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PubMed1984

[Extracorporeal fertilization and embryo transfer: a medico-ethical topic?].

In vitro fertilization and subsequent embryo transfer remains one of the most burning topical issues of medicine and medical ethics today. Like every individual ethical problem, extracorporeal fertilization initiated the question of the ethical and metaethical (anthropological) context of the origin of the problem and from which an answer may be forthcoming. The fact has to be taken into account that a uniform ethical culture is no longer possible on the grounds of the pluralism of creeds and world opinions. Ethically acceptable compromises have again and again to be looked for. However, the search for an ethical consensus of views runs the risk of being unable to keep pace with the dynamics of medical and technical progress.

Embryo Transfer↗

PubMedDate not supplied

[Pregnancy after fertilization in vitro and embryo transfer].

The first 13 pregnancies established by in vitro fertilization and embryo transfer. A tubal factor was the main indication for in vitro fertilization (IVF) in 10 patients, whereas in three couples infertility was caused by the infertile sperm. The mean age and duration of infertility in female patients were 33.5 and 11.4 years, respectively. Multiple follicular growth was stimulated by either clomiphene citrate (100-150 mg during 5 days), clomiphene citrate + HMG + HCG, or HMG + HCG. Timing of ovulation was determined by assaying serum estradiol, progesterone and LH levels. The ultrasound monitoring of follicular growth was determined on a daily basis. Endogenous LH surge was observed in one patient, whereas in others 5000-10,000 IU HCG were needed to induce ovulation. All oocytes were recovered by laparoscopy. There were 3.8 oocytes per patient on an average. Fifty-six percent of oocytes were preovulatory. All oocytes were allowed to mature in vitro for 3 to 7 hours (mean 5.7 hours). The fertilization and cleavage rates were 76% and 72% respectively. Only one polyspermic fertilization was observed. Forty-five hours after the insemination the embryos between the 2-cell and 6-cell stages were reimplanted into the uterus. Using various ET cannulas, one to seven embryos per patient (2.7 embryos on the average) were replaced into the uterine cavity, 5 mm below the fundus. Only four embryo replacements were completely atraumatic. No medications were used for the luteal phase support. The corpus luteum function and early pregnancy were controlled by serial measurements of serum progesterone, estradiol and beta HCG. Three clinical miscarriages and full-term deliveries were recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1999

A case of an embryo transfer calf infected with bovine leukemia virus from the recipient cow.

A case was discovered where the embryo transfer (ET) calf had been infected with bovine leukemia virus (BLV) from the recipient cow. The embryo was transferred from the BLV-uninfected donor cow to the recipient cow. However, the BLV test had not been performed to the recipient cow before ET was performed. The ET calf was raised in a calf hatch from birth to 1-month old and was given the recipient cow's colostrum and milk artificially. The ET calf was raised with the two other calves from a 1-month old to a 6-month old. The BLV test was performed to the ET calf by agar gel precipitation (AGP) and passive haemagglutination (PHA) assay when the ET calf was 6 months old. Because the ET calf was positive, the BLV test was performed to the recipient cow, the two other calves raised with the ET calf and the two dams of the two other calves. Because the recipient cow only was positive at the time of the first test, we judged that the ET calf had been infected with BLV from the recipient cow. The importance of the BLV test being carried out on the recipient cow for the prevention of enzootic bovine leukemia in a case of ET was recognised.

Animals↗

PubMed2004

Effect of activation time on the nuclear remodeling and in vitro development of nuclear transfer embryos derived from bovine somatic cells.

