Sorption of Benzene by Y Zeolites Exchanged with Chromic Ions and Protons

The sorption of benzene over a series of CrNaHY zeolites has been measured at 370–530 K. Although neither series of isotherms entirely satisfies the Langmuir or Dubinin model, both formulae give identical values for the saturation limit. The free volumes were found to decrease with increasing H+ or Crn+ ion concentration, and have been related to extra-framework phases. The initial heats of sorption indicate that the affinity of benzene for the different sorption sites varies in the order Na+ > Crn+ ≃ H+. For the sodium-rich zeolites, it was found that the sorption heats increase at temperatures above 430 K.

Uro-retroperitoneum after ultrasound-guided transvaginal follicle puncture in an oocyte donor: a case report

Ultrasound-guided transvaginal follicle aspiration is the standard technique for oocyte retrieval prior to IVF. Complications are rare, but some are potentially serious. We report a case of ureteral injury with acute-onset uro-retroperitoneum in a volunteer oocyte donor. The patient recovered rapidly after ureteral stenting. This case underlines the need for all candidate oocyte donors to receive proper information on serious procedure-related complications.

[Oocyte donation after the bioethics law. Medical, ethical and legal implications drawn form a series of 300 cases at the Tenon hospital]

This is the perfect example of the problems which are the consequences of the actual medicine. We carried out an ovocyte donation study at the Tenon Hospital, in Paris, between 1994 and 1999 involving 177 cryopreserved thawed embryo transfers among 300 recipients. This study enables us to stress the ethical difficulties posed by the so called bioethical laws of 1994. Simultaneously two consequences became clearly evident: a paucity of donors, and the necessity to only transfer frozen embryos due to decree of 1996 upon sanitary security that imposes the quarantine of embryos for six months. On the other hand, the use of this method has yielded important new information regarding embryo implantation and the importance of ovocyte quality that is closely correlated to donor age.

[Therapeutic management of ovarian dystrophy and insufficiency in abortion disorders: recent data]

Many reports suggested that the high rate of miscarriage in women with polycystic ovaries may be due to increased urine and/or plasma LH concentration. In fact, with the exception of pulsatile GnRH, any treatment likely to increase the plasma LH level results in unchanged or rather low miscarriage rates. Conversely, a reduction in this rate by GnRH agonists is not conclusive. Excess weight may also increase the risk of miscarriage. In women with incipient ovarian failure, the miscarriage rate is mainly linked to age. No stimulation has been found to be effective in these patients. There is a need for more extensive evaluation in GnRH analog microdoses, recombinant FSH and GnRH antagonists. Oocyte donations from younger women are difficult to obtain because of the lack of donors in France.

The influence of psychological factors on the outcome of the fertilization step of in vitro fertilization

Our objective was to determine whether psychological factors have an influence on the outcome of the fertilization step of in vitro fertilization (IVF) trials. The design was a prospective cohort study. We studied 48 women and 32 of their spouses. Each subject was assessed psychologically on the day before oocyte retrieval (OR) with the Child Project Questionnaire (CPQ) and the Ways of Coping Checklist. In addition, the State-Trait Anxiety Inventory was filled in by subjects 2 days before OR, and the State form was completed again for 6 additional days. The outcome measure was the success of the fertilization step. Logistic regression analysis was used to test the influence of psychological factors while taking into account the effect of medical and sociodemographic variables. The following variables were found to be statistically significant predictors of fertilization: normal sperm; tubal lesions or occlusion; women's factor II of the CPQ, i.e. Perception of Marital Harmony in the Project to Conceive a Child. We conclude that, even when the influence of biomedical variables is taken into account, the women's Perception of Marital Harmony in the Project to Conceive a Child, is a statistically significant predictor of the success of the fertilization step of IVF.

[Can we define the indications for oocyte donation?]

