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Biomedical subjects

F Zegers-Hochschild

Publications and source records attributed to F Zegers-Hochschild.

At least 19 recordsLinked to original sources
PubMed2006

Deficient expression of monoamine oxidase A in the endometrium is associated with implantation failure in women participating as recipients in oocyte donation.

Successful implantation depends both on the quality of the embryo and on the endometrial receptivity. The latter depends on progesterone-induced changes in gene expression, a process that has been characterized by microarray analysis. One of the genes whose transcription appears to be enhanced during the receptive period is monoamine oxidase A (MAO-A). Our first objective was to confirm the increased expression of MAO-A in the endometrium during the receptive phase of spontaneous normal cycles using real time PCR and immunofluorescence. The second objective was to examine the endometrial expression of MAO-A during the receptive phase induced by exogenous estradiol (E(2)) and progesterone in patients whose endometrium was shown to have been either receptive or non-receptive to embryo implantation in repeated cycles of oocyte donation. Results showed that MAO-A transcript levels increased between the pre-receptive (LH+3) and receptive phase (LH+7) in all spontaneous cycles examined, with a median increase of 25-fold. Immunofluorescent labelling demonstrated MAO-A localization to the glandular and luminal epithelium with an increasing positive score between LH+3 and LH+7. Conversely, prior failure of embryo implantation was associated with a 29-fold decrease in MAO-A mRNA levels and a substantial reduction in MAO-A protein immunofluorescent label score. These results show a strong association between endometrial receptivity and MAO-A expression in the endometrial epithelium, suggesting an important role for this enzyme in normal implantation.

Adult↗
PubMed2005

Influence of embryonic conditioned media upon the endometrial beta-adrenergic receptor.

The main objective of this study was to evaluate the influence of the products secreted by the human embryo upon the three subtypes of beta-AR (beta1, beta2, beta3). Cell cultures were developed using endometrial biopsies, taken on day 7 after ovulation, from four healthy women <35 years of age, with regular cycles and infertility due only to male factors. Embryos from women with a normal uterine cavity and endometrial lining were incubated until they reached the 4-cell stage, before being transferred to their mother's uterus. Culture media for embryo incubation were derived from two groups: (i) embryos that achieved pregnancy, (ii) embryos which failed to implant. Control and experimental endometrial cell culture plates were treated with the two embryo culture media, with or without 10(-9) mol/l oestradiol and 10(-7) mol/l progesterone for 48 h. Expression of the three subtypes of beta-AR was assessed by RT-PCR. Beta1-AR was expressed in both control and experimental plates; beta2-AR was expressed only in plates incubated with embryonic culture media of embryos which achieved pregnancy, in both hormonal conditions, with or without oestradiol and progesterone. Beta3-AR was not expressed in any condition. Thus secretory products of human embryos may influence gene expression of beta2-AR concentrations in the human endometrium, and this subtype of beta-AR may be involved in implantation.

Adult↗
PubMed2004

Multiple gestation as a marker of reproductive efficacy: learning from assisted reproductive technologies.

This study postulates that apart from the number of embryos transferred, women with multiple gestation represent a subgroup of highly fertile individuals, whose embryos implant with higher efficiency than women with single gestation. Furthermore, each embryo generated from these women has a higher chance of reaching full term. The objective of this study was to compare implantation rate with the outcome of pregnancy (up to week 20) in multiple gestations following assisted reproductive techniques. The study group comprised 162 women with multiple gestation after assisted reproduction, followed prospectively with at least three ultrasound examinations performed between weeks 5 and 20 after the last menstrual period. Control group A comprised 344 fertile women with spontaneous single pregnancy followed with transvaginal ultrasound. Control group B consisted of 317 infertile women conceiving with single gestation after assisted reproduction and followed prospectively as in the study group. Embryo implantation rate and spontaneous embryo/fetal reduction, either partial or total (abortion), were registered in each case. Overall implantation in women with multiple gestation was higher (54.6%) than in the corresponding controls (25.6%). Furthermore, spontaneous embryo/fetus reduction was similar in the study cases and in fertile women (12.6 and 10.8% respectively) and significantly smaller than in the control group B (20.8%). Women with high reproductive efficacy exposed to assisted reproductive techniques generate cohorts of good quality embryos, with a high chance of implantation and of reaching birth.