This study was conducted to investigate the effect of recipient activation time on the chromatin structure and development of bovine nuclear transfer embryos. Serum-starved skin cells were electrofused to enucleated oocytes, activated 1-5 hr after fusion, and cultured in vitro. Some fused eggs were fixed at each time point after fusion without activation, or 3 or 7 hr after activation. Some nocodazole treated zygotes were fixed to analyze their chromosome constitutions. The proportion of eggs with a morphologically normal premature chromosome condensation (PCC) state increased 1-2 hr after fusion. Whereas eggs with elongated chromosome plate increased as activation time was prolonged to 3 hr, and 5 hr after fusion, 58.1% of eggs showed more than two scattered chromosome sets. The proportion of eggs with a single chromatin mass (40.6-56.7%) significantly increased when eggs were activated within 2.5 hr after fusion (P < 0.05). Only 23.3% of reconstituted embryos activated 5 hr after fusion formed one pronucleus-like structure (PN), whereas, 64.5-78.3% of embryos activated 1-2.5 hr after fusion formed one PN. The proportion of embryos with normal chromosome constitutions decreased as activation time was prolonged. Development rates to the blastocyst stage were higher in eggs activated within 2 hr after fusion (17.3-21.7%) compared to those of others (0-8.6%, P < 0.05). The result of the present study suggests that activation time can affect the chromatin structure and in vitro development of bovine nuclear transfer embryos.

Animals↗

PubMed2001

Effects of vaginal progesterone administration on uterine contractility at the time of embryo transfer.

OBJECTIVE: To investigate whether uterine contractility at the time of embryo transfer (ET) can be reduced by early onset of luteal support with progesterone administered vaginally. DESIGN: Prospective analysis. SETTING: Assisted reproduction unit. PATIENT(S): Eighty-four women undergoing 84 GnRH-a and FSH/hCG cycles for IVF-ET were studied. INTERVENTION(S): Vaginal progesterone was randomly started on the day of oocyte retrieval (group A, n = 43) or on the evening of ET (group B, n = 41). On the day of hCG administration and just before ET, 2-minute sagittal uterine scans were obtained by ultrasound and digitized with an image analysis system for assessing uterine contraction frequency. MAIN OUTCOME MEASURE(S): Uterine contraction frequency. RESULT(S): Whereas uterine contraction frequency was similar in both groups on the day of hCG (4.6 +/- 0.3 and 4.5 +/- 0.3 contractions per minute, respectively), only women in group A showed decreased uterine contraction frequency on the day of ET (2.8 +/- 0.2 vs. 4.2 +/- 0.3 contractions per minute). CONCLUSION(S): Vaginal progesterone administration starting on the day of oocyte retrieval induced a decrease in uterine contraction frequency on the day of ET as compared with preovulatory values. Uterine relaxation before ET is likely to improve IVF-ET outcome by avoiding the displacement of embryos from the uterine cavity.

Adult↗

PubMed1986

Clinical study on embryo transfer after human in vitro fertilization.

One hundred forty-six embryo transfers were carried out in the In Vitro Fertilization (IVF) Clinic at St. Pierre Hospital, Brussels, between November 1983 and February 1985. In each of these cases a series of characteristics of the replacement procedure was systematically recorded. Analysis of these data in relation to pregnancy rates indicated that no significant differences appeared among three different operators, the absence or occurrence of cervical bleeding and subjective evaluation of the procedure were related to the chances of establishing a pregnancy, and the duration of replacement had no influence on the outcome of trials. A prospective randomized study of 100 replacements showed that no better pregnancy rate was obtained by placing patients in the knee-to-chest rather than the dorsal position and the addition of a rigid external sleeve to the catheter did not provide any advantage. A simplified method of replacement is thus advocated.

Catheterization↗

PubMed1984

Interspecific chimerism--the characterization and immunological responsiveness of Bos taurus-Bos indicus haemopoietic chimeras produced by embryo transfer.

