O-201 Prenatal and postnatal outcome of mosaic embryo transfers: multicentric study of one thousand mosaic embryos diagnosed by preimplantation genetic testing with trophectoderm biopsy

Study question

To explore the effect of chromosomal mosaicism detected in preimplantation genetic testing (PGT-A) on prenatal and postnatal outcome of mosaic embryo pregnancies

Summary answer

No significant difference between euploid and mosaic embryos was observed in terms of weeks of gestation, average weight, and developmental defect of the babies born

What is known already

Mosaic embryos have the potential to implant and develop into healthy babies. Transfer of these embryos is now offered as an option for women who undergo IVF resulting in no euploid embryos. While, prenatal diagnosis has shown the depletion of chromosomal mosaicism in mosaic embryos, several concerns remain. For instance, the direct effects of different kind of mosaicism on prenatal/postnatal outcome and the possibility that intra-biopsy mosaicism in the TE is a poor predictor of the ploidy status of the ICM. Thus, there is certainly a need for comprehensive analyses of obstetrical and neonatal outcome data of transferred mosaic embryos.

Study design, size, duration

Compiled analysis from multicenter data on transfers of mosaic embryos (n = 1,000) and their outcome, with comparison to a euploid control group (n = 5,561). To explore the effect of embryonic mosaicism on newborns, we matched mosaic embryos resulting in a birth with a euploid embryo by a series of parameters (maternal age, embryo morphology, and indication for PGT-A). Prenatal tests and birth characteristics of > 200 neonates from mosaic embryo transfers were compared to > 200 euploid embryos.

Participants/materials, setting, methods

PGT-A was performed on blastocyst-stage embryos with 24-Chromosome whole genome amplification (WGA)-based Next Generation Sequencing (NGS). In accordance with established guidelines, embryos were categorized as mosaic when PGT-A results indicated 20-80% aneuploid content. Prenatal testing where performed in 30% of pregnancies with amniocentesis, 4% did an extra analysis for potential UPD for the suspected mosaic chromosome, and an additional 16% performed chorionic villus sampling (CVS) and 9.5% performed noninvasive prenatal testing (NIPT).

Main results and the role of chance

Of the 465 mosaic embryos that implanted, about 20% miscarried, and out of those, 75% were early spontaneous abortions. Of the pregnancies, 3 out of 368 were stillborn (2 out of them were twins that were extremely premature at 23 weeks, and the other died during pregnancy from a heart defect). The remaining 99% of those have been born or are late ongoing pregnancies at the time of analysis. Prenatal tests were performed in > 200 pregnancies and the vast majority tested normal. All 5 abnormal cases were amniocentesis tests showing microdeletions or insertions of sizes smaller than the resolution used during PGT-A, so they were unrelated to the mosaicism detected with PGT-A. In fact, in none of the cases did the prenatal test reflect the mosaicism detected at the embryonic stage. Matching each of the 162 mosaic embryos resulting in a birth with a euploid embryo, we found that the length of gestation was similar on average, and so was the average weight of the babies at birth. We also gathered information on the routine physical examination performed on babies at birth, and of those 162 babies from mosaic embryo transfers, none had obvious developmental defects or gross abnormalities.

Limitations, reasons for caution

Even though newborns resulting from mosaic embryo transfers in this study invariably appeared healthy by routine examination, concerns for long-term health cannot yet be entirely dispelled. The question must therefore be carefully considered by each clinic and patient situation.

Wider implications of the findings

Prenatal testing of > 200 pregnancies from mosaic embryo transfers showed no incidence of mosaicism that matched the PGT-A findings, indicating the involvement of self-corrective mechanisms. Pregnancy and obstetric data indicates that mosaic embryos prevailing through gestation and birth have similar chromosomal and physiological health compared to euploid embryos.

Trial registration number

none

Ooplasmic influence on nuclear function during the metaphase II-interphase transition in mouse oocytes

Nuclear and pronuclear transfer procedures were used to assess the functional competence of the nucleus and cytoplasm of mouse germinal vesicle-stage oocytes denuded of granulosa cells and matured in vitro or in vivo before artificial activation using a sequential treatment of A23187 + cycloheximide. Following activation, in vitro-matured oocytes were "fertilized" by inserting a male pronucleus (PN), cultured to the 2-cell stage, and then transferred to the oviducts of foster mothers. No live births were noted, whereas a 17% live birth rate was observed when in vivo-matured oocytes were used. The developmental competency of other zygotes was similarly assessed following the exchange of haploid PN of matured and activated eggs with the female PN of fertilized zygotes. When PN of oocytes subjected to maturation and activation in vitro were transferred, only 1 of 79 reconstructed zygotes developed to term. In contrast, the live birth rate was 21% (11 of 53) for zygotes reconstructed with PN from in vivo-matured oocytes. Moreover, a live birth rate of 23% (8 of 35) was observed for reconstructed zygotes with female PN from "hybrid" oocytes created by transferring the metaphase II nuclei of in vitro-matured oocytes into enucleated, in vivo-matured oocytes before activation. Such results suggest that the nucleus of an in vitro-matured oocyte can support embryonic development, but only when it is activated in the proper ooplasmic milieu. The cellular factors creating this ooplasmic milieu appear to develop normally in vivo during follicle maturation to metaphase II, but they fail to do so when the oocytes are denuded of granulosa cells and cultured in vitro before the final stages of maturation. In parallel studies, male and female PN of in vivo-fertilized zygotes were inserted into oocytes that were activated and enucleated following either in vitro or in vivo maturation. Live birth rates were comparable at 19% (5 of 27) and 18% (9 of 49), respectively, suggesting that, regardless of the environment of the final stages of oocyte maturation, the resultant ooplasm is competent to support all aspects of embryonic development once activation and PN formation has been completed. Such findings only point further toward the importance of the condition of the ooplasmic milieu at the time of chemical activation. Whether a similar situation exists when eggs are activated following sperm penetration remains to be determined.

Uterine transplantation, abdominal trachelectomy, and other reproductive options for cancer patients

More and more women with cancer issues are now raising fertility concerns as survival improves and childbearing is delayed. Pregnancy is no longer contraindicated in cancer patients including breast and endometrial cancer survivors. In fact, survival in patients treated for breast cancer who subsequently become pregnant is actually higher than that in patients who do not become pregnant. "Therapeutic" abortions are no longer recommended. Assisted reproductive technology (ART) have been associated with ovarian neoplasms, but the association is probably not causal. Neither ART nor hormone replacement is contraindicated in cancer patients. Our institution is very supportive of patients and the difficult decisions cancer survivors face. Using a program of counseling and close collaboration between oncologists, perinatologists, and reproductive endocrinologists, informed patients are offered every possible option, including ART and uterine transplantation, to achieve their family planning objectives.

