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Biomedical subjects

A D Dorfmann

Publications and source records attributed to A D Dorfmann.

12 recordsLinked to original sources
PubMed1996

Frequency of abnormal karyotypes among abortuses from women with and without a history of recurrent spontaneous abortion.

OBJECTIVE: To compare the frequency of chromosomal abnormalities in products of conception from women with and without a history of recurrent spontaneous abortion. DESIGN: Retrospective analysis of prospectively collected material. SETTING: Private practice at the Genetics and IVF Institute, Fairfax, Virginia and Grupo de Reproducción AGY Asociados, México City, México. PATIENTS: Women with (n = 94) and without (n = 130) a history of recurrent spontaneous abortion who had a spontaneous abortion between January 1, 1992 and November 1, 1994. INTERVENTION: Chromosomal analysis performed on products of conception using standard G-banding technique. MAIN OUTCOME MEASURE: The percentage of chromosomal abnormalities among products of conception from women with and without recurrent spontaneous abortion was compared. RESULTS: Among products of conception from women with recurrent spontaneous abortion, 57% (54/94) had abnormal and 43% (40/94) had normal chromosome analyses. Products of conception from women without recurrent spontaneous abortion had abnormal chromosome analyses in 57% (74/130) and normal results in 43% (56/130). CONCLUSIONS: No differences in frequency of abnormal karyotype were observed in products of conception from women with recurrent spontaneous abortion compared with women without recurrent spontaneous abortion.

Abortion, Habitual↗
PubMed1993

Acrosome reaction inducing activity in follicular fluid correlates with progesterone concentration but not with oocyte maturity or fertilizability.

Follicular fluid is a potent mediator of sperm acrosome reaction (AR) in vitro. The aim of this study was to investigate whether individual follicular fluids vary quantitatively in their ability to stimulate an AR, and whether such variability relates to fertilizability of the corresponding egg, its maturational level and/or progesterone content. Individual follicular fluids were obtained from 24 women undergoing in-vitro fertilization and assayed for their ability to induce an AR in normal human spermatozoa. After incubation in capacitation medium for 18 h, spermatozoa were challenged with the individual follicular fluids for 30 min. AR was detected by immunofluorescence, using fluorescein-labelled Pisum sativum lectin. We found that individual follicular fluids varied markedly in their ability to induce AR. Acrosome reaction correlated linearly with progesterone concentration (Spearman's r = 0.735, P = 0.01) at constant protein level, but no correlation was found between AR and protein concentration at constant progesterone level. Progesterone concentrations were not only higher (ANOVA, P = 0.002) in fluids from mature oocytes compared to those from less mature or post-mature eggs but also in fluids from fertilized compared to unfertilized eggs (ANOVA, P = 0.015, n = 13 patients with both fertilized and unfertilized eggs). In contrast, AR-inducing ability of individual follicular fluids did not differ for fertilized and unfertilized eggs. While AR-inducing ability appeared to increase with maturational stage of the egg, this trend was not statistically significant, probably due to small sample size. Our data suggest that progesterone rather than protein is the principal mediator of acrosome reaction induced by follicular fluid in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrosome↗
PubMed1992

Rare non-mosaic trisomies in chorionic villus tissue not confirmed at amniocentesis.

This paper reports eight cases of non-mosaic, rare, and typically lethal trisomies diagnosed in chorionic villi and not confirmed by amniocentesis. Four cases were 47,XX,+16; two cases were 47,XX,+2; one was 47,XX,+12; and one was 47,XY,+7. There have been no known complications in any of these gestations. These eight cases were found in a series of approximately 12,000 samples processed in our laboratory (0.07 per cent). We conclude that (1) rare non-mosaic trisomy not reflecting the fetal condition is an occasional source of diagnostic ambiguity in chorionic villus sampling; and (2) when encountered, a follow-up amniocentesis should be recommended to the patient to confirm or rule out the abnormality. We propose the term 'confined placental abnormality' to describe non-mosaic trisomies and other related abnormalities found only in chorionic tissue.

Adult↗
PubMed1991

Human preimplantation embryo cryopreservation: selected aspects.

This report describes the results of cryopreserving human preimplantation zygotes and cleaved embryos (2-4 cells) in our in-vitro fertilization programme. Cryopreserved zygotes and cleaved embryos resulted in similar post-thaw survival rates (74.8 versus 70.9%). Pregnancy rates per retrieval cycle (RC) and embryos transferred per pregnancy for frozen-thawed zygotes versus frozen-thawed cleaved embryos were 21.8 versus 11.5% (P less than 0.2) and 12.6 versus 17.5 (P less than 0.2), respectively. Pregnancy rates increased significantly for both fresh (P less than 0.0005) and frozen-thawed (P less than 0.05) embryos as the number of embryos replaced per transfer increased from one to three or more. Frozen-thawed embryos resulted in multiple implantation rates per transfer of 25 compared to 6.4% (P less than 0.1) for fresh embryos when two embryos were replaced. Pregnancy rates were reduced for fresh (P less than 0.05) and frozen-thawed (P less than 0.1) embryos obtained from patient retrieval cycle numbers greater than 3. The method of follicular stimulation during the retrieval cycle did not affect frozen-thawed embryo survival rates. There was no difference in pregnancy rates from frozen-thawed embryos replaced during natural or clomiphene citrate transfer cycles. Patients with cryopreserved embryos had cumulative pregnancy rates of 37.1% (66/178) compared to 23.5% (110/468) (P less than 0.01) for patients with no embryos cryopreserved; cryopreservation of preimplantation embryos is a reliable therapeutic procedure that enhances achievement of pregnancy through in-vitro fertilization.