Bos taurus-Bos indicus twin calves were produced by embryo transfer and their degree of haemopoietic chimerism and immune responsiveness examined. All 10 pairs of Friesian-Brahman twins were chimeric compared with only 6 out of 12 pairs of Jersey-Brahman twins. In the Friesian-Brahman twins, Friesian lymphocytes predominated in all calves while in the Jersey-Brahman twins there was no uniform dominance of one cell type over another. All calves that had chimeric lymphocyte populations were also erythrocyte chimeras, although in two pairs of twins the genotype of the erythrocytes was different from the genotype of the lymphocytes. The lymphocytes of all chimeric calves failed to respond in mixed lymphocyte culture (MLC) tests to the lymphocytes of their co-twins but gave vigorous responses to cells from other calves. Primary and secondary immune responses to keyhole limpet haemocyanin (KLH) antigen were studied in the efferent prefemoral lymph in normal Jersey, Friesian and Brahman calves, in 1 set of Jersey-Brahman twins and in 5 sets of Friesian-Brahman twins. The immune responses of chimeric twins with genetically identical lymphocyte populations were quite dissimilar and were characteristic of the somatic genotype of the calf and not of the genotype of the lymphocyte population. The chimeric status of the cell population in the lymph did not change significantly during the response. These results suggest that either the genetic capacity of a population of lymphocytes to recognize and respond to antigens can be modified during ontogeny in an alien genetic environment or that a crucial determinant of the final outcome of an immune response is not the immunocompetent cell itself but the physiological and anatomical environment in which it exists.

Animals↗

PubMed1997

Assisted implantation: direct intraendometrial embryo transfer.

We report herein a technique for direct intraendometrial transfer (DIET) of human embryos. In this study we evaluated whether 2-day embryos injected into the endometrial stroma can develop normally into viable pregnancies. After in vitro fertilization the embryos were injected into the endometrium of 14 women under direct visualization using a CO2-pulsed flexible hysteroscope. A total of 44 embryos were transferred, resulting in 2 clinical (14.3% per cycle) and 2 chemical pregnancies. In 1 patient, amniocentesis revealed monosomy X and the pregnancy was terminated at 18 weeks. The 2nd patient had an uneventful pregnancy and delivered a healthy baby. The results from the present study, demonstrating a low implantation rate after DIET of 2-day embryos, suggest that the endometrial stroma does not provide an optimal environment for early embryonic development. The acidifying effect of CO2 used for insufflation may also explain the low pregnancy rate after DIET. We conclude that it is possible to achieve pregnancy by DIET in humans, but presently this procedure can be considered only in cases where the implantation site needs to be precisely determined.

Adult↗

PubMed1988

Mechanisms and factors of early pregnancy wastage in in vitro fertilization-embryo transfer patients.

Although the pregnancy rate per transfer of the Norfolk In Vitro Fertilization-Embryo Transfer (IVF-ET) program has been reported as between 25% and 35%, the viable pregnancy rate per transfer is only 15% to 20%. An understanding of the mechanism(s) and etiologic factors of miscarriage among IVF patients might suggest changes that could prevent some early pregnancy wastage. Forty-seven consecutive single pregnancies and 26 miscarriages (October 1985 to November 1986) were included in this study. Factors such as implantation time, date of corpus luteum rescue (CLR), embryo quality, and corpus luteum activity after rescue were studied and compared between term pregnancy and miscarriage groups. Results are discussed in detail in this paper.

Abortion, Spontaneous↗

PubMed2005

Belgian legislation and the effect of elective single embryo transfer on IVF outcome.

In order to reduce the number of multiple pregnancies following IVF, the Belgian government agreed to reimburse laboratory expenses for six IVF cycles up to the age of 42 years, in exchange for restriction of the number of embryos replaced. Data on assisted reproduction outcome before and after the introduction of this new legislation were analysed retrospectively in terms of implantation, pregnancy and multiple pregnancy rates. After the introduction of the new law, the percentage of single embryo transfer increased from 14 to 49%. Implantation rates were 25.9 and 23% respectively. There was no difference in the overall pregnancy rate before and after the introduction (36 versus 37%). Twin pregnancies, however, decreased from 19 to 3%. These findings indicate that elective single embryo transfer significantly decreases the twin pregnancy rate without a reduction in the overall pregnancy rate.

