Dental workplace exposure and effect on fertility.
(49/1639)
OBJECTIVES: This study assessed occupational exposure in dental surgeries on the basis of the reported use of dental materials and techniques and applied waiting-time-to-pregnancy methodology to study fertility in relation to the occupational exposure. METHODS: Data were collected retrospectively using a self-administered postal questionnaire addressing the occupational and reproductive history of the participants. The study groups consisted of 558 female dental surgeons and 450 high school teachers that had given birth in Norway to at least 1 living child. The present study comprised data from a total of 1408 pregnancies. The effects of practicing dentistry and of the given workplace exposure on fertility were analyzed with the discrete proportional hazard regression method. RESULTS: Most of the female dental surgeons were using amalgam for fillings during the period they tried to conceive, and 1/3 placed more than 50 fillings a week. Tooth-colored fillings were in limited use. Prior to 75% of the pregnancies, the dental surgeons reported handling chloroform-based root canal sealers. Forty percent of the dental surgeons were daily exposed to disinfectants containing ethanol and benzene. No difference was found in fertility between the dental surgeons and the high school teachers. Exposure to mercury, chloroform, and benzene was not associated with decreased fertility, except for a possible effect of mercury in the last pregnancy of multiparous dental surgeons. CONCLUSIONS: Occupational exposures had no clear adverse effects on fertility among the female dental surgeons studied. (+info)
A simplified coculture system using homologous, attached cumulus tissue results in improved human embryo morphology and pregnancy rates during in vitro fertilization.
(50/1639)
PURPOSE: This study was undertaken to evaluate simplified methods of human embryo coculture using either attached or nonattached autologous cumulus tissue. METHODS: Eight hundred one zygotes were cultured for 48 hr in a prospective, randomized trial comparing culture of embryos either with intact cumulus tissue, with cumulus tissue added to the droplet of culture medium, or without any cumulus tissue. In a follow-up study, embryo quality, pregnancy rates, and implantation rates were compared in 120 consecutive patients undergoing in vitro fertilization with a coculture system using cumulus tissue compared to a cohort of 127 patients undergoing IVF immediately preceding the institution of the coculture protocol. RESULTS: Embryo morphology was significantly improved (P < 0.05) following culture with attached cumulus tissue (5.61 +/- 0.29) and culture with added cumulus tissue (4.72 +/- 0.31) compared to that of embryos grown in culture medium without cumulus tissue (3.95 +/- 0.26). The clinical pregnancy rate improved from 39.4% (50/127) to 49.2% (59/120) following institution of a system of coculture with attached cumulus tissue. CONCLUSIONS: These data indicate that a simple coculture system using autologous cumulus tissue can result in improved embryo morphology, implantation rates, and clinical pregnancy rates during in vitro fertilization. This coculture system is simple, is non-labor intensive, and eliminates many of the risks which may be present in other embryo coculture systems. (+info)
The effect of hydrosalpinges on IVF-ET outcome.
(51/1639)
PURPOSE: Our purpose was to determine if the presence of a hydrosalpinx effects the outcome of in vitro fertilization (IVF)-embryo transfer. METHODS: We performed a retrospective analysis of IVF cycle stimulation sheets. RESULTS: A total of 1000 patients with tubal factor infertility was analyzed. There were 60 hydrosalpinx patients who underwent 116 initiated cycles with 106 embryo transfers, compared to 940 control patients undergoing 1428 initiated cycles with 1150 embryo transfers. Both groups had a similar response to ovarian stimulation, number of oocytes retrieved, and number of embryos transferred. The hydrosalpinx group had a significantly higher preclinical loss rate (22/59 = 37% vs 80/566 = 14%; P = 0.001), a significantly lower implantation rate (55/352 = 16% vs 795/3795 = 21%; P = 0.013), a trend toward a reduced delivery rate per transfer (28/106 = 26% vs 387/1150 = 34%; P = 0.066), a significantly higher ectopic pregnancy rate (5/59 = 8% vs 16/566 = 3%; P = 0.04), and a similar spontaneous abortion rate (9/37 = 24% vs 99/486 = 20%; P = 0.28) compared to the control tubal factor group. CONCLUSIONS: This study demonstrates a decrease in implantation rates and an increase in preclinical miscarriages and ectopic pregnancies in patients with hydrosalpinges compared to tubal-factor patients without sonographic evidence of dilated fallopian tubes. (+info)
Comparison of pregnancy outcome of pronuclear- and multicellular-stage frozen-thawed embryo transfers.
(52/1639)
PURPOSE: Our purpose was to determine if supernumerary embryos generated by in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) should be frozen (using 1,2-propanediol) at the pronuclear or multicellular stage. METHODS: The study was a retrospective analysis conducted at the Dubai Gynaecology & Fertility Centre of the Department of Health & Medical Services, Dubai, U.A.E. One hundred forty-one women undergoing frozen-thawed embryo replacement cycles with IVF generated embryos and 84 women undergoing the same with ICSI generated embryos. RESULTS: Supernumerary, IVF-generated embryos frozen at the multicellular stage had a significantly higher rate of survival on thawing (73.9%) than embryos frozen at the pronuclear stage (64.4%). The morphological grades of the embryos in the two groups were similar, but a significantly higher pregnancy rate was obtained with embryos frozen at the multicellular stage (22.8%) than with pronuclear-stage embryos (14.8%). Similarly, with ICSI-generated embryos, significantly higher survival was seen with multicellular-stage frozen embryos (74.8%) than pronuclear-stage embryos (64.4%). The morphological grades of the embryos and pregnancy outcomes of the two groups were similar. CONCLUSIONS: Supernumerary embryos generated by IVF and ICSI should be frozen at the multicellular stage so as to allow selection of the best embryos for transfer and embryo freezing of only robust embryos. (+info)
Exogenous luteinizing hormone (LH) increases estradiol response patterns in poor responders with low serum LH concentrations.
