Showing papers in "Human Reproduction in 1993"

High fertilization and implantation rates after intracytoplasmic sperm injection

Abstract: Previously reported better fertilization rate after intracytoplasmic single sperm injection (ICSI) than after subzonal insemination of several spermatozoa was confirmed in a controlled comparison of the two procedures in 11 patients. Intracytoplasmic sperm injection was carried out in 150 consecutive treatment cycles of 150 infertile couples, who had failed to have fertilized oocytes after standard in-vitro fertilization (IVF) procedures or who were not accepted for IVF because not enough motile spermatozoa were present in the ejaculate. A single spermatozoon was injected into the ooplasm of 1409 metaphase II oocytes. Only 117 oocytes (8.3%) were damaged by the procedure and 830 oocytes (64.2% of the successfully injected oocytes) had two distinct pronuclei the morning after the injection procedure. The fertilization rate was not influenced by semen characteristics. After 24 h of further in-vitro culture, 71.2% of these oocytes developed into embryos, which were transferred or cryopreserved. Only 15 patients did not have embryos replaced. Three-quarters of the transfers were triple-embryo transfers. High pregnancy rates were noticed since 67 pregnancies were achieved, of which 53 were clinical, i.e. a total and clinical pregnancy rate of 44.7% and 35.3% per started cycle and 49.6% and 39.2% per embryo transfer. A total of 237 supernumerary embryos were cryopreserved in 71 treatment cycles.

Diagnosis of major chromosome aneuploidies in human preimplantation embryos.

Abstract: A short fluorescence in-situ hybridization (FISH) procedure using fluorochrome and digoxigenin labelled DNA probes was developed for application in human preimplantation embryos in order to analyse the five chromosomes most involved in human aneuploidy (X, Y, 18, 13 and 21). The chromosomes were fluorescent-stained and detected simultaneously in 157 blastomeres from 30 human embryos. Successful FISH analysis was achieved in 93% of the blastomeres. Aberrations for these chromosomes were found in 70% of abnormally developing monospermic embryos. The majority of normally developing monospermic embryos obtained from older patients were also chromosomally abnormal. By analysing all or most of the cells from these embryos, true mosaicism was distinguished from technique failure. Mosaic embryos, polyploid embryos with ploidies as high as 8n, haploid embryos, embryos monosomic for 13/21 and for X, and embryos trisomic for 13/21 and 18, were common in abnormally developing embryos. In contrast, aneuploidy was the main chromosome abnormality found in normally developing monospermic embryos.

Higher success rate by intracytoplasmic sperm injection than by subzonal insemination. Report of a second series of 300 consecutive treatment cycles

Abstract: Subzonal insemination (SUZI) and intracytoplasmic sperm injection (ICSI) were carried out in 300 treatment cycles in couples unable to be helped by conventional in-vitro fertilization treatment. More oocytes were damaged by ICSI (13.5%) than by SUZI (7.1%). The normal fertilization rate was substantially higher after ICSI (51.0%) than after SUZI (14.3%) and was related to the semen characteristics. The cleavage rate was similar for both procedures (77%). After 217 embryo transfers (72.3% of the treatment cycles) 66 pregnancies were established, i.e. pregnancy rates of 22.0% per started cycle and 30.4% per embryo transfer. So far, pregnancy loss has occurred in 27.3% of the pregnancies, nine healthy children have been born after eight deliveries and 41 clinical pregnancies are progressing uneventfully. Chorionic villus sampling or amniocentesis have been performed in 35 pregnancies and 39 normal fetal karyotypes have been obtained after cytogenetic analysis.

Reproductive performance of women with uterine malformations

Abstract: The fertility problems of 176 patients with uterine malformations [arcuate (n = 40), bicornuate (n = 49), bicornis-bicollis (n = 17), didelphys (n = 15), unicornuate (n = 24), subseptus (n = 14) and septate uterus (n = 17)] and of 28 women with other genital and/or urinary anomalies but with a normal uterus were studied. Ten patients with a uterine anomaly experienced infertility without other causes (6%). 142 women with uterine malformations and 26 with a normal uterus achieved pregnancy, the total number of pregnancies to date being 383 and 47 in these groups respectively. The outcome of the first pregnancy from women with uterine malformations was similar to that of all pregnancies though less significant. Only 53% of pregnancies in women with uterine malformations ended with a child surviving > 7 days, compared to 89% in women with a normal uterus. The poorest viability results were found in the bicornuate (40%) (47% of pregnancies in this group ended in early abortions), arcuate (45%) and septate uterus groups (59%). The rates of children surviving > 7 days were around 70% in the bicornis-bicollis, didelphys, unicornuate and subseptus uterus groups. Metroplasty in four cases corrected the infertility or repeated abortions in three patients. Cerclages (21) in 14 women increased the live birth rate from 21 to 62%. These results confirm earlier reports that patients with uterine malformations have higher rates of reproductive loss, pre-term delivery, breech presentation and complications that increase obstetric intervention and perinatal mortality. Moreover in our study, pregnancy outcome was poorer in the bicornuate and arcuate uterus groups than in the septate group.(ABSTRACT TRUNCATED AT 250 WORDS)

