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PubMed2006

Artificial reproduction technologies (RTs) - all the way to the artificial womb?

In this paper, I argue that the development of an artificial womb is already well on its way. By putting together pieces of information arising from new scientific advances in different areas, (neo-natal care, gynecology, embryology, the human genome project and computer science), I delineate a distinctive picture, which clearly suggests that the artificial womb may become a reality sooner than we may think. Currently, there is a huge gap between the first stages of gestation (using in vitro fertilization) and the 22nd week (inside the womb). At the present time this gap seems an insurmountable barrier for fully developing a fetus outside a natural womb - a notion better known as ectogenesis. The history of science however, suggests that impenetrable barriers are such only temporarily. It is just a matter of time (and due research) until someone - intentionally or by chance - accesses the right answer and finds a way to overcome existing obstacles. Despite misgivings that the case of the artificial womb presents too many barriers, it would be naive to suppose things would happen any differently. I observe in this paper, that it is time to acknowledge the consequences of new developments in different areas of scientific research which are leading to the advent of an artificial womb; and I modestly suggest that we might initiate a discussion on this topic now, while we have still enough time to decide what we may want and why.

Cell Differentiation↗
PubMed1992

Endometrial pattern and thickness associated with pregnancy outcome after assisted reproduction technologies.

The endometrial pattern and thickness was analysed prospectively on the day of administration of human chorionic gonadotrophin (HCG) in 200 in-vitro fertilization (IVF), gamete intra-Fallopian transfer (GIFT) and tubal embryo transfer (TET) cycles. Increasing maturity of the endometrial pattern was positively correlated with oestradiol levels (r = 0.20; P = 0.005), number of mature eggs (r = 0.13; P less than 0.05) and the number of top quality embryos (r = 0.40; P less than 0.001). The endometrial thickness was positively correlated with the number of follicles greater than or equal to 15 mm (r = 0.15; P less than 0.02) and the cycle day on which HCG was administered (r = 0.14; P less than 0.03). It was unaffected by the dose of human menopausal gonadotrophin and was negatively correlated with the use of clomiphene citrate (r = 0.40; P less than 0.001). Fecundity was increased for IVF when the endometrial thickness was greater than or equal to 9 mm (P less than 0.05) and for GIFT and TET when a Type C triple-line endometrial pattern was present (P less than 0.05). Biochemical pregnancies for the combined methods increased from 2.5% of all pregnancies when the endometrial thickness was 9-13 mm, to 27.8% when the thickness was less than 9 mm or greater than 13 mm (P less than 0.01). Biochemical pregnancies occurred in 67% of IVF pregnancies when the endometrial thickness was greater than or equal to 3 mm.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2006

Development of sperm sexing and associated assisted reproductive technology for sex preselection of captive bottlenose dolphins (Tursiops truncatus).

Research was conducted to develop sperm sorting and novel sperm preservation methodologies for sex predetermination in the bottlenose dolphin (Tursiops truncatus) using artificial insemination. In Study 1, the effect of seminal plasma (SP), sperm concentration and freezing rate (FR) on in vitro sperm quality of liquid-stored, non-sorted spermatozoa was examined. There was no effect (P > 0.05) of prefreeze SP addition on post-thaw quality (progressive motility, kinetic rating, sperm motility index (SMI), viability and acrosome integrity). Post-thaw motility parameters and viability were higher (P < 0.05) for slow FR than fast FR samples. In Study 2 investigating the effects of liquid storage and sorting on sperm quality, motility and SMI after sorting and centrifugation were lower (P < 0.05) than those of the initial ejaculate. The sort rate for enrichment (91 +/- 4% purity) of X- and Y-bearing spermatozoa was 3400 +/- 850 spermatozoa sex(-1) s(-1). In Study 3, compared with a modified straw method, directional freezing resulted in enhanced in vitro quality of sorted and non-sorted spermatozoa derived from liquid-stored semen (P < 0.05). In Study 4, endoscopic insemination of three dolphins with sorted, frozen-thawed X-bearing spermatozoa resulted in one conception and the birth of a female calf. High-purity sorting of dolphin spermatozoa, derived from liquid-stored semen, can be achieved with minimal loss of in vitro sperm quality and samples are functional in vivo.

Animals↗
PubMed2003

Interleukin-2 production in whole blood cell cultures of women undergoing controlled ovarian hyperstimulation for assisted reproduction technology cycles.