Abortion, Spontaneous↗
PubMed2001

Results of assisted reproduction techniques in Latin America.

The fact that today it is possible to write a comprehensive report on assisted reproduction technologies in Latin America is the result of a serious and systematic effort, accomplished by more than 80 centres, from Mexico to Chile. Over the past 10 years, these centres representing the vast majority of assisted reproductive treatment cycles performed in Latin America, have agreed voluntarily to report their work to our regional registry using a pre-established format. Furthermore, during 1999 and part of 2000, all centres were visited by a team of biologists and clinicians, who evaluated for consistencies in the data reported. This activity also included an evaluation of personnel, facilities, etc. It can be proudly said that the data reported are a true reflection of the actual situation in our region.

Journal Article↗
PubMed2000

Selection of the most common chromosome abnormalities in oocytes prior to ICSI.

So far, all preimplantation genetic diagnosis (PGD) protocols in use produce results after the eggs have been fertilized. However, these approaches are not acceptable for patients with moral objections to the generation and discard of supernumerary zygotes or embryos. In these circumstances, only those oocytes to be replaced may be inseminated. The purpose of this study was to develop a PGD protocol to diagnose first polar bodies (PBs) prior to Intracytoplasmatic Sperm Injection (ICSI) in order to inseminate only those oocytes found to be chromosomally normal. PB biopsy was performed 1 hour after ovum pick up, and after fixation, the PBs were analysed by FISH and the eggs inseminated by ICSI no later than 7 hours after retrieval. One third (33.3%) of the PBs were aneuploid. Fifty-four normal and 12 non-resolved oocytes were injected by ICSI, of which 65% became 2-PN zygotes. Embryo transfer on day 2 was possible in all 10 patients (average maternal age 35.2+/-3.2, range 29-39 years), of which 6 became pregnant with 8 fetuses (28.6% or 8/28 transferred embryos). The results indicate that PB analysis of some common chromosome abnormalities is feasible within time limits imposed by ICSI insemination (6 hours or less).

Adult↗
PubMed2000

Prospective randomized trial to evaluate the efficacy of a vaginal ring releasing progesterone for IVF and oocyte donation.

A polysyloxane vaginal ring containing 1g of natural progesterone was developed as luteal supplementation for women treated with IVF-embryo transfer and for agonadal women participating in an oocyte donation programme. The ring provides continuous release of progesterone (10-20 nmol/l) for 90 days. The efficacy of this form of progesterone supplementation was evaluated in two multicentre prospective randomized trials. IVF-embryo transfer trial: After oocyte aspiration, 505 women were randomly allocated to progesterone supplementation with vaginal ring or i.m. progesterone (50 mg/day). The clinical pregnancy rate was 36.6% in both groups. Implantation rate was 15.9% in the vaginal ring and 16.0% in i.m. progesterone. Oocyte donation trial: After endometrial proliferation with micronized oestradiol, 153 women were allocated to progesterone replacement with a vaginal ring or i.m. progesterone (100 mg/day). Clinical pregnancy rate was 39.8 and 28.6% respectively. Implantation rate was significantly higher with the vaginal ring compared with i.m. progesterone (19.9 and 11.6% respectively, P = 0.006). The vaginal ring is a novel development which provides continuous release of progesterone for 90 days. In IVF-embryo transfer, its effectiveness is similar to daily i.m. injections. In oocyte donation the ring provides a progestative milieu which improves the implantation rate and eliminates the discomfort of daily i.m. injections.

Adult↗
PubMed1999

Preliminary results on the role of embryonic human chorionic gonadotrophin in corpus luteum rescue during early pregnancy and the relationship to abortion and ectopic pregnancy.

