group compared to the normal group, but no difference in fetal outcome or neonatal morbidity. All of these outcome measures were increased in the Type 1 diabetic pregnancies.

Effects of pentoxifylline on human sperm motility in normospermic individuals using computer-assisted analysis

OBJECTIVE

To determine if pentoxifylline has an in vitro effect on human sperm motility in subjects with normal semen analysis.

DESIGN

Prospective, longitudinal study of the effect of pentoxifylline on normospermic semen samples using computerized analysis.

SETTING

The Assisted Conception Unit, Royal Maternity Hospital, Belfast.

SUBJECTS

Eight healthy male volunteers of proven fertility within 2 years of study and whose general health was unchanged in the intervening period.

RESULTS

Pentoxifylline did not consistently increase the number of progressively motile sperm or their straight line velocity (VSL). In marked contrast, the curvilinear velocity (VCL) was increased significantly at all times, up to and including 240 minutes of exposure to the drug. This resulted in a substantial reduction in the linearity (VSL/VCL) of sperm progression. The most dramatic effect that pentoxifylline had on sperm movement was to increase the amplitude of lateral head displacement (ALH) over the same time interval. This change was accompanied by an increase in the beat cross frequency.

CONCLUSIONS

The addition of pentoxifylline to prepared sperm samples from normospermic men does not increase the number of progressively motile sperm nor the progressive velocity. However, it does significantly alter the quality of certain characteristics of already motile sperm.