PROBLEM: To determine whether human chorionic gonadotropin (hCG) modulates the in vitro release of interleukin (IL-2) from human peripheral lymphocytes and monocytes derived from patients undergoing controlled ovarian hyperstimulation (COH). METHOD OF STUDY: A large university-based IVF unit was used for the study. Blood was drawn thrice from 12 women undergoing our routine IVF long gonadotropin-releasing-hormone-analog protocol during the COH cycle: (1) day on which adequate suppression was obtained (Day-S); (2) day of or prior to hCG administration (Day-hCG); and (3) day of ovum pick-up (Day-OPU). At each point of time, blood was tested for sex-steroid levels and then cultured for 72 hr either without (control-culture) or with hCG (hCG-culture) or with mitogenic stimulation by phytohemagglutinin (PHA-culture). The culture-medium supernatants were tested for IL-2 levels with a commercial sandwich enzyme-linked immunoassay. RESULTS: Whole blood culture IL-2 levels increased significantly during COH until peak E2, and then decreased significantly after hCG administration. IL-2 levels were decreased in the control- and PHA-culture media on Day-OPU compared with Day-hCG. There were no significant correlations between IL-2 levels in the culture media and serum estradiol, progesterone or human chorionic gonadotropin levels. CONCLUSION: Apparently, hCG attenuates IL-2 production by mononuclear cells with and without mitogenic stimulation, irrespective of the estradiol level. This suggests that hCG may indirectly modulate the inflammatory response, resulting in the ovarian hyperstimulation syndrome.

Adult↗
PubMed1992

Ovarian hyperstimulation syndrome in novel reproductive technologies: prevention and treatment.

OBJECTIVE: To overview the world literature on ovarian hyperstimulation syndrome (OHSS) and modes of prevention and treatment of OHSS. STUDY SELECTION: All the pertinent literature on OHSS, its prevention, and strategies for treatment were reviewed. PREVENTION: Key to prevention is proper identification of the population at risk, which includes women with either the hormonal or the morphological signs of polycystic ovarian disease, high serum estradiol (E2) before human chorionic gonadotropin (hCG) administration (E2 greater than 4,000 pg/mL), multiple follicular response (greater than 35), younger age, and lean habitus. When a high risk situation is recognized, ovulatory dose of hCG may be reduced, avoided (with cycle cancellation), or substituted by gonadotropin-releasing hormone or its agonist. Luteal support with hCG is to be bypassed. To minimize risk of OHSS, endogenous pregnancy-drived hCG may be eluded by judicious cryopreservation of all embryos. Last, follicular aspiration will allow higher levels of E2 and larger number of follicles to be matured with lesser risk of OHSS than conventional ovulation induction without follicular aspiration. TREATMENT: In-house for the severe and intensive care for the critical form. Meticulous fluid and electrolyte balance using both crystalloids and colloids (albumin) until hemoconcentration abates. Paracentesis is indicated for tight ascites, deteriorating kidney functions, and symptomatic relief. Diuretics may be prudently used once hemodilution is achieved. Dopamine drip may be used as a renal rescue, whereas heparin is indicated for thromboembolic phenomena and surgery reserved for abdominal catastrophies. Therapeutic interruption of an early gestation may be lifesaving when all other measures have failed. CONCLUSIONS: Although severe and critical OHSS may not be completely avoided, early recognition of high-risk factors, judicious prevention schemes, and treatment strategies should reduce the complication and long-term sequelae of this iatrogenic syndrome.

Chorionic Gonadotropin↗
PubMed2001

Polycystic ovarian syndrome and the risk of spontaneous abortion following assisted reproductive technology treatment.

BACKGROUND: A high proportion of infertile patients have polycystic ovarian syndrome (PCOS) with a reportedly greater risk of spontaneous abortion. Because of the close link between PCOS and obesity and the independent association of obesity with poor pregnancy outcomes, it is important to distinguish the possible confounding effect of body mass index (BMI) or other variables from that of PCOS. This study aims to determine the effect of PCOS status on the risk of spontaneous abortion with adjustment for body mass and several other confounding factors in a large cohort of pregnant infertile women. METHODS: The patients (n = 1018) were treated in a tertiary infertility centre. Their PCOS status was determined by standard criteria and their BMI had been taken less than 1 year before the pregnancy. Patients whose PCOS status or BMI measurements were not assessed were excluded. Student's t-test or chi2 test were used to test the difference between the PCOS and non-PCOS groups while a multivariate logistical regression model was used to assess the effect of PCOS, BMI and other confounding factors. RESULTS: Overall, the incidence of PCOS was 37% in this cohort. The overall incidence of spontaneous abortion in the study population was 21%. Univariate analysis showed that women with PCOS had a significantly greater risk of spontaneous abortion compared with non-PCOS women (25 versus 18%, P < 0.01). However, using multivariate logistic regression analysis this effect was reduced to a non-significant level [odds ratio (OR) = 1.10, 95% confidence interval (CI) 0.85-1.36] after adjusting for obesity and patients/treatment combination factor, and to nil after adjusting for all confounding factors considered in this study (OR = 0.98, 95% CI 0.75-1.28). CONCLUSION: The results of this study suggest that the higher risk of spontaneous abortion observed in women with PCOS is likely to be due to their high prevalence of obesity and the type of treatment they receive.