(53/1639)
PURPOSE: Our purpose was to investigate whether the addition of exogenous leuteinizing hormone (LH) increases estradiol secretion in LH-depleted women undergoing controlled ovarian hyperstimulation (COH) with purified follicle stimulating hormone (FSH). METHODS: We carried out case series and retrospective analysis of midfollicular serum LH concentrations and estradiol response patterns in COH cycles. All patients initially received gonadotropins containing purified FSH. Human menopausal gonadotropin containing LH was added to poor responders with low midfollicular LH concentrations. RESULTS: The addition of exogenous LH to the COH regimen significantly increased estradiol secretion in poor responders with low midfollicular endogenous LH concentrations. This was confirmed statistically by an average change in the slope of the estradiol patterns from 27.54 to 85.49 after the addition of exogenous LH. Furthermore, patients with midfollicular serum LH concentrations < 3.0 mIU/ml had significantly lower midfollicular and peak estradiol (E2) concentrations compared to patients with LH concentrations > or = 3.0 mIU/ml (352.3 and 2094.3 vs 855.6 and 3757.1 pg/ml, respectively). CONCLUSIONS: The addition of exogenous LH increases E2 response patterns in poor responders with low midfollicular serum LH concentrations. Low midfollicular serum LH concentrations are associated with significantly lower midfollicular and peak E2 concentrations. (+info)
Effect of a sonographically diffusely enlarged uterus without distinct uterine masses on the outcome of in vitro fertilization-embryo transfer.
(54/1639)
PURPOSE: Our objective was to study the effect of a sonographically diffusely enlarged uterus without distinct uterine masses on the outcome of in vitro fertilization-embryo transfer (IVF-ET). METHODS: Nineteen primary infertility patients undergoing IVF-ET who had a sonographically diffusely enlarged uterus without distinct uterine masses were enrolled. An age-controlled group of 144 primary infertility patients undergoing IVF-ET with a normal uterus and no history of uterine surgery was included. RESULTS: The age, day 3 follicle stimulating hormone, antral follicle count, ovarian response, endometrial thickness, number of retrieved and fertilized oocytes, number of transferred embryos, clinical pregnancy rate, and total delivery rate were not statistically different between the two groups (P < 0.05). Patients with a sonographically diffused enlarged uterus without distinct uterine masses had a higher spontaneous abortion rate (66.7%) than controls (P < 0.04; odds ratio = 7.5; 95% confidence interval, 1.16-48.56). CONCLUSIONS: A high spontaneous abortion rate was found in patients with a sonographically diffusely enlarged uterus without distinct uterine masses undergoing IVF-ET. Enhanced luteal support was required. (+info)
Expression of the mouse metallothionein-I and -II genes provides a reproductive advantage during maternal dietary zinc deficiency.
(55/1639)
The function of metallothionein in zinc homeostasis was examined by using mice homozygous for knockout (KO) of the metallothionein-I or -II (MT-I and MT-II) genes. Pregnant MT-I/II KO mice or control mice were fed a zinc-deficient (1 microg/g or 5 microg/g) diet or a zinc-adequate (50 microg/g) diet during specific periods of pregnancy, and the effects on morphogenesis of the embryos were determined at day 14 of pregnancy (day 1 = vaginal plug). In the homozygous MT-I/II KO, as well as in the nontransgenic control mice, severe dietary zinc deficiency (1 microg/g) beginning on day 1 of pregnancy was embryotoxic and teratogenic, and the majority of the embryos in both strains were dead by mid-gestation. However, 53% of the surviving embryos in the MT-I/II KO mice were morphologically abnormal compared to only 32% of the embryos in the control mice. In subsequent experiments, moderate dietary zinc deficiency (5 microg/g beginning on day 1 of pregnancy or 1 microg/g dietary zinc beginning on day 8 of pregnancy) exerted teratogenic, but not embryotoxic effects. Embryos in the MT-I/II KO mice were 260 to 290% as likely to develop abnormally than were embryos in the control mice fed these same diets. These results demonstrate that the expression of the MT-I and -II genes in pregnant females improves reproductive success during maternal dietary zinc deficiency. (+info)
Association of oestrogen receptor gene polymorphisms with outcome of ovarian stimulation in patients undergoing IVF.
(56/1639)
Oestrogen plays an important role in follicular formation and oocyte maturation via its receptor (ER). Many studies have shown association of the ER gene polymorphisms with a variety of pathological conditions. In this study we have examined the relationship of a common PvuII and a rare BstUI polymorphism in the ER gene to the mean numbers of follicles and oocytes, their mean ratios, mean number of embryos, mean oestrogen concentrations, mean size of the follicles and pregnancy rates. Analyses were carried out in 200 local Chinese patients undergoing in-vitro fertilization (IVF) and embryo transfer in three consecutive cycles. The mean follicular number, oocyte number, embryo number, follicular size and pregnancy rate were significantly smaller in patients homozygous for PvuII polymorphism (P < 0.001). These results indicate that PvuII polymorphism may be associated with ovarian follicular development and subsequently with the pregnancy rate. This study supports the view that genetic variability in the ER gene may have a role in the quality of the ovarian follicles in stimulation, which may affect implantation. However BstUI polymorphism was not found in either the IVF or control groups, suggesting that it has no role in the local Chinese population. (+info)