Analysis of Oct-4 expression and ploidy in individual human blastomeres

Oct-4, a decisive factor that maintains totipotency in murine embryonic and germ cells, is exclusively expressed in such cells. In mice, different levels of oct-4 expression in blastomeres predict development towards inner cell mass (ICM) (high oct-4) or trophectoderm (TE) (low oct-4). To address whether the mouse model also applies to human embryos, the cytoplasm of individual human blastomeres from normally and abnormally fertilized embryos was tested for Oct-4 expression by reverse transcription-polymerase chain reaction (RT-PCR). The nuclei of the same blastomeres were subjected to fluorescence in-situ hybridization (FISH) to determine ploidy. A significant difference in Oct-4 mRNA levels was revealed between blastomeres. The distribution of blastomeres with high Oct-4 levels varied according to the cleavage stage of the embryo: the more blastomeres, the lower the percentage with high Oct-4 levels. Aneuploid blastomeres did not exhibit lower Oct-4 mRNA levels than diploid ones. Thus, differential Oct-4 expression in individual human blastomeres appears to direct cells towards the ICM or TE lineages without regard to chromosomal status. Oct-4 might be used as a marker in preimplantation genetic diagnosis to identify embryogenic blastomeres.

Oct-4 expression in inner cell mass and trophectoderm of human blastocysts

The expression of the transcription factor Oct-4 is thought to be one of the decisive factors that maintain totipotency in embryonic and germ cells. In mice, oct-4 is exclusively expressed in germ cells and totipotent cells of the embryo. In humans, Oct-4 is expressed in germ cells, embryonic stem cells and whole embryos at various stages of development. However, there is limited information about the distribution of Oct-4 expression in human embryos. In an attempt to address this issue, the inner cell mass (ICM) and trophectoderm (TE) of 17 human blastocysts were separated and Oct-4 mRNA expression individually assessed by reverse transcription-polymerase chain reaction (RT-PCR). In discarded blastocysts that developed from two pronuclear zygotes, the mean Oct-4 expression was 31 times higher in totipotent ICM cells than in differentiated TE cells. This finding suggests that, in accordance with data from the mouse, Oct-4 is highly expressed in human ICM cells as opposed to TE cells; this in turn supports the hypothesis that Oct-4 plays a similar role to maintain totipotency in these two species.

In-vitro development of mouse zygotes following reconstruction by sequential transfer of germinal vesicles and haploid pronuclei

We evaluated whether mouse oocytes reconstructed by germinal vesicle (GV) transfer can develop to blastocyst stage. The oocytes were artificially activated with sequential treatment of A23187 and anisomycin; fertilization was then established by transfer or exchange of pronuclei with those of zygotes fertilized in vivo. Type 1 zygotes were constructed by placing the male haploid pronucleus from a zygote into the cytoplasm of an oocyte that underwent GV transfer, in-vitro maturation and activation; for type 2 zygotes, the female pronucleus was removed from a zygote and replaced with the female pronucleus of an oocyte subjected to GV transfer, in-vitro maturation and activation. Karyotypes of activated oocytes and type 2 zygotes were also subjected to analysis. When cultured in human tubal fluid (HTF) medium, reconstructed oocytes matured and, following artificial activation, consistently developed a pronucleus with a haploid karyotype; the activation rate for this medium was two- to three-fold higher than that of oocytes cultured in M199 (87% versus 30% respectively). Following transfer of a male pronucleus, only 47% of the type 1 zygotes developed to morula or blastocyst stage and embryo morphology was poor. In contrast, 73% of the type 2 zygotes developed to morula or blastocyst stage, many even hatching, with few morphological anomalies. Normal karyotypes were observed in 88% of the type 2 zygotes analysed. These observations demonstrate that the nucleus of a mouse oocyte subjected to sequential nuclear transfer at GV and pronucleus stages is, nonetheless, capable of maturing meiotically, activating normally and supporting embryonic development to hatching blastocyst stage. In contrast, the developmental potential of the cytoplasm of such oocytes appears to be compromised by these procedures.

Preimplantation genetic diagnosis in two families at risk for recurrence of Herlitz junctional epidermolysis bullosa

The Herlitz type of junctional epidermolysis bullosa (H-JEB) is a severe inherited bullous disease which leads to the early demise of the affected newborn. Mutations in the genes encoding the 3 polypeptides of the anchoring filament protein laminin 5 underlie this condition. We studied 2 families with affected children who previously died from H-JEB. Mutation screening using heteroduplex analysis and direct sequencing of the PCR products revealed a previously described hotspot mutation in LAMB3 (R635X), and a novel delayed termination codon in LAMB3 in the first proband. In the second proband, we found a novel initiation codon mutation in LAMB3, and a novel 2 bp deletion in LAMB3. For preimplantation genetic diagnosis (PGD) in these families, we developed nested multiplex PCR assays, amplifying the mutations and informative intragenic polymorphisms in the probands. Single embryonic cells were biopsied from 8-cell embryos using standard techniques, and subjected to the multiplex PCR assay followed by restriction enzyme digestion. Embryos found not to carry either mutation were transferred to the mothers, and a pregnancy was established in the second family as evidenced by the elevated level of HCG, although the pregnancy did not persist. This study illustrates the feasibility of PGD for an inherited skin disorder for the first time.

Electrical activation and in vitro development of human oocytes that fail to fertilize after intracytoplasmic sperm injection

OBJECTIVE

To determine whether electrically stimulated Ca2+ influx can "rescue" fertilization and early embryogenesis in human oocytes that fail to fertilize after intracytoplasmic sperm injection (ICSI).

DESIGN

Prospective, randomized trial of a laboratory procedure.

SETTING

A research laboratory at a university medical center.

PATIENT(S)

Discarded oocytes from ICSI-IVF cycles.

INTERVENTION(S)

Oocytes (n = 104) that showed no evidence of fertilization 16-24 hours after ICSI were assigned to three treatment groups: group 1 (one direct current electrical pulse at 1.36-1.50 kV/cm for 40-60 micros), group 2 (three pulses every 15-20 minutes), or group 3 (treated the same as group 2 but with no electrical stimulation).

MAIN OUTCOME MEASURE(S)

After stimulation, the oocytes were cultured in vitro for 3-5 days. Oocytes that displayed two pronuclei and a second polar body within 16 hours were considered to have fertilized normally. Fertilization and embryo cleavage rates were compared between groups.

RESULT(S)

Fertilization occurred in 26 (70%) of 37 and 38 (78%) of 49 group 1 and 2 oocytes, respectively, but in only 5 (27%) of 18 group 3 oocytes. Within 3 days, group 2 embryos routinely developed beyond the two-cell to four-cell stage (61% versus 13% in group 1); 11% of these oocytes developed to the morula or early blastocyst stage. Sex chromosome analyses indicated 10 male and 8 female embryos.

CONCLUSION(S)

Oocytes that fail to fertilize by 24 hours after ICSI can resume apparently normal fertilization and early embryonic development in response to electrical stimulation. Moreover, the degree of cytoplasmic activation as determined by the number of pulses applied affects fertilization efficiency and early embryonic development.