Belgium↗

PubMed2001

[Ectopic pregnancy after in vitro fertilization and embryo transfer. Analysis of literature].

The incidence of ectopic pregnancy has dramatically increased in the last decade. The triggering factors may be different and among them there is the introduction of medical assisted procreation techniques. Tubal pathologies in 80% of women undergoing artificial insemination techniques, the transfer in the womb of more than one embryo and the method of the same embryo-transfer may influence the onset of an ectopic pregnancy. This study aims to detect the factors that can prevent or reduce thc incidence of this pathology, after a close examination of the literature.

Embryo Transfer↗

PubMed1969

Suppression of heavy and light chain allotypic expression in homozygous rabbits through embryo transfer.

Homozygous suppression of allotypic specificities on both the heavy and light chains of rabbit immunoglobulin has been achieved by two methods involving embryo transfer. In the first method, young were transplanted into does producing antibody against an allotypic specificity homozygously present in the genome of the embryo. In this case, the suppression is caused by antibody transmitted in utero. In the second method, young from a nonimmunized surrogate mother lacking their allotypic genotype are injected neonatally with the antiallotype serum. Release from homozygous suppression appears to be achieved more readily than from heterozygous suppression.

Allergy and Immunology↗

PubMed1998

Effect of danazol on the pregnancy rate in patients with unsuccessful in vitro fertilization-embryo transfer.

OBJECTIVE: To determine the effect of danazol on in vitro fertilization-embryo transfer (IVF-ET) patients who failed to conceive in previous attempts despite having embryos with optimal morphology, whether endometriosis is present or not. STUDY DESIGN: In this prospective, randomized, controlled study, of 81 patients who experienced unexplained failures of IVF-ET despite having good-morphology embryos, 40 received danazol (400 mg/d orally for 12 weeks) following the unsuccessful IVF-ET cycle. The next IVF-ET was performed within three months of the first spontaneous ovulation after danazol administration. The remaining 41 patients constituted the control group, and in them the next IVF-ET was performed within six months after the previous failed cycle. RESULTS: Conception occurred in 16 of 40 (40%) danazol-treated patients at the subsequent cycle and showed a significant increase when compared with 8 of 41 (19.5%) control subjects (P < .05), though the number of embryos with optimal morphology decreased after danazol treatment. CONCLUSION: Danazol may be used for patients who have had repeated failures of IVF-ET despite having morphologically optimal embryos and may be useful for increasing receptivity of the endometrium in these patients.

Autoantibodies↗

PubMed2004

In vitro development of preimplantation porcine nuclear transfer embryos cultured in different media and gas atmospheres.