Abortion, Spontaneous↗
PubMed1996

[Elucidation of the mechanism of fertilization and clinical application of assisted reproductive technology].

Fertilization is the process including many events such as maturation of egg and sperm, attachment, binding, acrosomal reaction, penetration, fusion, cortical reaction, zona reaction and nuclear fusion of both gamete, whereby individual gametes from the female and male unite to create offspring. Although the reason for mechanism of fertilization is still not clearly understood, this process may accelerate the rate adaptation in evolution. In this special lecture, I would like to present our experimental and clinical results especially concerning with morphological, physiological, biochemical and molecular approach on the mechanism of fertilization. 1. Development and maturation of follicles and oocytes. It is well known that pituitary FSH, LH control the ovarian function. Follicular development and ovum maturation are also controlled by both pituitary gonadotropins and local factors such as autocrine and paracrine agents. When hMG is injected during 1-6 day of menstrual cycle, several dominant follicles are developed. If hMG is injected after selection of dominant follicles, only one dominant follicle develop in the ovary. When PMS-treated immature rats were injected with immature or mature follicle fluids, rats injected with mature follicular fluid showed strongly suppress in the ovarian weights and numbers of ovulated follicles. Also mature follicle suppress aromatization from and androstenedione to estradiol. These findings mean that mature follicular fluid contains inhibitory factors. Apoptosis of granulosa cells and follicular steroids are related to fertilization. 2. Intracellular calcium of oocyte. Intracellular calcium concentration is known to start to increase in a periodic manner after fertilization in oocytes of mammalians. In 65% of tested mouse oocytes, fertilization occurred during 4 hours observation after sperm insemination in vitro. An initial long lasting intracellular calcium concentration was observed and followed by periodic manner. This calcium oscillation is inhibited by calcium blockers such as verpamil and nifedipine, but increased by high concentration of extracellular calcium concentration in the medium. Role of increase of intracellular calcium are understood to prevent polysperm and activate metabolism of oocytes. 3. Glucose metabolism of oocytes. Mouse embryo utilizes pyruvate as an essential nutrient until the 8-cell stage, and glucose thereafter. We have devised non-radiometrie and enzymatic microassay method to measure glucose, deoxyglucose, deoxyglucose 6-phosphate incorporated into individual mouse oocytes and preimplantation embryo. In parallel, the activities of several enzymes of glycolytic pathway were also determined. In this study, glucose metabolism is necessary to develop in fertilized ova with changing activity of enzymes. 4. Molecular bases of ovarian fluid. The zona pellucida ZP is involved in a number of events in fertilization, all these fertilization events occur in the oviduct. Oviductal glycoprotein 200-240 KD has been identified from oviductal zona pellucida. Monoclonal antibody of oviductal glycoprotein reacted with ZP of oviductal egg but not with the ovarian egg. Anti-ZPO antibody inhibit to bind sperm to ZP. Sequences in mouse and hamster oviduct specific glycoprotein are estimated, this glycoprotein mRNA was observed in only oviduct by northern blotting method. These molecular gene expression was observed by in situ hybridization in the oviduct of estrous cycle of hamster. 5. Microinsemination of sperm. Microinsemination of sperm into oocyte is widely used in clinical medicine. Sperm penetration assay (hamster test) is useful method to estimate fertilization capacity of sperm. But immotile sperm cannot estimate it. So modified micro sperm penetration assay was established to estimate fertilization capacity of sperm by using micro-manipulator. Subzonal sperm injection (SUZI) and intracytoplasmic sperm injection (ICSI) promotes fertilization and cleavage rate in immotile

Animals↗
PubMed1994

Minimum essential medium alpha (MEM) enhances assisted reproductive technology results. I. Mouse embryo study.

