Efficacy of luteal estrogen administration and an early follicular Gonadotropin-releasing hormone antagonist priming protocol in poor responders undergoing in vitro fertilization

OBJECTIVES: We investigated whether luteal estrogen administration and an early follicular Gonadotropin-releasing hormone antagonist (E/G-ant) priming protocol improves clinical outcomes in poor responders to controlled ovarian stimulation for in vitro fertilization (IVF)-embryo transfer, and identified underlying mechanisms. METHODS: This restrospective study consisted of 65 poor responders who underwent the E/G-ant priming protocol. Sixty-four other poor responders undergoing conventional protocols without pretreatment were included as the control group. Clinical outcomes were compared between 2 groups. RESULTS: The E/G-ant priming protocol group exhibited improvements over the control group in terms of the number of retrieved oocytes (3.58±2.24 vs. 1.70±1.45; P=0.000), mature oocytes (2.68±2.11 vs. 1.65±1.23; P=0.000), fertilized oocytes (2.25±1.74 vs. 1.32±1.26; P=0.001), good embryos (1.62±0.91 vs. 1.14±0.90, P=0.021). Day 3 follicle-stimulating hormone (FSH; 8.40±4.84 vs. 16.39±13.56; P=0.000) and pre-ovulation progesterone levels (0.67 vs. 1.28 ng/mL; P=0.016) were significantly higher in the control group than in the E/G-ant priming group. The overall rate of positive human chorionic gonadotropin tests was higher in the E/G-ant priming group than in the control group (32.3% vs.16.1%; P=0.039). Also, clinical pregnancy rate (26.2% vs. 12.5%; P=0.048) and the rate of live births (23.1% vs. 7.1%; P=0.023) were significantly higher in the E/G-ant priming group than in the control group. CONCLUSION: The E/G-ant priming protocol would lead to promising results in poor responders to IVF by suppressing endogenous FSH and by preventing premature luteinization.

Reproductive outcomes of retransferring retained embryos in blastocyst transfer cycles / 대한생식의학회지

OBJECTIVE: To determine the incidence of embryo retention (ER) in the transfer catheter following embryo transfer (ET) in blastocyst transfer and investigate whether retransferring retained embryos has an impact on reproductive outcomes in patients undergoing in vitro fertilization-ET. METHODS: We retrospectively analyzed the records of 1,131 blastocyst transfers, which comprised 223 single blastocyst transfer (SBT) and 908 double blastocyst transfer (DBT) cycles. Each SBT and DBT group was classified depending on whether ET was performed without retained embryos in the catheter during the first attempt (without-ER group) or whether any retained embryos were found following ET (ER group) for the purpose of comparing reproductive outcomes in a homogenous population. RESULTS: The overall incidence of finding retained embryos was 2.8% (32/1,131). There were no retained embryos in SBT cycles. In DBT cycles, implantation rates (30.0% vs. 26.6%), positive β-hCG rates (57.2% vs. 56.2%), clinical pregnancy rates (45.3% vs. 46.9%), and live birth rates (38.9% vs. 43.8%) were not significantly different between the without-ER and ER groups. There were no significant differences in the mean birth weight (g) 2,928.4±631.8 vs. 2,948.7±497.8 and the mean gestational age at birth (269.3±17.2 days vs. 264.2±25.7 days). A total of nine cases of congenital birth defects were found in this study population. Eight were observed in the without-ER group and one in the ER group. CONCLUSION: Our results suggest that retransfer of retained embryos does not have any adverse impact on reproductive outcomes in blastocyst transfer cycles. Furthermore, our results support finding that SBT might be advantageous for decreasing the incidence of retained embryos in catheters.

Elevated natural killer cell levels and autoimmunity synergistically decrease uterine blood flow during early pregnancy

OBJECTIVE: To investigate whether natural killer (NK) cell and autoimmune antibody acts synergistically, by the action of autoantibodies to increase NK cell number and cytotoxicity, to decrease uterine blood flow during early pregnancy in pregnant women with a history of recurrent spontaneous abortion (RSA). METHODS: Seventy-five pregnant women (between 5 and 7 weeks gestation) with a history of unexplained RSA were included in the study group. Forty-one pregnant women without a history of RSA were included as controls. All women with a history of RSA were tested for autoantibodies and number of peripheral blood natural killer (pbNK) cell by flow cytometry. Study populations were stratified into four groups by existence of autoantibody and degree of increase of pbNK cells. The uterine radial artery resistance index (RI) was measured by color-pulsed Doppler transvaginal ultrasound. RESULTS: The mean RI of the autoimmune antibody-positive (AA+) group (0.63+/-0.09) was significantly higher than that of the normal control group (0.53+/-0.10, P=0.001). The mean RI of the AA+/only-NK elevated (eNK) group (0.63+/-0.09) was significantly higher than those of the only-AA+ group (0.55+/-0.07, P=0.019) and the only-eNK group (0.57+/-0.07, P=0.021). CONCLUSION: Concurrent elevation in NK cells and autoimmunity results in decreased uterine blood flow during early pregnancy. However, the majority of cases of RSA remain unexplained and larger scale studies are needed to confirm our conclusion and to develop diagnostic and therapeutic plans for women with a history of RSA.

An in-vitro wear study of indirect composite resins against human enamel / 대한치과보철학회지

STATEMENT OF PROBLEM: Second-generation indirect composite resins have been improved flexural strength, compressive strength, hydrolytic degradation resistance, wear resistance compared to first-generation indirect composite resins, but there are still some problems as hydrolysis and low wear resistance. Some manufacturers claim that wear resistance of their materials has been improved, but little independent study has been published on wear properties of these materials and the properties specified in the advertising materials are largely derived from in-house or contracted testing. PURPOSE: This study was to evaluate the wear of indirect composite resins (SR Adoro, Sinfony, Tescera ATL) and gold alloy against the human enamel. MATERIAL AND METHOD: Extracted human incisors and premolars were sectioned to 2*2*2mm cube and embedded in the clear resin and formed conical shaped antagonist to fit the jig of pinon-disk tribometer. Total 20 antagonists were stored in distilled water. Five disk samples, 24mm in diameter and 1.5mm thick, were made for each of three groups of indirect composite resins and gold alloy group, and polished to #2,000 SiC paper on auto-polishing machine. Disk specimens were tested for wear against enamel antagonists. Wear test were conducted in distilled water using a pin-on-disk tribometer under condition (sliding speed 200rpm, contact load 24N, sliding distance 160m). The wear of the enamel was determined by weighing the enamel antagonist before and after test, and the weight was converted to volumes by average density. The wear tracks were analyzed by scanning electron microscopy and surface profilometer to elucidate the wear mechanisms. Statistical analysis of the enamel wear volume, wear track depth and wear tract width of disk specimens were accomplished with one-way ANOVA and the means were compared for significant differences with Scheffe's test. RESULTS: 1. The enamel wear was most in gold alloy, but there were no statistically significant differences among all the groups (P>.05). 2. In indirect composite resin groups, the group to make the most shallow depth of wear tract was Sinfony, followed by Tescera ATL, SR Adoro (P.05). 3. The width of wear tract of SR Adoro was larger than the other groups (P.05). 4. SEM analysis revealed that Sinfony and gold alloy showed less wear scars after test, Tescera ATL showed more wear scars and SR Adoro showed the most. CONCLUSION: Within the limits of this study, Sinfony and gold alloy showed the least wear rates and showed similar wear patterns.