Reconstruction of mouse oocytes by germinal vesicle transfer: maturity of host oocyte cytoplasm determines meiosis

We evaluated the maturational competence of mouse oocytes reconstructed by the transfer and electrofusion of germinal vesicles (GV) into anuclear cytoplasts of GV stage oocytes (both auto- and hetero-transfers), metaphase II stage oocytes or zygotes. Following in-vitro culture, the maturation rates of the reconstructed oocytes to metaphase II did not significantly differ between auto- and hetero-transfers (40/70 versus 95/144 respectively); these rates also did not differ from those of control oocytes (57/97) which were matured in vitro without micromanipulation and electrofusion. In contrast, when a GV was transferred into an enucleated metaphase II oocyte or a zygote, only a few reconstructed oocytes underwent germinal vesicle breakdown (5/30 and 2/21 respectively); moreover, none reached metaphase II stage. Cytogenetic and immunofluorescence analyses were conducted on hetero-GV oocytes that extruded a first polar body. Each oocyte showed two groups of chromosomes, one in the cytoplast and one in the polar body, as well as a bipolar spindle with twenty univalent chromosomes. Our findings suggest that oocytes reconstructed by GV transfer into a cytoplast of the same developmental stage mature normally in vitro through metaphase II. Such oocytes may be a useful research model to elucidate the cytoplasmic and nuclear mechanisms regulating meiosis and the relationships between meiotic errors and age-related changes in the oocyte.

Fertility after hysteroscopic resection of submucous myomas

STUDY OBJECTIVE

To analyze fertility outcomes after resection of submucous myomas by operative hysteroscopy in infertile women.

DESIGN

Retrospective analysis (Canadian Task Force classification II-2).

SETTING

Academic tertiary referral center.

PATIENTS

Forty-one women (age 28-42 yrs) old with primary and secondary infertility, and histologically proved submucous myomas. Intervention. Hysteroscopic myomectomy performed with a rigid resectoscope.

MEASUREMENTS AND MAIN RESULTS

Of the 41 patients, 25 (60.9%) became pregnant overall and 20 (48.7%) delivered at term. Seventeen patients delivered a single fetus. Five delivered twins, three at term and two at 33 and 35 weeks. One woman delivered triplets at 31 weeks. The total delivery rate was 56.0%. Two women miscarried, at 6 and 8 weeks. One patient developed postoperative Asherman's syndrome.

CONCLUSION

Our results indicate that hysteroscopic myomectomy improves fertility in previously infertile women. Resection is a viable alternative to abdominal myomectomy for submucous myomas. (J Am Assoc Gynecol Laparosc 6(2):155-158, 1999)

Oral versus intramuscular progesterone for in vitro fertilization: a prospective randomized study

OBJECTIVE

To evaluate the efficacy of oral micronized progesterone compared with IM progesterone in oil for luteal support in patients undergoing IVF who are treated with a GnRH agonist.

DESIGN

Randomized prospective clinical trial.

SETTING

University-based IVF center.

PATIENT(S)

Women <40 years of age who were undergoing IVF with luteal GnRH pituitary down-regulation.

INTERVENTION(S)

Patients were randomized to receive either oral micronized progesterone (200 mg three times daily) or IM progesterone (50 mg daily).

MAIN OUTCOME MEASURE(S)

Progesterone levels at standardized days 21 and 28, and pregnancy and embryo implantation rates.

RESULT(S)

Day 21 progesterone levels were 77.6+/-13.2 ng/mL in the IM group and 81.5+/-16.2 ng/mL in the oral group. Day 28 progesterone levels were 76.3+/-15.0 ng/mL in the IM group and 53.6+/-10.1 ng/mL in the oral group. The clinical pregnancy rates were 57.9% and 45.8% for the IM and oral groups, respectively. The implantation rate per embryo was significantly higher in the IM group (40.9%) than in the oral group (18.1%).

CONCLUSION(S)

When used according to our protocols, oral progesterone and IM progesterone result in comparable levels of circulating progesterone. However, oral progesterone results in a reduced implantation rate per embryo.

Elevated day 3 serum follicle stimulating hormone and/or estradiol may predict fetal aneuploidy

OBJECTIVE

To determine whether baseline serum FSH and/or E2 concentrations can predict the risk for fetal chromosomal abnormalities.

DESIGN

Case control study.

SETTING

Reproductive technology program at a university hospital.

PATIENT(S)

Patients who underwent dilation and curettage (D + C), and whose products of conception were karyotyped.

INTERVENTION(S)

Patients underwent natural conception or controlled ovarian hyperstimulation followed by intrauterine insemination, in vitro fertilization and embryo transfer, gamete intrafallopian transfer, or zygote intrafallopian transfer.

MAIN OUTCOME MEASURE(S)

Baseline serum FSH and E2 concentrations and fetal karyotype.

RESULT(S)

Genetic evaluation of 78 D + C specimens revealed 34 normal and 44 abnormal fetal karyotypes. A significantly greater proportion of women with abnormal fetal karyotype had elevated baseline serum FSH (> or =15 mIU/mL [RIA] or 10 mIU/mL [Immulite]) and/or E2 > or = 50 pg/mL [Immulite]) compared with women of normal fetal karyotype. Among karyotypically abnormal abortuses, autosomal trisomy was the most common abnormality noted (79.5%), followed by mosaicism (6.8%), triploidy (6.8%), monosomy XO (4.5%), and balanced translocation (2.3%).

CONCLUSION(S)

Baseline serum FSH and/or E2 concentrations may be valuable as predictors of fetal aneuploidy.

Genetics, age, and infertility

OBJECTIVE

To review the genetics of aging specifically as it pertains to human fertility, as well as the recent advancements in the diagnosis of genetic diseases prior to embryo implantation.

METHODS

A review of our own experience as well as the scientific literature with regards to the decline in female fertility with age, the success of IVF in women of older reproductive age, and the role of preimplantation genetic diagnosis (PGD) in the evaluation of the patient at risk for fetal genetic anomalies.

RESULTS

The decline in female fertility occurs primarily as a result of a decline in oocyte quality as well as quantity. The frequency of chromosomal anomalies in recognized abortuses increases in parallel with the age-specific rise in the incidence of spontaneous abortions. PGD is an accurate diagnostic tool for exclusion of genetically deficient embryos prior to initiation of pregnancy.

CONCLUSION

Reproductive failure in women of older age appears to be directly related to ovarian age. Recent techniques such as cytoplasmic or germinal vesicle transfer are designed to replace the senescent cellular machinery believed to be responsible for genetic errors that occur during early cell division. PGD can accurately identify embryos with genetic deficiencies prior to implantation.

Genetic screening of prospective oocyte donors

OBJECTIVE

To report our experience with genetic screening of oocyte donor candidates and to determine the frequency with which significant genetic issues are identified.

DESIGN

Prospective genetic screening of oocyte donor candidates.

SETTING

University hospital oocyte donation program.

PATIENT(S)

Women presenting consecutively as volunteer oocyte donors.

INTERVENTION(S)

Genetic screening was performed by pedigree analysis and laboratory studies.

MAIN OUTCOME MEASURE(S)

Inclusion in the oocyte donor pool based on the results of clinical evaluation and laboratory tests consisting of polymerase chain reaction based mutational analysis for cystic fibrosis carrier status, cytogenetic analysis for karyotype, enzymatic assay for Tay-Sachs disease carrier status, and complete blood count and hemoglobin electrophoresis.

RESULT(S)

Eight (11%) of 73 oocyte donor candidates were excluded from the donor pool because of a potentially serious genetic finding. Cystic fibrosis mutations were identified in 5 candidates (7%), abnormal karyotypes were found in 2 (3.5%), and an autosomal dominant skeletal dysplasia was identified in 1 (1.4%).