Cryopreservation of mouse and human oocytes using 1, 2-propanediol and the configuration of the meiotic spindle

Abstract: Human and mouse oocytes were cryopreserved by a slow freeze, rapid thaw method, using propanediol (PROH) as the cryoprotectant. A simulated cryopreservation was also included in the study to detect the level of damage attributable to the PROH alone. Comparison of the mouse and human oocytes cryopreserved by the same method showed opposing results, with a poor morphological survival rate of 4% observed for mouse oocytes and a subsequent normal fertilization rate of 0%. In 171 cryopreserved human oocytes a higher survival rate of 64% was achieved, and this showed more similarity to the mouse pronuclear oocytes survival of 53%. A comparison of human oocytes, cryopreserved within the cumulus and denuded of cumulus and corona prior to cryopreservation, demonstrated a higher survival rate in the denuded oocytes of 69% compared to 48%. A delay prior to cryopreservation of 1 or > or = 2 days had no effect on the immediate survival of oocytes, but culture for a further 24 h after thawing reduced survival, with the day 1 oocytes exhibiting the most dramatic reduction in survival (28%). Using a lectin binding method, abundant cortical granules were observed in all cryopreserved oocytes analysed. The meiotic spindle and chromosomes were examined in cryopreserved oocytes using fluorescence microscopy and 60% of the surviving oocytes had a normal spindle and chromosome configuration.

A prospective randomized comparison of levonorgestrel with the Yuzpe regimen in post-coital contraception

Abstract: A prospective randomized study was conducted at the Family Planning Association of Hong Kong to compare the efficacy of the Yuzpe regimen and levonorgestrel (0.75 mg for 2 doses 12 hours apart) in post-coital contraception. A total of 424 subjects were recruited into the Yuzpe group and 410 subjects into the levonorgestrel group; 77 subjects in the Yuzpe group and 79 subjects in the levonorgestrel group had further acts of intercourse during the treatment cycle. 15 pregnancies (3.5%)occurred in the Yuzpe group and 12 pregnancies (2.9%) in the levonorgestrel group. After excluding the patients who had further acts of intercourse the failure rates in the Yuzpe group and the levonorgestrel group were 2.6 and 2.4 respectively. The incidence of nausea vomiting and fatigue in the Yuzpe group was significantly higher than in the levonorgestrel group. The authors conclude that levonorgestrel is an effective drug for post-coital contraception with a lower incidence of side effects than the Yuzpe regimen. (authors)

Placebo-controlled, double-blind, cross-over trial of glutathione therapy in male infertility.

Abstract: Glutathione therapy was used for 2 months in a placebo-controlled double-blind cross-over trial of 20 infertile patients with dyspermia associated with unilateral varicocele (VAR) or germ-free genital tract inflammation (INF). The patients received either glutathione (group 1) or placebo (group 2) for 2 months, then they crossed over to the alternative treatment for a further 2 months. The patients were randomly and blindly assigned to treatment (one i.m. injection every other day of either 600 mg glutathione or an equal volume of a placebo preparation). The standard semen analysis and the computer-assisted sperm motility analyses were carried out before treatment and during the trial. Statistical cross-over analysis, case-control study and treatment efficacy test were carried out on groups 1 and 2 and differences in the effects of therapy between VAR and INF patients with varicocele or inflammation were tested. Glutathione therapy demonstrated a statistically significant positive effect on sperm motility, in particular on the percentage of forward motility, the kinetic parameters of the computerized analysis and on sperm morphology. The findings of this study indicate that glutathione therapy could represent a possible therapeutical tool for both of the selected andrological pathologies.