The precise mechanisms by which corpus luteum (CL) function is modulated during early pregnancy are not known. Evidence in failed pregnancies (ectopic, abortions), shows that factors other than human chorionic gonadotrophin (HCG) could be involved in its regulation. The objective of this study was to investigate the dynamics of beta-HCG, progesterone and oestradiol production in early pregnancy and its relation to embryonic quality and topographic localization. Plasma concentrations of progesterone, oestradiol and beta-HCG were studied between days +12 and +21 after an in-vitro fertilization (IVF) embryo transfer in 11 intrauterine pregnancies, 10 intrauterine abortions and seven tubal pregnancies. Tubal pregnancies and abortions were grouped according to doubling time (DT) of HCG. Results showed that oestradiol concentrations were apparently reduced in both ectopic pregnancies and abortions compared with normal pregnancies. The fall in oestradiol concentrations was seen in ectopic pregnancies with an abnormal DT for HCG and in all abortions. When the ectopic pregnancy had a normal DT, oestradiol and progesterone concentrations were normal. In abortions, the fall in oestradiol and progesterone concentrations was less influenced by the DT of HCG. These findings suggest that corpus luteum function depends on an adequate DT of HCG more than an absolute value, and with normal trophoblastic tissue the site of implantation does not affect CL function.

Abortion, Spontaneous↗
PubMed1998

[Dilemmas in assisted reproduction]

Modern reproductive technologies, particularly in vitro fertilization (IVF) and gamete intrafallopian transfer (GIFT), have made possible the establishment of new families through the birth of hundreds of thousands of children worldwide. Meanwhile, these technologies have compelled men to face the possibility of intervening at the very origins of their own biological existence, hence creating doubts and questions beyond the domain of medical science. Society is now asking itself whether all that is scientifically and technically possible is necessarily beneficial to mankind. The answer to this question is not to be found in biological science alone, but instead requires multidisciplinary reflection including all forms of knowledge: philosophical, bioethical, and religious, all contributing to the unavoidable adventure that we are endowed with in the search for a better life.

Journal Article↗
PubMed1998

Comparison of ultrasonography and hysteroscopy in the diagnosis of intrauterine lesions in infertile women.

STUDY OBJECTIVE: To compare the effectiveness of transvaginal ultrasound versus hysteroscopy in the diagnosis of benign intrauterine lesions, with histology as the gold standard. DESIGN: Retrospective study (Canadian Task Force classification II-1). SETTING: Unit of Reproductive Medicine, Department of Obstetrics and Gynecology of Clinica Las Condes, Santiago, Chile. PATIENTS: Infertile women who had undergone complete fertility evaluation. INTERVENTION: Transvaginal ultrasound, hysteroscopy, and histologic evaluation of endometrial samples performed in all 126 women. MEASUREMENTS AND MAIN RESULTS: The most frequent condition was a normal cavity (59.5%), followed by endometrial polyps (34.9%) and fibromyomas (3.9%). Synechiae and bone metaplasia were extremely rare. Sensitivity of transvaginal ultrasound for the diagnosis of endometrial polyps was 95.6% compared with 89.9% for hysteroscopy (NS). Specificity was 97.4% with transvaginal ultrasound versus 93. 3% with hysteroscopy (NS). Positive and negative predictive values were similar for both methods. CONCLUSION: Transvaginal ultrasound is as effective as hysteroscopy in diagnosing benign intrauterine lesions. It could be the first clinical diagnostic test in the investigation of the uterine cavity.

Female↗
PubMed1996

Comparison of Ultrasonography and Hysteroscopy in the Diagnosis of Intrauterine Lesions in Infertile Women

Transvaginal ultrasound is a noninvasive diagnostic technique that remains to be proved as accurate as hysteroscopy in the diagnosis of benign intrauterine lesions. We compared its efficacy with that of hysteroscopy in the diagnosis of benign intrauterine pathology in 126 infertile women in whom the diagnosis was confirmed by histologic studies. The women had a complete evaluation with preoperative transvaginal ultrasound, hysteroscopy, and histologic analysis of uterine cavity specimens. Sensivity, specificity, and predictive values were calculated for ultrasound and hysteroscopy considering the histologic study as 100%. Sensivity was 95% and 100%, and specificity 97.4% and 93.7% for transvaginal ultrasound and hysteroscopy, respectively. The positive predictive value for benign intrauterine lesions was 100% for ultrasound and 89.8% for hysteroscopy. The most frequent intrauterine lesions found were polyps and myomas. Transvaginal ultrasound is a valuable method of diagnosing benign intrauterine lesions in infertile women, and is especially important as a noninvasive technique to plan hysteroscopic surgery.

Journal Article↗
PubMed1996

Effect of copper ion on the motility, viability, acrosome reaction and fertilizing capacity of human spermatozoa in vitro.