The outline of oocyte donation's indications is defined in France by the law of the 29 july 1994. A great number of situations do not pose any problem with regard to this principles: gonadal dysgenesis, premature ovarian failure, ovariectomy, castration following chimiotherapy or radiotherapy. However, others indications drive us progressively outside legal limits. What is the normal age of physiological menopause? Which threshold to justify oocyte donation for low responders? Is oocyte donation an alternative for other treatments failures? Ovocyte donation for genetic reason presents a risk of eugenic drift. Answering these questions is uneasy, though it is urgent for our patients to offer them a better uniformity.

[Oocyte donation: psychological and sociological aspects, the clinician's viewpoint]

Among the treatment for medical assisted procreation, oocyte donation presents the more complex implications on psycho-sociological aspects. French law of the 29th July 1994, tries to prevent risk for the principal actors of oocyte donation, but has created new problems: 1) the shortage of donors lengthens the waiting list and reduces the succes's chance, 2) the absence of uniformitybetween different countries opens the door to an international market of the oocyte. Medical progress give new possibilities for situations that presented no problem in the past, for instance, pregnancies after menopause. Natural markers are questionned, it is too soon to conclude and to mesure all the consequences of our treatment on the well-being of the child, the recipient's couple, and the donor.

[Clinical use of recombinant gonadotropins (FSH, LH, hCG)]

The production of recombinant gonadotropins is independent of urine collection. They have a high specific activity and a better batch to batch consistency than urinary gonadotropins. In our IVF programme 62 normo-ovulatory patients less than 38 years old, with tubal or idiopathic infertility and normal sperm, were treated by r-FSH and randomized into four groups : with or without LHRH agonist, step-up or step-down stimulation. The overall results were higher in the agonist groups, but did not reveal any significant difference between step-up and step-down stimulation.

[Oocyte donation -- embryo donation]

From 1993 to 1995, 82 donors have permitted the retrieval of 810 oocytes allowing to obtain 411 embryos. 95 receiving couples have been included : 30 obtained a pregnancy, 7 abandoned and 38 are waiting for a transfer. The rate of pregnancies by transfer is superior to the one observed with the transfer of frozen embryos (40.5% versus 27%).

[Oocyte fertilizability and embryo development in poor responders]

Oocyte quality (atresia, immaturity), fertilizability, the incidence of abnormal fertilization (parthenogenesis, triploidy) and embryo development (rate of division and morphology) are similar in poor and normal responders. Only, the small number of available embryos (0.9/patient vs 4.4) penalize these patients.

[Influence of infertility etiology and follicular stimulation protocols on pregnancy outcomes by in vitro fertilization]

During a retrospective study on 152 singles pregnancies obtained by in vitro fecondation at Tenon hospital, and followed in this department between January 1990 and December 1994, we have studied the influence of the IVF (tubal origin, masculine or idiopathic) and the type of stimulation (human menopausal gonadotrophin: hMG or follicle stimulating hormone: FSH) on the weight of the newborn and the pathologies that occurred during the pregnancy. No difference in the antecedents has been found in the different group of patients. This study shows a significative difference (p < 0.001) of the newborn's weight when the indication of IVF is tubal origin or masculine. Also, in all IVF indications, the weight is significantly (p < 0.01) higher after a follicular stimulation by FSH versus hMG. For the pregnancy pathologies, no significative difference has been noted, although arterial hypertension, fetal growth retardation and gestational diabetes appear to be more frequent in the group of women who had stimulation by hMG.

Psychological aspects in anonymous and non-anonymous oocyte donation

A study, in which 110 patients were screened by a psychoanalyst, included 69 recipients who chose non-anonymous oocyte donation, i.e. they received oocytes from a known donor, most frequently a sister or a close relative. Another 41 recipients received anonymous oocytes, but had to bring a donor. Psychological motivations for either choice are reported, and significant topics such as attitudes towards confidentiality and links to the child are compared. No specific psychopathology is reported at this stage. An additional study on children born by these techniques is ongoing.