Miscarriage rates following in-vitro fertilization are increased in women with polycystic ovaries and reduced by pituitary desensitization with buserelin

Abstract: To assess the risk of miscarriage after in-vitro fertilization (IVF) with respect to age, cause of infertility, ovarian morphology and treatment regimen, a retrospective analysis was performed of the first 1060 pregnancies conceived between June 1984 and July 1990 as a result of 7623 IVF cycles. Superovulation induction was achieved with human menopausal gonadotrophin (HMG) and/or purified follicle stimulating hormone (FSH) together with either clomiphene citrate or the gonadotrophin hormone-releasing hormone (GnRH) agonist buserelin, the latter either as a short 'flare' regimen or as a 'long' regimen to induce pituitary desensitization. There were 282 spontaneous abortions (26.6%) and 54 ectopic pregnancies (5.1%). The mean age of women with ongoing pregnancies was 32.2 (SD 3.9) years compared with 33.2 (SD 4.1) years in those who miscarried, which were significantly different (P = 0.008). There was no relation between the miscarriage rate and the indication for IVF. The miscarriage rate was 23.6% in women with normal ovaries compared with 35.8% in those with polycystic ovaries [P = 0.0038, 95% confidence interval (CI) 4.68-23.10%]. There was no difference in the miscarriage rate between treatment with HMG or FSH. Women whose ovaries were normal on ultrasound were just as likely to miscarry if they were treated with clomiphene or with the long buserelin protocol. Those with polycystic ovaries, however, had a significant reduction in the rate of miscarriage when treated with the long buserelin protocol, 20.3% (15/74), compared with clomiphene citrate, 47.2% (51/108) (P = 0.0003, 95% CI 13.82-40.09%).

Involvement of leukocytes and cytokines in the ovulatory process and corpus luteum function

Abstract: The role of leukocytes and cytokines in ovarian physiology is now established, although the function of each cell type and cytokine remains to be determined in detail. Current knowledge of these effects on follicle development, ovulation, luteinization and luteotrophic process and luteolysis is reviewed. It is possible that further research will help to unravel some of the clinical mysteries in ovarian function, including polycystic ovary syndrome, premature menopause, ovulatory disorders, and luteal phase defect. Furthermore, the increasing use of cytokines and their antagonists in clinical practice may have significant effects upon reproductive function.

A controlled study comparing patients with and without polycystic ovaries undergoing in-vitro fertilization

Abstract: The outcome of in-vitro fertilization and embryo transfer (IVF-ET) was compared in 76 patients with polycystic ovaries (PCO) diagnosed on pre-treatment ultrasound scan, and 76 control patients who had normal ovaries and were matched for age, cause of infertility and stimulation regimen. Despite receiving significantly less human menopausal gonadotrophin (HMG), patients with PCO, as compared with controls, had significantly higher serum oestradiol levels on the day of human chorionic gonadotrophin administration (5940 +/- 255 versus 4370 +/- 240 pmol/l, P < 0.001), developed more follicles (14.9 +/- 0.7 versus 9.8 +/- 0.6, P < 0.001) and produced more oocytes (9.3 +/- 0.6 versus 6.8 +/- 0.5, P = 0.003). However, fertilization rates were reduced in the PCO patients (52.8 +/- 3.4% versus 66.1 +/- 3.4%, P = 0.007). There was no significant difference in cleavage rates. The pregnancy rate/embryo transfer was 25.4% in the PCO group and 23.0% in the group with normal ovaries. There were three high order multiple pregnancies in the PCO group compared with none in the group with normal ovaries. Of the PCO patients, 10.5% developed moderate/severe ovarian hyperstimulation syndrome (OHSS) compared with none of the controls (P = 0.006). Patients with and without PCO undergoing IVF have comparable pregnancy and livebirth rates. However, it is important to diagnose PCO before ovarian stimulation is initiated as these patients are more likely to develop moderate or severe OHSS following IVF-ET.

Human blastocyst grading: an indicator of developmental potential?

Abstract: We have observed marked variation in the in-vitro development of individual human embryos to the blastocyst stage which was poorly associated with the grade of the embryo on the day of transfer (day 2). Therefore we also graded embryos at the blastocyst stage to determine if their development potential can be better predicted at this stage. A total of 41 blastocysts were categorized into three grades depending on their morphology. Various parameters such as hatching, adherence, growth and amount of human chorionic gonadotrophin (HCG) secreted were documented. The number of nuclei in another 34 blastocysts belonging to the three grades were measured. Also morula stage embryos with large vacuoles but no morphological differentiation were included in a separate group called 'vacuolated morulae'. Overall, there was no significant difference between grade 1 and 2 blastocysts as assessed by their development to day 14, cumulative HCG secretion and nuclei counts. Grade 3 blastocysts reflected 'poor' morphology, secreted significantly lower levels of HCG and had significantly fewer nuclei than the other two grades. Vacuolated morulae did not resemble blastocysts in their morphological development, secreted no HCG and had significantly fewer nuclei than grade 1 and 2 blastocysts. This study illustrates the need for selecting blastocysts for transfer to the uterus or for cryopreservation to allow a better assessment of the success of these techniques. In addition, the data will be useful for evaluating the effects of techniques such as co-culture with feeder cells on the development of embryos to the blastocyst stage and beyond.