PURPOSE: Our purpose was to find a medium to enhance mouse zygote development and, hopefully, to apply the results to a coculture system and to enhance the ART pregnancy rate. DESIGN: The study was designed to compare different media's support of mouse zygote development with/without serum supplement. The outcome measure was the percentage of mouse zygotes/embryos that developed to the expanded blastocyst and hatchout stage. RESULTS: (1) Using human tubal fluid (HTF), one-cell zygotes had a 34.6 +/- 5.2% (mean +/- standard deviation) development rate, and two-cell embryos a 86.5 +/- 3.2% development rate. (2) Minimum essential medium alpha (MEM) showed the best results (52.2 +/- 14.5%) among Ham's F-10 (19.1 +/- 6.3%), HTF (26.8 +/- 8.2%), NCTC-135 (38.8 +/- 12.6%), MEM with nuclei acid (24.6 +/- 10.0%), and Dulbecco's modified Eagle medium (28.0 +/- 20.2%). (3) With the serum supplement, there was no significant difference among Ham's F-10 (21.5 +/- 23.7), HTF (29.3 +/- 10.4%), NCTC-135 (36.5 +/- 6.2%), and MEM (38.8 +/- 17.9%). CONCLUSION: MEM is the best medium among the six media examined. Preliminary study showed that MEM gave a good clinical pregnancy rate (29%).

Animals↗
PubMed2005

Algorithm to predict assisted reproductive technology pregnancy outcome reveals minimal embryo synergy.

A mathematical model was developed to calculate the implantation probability for individual embryos based on the pregnancy outcome of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cases with multiple embryos transferred. This model was used to calculate implantation probabilities of embryos of 31 morphological types using the outcome of 1,200 IVF/ICSI cases. The algorithm was validated by comparing the calculated pregnancy probability and multiple pregnancy probability with the actual outcome of 281 separate IVF/ICSI cases. Finally, an estimation of embryo synergy was calculated.

Algorithms↗
PubMed2005

Optimum number of embryos to transfer in women more than 40 years of age undergoing treatment with assisted reproductive technologies.

OBJECTIVE: To determine whether increasing the number of embryos transferred beyond five increases pregnancy rates in women aged > 40 years. DESIGN: Retrospective analysis of cycles performed between January 1998 and July 2003. SETTING: University-affiliated teaching hospital. PATIENT(S): Women aged > 40 years undergoing a fresh cycle with a day-3 ET (n = 863). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Pregnancy, chemical pregnancy, miscarriage rates, number of viable fetuses at 12 weeks' gestation, live birth rates, and number of babies delivered. RESULT(S): Compared with patients with fewer than five embryos transferred, those having five or more embryos transferred had significantly increased pregnancy rates and live birth rates, more viable fetuses at 12 weeks, and significantly decreased miscarriage rates. None of these outcome variables differed between the five-embryo and more-than-five-embryo groups. There were no differences in outcome when only five embryos were transferred, regardless of whether five or more than five embryos were available. The number of embryos transferred did not significantly influence multiple birth rates. CONCLUSION(S): The present study demonstrates that in women aged > 40 years, five embryos is the optimum number to transfer, and transferring more than five does not confer any additional benefit to clinical outcome.

Adult↗
PubMed2007

Predicting factors for endometrial thickness during treatment with assisted reproductive technology.

OBJECTIVE: To discover the factors contributing to endometrial thickness, and to assess the impact of endometrial thickness on pregnancy rates (PRs) according to these factors. DESIGN: Retrospective study. SETTING: In vitro fertilization unit in a university hospital. PATIENT(S): All women with primary infertility and no previous pregnancies who underwent IVF treatment at the Chaim Sheba Medical Center, Tel Hashomer, Israel, between August 9, 2001-December 31, 2004. INTERVENTION: Measurement of endometrial thickness by the use of transvaginal ultrasound probe on the day that hCG was administered during an IVF cycle. MAIN OUTCOME MEASURE(S): Factors influencing endometrial thickness and the relationship between endometrial thickness and PRs. RESULT(S): The mean endometrial thickness decreased as a function of the patient's age. The thickest endometrium was found in patients <25 years of age (11.9 +/- 2.5 mm), and the thinnest endometrium was found in patients >40 years of age (9.6 +/- 2.3 mm). Other factors, such as E(2) levels, etiology of infertility, induction of ovulation protocol, and type of gonadotropin used, were also found to contribute to endometrial thickness. CONCLUSION(S): Our data support the case for an "aging" of the endometrium. The chances of achieving a thick endometrium for patients >40 years of age are lower than for younger patients. Furthermore, a thicker endometrium is correlated with a higher PR only for patients >35 years of age.

Adult↗