[Hyperstimulation for in vitro fertilization with the "step-down" technique. Preliminary results from a prospective randomized study with and without LHRH agonists]

Twenty six normo-ovulatory patients < 38 years with tubal or idiopathic infertility and normal sperm were treated for IVF by FSH +/- hMG and randomized into four groups: with and without LHRH agonist, "step-up" or "step-down" stimulation. In the step down protocol, after 4 days with 4 amps plasmatic FSH reached its top level, then decreased. Despite reduction to only two amps, estradiol continued to increase in all the 5 women without agonist, whereas 3/7 with the long protocol were considered as low responders and stopped. The fertilization/cleavage rate was 69.2% in step-down and 45.7% in step-up (p < 0.04) with the short protocol, and respectively 65.6% and 41.9% (p < 0.03) with the long one. The pregnancy rate was equivalent in all groups.

Is there an indication for embryo reduction?

The selective reduction of embryos in multiple pregnancies poses numerous medical, technical, ethical and psycho-social problems. In a retrospective study, we analysed nine hundred and twenty-two pregnancies obtained using medically assisted procreation between May 1982 and May 1990. Among 922 successful pregnancies, 372 were singleton, 102 were twin and 13 were triplet. Data from this analysis and from a French multicentre study of 262 embryo reduction procedures demonstrated the value of an embryo quality score for minimizing the risk of multiple pregnancy and the existence of extremely infrequent, ethically acceptable indications for embryo reduction. These indications included ultrasound-proven malformations of one fetus, multiple pregnancies in patients with extensive uterine scarring, and multiple pregnancy despite the appropriate use of preventative measures which can be expected to make this technique unnecessary in the future.

Hormonal secretions in singleton pregnancies arising from the implantation of fresh or frozen embryos after oocyte donation in women with ovarian failure

OBJECTIVE

To determine whether levels of human chorionic gonadotropin (hCG), 17 beta-estradiol (E2), and progesterone (P) are different in the peri-implantation phase of fresh versus frozen embryos.

DESIGN

Hormonal secretions were measured on days 9 and 11 after implantation and at 4, 5, and 6 weeks gestation.

PATIENTS

Thirty-one pregnancies were achieved in 65 patients with ovarian failure. Seventeen singleton pregnancies developed after implantation of 4 frozen and 13 fresh embryos.

RESULTS

Human chorionic gonadotropin and E2, contrary to P, were higher in cases of fresh embryos from the 9th day after transfer to the 5th week at which time they become statistically significant (respectively, for hCG and E2, 5,800.3 +/- 332.3 versus 2,027.3 +/- 916.3 [mean +/- SD] mIU/mL for hCG and 562.3 +/- 215 versus 291 +/- 152 pg/mL for E2).

CONCLUSIONS

This difference might be explained by either the higher number of fresh embryo replaced or by the fact that the number of blastomeres and also their metabolic activity could be reduced after freezing and thawing.

Obstetric evolution of pregnancies obtained from donated oocytes

Of 44 pregnancies obtained at the Tenon Maternity Hospital by in vitro fertilization (IVF) using donated oocytes, 25 have already been completed by spontaneous delivery or cesarean section: 22 (88%) single; 2 (8%) twins, and 1 (4%) triple. The most frequently seen complications of pregnancy were hypertension (16%) and preterm labor in the last 3 months (12%). However, as compared to a control group of 275 pregnancies resulting from classical IVF, the only difference was a very high percentage of cesarean sections (72%). No fetal deaths or neonatal malformations were reported.