This study investigated the effect of culture media and gas atmospheres on the development of porcine nuclear transfer embryos. Oocytes derived from a local abattoir were matured for 42-44 h and enucleated. Fetal fibroblasts were prepared from a Day 35 porcine fetus. Confluent stage fetal fibroblasts were introduced into the perivitelline space of enucleated oocytes. Fusion and activation were induced simultaneously with two direct current (1.2 kV/cm for 30 micros) in 0.3 M mannitol medium. For parthenogenetic activation, the same pulses were used. In Experiment 1, parthenogenetically activated oocytes were cultured in North Carolina State University-23 (NCSU-23), Porcine Zygote Medium-3 (PZM-3), or Beltsville Embryo Culture Medium-3 (BECM-3). Parthenogenetically activated oocytes cultured in PZM-3 had a higher (P < 0.05) developmental rate to the blastocyst stage (15.2% versus 3.7-9.6%) as compared to BECM-3 or NCSU-23. The number of nuclei in Day 6 blastocysts was higher (P < 0.05) in PZM-3 (23.6) and NCSU-23 (21.4) than BECM-3 (14.2). In Experiment 2, parthenogenetically activated oocytes were cultured in NCSU-23 under a gas atmosphere of 5% CO(2) in air for 6 days (T1), 5% CO(2), 5% O(2), 90% N(2) for 6 days (T2), 5% CO(2) in air for 3 days, then 5% CO(2), 5% O(2), 90% N(2) for 3 days (T3), or 5% CO(2), 5% O(2), 90% N(2) for 3 days, then 5% CO(2) in air for 3 days (T4). Blastocyst formation rates were not different among treatments (12.9 =/-3.6 %, 13.5 +/- 4.2%, 10.8+/-2.4%, and 12.6+/-2.7%, respectively). However, T2 (36.7+/-2.9) and T3 (33.8+/-3.0) resulted in more nuclei per blastocyst than T1 (23.2+/-2.1) or T4 (26.0+/-2.1 ). In Experiment 3, reconstructed porcine nuclear transfer (NT) embryos were cultured in NCSU-23 or PZM-3 under a gas atmosphere of 5% CO(2) in air or 5% CO(2), 5% O(2), 90% N(2). Developmental rates to blastocyst stage for porcine NT embryos cultured in NCSU-23 under a gas atmosphere of 5% CO(2) in air or 5% CO(2), 5% O(2), 90% N(2) were 7.2+/-1.4% and 12.3+/-1.4%, and the number of nuclei was 12.2=/-0.8% and 19.4+/-1.0, respectively. NT embryos cultured in PZM-3 under a gas atmosphere of 5% CO(2) in air or 5% CO(2), 5% O(2), 90% N(2) had developmental rates to blastocyst stage of 18.8+/-1.9 %, and 17.8+/-3.8% the nuclei number was 20.9 +/- 1.9 and 21.9+/-3.3, respectively. NT embryos cultured in NCSU-23 had a higher developmental rate to the blastocyst stage in 5% CO(2), 5% O(2), 90% N(2) than in 5% CO(2) in air (P < 0.05). Regardless of gas atmospheres, NT embryos cultured in PZM-3 had a higher developmental rate (18.3 =/- 1.7% versus 16.9 +/- 1.2%) and nuclei number (21.4 +/-1.8 versus 16.9 +/- 1.2) than in NCSU-23 (P < 0.05). In conclusion, a gas atmosphere of 5% CO(2), 5% O(2), 90% N(2) supported a higher development rate of porcine NT embryos than 5% CO(2) in air when the porcine NT embryos were cultured in NCSU-23. Furthermore, regardless of atmosphere, PZM-3 supported a higher development rate of porcine nuclear transfer embryos than NCSU-23.

Animals↗

PubMed2001

Effect of fibroblast donor cell age and cell cycle on development of bovine nuclear transfer embryos in vitro.

The effects of cell cycle stage and the age of the cell donor animal on in vitro development of bovine nuclear transfer embryos were investigated. Cultures of primary bovine fibroblasts were established from animals of various ages, and the in vitro life span of these cell lines was analyzed. Fibroblasts from both fetuses and calves had similar in vitro life spans of approximately 30 population doublings (PDs) compared with 20 PDs in fibroblasts obtained from adult animals. When fibroblasts from both fetuses and adult animals were cultured as a population, the percentage of cells in G1 increased linearly with time, whereas the percentage of S-phase cells decreased proportionately. Furthermore, the percentage of cells in G1 at a given time was higher in adult fibroblasts than in fetal fibroblasts. To study the individual cells from a population, a shake-off method was developed to isolate cells in G1 stage of the cell cycle and evaluate the cell cycle characteristics of both fetal and adult fibroblasts from either 25% or 100% confluent cultures. Irrespective of the age, the mean cell cycle length in isolated cells was shorter (9.6-15.5 h) than that observed for cells cultured as a population. Likewise, the length of the G1 stage in these isolated cells, as indicated by 5-bromo-deoxyuridine labeling, lasted only about 2-3 h. There were no differences in either the number of cells in blastocysts or the percentage of blastocysts between the embryos reconstructed with G1 cells from 25% or 100% confluent cultures of fetal or adult cell lines. This study suggests that there are substantial differences in cell cycle characteristics in cells derived from animals of different ages or cultured at different levels of confluence. However, these factors had no effect on in vitro development of nuclear transfer embryos.

