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Biomedical subjects

A Mackenna

Publications and source records attributed to A Mackenna.

18 recordsLinked to original sources
PubMed2004

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

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

Abortion, Spontaneous↗
PubMed2001

Results of assisted reproduction techniques in Latin America.

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

Journal Article↗
PubMed2000

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

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

Adult↗
PubMed2000

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

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

Adult↗
PubMed1998

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

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

Female↗
PubMed1998

Fetal prognosis in varix of the intrafetal umbilical vein.

To assess the clinical significance of varix of the intraabdominal portion of the umbilical vein, we reviewed 10 cases diagnosed prenatally by ultrasonography at a median gestational age of 27 weeks. A comprehensive anatomic survey and serial follow-up scans were performed in each case. All three fetuses with associated anomalies died in utero, and prenatal karyotyping revealed that two of them had a chromosomal abnormality. In six of the seven cases with structurally normal fetuses the pregnancy proceeded uneventfully, and no neonatal complications were attributed to the umbilical vein varix. Our experience and the review of the literature revealed 42 cases with information on fetal outcome. Overall, 24% of the fetuses died, 12% had a chromosomal abnormality, and 5% developed hydrops. We conclude that fetuses with varix of the intrafetal umbilical vein should be considered at risk for poor outcome. However, if no other anomalies are present, the prognosis is generally good.

Female↗
PubMed1996

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

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

Journal Article↗
PubMed1995

The empty follicle syndrome: a pharmaceutical industry syndrome.

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

Adult↗
PubMed1995

Contribution of the male factor to unexplained infertility: a review.

The more exhaustive the evaluation of couples with unexplained infertility, the more likely is the opportunity for detecting the aetiological factor responsible for infertility. Transport of spermatozoa through the upper genital tract and their ability to fertilize the oocyte are two obscure areas for the conventional evaluation of infertility. Although research in the former area is limited, there is indirect evidence that impaired sperm transport could be one of the causes of infertility in some couples with otherwise unexplained infertility. on the other hand, the availability of sperm function tests and the correlation of their results with in-vitro fertilization rates have allowed the detection of a previously hidden male factor in couples with unexplained infertility. It has been demonstrated that couples suffering unexplained infertility have significantly lower in-vitro fertilization rates in comparison with patients with tubal problems. These results can be explained because of several case control studies in patients with unexplained infertility have reported defects in capacitation and sperm motion characteristics, binding of the spermatozoa to the zone pellucida, acrosome reaction, acrosin activity of the spermatozoa, and the ability of the spermatozoa to penetrate zona-free hamster oocytes. These observations suggest that methods for assessing the fertilizing capacity of the spermatozoa have to incorporated in the evaluation of couples with unexplained infertility in order to amplify the scope of the workup and to better decide the appropriate treatment for these couples.

Animals↗
PubMed1994

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

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

Abortion, Spontaneous↗
PubMed1993

The contribution of a hidden male factor to unexplained infertility.

OBJECTIVE: To assess sperm function in patients with unexplained infertility in comparison with normal fertile men. DESIGN: Prospective study. SETTING: Infertility outpatient clinic and donor insemination program, University Department of Obstetrics and Gynecology at the Jessop Hospital for Women, Sheffield, United Kingdom. PATIENTS: Nineteen patients with unexplained infertility and nineteen normal fertile men from a donor insemination program. MAIN OUTCOME MEASURES: Monitoring of reactive oxygen species generation; computerized assessment of the hyperactivated motility pattern of the spermatozoa under capacitating conditions, with and without the addition of follicular fluid (FF); evaluation of sperm-zona pellucida (ZP) binding. RESULTS: Reactive oxygen species generation was not significantly different between the study and control group. Follicular fluid-induced hyperactivation (HA) was significantly lower in patients with unexplained infertility than in the donors, but no difference was found comparing spontaneous HA (without FF) between the two groups. Follicular fluid-induced HA was completely absent in 39% of infertile men and only one fertile man. A low sperm-ZP binding ratio (< or = 0.3) was observed in 28% (5/18) of patients with unexplained infertility. In all, nine infertile men (47%) had 0% FF-induced HA and/or low sperm-ZP binding ratio. CONCLUSIONS: Assessing FF-induced HA and sperm-ZP binding may have clinical significance in distinguishing a subgroup of men with unexplained infertility with sperm function abnormalities in which the fertilizing capacity of the spermatozoa might be reduced. These patients cannot be identified by the conventional semen analysis. Both tests may also be useful in planning the appropriate treatment for couples with unexplained infertility.