CONCLUSION(S)

A significant proportion of women who present as candidates for oocyte donation are inappropriate for donation because of their genetic history or genetic testing results. A thorough genetic evaluation, including a history and laboratory screening, is essential to any oocyte donation program to maximize positive outcomes in pregnancies achieved through assisted means.

Successful outcome with day 4 embryo transfer after preimplantation diagnosis for genetically transmitted diseases

Preimplantation genetic diagnosis was performed in 61 day 3 embryos obtained by in-vitro fertilization from seven patient carriers of haemophilia, Marfan's syndrome, Bloch-Sulzemberg syndrome (incontinentia pigmentosa) or X chromosome-linked immune deficiency, retinitis pigmentosa, and FG syndrome, which is characterized by mental retardation and hypotonia. After multiplex polymerase chain reaction, 16 embryos were diagnosed as being unaffected, and these were transferred to the uterus on the following day (day 4). Of these embryos, six (37.5%) implanted, resulting in the delivery of a singleton and a twin pregnancy, a late second trimester miscarriage (twins at week 20) and a first trimester miscarriage at week 8. All the diagnoses were confirmed by amniocentesis. We report for the first time a late day 4 transfer of biopsied human embryos undergoing preimplantation genetic diagnosis. This transfer schedule allows an extra day to perform genetic analyses on single blastomeres and to monitor any adverse effect of the biopsy procedure.

Preimplantation genetic diagnosis of human embryos for Marfan's syndrome

PURPOSE

Single-cell nested polymerase chain reaction (PCR) and Ddel endonuclease digestion were used to detect the presence of a Marfan's syndrome mutation in human preimplantation embryos derived from in vitro fertilization (IVF). These procedures were conducted to eliminate the possibility of transmission of the affected allele from the father to his offspring. The mutation on chromosome 15 is transmitted as an autosomal dominant trait, and the chance of having a child affected with the disease is 50%.

METHODS

A couple presented to the Program for In Vitro Fertilization, Reproductive Surgery and Infertility for preimplantation genetic diagnosis. IVF was performed and embryo biopsy was done on day 3 embryos. Single blastomeres were removed from embryos and subjected to nested PCR analysis and endonuclease digestion to detect a Marfan's syndrome mutation located on chromosome 15 inherited from the father.

RESULTS

Thirteen oocytes were injected with spermatozoa using intracytoplasmic sperm injection, and nine fertilized normally. Following embryo biopsy and polymerase chain reaction amplification-Ddel endonuclease digestion, five embryos were detected that were positive for the mutation. The four non-affected embryos were transferred to the uterus, resulting in a healthy and normal ongoing pregnancy.

Simultaneous assessment of sperm chromatin condensation and morphology before and after separation procedures: effect on the clinical outcome after in vitro fertilization

OBJECTIVE

To look for correlations between acridine orange (AO) staining and semen parameters before and after sperm separation procedures and to assess whether the AO test predicts fertilization or pregnancy outcomes after standard IVF and intracytoplasmic sperm injection.

DESIGN

Prospective study that simultaneously assesses sperm morphology and nuclear protein maturity on a cell-by-cell basis before and after preparative procedures.

SETTING

University teaching hospital.

PATIENT(S)

Men (n = 140) undergoing diagnostic semen analysis.

MAIN OUTCOME MEASURE(S)

Acridine orange fluorescence of sperm nuclei, semen parameters, IVF outcome.

RESULT(S)

In unprocessed samples, 90% of sperm with normal heads displayed green fluorescence (mature nuclear protein); significantly lower percentages of green fluorescence were observed in sperm with abnormal heads. The percentage of mature normal sperm in the specimen correlated with motility. Sperm maturity after swim-up or Percoll gradient was significantly improved for sperm with normal or abnormal heads. The percentage of mature normal sperm correlated with motility after either Percoll or swim-up. Neither the percentages of mature nuclei nor mature normal nuclei correlated with fertilization or pregnancy outcome.

CONCLUSION(S)

Nuclear protein maturation correlates with sperm motility and morphology. Because morphologically normal and motile sperm are more mature, separation procedures should generate a population of sperm with the highest fertilization capacity. Acridine orange staining, however, did not predict fertilization efficiency or pregnancy outcome in IVF cycles.

Laparoscopy for pelvic pain in the Mayer-Rokitansky-Kuster-Hauser syndrome. A case report

BACKGROUND

The Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome occurs in 1 of every 4,000-5,000 female births. It is characterized by normal external genitalia, an absent vagina, absent or rudimentary uterus, and normal fallopian tubes and ovaries. When associated with a rudimentary uterine horn, cyclic catamenial pelvic pain may result. The standard procedure for pain relief has been removal of the uterine horn by laparotomy.

CASE

A rudimentary uterine horn was diagnosed in a woman with MRKH syndrome who developed monthly severe pelvic pain. Removal of the structure was performed via laparoscopy. The patient had complete resolution of her pain.

CONCLUSION

As an alternative to laparotomy, laparoscopic resection of a rudimentary horn in patients with MRKH syndrome is both feasible and beneficial in the treatment of pelvic pain.

A simple and objective approach to identifying human round spermatids

Although round spermatids have been studied extensively using staining techniques and electron microscopy, little information is available about their appearance in living conditions. We describe a method of collecting and identifying round spermatids from ejaculates and testicular biopsies. The validity of the selection procedure was confirmed by fluorescence in-situ hybridization. Based on cell size, morphological characteristics of nucleus and cytoplasm, and on the nucleus/cytoplasm ratio, we harvested a population of cells that was 84% haploid. This procedure can be applied to select spermatids for clinical or research purposes.

Update in preimplantation genetic diagnosis. Age, genetics, and infertility

PGD has been successfully used for several years. Over 40 babies have been born worldwide by use of these techniques. Unfortunately, a number of misdiagnoses have been made, a distressing consequence of a new frontier. Significant advances have been made to improve the efficiency and accuracy of PCR and FISH. The widespread use of this technology awaits further documentation of safety and accuracy. Other issues must also be addressed. First, the cost-effectiveness of the techniques relative to the traditional alternatives must be evaluated. A number of ethical issues regarding embryo screening must be addressed including what diseases are serious enough to warrant the procedure. Another concern is the use of this technology for nongenetic disorders such as gender selection. Finally, the experimental nature of these procedures must continually be discussed with patients, and long-term follow-up studies must be undertaken. Development of more accurate and less expensive assays coupled with improved IVF success rates may make PGD a more widely used clinical tool. The future awaits these developments.

Laparoscopic resection of a noncommunicating rudimentary uterine horn

Two women had infertility due to a symptomatic unicornuate uterus associated with rudimentary contralateral horn. Both carried successful pregnancies after laparoscopic resection of the horns.