Blastocyst↗
PubMed1990

Transvaginal chorionic villus sampling.

Chorionic villus sampling (CVS) with either transcervical catheters or transabdominal needles is a widely-accepted method for prenatal diagnosis. However, there exists a small subset of patients in whom sampling is difficult or impossible with either route because of individual anatomic variations. A new method of chorionic villus biopsy has been developed to circumvent these problems, utilizing transvaginal chorionic needle aspiration guided by an intravaginal ultrasound probe. This technique was performed successfully in 15 patients in whom villi could not be obtained by either of the conventional methods. This method now makes CVS possible in essentially all women regardless of their uterine anatomy or placental placement; it may also prove useful for very early chorionic sampling.

Adult↗
PubMed1989

Cell-free human amniotic fluid as culture medium for mouse and human embryos.

Differences between murine and human preimplantation embryonic growth in cell-free human amniotic fluid and medium F-10 supplemented with human fetal cord serum were assessed. Two-cell mouse embryos cultured in human amniotic fluid developed more consistently to the expanded blastocyst stage than those cultured in F-10. No significant difference in human preimplantation embryo cleavage was observed between the two culture conditions. However, amniotic fluid was significantly worse than F-10 + human serum in its ability to maintain embryos that could establish pregnancy after transfer.

Amniotic Fluid↗
PubMed1988

Embryonic development and pregnancy from fresh and cryopreserved sibling pronucleate human zygotes.

The number of pronucleate (PN) zygotes that cleave, rates of cell division, and pregnancy rates were compared from fresh and frozen sibling PN zygotes. Of 57 patients with randomly selected zygotes frozen at the PN stage, 26 have had 82 PN zygotes thawed with 76 (92.7%) morphologically intact immediately post-thaw. There was no significant difference (P greater than 0.05) in the proportion of fresh (110/123 [89.4%]) and frozen-thawed intact (62/76 [81.6%]) sibling PN zygotes that had cleaved by transfer. The number of fresh versus frozen-thawed sibling PN zygotes that developed into 2-, 3-, 4-, 5-, 6-, 7-, and 8-cell embryos after 24 hours in culture were not significantly different. The numbers of pregnancies per patient cycle for fresh and frozen-thawed sibling PN zygotes were 12/60 (20.0%) and 5/27 (18.5%), respectively (P greater than 0.05). The current cumulative pregnancy rate per retrieval in all cycles with frozen zygotes is 28.3%, considerably higher than observed in single transfers of embryos without cryopreservation (19.8%); predicted cumulative pregnancy rate after eventual transfer of all frozen zygotes is 37.9%. It is concluded that embryo survival and pregnancy rates of cryopreserved PN zygotes are very similar to those from their fresh sibling counterparts and cryopreservation substantially enhances in vitro fertilization pregnancy attainment.

Cleavage Stage, Ovum↗
PubMed1987

Maternal serum alpha-fetoprotein screening after chorionic villus sampling.

To evaluate whether maternal serum alpha-fetoprotein (MSAFP) concentrations at 15-18 weeks' gestation are influenced by chorionic villus sampling performed three to ten weeks earlier, MSAFP levels were determined for 417 postchorionic villus sampling patients and 967 control subjects without previous chorionic villus sampling. Statistical comparison of the medians, distributions, and proportions above defined multiples of the median demonstrated no significant difference between the two populations. These results indicate that MSAFP screening in postchorionic villus sampling patients should be reliable and that values may be interpreted using criteria similar to those used for the general population.

Adult↗
PubMed1987

Outpatient in vitro fertilization using transvaginal ultrasound-guided oocyte retrieval.

Of 80 patients who initiated in vitro fertilization cycles in an integrated outpatient facility, 61 had oocyte retrievals performed under local anesthesia with ultrasound-guided transvaginal aspiration of ovarian follicles. Ten patients conceived, all in the group of 49 who had human chorionic gonadotropin (hCG)-timed retrievals. Our results indicate that in vitro fertilization can be performed to a high standard with this method, with excellent patient acceptance and reduced cost without general anesthesia, laparoscopy, or in-hospital setting.

Adult↗