Comparison of plasma and follicular fluid hormone profiles following stimulation with HMG, with or without LHRH agonists, for in-vitro fertilization

Plasma and follicular fluid (FF) hormone assays for follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), oestradiol (E2), progesterone (P), delta-4-androstenedione (A4) and testosterone (T) were performed on the day of oocyte retrieval in two groups of normo-ovulatory women enrolled in an in-vitro fertilization (IVF) programme: 24 were treated using the decapeptyl agonists DTRP6, of luteinizing hormone-releasing hormone (LHRH) in the long protocol associated with human menopausal gonadotrophin (HMG) (49 FF) and 14 were stimulated with HMG alone (33 FF). In both FF and plasma the mean concentration of P was greater, and the E2/P ratios as well as the LH levels were lower in the agonist-treated group. In this group the follicular concentration of P was greater and the E2/P ratio lower when pregnancy occurred following IVF. The hormonal modifications may be due to greater functional maturity of the granulosa cells.

A multiparametric analysis of endometrial estrogen and progesterone receptors after the postovulatory administration of mifepristone

A double-blind randomized study was performed in two groups of eight normally cycling patients: group I received 10 mg/d of RU486 for 4 days from the date of ovulation and group II received a placebo. On day +5, cytosol and endometrial estrogen receptors (ERs), and progesterone receptors (PRs) were analyzed by radioligand binding assay as well as by enzyme immunochemistry. Histologic studies showed that all the endometria of group I were abnormal (luteal insufficiency and/or E/P imbalance). The nuclear PR levels were significantly higher in group I (843 +/- 422 fmol/mg) deoxyribonucleic (DNA) compared with 482 +/- 232 fmol/mg DNA in group II. Immunohistochemical study showed that ER and PR staining was higher for both glands and stroma in group I (52% and 72% for the respective receptors), compared with the receptor-immunostained surface observed in group II, which was reduced to 40% for ER and to 4% for PR. This study demonstrates that RU486 administered in the immediate postovulatory period blocks normal tissue evolution in the follicular phase as well as the processing of PR.

[Oocyte and embryo donations]

Oocyte donation was introduced in 1983 either to treat infertility due to the absence of ovocytes (gonadal dysgenesis, premature menopause, etc.) or to avoid the risk of genetic disease transmitted by ovocytes. Practical problems have been solved by using substitutive treatments including natural steroids and by freezing embryos that are not synchronous with the recipient. However, ethical problems are more delicate and notably, they raise the issue of non-anonymous donation. A review of the literature shows that up to now 327 transfers have been performed, with a 24 p. 100 rate of maintained pregnancy.

Ovarian stimulation using human menopausal gonadotrophins with or without LHRH analogues in a long protocol for in-vitro fertilization: a prospective randomized comparison

In order to evaluate the exact role of GnRH agonists, we have undertaken a randomized prospective study comparing two groups of 90 normo-ovulatory patients, aged less than 38 years and with tubal infertility with no male factor. Luteinizing hormone releasing hormone analogue (DTRP6 administered in a long protocol, for at least 15 days) was associated with human menopausal gonadotrophin (HMG) induction in group I. In group II, stimulation was performed using HMG alone (three ampoules per day in general, from days 2 to 7 of the cycle). Apart from the well known results demonstrated in the literature of a reduced incidence of inadequate responses, an absence of premature luteinization and a greater number of oocytes per retrieval (8.8 +/- 4.9 versus 6.8 +/- 3.2, P less than 0.01 in group II), this study confirms the higher pregnancy rate (21.1 versus 12.2% per cycle and 24.7 versus 17.1% per oocyte retrieval, not significant) and underlines the higher plasma progesterone levels and lower E2/P ratio in group I from D - 1 to D + 5, which could explain a better maturation of the oocytes and the endometrium.