The objective of this study is to provide additional information on the effect of copper ion (Cu2+) in preventing pregnancy. Human spermatozoa, selected by the swim-up method, were incubated for 0, 5 or 24 h in the presence of 10 ng, 1 microgram, 10 micrograms or 100 micrograms of Cu2+ mL-1 in BWW culture medium, and then evaluated in terms of their motility, viability, acrosome reaction (AR) and the capacity to penetrate zona-free hamster eggs. AR and penetration in zona-free hamster eggs were assessed at 5 h of incubation. Motility, viability and AR in sperm incubated for 5 h were significantly affected by Cu2+ at a concentration of 100 micrograms mL-1, but not at the lower concentrations. Incubation for 24 h did not affect motility and viability of sperm incubated in the presence of concentrations of Cu2+ ranging from 10 ng mL-1 to 10 micrograms mL-1, but a concentration of 100 micrograms mL-1 caused a significant decrease in both parameters. In contrast, the penetration rate of zona-free hamster oocytes significantly decreased compared with that of controls, when only sperm were incubated in the presence of concentrations of Cu2+ ranging from 10 ng mL-1 to 10 micrograms mL-1, and no penetration was observed in the presence of 100 micrograms mL-1 of Cu2+ . When only oocytes were exposed to Cu2+, the penetration rate dropped to 50% of that of the controls. Finally, when both gametes were exposed to Cu2+ before co-incubation, the penetration rate fell to zero for every concentration tested. Results showed that copper, at concentrations similar to those released from intrauterine devices (IUD), affects the fertilizing capacity of human gametes in vitro and interferes with the sperm-oocyte interaction leading to fertilization. These effects suggest that the principle action of Cu2+ released from Cu-IUD is to act as a preconception contraceptive agent when delivered in endometrial and oviducal fluids.

Acrosome↗
PubMed1995

The empty follicle syndrome: a pharmaceutical industry syndrome.

The purpose of this study is to provide evidence that empty follicle syndrome (EFS) is a result of an abnormality in the in-vivo biological activity of some batches of commercially available human chorionic gonadotrophin (HCG). This is a comparative study between six consecutive in-vitro fertilization (IVF) cases with EFS (study group) and 10 IVF pregnancy cycles (control group). Both groups received the same ovarian stimulation protocol consisting of leuprolide acetate and human menopausal gonadotrophin (HMG). An i.m. injection of 10,000 IU of HCG was administered once follicles had reached 18-20 mm and oestradiol/follicle > or = 16 mm was at least 900 pmol/l. Transvaginal aspiration was performed 36 h later. Plasma HCG prior to and 12 h after i.m. injection as well as the follicular fluid (FF) concentrations of oestradiol, progesterone, luteinizing hormone (LH) and HCG were determined in the study group and controls. The in-vitro biological activity of the batch of HCG used by the EFS cases and the control group was determined using a Leydig cell preparation from adult rats. Furthermore, the plasma clearance rate after i.v. injection of 5000 IU of HCG, from the same batches, was studied in three male volunteers. In the IVF cycles, no HCG was detected in plasma prior to the injection of commercial HCG. After 12 h, no HCG was detected in the study group compared to a mean of 207.5 IU/l (110-360) in controls. Mean FF concentration of LH, HCG, progesterone and oestradiol was 0.9 IU/l, 0 IU/l, 3.1 nmol/ml and 4.4 nmol/ml in EFS compared to 1.0, 98.3, 32.0 and 3.7 in pregnancy cycles. The in-vitro biological activity in both HCG batches was not significantly different; however, immunoreactive HCG used in EFS cases was undetectable in plasma of male volunteers as soon as 10 min after i.v. injection of 5000 IU of HCG. The endocrine abnormalities found in follicular fluids of EFS are not a consequence of an ovarian problem but the result of a lack of exposure to biologically active HCG. The rapid clearance of the drug after i.v. injection and the high affinity of desialylated HCG to liver cells suggest this to be a possible explanation for this infrequent but unfortunate event.

Adult↗
PubMed1994

Predictive value of human chorionic gonadotrophin in the outcome of early pregnancy after in-vitro fertilization and spontaneous conception.