The ecological context of human ovarian function

Abstract: New methods for monitoring ovarian function have allowed an extension of research venue beyond typical clinical settings to studies of human populations in their natural settings. Such studies have confirmed that patterns of variation in ovarian function with age and energetic factors are general features of human reproductive biology. Age patterns of ovarian function are extremely robust across populations of distinct genetic, ecological and cultural backgrounds. Comparable ovarian responses to energetic stresses are likewise observable in different populations where they arise as correlates of local ecologies rather than as correlates of voluntary patterns of diet or exercise. Maternal age and energetic factors also appear to interact with lactation in the modulation of postpartum, ovarian function. Average levels of ovarian function, however, differ considerably between populations, perhaps correlated with chronic environmental conditions that affect growth, development, and the establishment of adult set-points. Western populations appear to represent an extreme of the spectrum of variation in ovarian function, a fact which may relate to the epidemiology of breast and ovarian cancer.

Transplantation of frozen-thawed mouse primordial follicles.

Abstract: Primordial follicles were isolated from juvenile mouse ovaries and cryopreserved by slow freezing with dimethylsulphoxide as the cryoprotectant. After thawing, approximately 80% of the oocytes and 65% of the somatic cells excluded Trypan Blue dye, indicating that cell membranes were still intact. Frozen-thawed cells were suspended in plasma clots and transplanted to the ovarian bursas of host animals that had been sterilized by oophorectomy. The grafts of frozen-thawed cells reorganized into morphologically distinguishable ovaries which produced signs of oestrogenic activity. After natural mating, host females produced normal offspring that were demonstrated by genetic markers to be derived from the transplanted frozen-thawed primordial follicles.

Ultrastructure of human ovarian primordial follicles after combination chemotherapy for Hodgkin's disease.

Abstract: Ovarian damage, with consequent permanent infertility, is one of the more common side-effects which occurs during chemotherapeutic treatment of patients affected by Hodgkin's disease. This damage is morphologically represented by a marked loss of primordial and primary follicles. The administration of contraceptive drugs before starting chemotherapy enhances survival of a greater number of ovarian follicles, as revealed by morphometric analyses, nevertheless, total ovarian protection is not assured. This study evaluated the number and the morphology of ovarian follicles, by means of transmission electron microscopy, in patients with Hodgkin's disease treated with multi-drug chemotherapeutic protocols following the administration of medroxyprogesterone acetate. Ovarian biopsies were performed prior to any pharmacological treatment, after medroxyprogesterone therapy, and after this therapy plus chemotherapy. Particular attention was given to the ultrastructure of primordial follicles. After morphometric evaluation, primordial follicles were numerous in controls and medroxyprogesterone therapy (28.55 +/- 6.59/mm3 of ovarian cortex). After chemotherapy and medroxyprogesterone acetate, the number of follicles was slightly reduced (19.37 +/- 3.41/mm3 of ovarian cortex) in contrast to the dramatic loss usually observed when protection is not given, although more follicles were atretic. Medroxyprogesterone may protect follicles only from acute, toxic effects of chemotherapy, which dramatically reduce their number and lead to sterility. Nevertheless, the quality of follicles is still impaired, and many undergo atresia, resulting in a shortened fertility period.

Mitochondrial disease and reduced sperm motility.

Abstract: Mitochondrial dysfunction reduces aerobic energy production and results in symptoms from various tissues, depending on metabolic demands. Mitochondrial adenosine triphosphate (ATP) is essential for sperm motility. Sperm motility was investigated in a patient with a mitochondrial disease caused by reduced activity of the mitochondrial enzyme complexes I and IV, and in two control subjects. Spermatozoa were cultured in media containing various energy substrates. Motility was judged by light microscopy, and ultrastructure by transmission electron microscopy. In the patient with mitochondrial disease, 12% of the spermatozoa were motile in the medium containing only glucose. There was a three-fold increase in motile spermatozoa when pyruvate and succinate were present together with glucose. In contrast, the spermatozoa of both control subjects had best motility in the presence of substrates for complex I, and no further increase was observed when succinate was added. Glucose and pyruvate enter the respiratory chain at complex I, and succinate at complex II. Electron microscopy of spermatozoa from the patient with mitochondrial disease revealed mitochondria with increased matrix, thickening of membranes, parallelization of cristae and lipid inclusions, which are characteristic findings in mitochondrial disorders. Abnormal mitochondria were also found in a spermatid, suggesting that the ultrastructural changes of mitochondria are primary rather than secondary to degeneration of the spermatozoa. The results indicate that mitochondrial dysfunction causes reduced sperm motility in some men.