Expression of the 60 kDa heat shock protein in peritoneal fluids from women with endometriosis: implications for endometriosis-associated infertility

Proinflammatory cytokines and activated macrophages and T lymphocytes have been detected in peritoneal fluids of women with endometriosis and may impair fertility. Expression of the 60 kDa heat shock protein (hsp60) is one mechanism leading to a localized activation of macrophages and T lymphocytes and cytokine release. Peritoneal fluids, obtained from 68 women undergoing a diagnostic laparoscopy, were assayed for hsp60. As independent evidence of local immune activation, the fluids were analysed for interferon gamma (IFN gamma). Fluids were also tested for antibodies to Chlamydia trachomatis because a chronic asymptomatic infection by this organism may also release hsp60. At laparoscopy, 26 women were diagnosed with pelvic adhesions, 19 had endometriosis, 16 had a visibly normal pelvis, four had ovarian cysts while three had myomas. The prevalence of hsp60 was higher in peritoneal fluids from the women with endometriosis than in the other subjects (P = 0.005). Hsp60 was detected in seven (36.8%) of the endometriosis patients and in only one each of the women with adhesions, a normal pelvis or an ovarian cyst; all women with myomas were negative. Detection of IFN gamma in peritoneal fluids was highly correlated with the presence of hsp60 (P = 0.0003). IFN gamma was present in seven of nine (77.8%) women with hsp60 and in only five of 40 (12.5%) women lacking hsp60. Women with pelvic adhesions had an increased prevalence of immunoglobulin G antibodies to C.trachomatis compared with the other women (P = 0.01). There was no relationship between evidence of exposure to C.trachomatis and hsp60 in peritoneal fluids. These data suggest that hsp60 may be released into the peritoneal fluid as a consequence of implanted ectopic endometrium. Hsp60-mediated immune activation may be one mechanism leading to endometriosis-associated infertility.

Update in preimplantation genetic diagnosis: successes, advances, and problems

The field of preimplantation genetic diagnosis has undergone significant advances since the report of the first birth from this method in 1990. The first birth in the USA was reported in 1992, as was the first successful diagnosis and delivery of a baby free of a single gene defect disorder (cystic fibrosis and then Tay Sachs). Investigators have now reported approximately 40 births worldwide from preimplantation genetic diagnosis using the polymerase chain reaction and fluorescent in-situ hybridization methods to analyze single cells removed from early cleavage stage preimplantation embryos. The International Working Group on Preimplantation Genetics meets annually to discuss progress and pitfalls in this field. Although preimplantation genetic diagnosis offers hope to patients at risk of transmitting disease, there are many technical hazards of this experimental procedure. Technical difficulties must be overcome in order for preimplantation genetic diagnosis to become a standard clinical tool. This review will highlight some of the recent advances and problems in the field of preimplantation genetic diagnosis.

Ureaplasma urealyticum and Mycoplasma hominis detected by the polymerase chain reaction in the cervices of women undergoing in vitro fertilization: prevalence and consequences

PURPOSE

The prevalence of Ureaplasma urealyticum and Mycoplasma hominis in the endocervix at the time of oocyte collection in women undergoing in vitro fertilization (IVF) was examined using the polymerase chain reaction (PCR).

METHODS

All women were treated with tetracycline following sample collection.

RESULTS

U. urealyticum was identified in 56 (17.2%) of 326 women while M. hominis was present in only 5 (2.1%) of 235 women. U. urealyticum was detected at a higher frequency (P = 0.01) in those women whose IVF cycle failed prior to embryo transfer. This organism was present in 8 of 19 (42.1%) women with either no fertilization or no embryo transfer, 19 of 148 (12.8%) who had no evidence of pregnancy following embryo transfer, 6 of 30 (20.0%) who had only a transient (biochemical) pregnancy, 5 of 14 (35.7%) with a spontaneous abortion, and 18 of 115 (15.6%) with a term birth. Of the eight women with U. urealyticum who had no embryos transferred, male factor was the cause of infertility in five cases, two women had tubal occlusions while in one woman the diagnosis was idiopathic. Therefore, poor sperm quality, and not a U. urealyticum infection, might explain the failure of most of these cases to proceed to the stage of embryo transfer. Analysis of all patients revealed no association between male factor infertility and U. urealyticum in the cervix.

CONCLUSIONS

U. urealyticum, but not M. hominis, is present in the cervices of many culture-negative women. Its presence, however, does not influence IVF outcome subsequent to embryo transfer in women treated with tetracycline after oocyte retrieval.

Marfan syndrome as a paradigm for transcript-targeted preimplantation diagnosis of heterozygous mutations

Among the many clinical applications of the polymerase chain reaction (PCR) is its potential use in preimplantation diagnosis of genetic disorders. Performing PCR on single blastomeres from early cleavage stage (six- to eight-cell) human embryos should, in principle, enable reliable determination of disease status for certain inherited conditions. However, reports of misdiagnoses using this technique have diminished enthusiasm for its widespread clinical use. One principal source of error is the propensity for genome-targeted PCR to exclusively amplify one allele in reactions assaying a single heterozygous diploid cell. Complete reaction failure is also common. Employing the Marfan syndrome (MFS) as a paradigm, we have developed a reliable, reverse transcription-PCR-based method of genotyping single cells that overcomes these obstacles. The technique should facilitate accurate preimplantation diagnosis of MFS and other selected genetic diseases caused by heterozygous or compound-heterozygous mutations.

Chlamydia trachomatis detected by polymerase chain reaction in cervices of culture-negative women correlates with adverse in vitro fertilization outcome

The prevalence of Chlamydia trachomatis in the endocervices of 307 asymptomatic culture-negative women undergoing in vitro fertilization (IVF) was evaluated. C. trachomatis was detected by polymerase chain reaction (PCR) in 20 subjects (6.5%), and there were strong correlations between a positive finding and both failure to become pregnant (P = .013) and spontaneous abortion after embryo transfer (P = .004). C. trachomatis was identified in 2 (1.8%) of 112 who had term deliveries, 3 (27.3%) of 11 who spontaneously aborted, 1 (3.3%) of 30 with biochemical pregnancies, 13 (9.6%) of 135 with no pregnancy after embryo transfer, and 1 (5.3%) of 19 whose embryos did not become fertilized. There were no relationships between PCR findings and maternal age, cause of infertility, number of oocytes retrieved or fertilized, or number of embryos transferred; 55% of PCR-positive and 40% of PCR-negative women were undergoing at least their second IVF. An undetected C. trachomatis infection may be responsible for implantation failure or spontaneous abortion after IVF and embryo transfer.

Assessment of numeric abnormalities of X, Y, 18, and 16 chromosomes in preimplantation human embryos before transfer

OBJECTIVE

Our purpose was to determine the feasibility of ascertaining aneuploidy for chromosomes X, Y, 18, and 16 by use of multiple-probe fluorescence in situ hybridization in blastomeres from preimplantation human embryos.

STUDY DESIGN

A short fluorescence in situ hybridization procedure involving the simultaneous use of four deoxyribonucleic acid probes detected with red, green, blue, or a mixture of red and green fluorochromes was developed to determine numeric abnormalities of chromosomes X, Y, 18, and 16. Embryos underwent biopsy, and all or most cells were analyzed to distinguish true aneuploidy from mosaicism and to assess technique variations within the same embryo (n = 64).