This prospective study analyses the value of the beta-subunit of human chorionic gonadotrophin (beta-HCG) in 120 pregnancies obtained after in-vitro fertilization (IVF)--embryo transfer. Spontaneous conception cycles (n = 16) were also analysed allowing a comparison between these two forms of conception. Of the 120 clinical pregnancies, 48 started as single gestations and 50 started with two or more sacs. There were 14 clinical abortions and eight ectopic pregnancies. All subjects had blood samples taken under a fixed protocol on days 11, 14, 17, 20 and 23 after follicular aspiration. Weekly samples were obtained thereafter until day 60 from ovum retrieval. Transvaginal ultrasounds were performed at weekly intervals, starting on day 23 after follicular aspiration. In spontaneous conception cycles blood samples were obtained daily, starting on the day of follicular rupture. In spontaneous conception cycles and in IVF-embryo transfer conceptions, the doubling time (DT) of beta-HCG was 1.4 +/- 0.3 and 1.6 +/- 0.4 days respectively. This difference was not significant. In multigestations, the DT was 1.5 +/- 0.3 days. The absolute values of beta-HCG in early spontaneous gestations were significantly higher than in IVF-embryo transfer cycles, suggesting that the blastocyst implants with less cellular mass when initiated in vitro as compared with the in-vivo condition. The early prediction of ectopic pregnancy and spontaneous clinical abortion was analysed by the beta-HCG profile as well as the absolute values in comparison to normal pregnancies. Both parameters showed significant differences as early as the interval between days 11 and 23 from follicular aspiration.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Spontaneous↗
PubMed1993

Validation of the dual analyte assay of the oestrone:pregnanediol ratio in monitoring ovarian function.

The purpose of this study was to validate the dual analyte system (Boots Celltech Ltd, Slough, UK) as a marker of ovarian function. For this purpose the urinary profile of the ratio of oestrone-3-glucuronide to pregnanediol-3-glucuronide in urine (E13G/PD3G) was compared with plasma concentrations of oestradiol, progesterone, luteinizing hormone (LH) and follicle stimulating hormone from day 8-24 of the menstrual cycle in 23 women. Daily transvaginal ultrasound was also performed from day 8 of the cycle until sonographic evidence of follicular rupture. The ratio of urinary metabolites exhibited a maximum value close to ovulation. In the majority of cases this coincided with the day of LH peak, and was followed by follicular rupture within the next 24 h in 74% of cases. The assay gives a good marker of ovulation, however, it is unlikely to help in detecting the initiation of the fertile period or the quality of the menstrual cycle.

Adult↗
PubMed1992

Pregnancy rate in an oocyte donation program.

Oocyte donation programs offer an alternative treatment for infertile women with ovarian failure or abnormal ovarian function. Seventeen cycles of in vitro fertilization and embryo transfer with donated oocytes were performed in 13 women, with a mean age of 34.8 years. The hormonal replacement therapy consisted of a fixed dose of oral estradiol valerate, 6 mg daily, and intramuscular progesterone in oil, 100 mg daily. Estrogen and progesterone were continued for 10 more weeks after embryo transfer if pregnancy was established. After 13 embryo transfers, 8 pregnancies were obtained, for a pregnancy rate per transfer of 61.5%. Today seven pregnancies are progressing normally, including one set of twins. This results suggest that an oocyte donation program using a fixed and simple hormonal replacement therapy is an adequate treatment for these infertile couples.

Adult↗
PubMed1992

Fertilization rate in couples with unexplained infertility.

A group of 24 couples with unexplained infertility was scheduled for in-vitro fertilization and tubal embryo transfer between May 1989 and September 1990. In the same period, in-vitro fertilization and intrauterine transfer of embryos was planned in a control group of 44 women with tubal infertility. The mean age and duration of infertility were similar in both groups and the same scheme of ovarian stimulation was used. No statistically significant difference was obtained comparing oestradiol levels and numbers of mature oocytes retrieved between the group of patients with unexplained infertility and those with tubal infertility. The fertilization rate of the oocytes obtained from women with unexplained infertility (60.4%) was significantly lower (P less than 0.001) than that of the oocytes obtained from patients with tubal infertility (87.3%). There was no statistically significant difference in the cleavage rates between patients with unexplained infertility and those with tubal infertility. It is concluded that lack of fertilization is an unexplored cause of infertility in couples with unexplained infertility.

Adult↗