Aging↗

PubMed2002

[Prevention of twin pregnancy after IVF/ICSI using embryo transfer].

One of the negative aspects of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) is the increased risk of multiple pregnancies. Multiples of high order (triplets and pregnancies of higher order) are obsolete to both doctors and patients and need to be avoided. However, there is an epidemic of twin pregnancies with a higher risk of obstetric, perinatal and neonatal complications than singleton pregnancies and with an important psychosocial, economic and financial impact for the parents to be. A reduction in the number of twins can only be obtained by transfer of one embryo. If this guideline would be applied to all cycles, a dramatic fall in pregnancy rate would occur. In a selected patient group one selected embryo with an excellent implantation potential can be transferred.

Embryo Transfer↗

PubMed2000

Maternal serum inhibin A concentrations in early pregnancy after IVF and embryo transfer reflect the corpus luteum contribution and pregnancy outcome.

To compare maternal serum inhibin A concentrations in early pregnancy with pregnancy outcomes and treatment protocols, serum samples were collected from 237 women undergoing in-vitro fertilization (IVF) and embryo transfer cycles. Samples were collected on day 16 after oocyte retrieval for beta human chorionic gonadotrophin (HCG) pregnancy testing and inhibin A measurement. The samples were divided into non-pregnant (n = 128) and pregnant (n = 109) groups, the pregnancies were followed and outcomes determined. Inhibin A concentrations were significantly lower in non-pregnant women than in women with ongoing pregnancies (P: < 0.001) and those resulting in spontaneous abortions (P: < 0.001). In ongoing pregnancies, inhibin A concentrations were significantly lower in the absence of functioning ovaries (donor oocyte/embryo) (P: < 0.01) and in natural cycles (frozen-thawed embryo transfer) (P: < 0.01) compared with concentrations after ovarian stimulation. Further, since inhibin A concentrations were not significantly different between singleton and multiple pregnancies in the ovarian stimulation protocol, the size of the early trophoblast does not appear to influence the secretion of inhibin A. These data strongly support the concept that the corpus luteum is a major source of circulating inhibin A in early pregnancy. Additionally, low concentrations of serum inhibin A may be useful in predicting betaHCG-positive preclinical 'biochemical' pregnancies.

Abortion, Spontaneous↗

PubMed1990

[Use of synchronized heifer-recipients in view of the effectiveness of embryo transfer in cattle].

A possibility was investigated of using heifers prepared for embryo reception by i. m. double application of Oestrophan (Spofa) luteolytic preparation. After a clinical examination of ovaries and corpus luteum, out of the total number of 2894 animals synchronized for nonsurgical ipsilateral transfer in the D7 stage only 2038 (70.4%) recipients were used. Almost 30% (856) heifers were discarded from the role of recipients, mostly due to the functional disorders of the cyclic activity of ovaries manifesting themselves as luteal cysts (22.5%), cysts of corpus luteum (16.5%), small or young corpora lutea (12.7%), postovulation states (4.5%), and also as a high frequency of the follicular activity without the presence of corpus luteum (37.9%). The occurrence of follicular cysts (1.4%) and nonfunctional ovaries (2.8%) was considerably lower. The high number of discarded recipients which results, in the complex of causes, from qualitative nutritional disorders, husbandry and zoo-hygienic shortcomings and stress-inducing factors in the course of recipient selection and preparation, diminishes the transfer efficiency and considerably increases the claims for the numbers of recipient prepared for ovulation. In the conditions of our workplace where 10.6 to 12.8 transferable embryos are recorded from one successful superovulation and their survival is 65 to 68.6%, it will be necessary, at the present level of recipient discarding, to prepare 13.8 to 16.6 heifers per donor to make full use of the superovulation effect.

Animals↗