RESULTS

The analysis of all the blastomeres of an embryo was achieved in 91% of the embryos. Successful analyses including biopsy, fixation, and fluorescence in situ hybridization were achieved in 87.8% of the blastomeres. Of the four chromosomes tested, numeric aberrations were found in 23% and 42% of normally and abnormally developing embryos, respectively, including aneuploidy, polyploidy, haploidy, and mosaicism. When diploid embryos containing one or several tetraploid cells are counted as chromosomally abnormal, then 49% and 61% of normally and abnormally developing embryos, respectively, were chromosomally abnormal. Aneuploid embryos consisted of two monosomies for chromosome 16, one for chromosome 18, and a trisomy for chromosome 16. There was a tendency for aneuploidy to increase with maternal age.

CONCLUSIONS

Fluorescence in situ hybridization is a more efficient method than cytogenetic analysis to study specific aneuploidies at preimplantation stages of development in human embryos. In addition, the preimplantation genetic diagnosis of two blastomeres per eight-cell embryo may be sufficient to ensure successful analysis of polyploidy, haploidy, and specific aneuploidies without endangering the survival of the embryo. The technique can be easily modified to consider other chromosomes, including 13 and 21. Because most chromosomally abnormal embryos do not develop to term, the use of this technique may increase the delivery rate per embryo by allowing only transfer of embryos normal for the tested chromosomes. This technique would be most useful for older women undergoing in vitro fertilization, because aneuploidy appears to increase with advancing maternal age.

Laparoscopic resection of a noncommunicating rudimentary uterine horn. A case report

Patients who have a unicornuate uterus with a noncommunicating rudimentary horn that contains an endometrial cavity are at risk for endometriosis and obstetric complications. As in this case, resection of the rudimentary horn can be performed laparoscopically without increased risk to the patient and with some potential benefit.

Unsuspected Chlamydia trachomatis infection and in vitro fertilization outcome

OBJECTIVE

Chlamydia trachomatis infections of the female genital tract, although a major cause of infertility, are often asymptomatic and undetected. Since many infertile women now seek in vitro fertilization, a procedure whereby fertilization and embryo implantation are precisely timed, we sought to determine the relation between an unsuspected C. trachomatis infection and the ability of embryos to implant and develop after their transfer to the uterus.

STUDY DESIGN

At the time of oocyte aspiration, endocervical samples were obtained from 216 women and assayed by enzyme-linked immunoassay for immunoglobulin A antibodies to C. trachomatis structural membrane components and to recombinant C. trachomatis heat shock protein. The presence of C. trachomatis in the cervices was assessed by the polymerase chain reaction. The outcome of each in vitro fertilization cycle was then ascertained.

RESULTS

Oocytes from 198 (91.7%) of the women were fertilized in vitro and subsequently transferred to the uterus. Term deliveries of healthy infants occurred after 68 (34.3%) of these transfers. Cervical immunoglobulin A antibodies to chlamydial heat shock protein were detected in 5 (7.3%) of the women with term births, and 1 (1.5%) also had immunoglobulin A antibody to chlamydial structural components; 3 (4.4%) were positive by the polymerase chain reaction for C. trachomatis. In contrast, among the 130 women whose embryo transfers did not result in an ongoing pregnancy, 36 (27.7%) had cervical antiheat shock protein immunoglobulin A (p = 0.0007) and 24 (18.5%) had antichlamydial structural component immunoglobulin A (p = 0.0002); 15 (11.5%) of these women had positive results of polymerase chain reaction for C. trachomatis. The majority of women with cervical antibodies to chlamydial structural antigens were also positive for antibody to heat shock protein. However, only 35% of the women with antibodies to heat shock protein were also positive for the other chlamydial antibodies. C. trachomatis was detected by polymerase chain reaction in 29.2% of women with anti-C. trachomatis antibodies and 7.8% of women with anti-heat shock protein antibodies. Women positive for antichlamydial immunoglobulin A were more likely to be undergoing a repeat in vitro fertilization cycle than were women who were antibody negative (p = 0.007).

CONCLUSION

Unsuspected C. trachomatis infection or reactivation of an immune response to the C. trachomatis heat shock protein may induce an inflammatory reaction in the uterus that impairs embryo implantation and/or facilitates immune rejection after uterine transfer of in vitro fertilized embryos.

Healthy deliveries from biopsied human embryos

Preimplantation genetic diagnosis was performed in 122 embryos obtained by IVF from 11 patients carriers of haemophilia, Duchenne's muscular dystrophy, Barth's syndrome, cystic fibrosis, Pelizaeus-Merzbacher syndrome or Rett's syndrome. After multiplex polymerase chain reaction (PCR) or fluorescence in situ hybridization (FISH) analysis with multiple probes, 28 embryos diagnosed as not affected were replaced. Of these, eight implanted (28%) and produced three ongoing pregnancies, three deliveries of four babies and a biochemical pregnancy. However, one case screened for cystic fibrosis was misdiagnosed and the pregnancy was terminated. In order to evaluate the efficiency of multiplex PCR, 55 non-replaced embryos were reassessed by PCR or by FISH. Identical results were obtained in all cases. However, one embryo which had only X-chromosome specific amplification by PCR was found to be XO in all its cells by FISH. Although multiplex PCR is demonstrated to be reliable for sexing of human embryos, FISH has the additional advantages of supplying ploidy assessment while not being affected by contamination.

Ectopic pregnancies after in vitro fertilization and embryo transfer

OBJECTIVE

Our objective was to analyze the risk factors, stimulation characteristics, and future fecundity of patients with ectopic pregnancies after in vitro fertilization (IVF).

METHODS

We retrospectively evaluated all cases of ectopic pregnancy occurring between January 1989 and March 1993 (Cornell series 1 to 17). A case-control group of intrauterine pregnancies was used for comparison of the stimulation and transfer characteristics.

RESULTS

Twenty-seven of 1123 pregnancies (2.4%) were ectopic, following 2812 fresh IVF embryo transfers, while 8 of 105 pregnancies (7.6%) were ectopic, following 405 frozen-thawed embryo transfers. Tubal factor was the cause of infertility in the majority (85.7%) of ectopic pregnancies. No difference was found between the ectopics and the matched controls in stimulation and transfer characteristics. Thirty ectopic pregnancies were ampullary, two were interstitial, two were cervical, and one was heterotopic. Twenty of the patients subsequently underwent 29 IVF attempts, with a pregnancy rate of 41.4% per transfer.

CONCLUSIONS

Ectopic pregnancy after IVF appears to be related to preexisting tubal pathology; embryo transfer of cryopreserved thawed embryos in a natural cycle may result in a higher ectopic rate in these patients; in subsequent IVF cycles the intrauterine pregnancy rate of these patients is not decreased.