Contraception: Endometrial microvascular density during the normal menstrual cycle and following exposure to long-term levonorgestrel

Abstract: The mechanisms that underlie progestogen-induced endometrial breakthrough bleeding are poorly understood. The aim of the present study was to quantify endometrial microvascular density in 54 controls and 42 women with 3-12 months' exposure to Norplant (levonorgestrel subdermal contraceptive implant) and to correlate it with bleeding pattern, endometrial histology, and peripheral plasma oestradiol and progesterone concentrations. Endometrial biopsies were processed routinely and sections immunostained using anti-CD34 antibody to identify vascular endothelial cells. Menstrual record card data were analysed using World Health Organization definitions. The mean microvascular density (+/- SEM) for control samples was 186 +/- 8 vessels/mm2, and there were no significant differences across the cycle. Norplant user's endometrial microvascular density was significantly elevated above controls (294 +/- 18 vessels/mm2, P = 3.36 x 10(-8)). Endometrial microvascular density in Norplant users did not correlate with oestrogen concentrations prior to biopsy, bleeding patterns or endometrial histology. The results from this study show that women receiving Norplant have significantly increased endometrial microvascular density compared to controls. Another finding from this study was that bleeding in Norplant users often occurred from thin atrophic endometrium. These results provide new insights into the physiological mechanisms that may be involved in progestogen-induced endometrial bleeding.

Avoidance of triplet pregnancies by elective transfer of two good quality embryos

Abstract: Attempts to increase the probability of a successful pregnancy in in-vitro fertilization (IVF) treatment by increasing the number of embryos transferred automatically also increase the probability of multiple pregnancies and their attendant risks. Even where the number of transferred embryos is limited to a maximum of three as in this and other centres, there is a high incidence of twins and triplets. The question therefore arises whether the number of transferred embryos should be further limited to a maximum of two in cases where the prognosis is otherwise good. The only objection to this idea is a possible lowering of pregnancy rate. The present study set out to investigate this question. No significant lowering of pregnancy rate was found, so that limiting the number of transferred embryos to two where the prognosis is otherwise good has now become standard practice in our centre. A good IVF prognosis was defined by the following criteria: first attempt for IVF, less than 37 years old, and good embryo development. From 183 patients fulfilling these criteria, 80 agreed to the transfer of two embryos (group 1) and 103 opted for a triple transfer (group 2). Patient characteristics and embryology results were similar in the two groups. In group 1, 34 patients (42.5%) became pregnant and in group 2, 50 (48.5%). This difference is not significant. Similarly, twin pregnancy rates in both groups were high; eight twin pregnancies (23.5%) in group 1 and 12 (24%) in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Gender preselection in humans ? Flow cytometric separation of X and Y spermatozoa for the prevention of X-linked diseases

Abstract: Human X- and Y-chromosome-bearing spermatozoa were separated based on their DNA content, using modified flow cytometric cell sorting technology. The resulting separation purity of the X-bearing from Y-bearing spermatozoa was evaluated using in-situ hybridization with alpha satellite DNA probes for the X- and Y-chromosomes. In the putative X-enriched-sorted populations, an average of 82% of the spermatozoa showed a hybridization signal with the X probe. Similarly, in the Y-sorted population 75% gave a signal with the Y probe. Sorted X- and Y-bearing spermatozoa were found to maintain their viability for several hours after sorting. These results demonstrate that the human sperm sex ratio can be significantly shifted to favour the selection of female-producing (X) spermatozoa or male-producing (Y) spermatozoa when spermatozoa are flow cytometrically sorted on the basis of DNA content. We propose that flow cytometrically sorted human spermatozoa, used in conjunction with in-vitro fertilization or intra-oviductal insemination, could be used by families who are at risk for X-linked diseases to preferentially produce female offspring. Sorted spermatozoa could also be used to pre-select for male offspring if that were medically indicated.