Female↗
PubMed1993

Placental protein 14 levels in uterine flushing and plasma of women with unexplained infertility.

OBJECTIVES: To measure concentrations of placental protein 14 (PP14) in uterine flushings and plasma samples obtained from patients with unexplained infertility and to compare the results of those of normal fertile women. DESIGN: Prospective study. SETTING: Infertility and gynaecology outpatient clinics at the Jessop Hospital for Women, Sheffield, United Kingdom. PATIENTS: Sixteen patients with unexplained infertility and 12 normal fertile women who had been previously sterilized. INTERVENTIONS: Daily monitoring of luteinizing hormone (LH) to detect the LH surge; uterine flushings and blood samples were obtained on days 7, 10, and 12 after the LH surge. MAIN OUTCOME MEASURES: The measurement of PP14 concentration in uterine flushings and plasma samples throughout the luteal phase. RESULTS: Levels of PP14 in uterine flushings of patients with unexplained infertility were significantly lower than those of normal fertile women on days LH +10 and LH +12. No significant differences were observed between the two groups in PP14 levels in uterine flushings on day LH +7 and plasma samples on days LH +7, LH +10, and LH +12. CONCLUSIONS: Patients with unexplained infertility have reduced concentrations of PP14 in uterine flushings but not in plasma samples as compared with normal fertile women. Placental protein 14 measurement in uterine flushings may be a more valuable method of assessing endometrial function in infertile patients than plasma levels of the protein.

Adult↗
PubMed1993

Uterine flushing: a method to recover spermatozoa and leukocytes.

The process of sperm transport from the cervix, where a leukocytic reaction is initiated, through the uterus to gain access to the site of fertilization is very poorly understood. This preliminary study was designed to utilize a uterine flushing technique to determine firstly, the number of spermatozoa that can be recovered from the uterine cavity at 4 h post-insemination, around the time of ovulation, and secondly, to establish whether the spermatozoa initiate a leukocytic response while present. Uterine flushing was carried out in 10 potentially fertile women at 4 h post-insemination with donor semen, 24-36 h after the onset of the luteinizing hormone (LH) surge. The flush fluid was analysed for the numbers of spermatozoa and leukocytes present. In 8/10 women spermatozoa were retrieved from the uterus, in consistently low numbers (median 46, range 3-415). In 5/5 women leukocytes were recovered (median, 2.75 x 10(8)/l, range 2.0 x 10(8)-12.7 x 10(8)/l) from an origin other than peripheral blood contamination. These results suggest firstly that the flushing technique was a consistent method for retrieving spermatozoa and leukocytes from the uterine cavity, secondly that only low numbers of spermatozoa can be retrieved on flushing and thirdly that the leukocytic reaction to spermatozoa extends to the uterine cavity.

Female↗
PubMed1992

Pregnancy rate in an oocyte donation program.

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

Adult↗
PubMed1989

[Importance of the suture material in the surgery of genuine stress urinary incontinence].

Between July 1978 and November 1985, 73 abdominal operations were performed for the surgical correction of genuine stress incontinence using the Marshall-Marchetti-Krantz technique. Non-absorbable suture materials were used in the vesicourethropexy in 30 case (41%) and absorbable suture materials in 43 cases (59%). A relapse was not observed after two years of follow-up in the group of patients operated on with nonabsorbable suture materials while a relapse of 5% after one month, 14% after six months, 22% after one year and 44% after two years was observed in the group of patients operated on with absorbable suture materials. A statistically significant difference was found between both groups after one year (p = 0.031) and after two years (p = 0.012) of follow up. The postoperative complications were similar in both groups, urinary infection being the most frequent one. We conclude that nonabsorbable suture materials offer definitive advantages with respect to absorbable suture materials in the abdominal surgical correction of genuine stress incontinence.

Female↗
PubMed1986

Sperm migration through human cervical mucus in women with copper IUD's.

Human cervical mucus from women using Lippes Loop and T-Cu-200 IUDs was used to study sperm migration in vitro using flat capillary tubes. Cervical mucus from women bearing no IUD was used as the control. 100% of the control samples, 83% of the Lippes Loop users, and 88% of the T-Cu-200 users had more than 100 spermatozoa/field of 100x. In 17% and in 11% there were between 40 and 100 spermatozoa/field of 100x in the Lippes Loop and T-Cu-200 users. The presence of copper IUDs does not interfere with sperm migration in vitro through human cervical mucus.

Biology↗