Primer extension preamplification for detection of multiple genetic loci from single human blastomeres

A new technology called primer extension preamplification (PEP), which has been applied to single spermatozoa, increases the amount of polymerase chain reaction (PCR) templates by amplifying DNA of the whole genome. The current investigation was aimed at applying PEP to single human blastomeres. Two blastomeres with nuclei from arrested embryos were selected for this study. Using three different PEP protocols (experiments I, II and III), DNA from single blastomeres was amplified using 15-base oligonucleotide random primers. The efficiency of the procedure was determined by further amplifications of aliquots of the PEP products with two specific sequences. Three aliquots from each PEP product were used as PCR templates for the human X chromosome (X) or the exon 10 of the cystic fibrosis gene (CF). PCR amplified products were analysed by gel electrophoresis. In experiment I, when X primers were used, positive signals were detected in all 10 embryos (100%), 90.0% (18/20) of the blastomeres, and in 80.0% (96/120) of the replicates. When CF primers were amplified, all embryos (100%, 10/10), 90.9% (18/20) of the blastomeres and 78.3% (47/60) of the replicates were positive. In experiment II, efficiency was significantly reduced when total time for the procedure was minimized from 8 h to 5 h and 45 min. Although the time was further reduced to 4 h and 40 min in experiment III, the efficiency remained the same as in experiment I when the volume of PEP was reduced from 60 microliters (experiments I and II) to 40 microliters. One out of 132 control replicates (0.8%) was contaminated.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of Chlamydia trachomatis in semen by the polymerase chain reaction in male members of infertile couples

OBJECTIVE

Our objective was to evaluate the presence of asymptomatic Chlamydia trachomatis infection by means of the polymerase chain reaction in male members of couples with previously undiagnosed infertility.

STUDY DESIGN

Twenty-eight infertile-couples who had negative cultures or negative results when tested by deoxyribonucleic acid probe for Chlamydia trachomatis in semen and cervical samples were studied. Semen samples were tested for Chlamydia trachomatis by means of the polymerase chain reaction. Sera from both partners were diluted 1:128 and tested for immunoglobulin M antibodies to Chlamydia. Sera and ejaculated sperm were evaluated for the presence of antisperm antibodies. Semen analyses were also performed.

RESULTS

Chlamydia trachomatis was identified in semen from 11 (39.3%) of the male partners. Its detection correlated with the presence in the ejaculate of motile sperm containing antisperm antibodies (p < 0.01). Either antisperm immunoglobulin G, immunoglobulin A, or both were located on sperm only from 5 (45.5%) of the 11 men whose results were positive when tested for Chlamydia trachomatis. Similarly, immunoglobulin G or immunoglobulin A antibodies to sperm were only detected in 5 (45.5%) of the spouses of men with Chlamydia in semen. Immunoglobulin M antibody to Chlamydia trachomatis was identified in only one of the men. However, antichlamydial immunoglobulin M antibodies were present in sera from 6 (54.5%) female partners of men with seminal Chlamydia trachomatis but in none of the other 17 women (p < 0.01).

CONCLUSION

Although undetected by culture of deoxyribonucleic acid probe of semen samples, Chlamydia trachomatis was nevertheless identified in semen of some symptom-free men by the polymerase chain reaction. This is probably a result of the increased sensitivity of the polymerase chain reaction to detect Chlamydia trachomatis. The increased prevalence of an autoimmune response to sperm in men with this organism in their semen suggests that a subclinical chlamydial infection may activate an immune response to sperm. A similar association between Chlamydia trachomatis in semen and circulating antisperm antibodies in female partners indicates that Chlamydia may also induce an immune response to sperm in women. Infertility in these couples may be the result of a direct inflammatory response in the cervix or endometrium to repeated Chlamydia exposure or of the ability of Chlamydia to evoke an immune response to spermatozoa.

Aldose reductase inhibition prevents galactose-induced ovarian dysfunction in the Sprague-Dawley rat

OBJECTIVE

Our objective was to determine whether impaired ovarian function induced by short-term creation of a galactosemic state in the rat might be prevented by the coadministration of an aldose reductase inhibitor.

STUDY DESIGN

Prepubertal Sprague-Dawley rats were fed four different diets including (1) control, (2) 40% galactose, (3) 40% galactose and an aldose reductase inhibitor, and (4) an aldose reductase inhibitor with the control diet. Percentage germinal vesicle breakdown, postovulatory oocyte quantities, hormonal parameters, ovarian histologic evaluation, and ovarian galactitol concentrations were determined.

RESULTS

The galactose-fed animals (group 2) had decreased germinal vesicle breakdown (47%) versus control (69%, p < 0.05). Galactose-exposed animals had significantly decreased quantities of postovulatory eggs (6.4 per animal) after menotropin ovarian stimulation in comparison with controls (14.1, p < 0.01). In rats exposed to high dietary levels of galactose (group 2) ovarian galactitol concentrations were significantly higher (protein 42.12 mumol/gm versus 0.0 for controls, p < 0.005). When galactose-fed animals received the aldose reductase inhibitor, ovarian accumulation of galactitol was significantly reduced and the observed detrimental effects on the oocyte were prevented.

CONCLUSION

Galactitol accumulation or metabolic flux through aldose reductase in galactosemic rodents may be involved in the demonstrated ovarian dysfunction.

Relation between antibodies to Chlamydia trachomatis and spontaneous abortion following in vitro fertilization

BACKGROUND

Many couples undergo in vitro fertilization due to occlusion of the fallopian tubes. Chlamydia trachomatis infections are a major cause of this tubal damage. Since this organism has also been associated with poor pregnancy outcome, we investigated whether a past exposure to C. trachomatis was associated with spontaneous abortion following in vitro fertilization and embryo transfer.

METHODS

Sera from 145 women undergoing IVF were diluted 1:128 and tested for IgG antibodies to C. trachomatis by an immunoperoxidase assay, using infected cells fixed to slides. All subjects and their partners were negative for C. trachomatis by culture or by DNA hybridization.

RESULTS

Serological evidence of a past chlamydial infection was observed in 33.8% of the women. The incidence of antichlamydial IgG was greater (P less than 0.001) in women whose infertility was due to known tubal disease (37 of 78; 47.4%) than in women whose infertility was due to other causes (12 of 67; 17.9%). Spontaneous abortions after embryo transfer occurred in 20% of the subjects. The incidence of antichlamydial IgG in aborting women (20 of 29; 69.0%) was greater (P less than 0.001) than the incidence in either women with successful pregnancies (9 of 38; 23.7%) or women who did not become pregnant (20 of 78; 25.6%) after IVF. No relation was observed between antichlamydial antibody status and maternal age, the number of oocytes aspirated, the number of oocytes fertilized, and the number of embryos transferred.

CONCLUSIONS

A previous infection with C. trachomatis may increase susceptibility to subsequent spontaneous abortion, even in the absence of a detectable current infection.

Baseline ovarian cysts do not affect clinical response to controlled ovarian hyperstimulation for in vitro fertilization

OBJECTIVE

To evaluate the effect of baseline ovarian cysts at the onset of controlled ovarian hyperstimulation for in vitro fertilization (IVF) on cycle outcome.

DESIGN, PATIENTS

A review of 82 IVF cycles in 29 women in which each patient served as her own control. The stimulation regimen for each patient remained constant over time. Each woman had at least one cycle in which an ovarian cyst measuring 14 to 53 mm was present at baseline and one cycle in which no such cyst was present.

SETTING

The In Vitro Fertilization Program at Yale University School of Medicine.

RESULTS

There was no statistically significant difference in cycle cancellation rates, baseline serum estradiol (E2), peak serum E2, number of follicles present at retrieval, number of oocytes retrieved, or fertilization rate between groups. Stimulation regimen, cyst size, and age were unrelated to outcome. The number of cysts present at baseline correlated positively with the number of follicles present at retrieval.