Early luteal phase treatment with mifepristone (RU 486) for fertility regulation

Abstract: Mifepristone (RU-486) is an antiprogestin which interacts with progesterone at the receptor level. The objective was to determine whether the effects on endometrial development and function and on uterine contractility of immediate post-ovulatory treatment with mifepristone could prevent pregnancy. 21 fertile sexually active women with regular menstrual cycles were treated with a single dose of 200 mg mifepristone 2 days after the luteinizing hormone (LH) surge (LH + 2) on a monthly basis for 1-12 months. The time of the LH peak was determined in the urine by the women themselves using a rapid LH test (Ovu-quick Organon) and this was confirmed later by radioimmunoassay. All the women except one had previously had at least 1 delivery and 1 pregnancy terminated. Each woman measured the urine concentration of LH twice daily starting about 4 days prior to the expected time of ovulation (normally day 10 of the cycle) and continuing until 1 day after the maximum LH concentration. The plasma concentration of progesterone was measured 5 days and human chorionic gonadotrophin (HCG) 2 weeks after the treatment in all cycles. The overall number of cycles studied was 169. In 12 cycles the women were unable to detect the LH peak. The remaining 157 cycles with a detectable LH peak were all ovulatory based on plasma progesterone measurement. 1 pregnancy occurred and was terminated by vacuum aspiration. Based on the time of the LH peak it was retrospectively calculated that in 124 cycles at least 1 act of intercourse occurred between 3 days before and 1 day after ovulation. The probability of pregnancy in this period of the menstrual cycle was thus 0.008. The were no treatment-related side effects apart from slight bleeding for 2-3 days starting a few days after the day of treatment in 35% of the cycles. The effect of mifepristone on the endometrium was sufficient to prevent pregnancy therefore it can be used for contraception.

The ovarian hyperstimulation syndrome in in-vitro fertilization: a Belgian multicentric study. I. Clinical and biological features.

Abstract: 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.

Fertilization and early embryology: The role of calcium in mammalian oocyte maturation and egg activation

Abstract: The maturation of the immature oocyte and the fertilization of a mature egg are two absolute prerequisites for mammalian embryo development. There is increasing evidence in mammals that both oocyte maturation and egg activation at fertilization are controlled by changes in intracellular free Ca2+ levels. The role of Ca2+ changes at fertilization is clear in that they are both required and sufficient for egg activation. However, it is not established how the sperm causes Ca2+ changes in eggs at fertilization, nor how different patterns of Ca2+ change affect embryo development. The role of Ca2+ in triggering oocyte maturation is less clear, although preventing intracellular Ca2+ changes can inhibit meiotic maturation at specific stages. Studies on how Ca2+ regulates meiosis and fertilization in mammals may provide new insights into the causes of failed fertilization in human IVF procedures.

Seasonality of reproductive function and weight loss in rural Nepali women

Abstract: In October-November 1990 and August-September 1991 anthropologists collected saliva samples from 24 17-46 year old nonpregnant nonlactating and normally menstruating Tamang women in a remote village in the foothills of the Himalayas in northwestern Nepal to measure progesterone levels (indicative of ovarian function). They used these levels to determine whether a very heavy workload during the monsoon season and changes in dietary intake affected ovarian function. Anthropometric measurements were also taken. The women served as their own controls. Seasonal changes in body mass ranged from -2.8 kg to 4.8 kg. Mean and mid-luteal progesterone levels fell 27% (104-76 pmol/l) and 38% (138-85 pmol/l) respectively between the winter and monsoon (p < .01). The levels of ovarian function were much lower than those of healthy regularly menstruating Western women and of menstruating Lese women of the Ituri forest in Zaire (mean luteal phase progesterone levels 104 pmol/l vs. 232 pmol/l for Boston women and 140 pmol/l for Lese women). Reduction in progesterone levels was most significant for 24-34 year old women. In fact the reduction in mid-luteal progesterone levels was only significant in this age group (p < .05). Body mass index did not influence progesterone levels regardless of changes in weight or age. Reduced progesterone levels was only significant for women who lost weight between the winter and the monsoon seasons suggesting that energy imbalance is linked to loss of fecundity. Younger women were more likely to gain weight than older women (.6 kg vs. -1.1 kg for middle aged women and -.2 for older women; p < .05). The regression between changes in progesterone levels and degree of weight loss was also significant (p < .01). Between the winter and the monsoon the percentage of ovulatory cycles decreased from 71 to 38%. These findings showed seasonal changes in the fecundity of these women and a direct association between ovarian function and weight loss regardless of current nutritional status.