Pregnancies following ovum donation in gonadal dysgenesis

Between February 1987 and February 1989, 13 women with primary ovarian failure due to gonadal dysgenesis were treated with embryo transfer following ovum donation in 22 cycles. Eight pregnancies were obtained (36.7% per transfer); four births of normal children, two spontaneous abortions and two other pregnancies currently ongoing (between 5 and 8 months). An association of percutaneous oestradiol, oestradiol valenate and intravaginal progesterone was used as hormone substitution and embryo transfer was only performed following assessment of the endometrium during a previous cycle. Apart from the day of embryo transfer, which was the same for all patients (the 2nd day after initiation of progesterone) various prognostic factors were analysed. These were the type of gonadal dysgenesis (45 XO, 46 XX or 46 XY), the number of embryos replaced, whether they had been frozen, whether the egg donor was anonymous and finally the influence of the hormone substitution protocol. Only the number of embryos replaced and the substitution protocol seemed to influence the implantation rate. The other parameters, and in particular the type of gonadal dysgenesis, seemed to have no effect on the results. The pregnancy rate per transfer was 30% for 45 XO (10 transfers), 25% for 46 XX (eight transfers) and 75% for 46 XY (four transfers).

Treatment of hyperstimulation during in-vitro fertilization

In 33 patients treated with a combination of an LHRH agonist (LHRH-A) and gonadotrophin in a long protocol, a biological hyperstimulation occurred (E2 greater than 2500 pg/ml on the day of HCG administration and 4722 +/- 1190 pg/ml the day after, with greater than 10 follicles greater than 12 mm on each ovary). The replacement of fresh embryos were deferred and LHRH-A was continued, and an endometrial biopsy was performed on the theoretical day of replacement (2 days after oocyte recovery). With this technique, we obtained a mean number of 17.9 +/- 7 oocytes, a fertilization rate of 49% and a replacement rate of 87% in a deferred cycles. The overall pregnancy rate of frozen-thawed embryos was 27% in the seven spontaneous cycles, 12 induced cycles and 10 artificial cycles. Only one severe hyperstimulation occurred and this case emphasizes that caution remains necessary even with this technique.

[Treatment of ovarian polycystic syndrome in vitro. Physiopathogenetic considerations]

More than 60% of patients with polycystic ovary disease (PCO) cannot conceive after repeated ovulation inductions with Clomifene citrate although there is ovulation or more frequently follicle luteinization. Because of hyperstimulation, therapy with hMG has been superseded by low doses of purified FSH with variable results according to authors. It has been even claimed that there was no benefit to replace hMG with FSH. However, on the basis of the PCO physico-pathology, namely LH hypersecretion and androgen hyperproduction, it would be rational to associate the desensitization of the pituitary with LH-RH agonist and the ovary stimulation with variable doses of hMG or purified FSH. In the series where such therapy associating LH-RH agonists with purified FSH was applied, the results concerning suppression of LH and androgen secretion, and the occurrence of pregnancy were interesting. However, the risk of hyperstimulation still occurred. Thus, the first part concerns the critical review of these results while, in the second part, our experience in in vitro fecundation will be reported.

[Evaluation criteria of the condition of the endometrium in relation to the presence of ovocytes]

18 patients with ovarian failure received cyclic steroid replacement therapy including estrogens and progesterone for embryo transfer. Hormonal results and endometrial histology are reported. The temporal window of endometrial receptivity 13 discussed, shedding some light on the respective role of embryo and endometrium in the implantation process.

Programmed ovulation induction and oocyte retrieval for in vitro fertilization

Forty-two patients underwent programmed ovulation induction for oocyte retrieval. They were treated in the preceding cycles with a progestagen, ethynodiol diacetate, at a dose of 2 mg twice daily. Two groups were defined based upon the stimulation protocol: Group A1 was stimulated with clomiphene citrate and human menopausal gonadotropin (hMG), and Group A2 with follicle-stimulating hormone (FSH) and hMG. They were compared to two randomized control groups of patients who received the same induction but were classically monitored. There was a high proportion of spontaneous ovulations in the programmed group (8/42) compared to the nonprogrammed group (0/42). There was a nonsignificant difference in the number of oocytes obtained or embryos replaced per cycle. Four pregnancies were obtained in the programmed group (24% per transfer), against 10 in the nonprogrammed patients (32% per transfer). The results of this method seem to be better using FSH for ovulation stimulation and a verification of the serum estradiol on the day of induction with human chorionic gonadotropin (hCG) and the following day (semiprogrammed method).