CONCLUSION

Baseline ovarian cysts in the setting of a low baseline E2 level do not affect the clinical response to controlled ovarian hyperstimulation in IVF cycles.

Preimplantation genetic diagnosis. In situ hybridization as a tool for analysis

In situ hybridization allows one to directly visualize DNA sequences of interest for which probes are available. Fluorescent signals can be detected in single cells in either metaphase or interphase nuclei, thus obviating the need for cell synchronization. The potential to use this technology in conjunction with in vitro fertilization techniques to genetically analyze an embryo before transfer could offer patients at genetic risk an alternative. Currently, these patients wait until 9 to 16 weeks' gestation to find out about the genetic makeup of their pregnancy. As such, sexing the embryos of patients at risk for transmitting sex-linked disorders or for performing numerical chromosome analysis could be performed before embryo transfer. Techniques for applying in situ hybridization to single cells obtained from embryos are presented. Hybridization of specific probes to blastomeres of mouse and human embryos as well as sperm is demonstrated.

Preembryo biopsy and analysis of blastomeres by in situ hybridization

We developed a method for the biopsy of preimplantation mouse embryos (preembryos) at the four- to eight-cell stage, which uses partial zona pellucida dissection. The preembryos were collected in calcium- and magnesium-free phosphate-buffered saline solution with 0.01% ethylenediaminetetraacetic acid, 0.1 mol/L sucrose, and 4 mg/ml of bovine serum albumin to facilitate removal of blastomeres. This allows entry of a fine micropipette into the perivitelline cavity with subsequent removal of a single blastomere by gentle suction. The majority of embryos (75%) from which biopsy specimens were obtained in this fashion developed to the blastocyst stage. The blastomeres obtained were mainly intact and they were fixed to glass slides. After permeabilization, in situ hybridization was performed with chromosome X- and chromosome 3-specific probes. Human unfertilized eggs and blastomeres from human polyspermic embryos also have been analyzed by in situ hybridization with chromosome specific probes. The combination of nondestructive embryo biopsy and in situ hybridization is a possible approach for preimplantation genetic diagnosis.

Term interstitial pregnancy with uterine torsion: sonographic, pathologic, and clinical findings

Interstitial pregnancy which resulted in a term, live infant was found in association with pathologic torsion of the uterus. Antenatal sonograms revealed a hypervascular area anterior to the uterus.

Interferon-gamma in the diagnosis and pathogenesis of pelvic inflammatory disease

Serologic markers were evaluated to determine if they could aid in the differential diagnosis of pelvic inflammatory disease in 48 consecutive women seeking evaluation for pelvic pain. On the basis of clinical and microbiologic parameters, 29 patients (60.4%) were diagnosed as having pelvic inflammatory disease. Neisseria gonorrhoeae only was isolated from the cervix of eight (27.6%) patients with pelvic inflammatory disease, five (17.2%) had only Chlamydia, and two (6.9%) had Neisseria and Chlamydia, whereas in 15 (48.3%) patients no pathogen was isolated. Interferon-gamma was present in significantly more sera (p less than 0.025) from patients with pelvic inflammatory disease (65.5%) than from women without pelvic inflammatory disease (15.8%). Sera from 10 healthy women lacked detectable interferon-gamma. In patients with only Neisseria, seven (87.5%) had circulating interferon-gamma; three (60%) of the women with only Chlamydia, one (50%) woman with Neisseria and Chlamydia, and eight (57.1%) with no identified pathogens were also positive for interferon-gamma. Sera from 11 of 28 patients with pelvic inflammatory disease (39%) but only one of 19 sera from women without pelvic inflammatory disease (5%) also inhibited the Candida-induced proliferation of control lymphocytes. This immunosuppressive activity was prevented by immunoprecipitation of interferon-gamma by anti-interferon-gamma antibody but not by treatment with anti-interferon-alpha antibody. The persistence of interferon-gamma in the sera of patients with pelvic inflammatory disease may aid in the differential diagnosis of this disease and increase our understanding of the pathogenesis of microbial-mediated tubal damage.

Influence of 5' proximal secondary structure on the translational efficiency of eukaryotic mRNAs and on their interaction with initiation factors

The effects of 5' proximal secondary structure in mRNA molecules on their translation and on their interaction with the eukaryotic initiation factors (eIF)-4F, eIF-4A, and eIF-4B have been examined. Secondary structures were generated in the 5' noncoding region of rabbit globin and reovirus mRNAs by means of hybridization with cDNA molecules. cDNAs hybridized to the first 15 bases downstream from the cap inhibited the translation of the mRNAs in both reticulocyte and wheat germ lysates. The degree of inhibition was directly related to the monovalent ion concentration and inversely related to reaction temperature. These hybrid structures also reduced the competitive ability of the messages. Hybrid structures beginning downstream from the first 15 bases did not inhibit the translation of beta-globin mRNA or reovirus s3 mRNA. None of the hybrid structures were detrimental to the interaction of the mRNAs with the 26-kDa cap binding protein of eIF-4F, as determined by chemical cross-linking assays. However, in the presence of ATP, hybrid structures immediately adjacent to the cap severely inhibited the cross-linking to the p46 subunit of eIF-4F or to additional eIF-4A or eIF-4B. In order to account for these observations, a two-step mechanism is proposed for the interaction of eIF-4F with the 5' end of an mRNA molecule. The first step involves a weak initial interaction of the p26 subunit with the cap. The second step requires the hydrolysis of ATP and results in the formation of a stable initiation factor-mRNA complex, which may involve eIF-4A and eIF-4B. This second step is inhibited by the presence of 5' proximal secondary structure. In any event, our results demonstrate that the effect of mRNA structure on translation rate depends strongly on its position with respect to the 5' end and that this effect is due at least in part to an inhibition of the action of initiation factors normally required for the unwinding of structure.

ATP-dependent unwinding of messenger RNA structure by eukaryotic initiation factors

Interaction of protein synthesis initiation factors with mRNA has been studied in order to characterize early events in the eukaryotic translation pathway. Individual reovirus mRNAs labeled with 32P in the alpha position relative to the m7G cap and eukaryotic initiation factor (eIF)-4A, -4B, and -4F purified from rabbit reticulocytes were employed. It was found that eIF-4A causes a structural change in mRNA, as evidenced by a nuclease sensitivity test: addition of high concentrations of eIF-4A greatly increase the nuclease sensitivity of the mRNA, suggesting that this factor can melt or "unwind" mRNA structure. ATP is required for this reaction. At low concentrations of eIF-4A, addition of eIF-4B is required for maximal unwinding activity. Thus eIF-4B enhances eIF-4A activity. Addition of eIF-4F also makes the mRNA sensitive to nuclease indicating a similar unwinding role to that of eIF-4A. Stoichiometric comparisons indicate that eIF-4F is more than 20-fold more efficient than eIF-4A in catalyzing this reaction. The unwinding activity of eIF-4F is inhibited by m7GDP, while that of eIF-4A is not. This suggests that eIF-4A functions independent of the 5' cap structure. Our results also suggest that the unwinding activity of eIF-4F is located in the 46,000-dalton polypeptide of this complex, which has shown by others to be similar or identical to eIF-4A.