Centrifugation of human spermatozoa induces sublethal damage; separation of human spermatozoa from seminal plasma by a dextran swim-up procedure without centrifugation extends their motile lifetime

Abstract: While washing of human sperm cells by centrifugation and resuspension is a procedure in widespread use, there have been indications that this procedure per se may be harmful to the cells. The objective of this study was to investigate this question. To this end, a method for the clean separation of motile human spermatozoa from seminal plasma in the absence of centrifugation was developed, using a modified swim-up procedure, in which liquefied semen was mixed with an equal volume of 30 mg/ml dextran in medium, and the mixture overlaid with medium containing 5 mg/ml bovine serum albumin, forming two discreet layers with stable interface. The percentage of motile cells in a given sample was consistently > 80% immediately after recovery. Damage to the cells was assessed by loss of motile cells during incubation up to 96 h post-recovery. Comparison of aliquots of spermatozoa obtained by the dextran swim-up procedure showed that the aliquot subjected to centrifugation had 4 +/- 3% motile cells after 48 h, while the untreated aliquot had 52 +/- 12%. The aliquots showed no difference 1 h post-recovery. Similar results were obtained with spermatozoa that had been centrifuged in seminal plasma and resuspended in fresh plasma, then recovered by dextran swim-up. The delayed onset of motility loss in the centrifuged samples implies that this treatment induces sublethal damage in the cells. Comparison of the standard swim-up and Percoll gradient methods for sperm recovery, both of which involve centrifugation steps, showed decline in motility of the samples similar to that seen with dextran swim-up of centrifuged cells. We conclude that centrifugation per se induces sublethal damage in human spermatozoa, independently of treatment method, and suggest that recovery methods for human spermatozoa which avoid centrifugation might partially alleviate the damage incurred by these cells during cryopreservation.

Sperm numbers and distribution within the human fallopian tube around ovulation

Abstract: This study aimed to determine the number and distribution of spermatozoa within the human Fallopian tubes around ovulation. Parous women, undergoing total abdominal hysterectomy for menorrhagia, were inseminated with either partner's semen (3/10) or donor semen (7/10). Approximately 18 h later both Fallopian tubes were ligatured into ampullary, isthmic and intramural regions. These were removed and assessed for sperm content by flushing, scanning electron microscopy (SEM) or homogenization. A median of 251 spermatozoa were recovered (range, 79-1386). The number of spermatozoa within each tube was not significantly different. The ovulatory ampulla contained a significantly (P < or = 0.01) larger percentage of spermatozoa than the non-ovulatory ampulla. The number of motile spermatozoa inseminated was not significantly correlated to the number of spermatozoa recovered, but a trend was identified. The time between the onset of the luteinizing hormone surge and hysterectomy was significantly correlated (P < or = 0.01) to the number of spermatozoa within the intramural regions, but not to the tubal sperm distribution. Spermatozoa were not observed, by SEM, bound to the tubal epithelium. These data suggest that, after artificial insemination at least, sperm access to the human Fallopian tube may be controlled, but that ovulation does not affect the redistribution of spermatozoa between tubal regions and that the isthmus does not appear to act specifically as a sperm reservoir.

Blastocysts prepare for the race to be male

Abstract: Recent findings in different mammalian species have demonstrated that XY embryos grow faster than XX embryos before the gonads are differentiated. In mice and cattle, accelerated development is already evident in XY blastocysts, while in the rat and in human fetuses a quantitative sex difference has been shown to be present before testicular differentiation has occurred. These data demonstrate that in these species the histological differentiation of the testis, which occurs early and rapidly, is preceded by an increased growth rate of the embryo. This may be expected to increase the probability of the gonad reaching the threshold for testis development, since it is known that developmental delay can result in ovarian differentiation. It is postulated that the fast development of the male may be an adaptation to the reproductive biology of eutherian mammals, in which development of both sexes occurs in the hormonal environment of the uterus. The question is raised as to a possible connection between sex-related growth and other sex differences, such as longevity.

Pregnancy: The increased risk of complication observed in singleton pregnancies resulting from in-vitro fertilization (IVF) does not seem to be related to the IVF method itself

Abstract: Singleton pregnancies resulting from in-vitro fertilization (IVF) seem to have an increased risk of obstetric and paediatric complications. In a retrospective study we compared, during the same period, 162 IVF singleton pregnancies with 263 pregnancies resulting from stimulated cycles (without IVF) and with 5096 natural pregnancies. No significant difference was found between the first two groups concerning complications (i.e. prematurity, low birthweight, small-for-gestational-age and perinatal mortality). The results indicate that an adverse outcome is more common for pregnancies after ovarian stimulation (with or without IVF) compared to natural pregnancies. Therefore the increased risk does not appear to be linked to the IVF method itself but rather to a common factor in these two populations, i.e. population characteristics, underlying infertile status and/or ovarian stimulation.

The effect of dose of mifepristone and gestation on the efficacy of medical abortion with mifepristone and misoprostol.

Abstract: Although it has been demonstrated that a combination of mifepristone and a prostaglandin is an effective method of inducing abortion in early pregnancy, the optimum dose of the antigestogen is unknown. Women (n = 220) requesting abortion in early pregnancy ( 56 days, this combination may result in too many incomplete abortions to be clinically acceptable.

The use of intravenous albumin in patients at high risk for severe ovarian hyperstimulation syndrome.

Abstract: Previous experiences in subjects with other forms of third space fluid accumulation have shown that albumin is efficacious in preventing and correcting haemodynamic instability. Using a similar approach in an effort to increase the serum oncotic pressure and to reverse the leakage of fluids from the intravascular space, high risk subjects for severe ovarian hyperstimulation syndrome (SOHS) were treated with albumin. In a recent large study two high risk factors were identified, i.e. the number of oocytes and levels of serum oestradiol. Thirty-six women undergoing assisted reproductive techniques who presented both these factors, received intravenous albumin at a dose of 5% in Ringers lactate in doses of 500 ml during oocyte retrieval and 500 ml immediately thereafter in the recovery room. Daily measurements of urine output, serum and urine electrolytes, weight, abdominal girth, and haematocrit prior to and after oocyte retrieval revealed normal serum and urine electrolyte levels, and no signs of haemoconcentration. No patient in this study developed SOHS, and of course none had to be hospitalized. Vaginal ultrasound performed in the majority of the subjects revealed < or = 100 ml of peritoneal fluid 48-72 h after oocyte retrieval. The only complication from the use of intravenous albumin was the appearance of a 'flu-like condition' (low grade temperature, nausea and muscle pains) developed by 12 women between days 3 and 5 after oocyte collection. Intravenous albumin had thus prevented the development of severe ovarian hyperstimulation syndrome in an assisted reproduction programme.(ABSTRACT TRUNCATED AT 250 WORDS)

Doubling the human menopausal gonadotrophin dose in the course of an in-vitro fertilization treatment cycle in low responders: a randomized study

Abstract: The effect of doubling the human menopausal gonadotrophin (HMG) dose in the same treatment cycle in which the ovarian response after 5 days of ovarian stimulation with 225 IU/day is 'low', has been evaluated in a prospective randomized study. Forty-six patients met the ultrasound and oestradiol criteria for enrollment in the study, one patient participated twice. In 22 patients treatment was continued with 225 IU HMG/day and in 25 patients the HMG dose was increased to 450 IU/day. No effect of doubling the HMG dose was found on the length of the ovarian stimulation, peak oestradiol values, number of follicles > or = 11 and > or = 14 mm in diameter respectively on ultrasound on the day of HCG administration, number of cancelled cycles, number of oocytes at follicular puncture and the number of patients with < or = 3 oocytes at retrieval. It is concluded that doubling the HMG dose in the course of an IVF treatment cycle is not effective in enhancing ovarian response in low responders. This is in accordance with current theories on follicular growth, which state that follicular recruitment occurs only in the late luteal and early follicular phase of the menstrual cycle.

Insulin-like growth factor (IGF), IGF binding protein (IGFBP), and IGF receptor gene expression and IGFBP synthesis in human uterine leiomyomata.

Abstract: Oestradiol is important in the growth of uterine leiomyomata and may act primarily or secondarily through mediators such as growth factors, including the insulin-like growth factors (IGF-I and IGF-II), mitogenic peptides. IGF binding proteins (IGFBPs) modulate IGF actions at their target cells. The objective of this study was to examine the possible steroid dependence of IGF, IGFBP and IGF receptor gene expression and IGFBP synthesis in uterine leiomyomata, using tissues from women cycling normally and made hypo-oestrogenic by a gonadtrophin-releasing hormone agonist (GnRHa). Using a solution hybridization ribonuclease protection assay, anti-sense RNA probes for IGF-I, IGF-II and beta-actin (control) were hybridized with total RNA isolated from leiomyomata exposed in vivo to a range of serum oestradiol ( >> IGFBP-3 >> IGFBP-5 > IGFBP-2 and was not dependent on the in-vivo oestrogen status. Type I and type II IGF receptor gene expression was investigated by polymerase chain reaction using gene-specific primers. Type I and type II IGF receptor mRNAs were detected in leiomyomata and were not dependent on cycle stage or in-vivo oestrogen status. Explant cultures of leiomyomata and myometrium synthesized IGFBP-3 (mol. wt = 38-43 kDa), IGFBP-4, and binding proteins of mol. wt = 34 and 31 kDa. Identification of IGFBP-2 was inconclusive, and IGFBP-1 was not detected. These data support the hypothesis that IGF-I, but not IGF-II, may be a mediator of oestradiol action in the growth of uterine leiomyomata, and that IGFBPs may further modulate, by an autocrine or paracrine mechanism, IGF-I action in this tissue.