Yoon Seok Chang

Influence of antithyroid antibodies in euthyroid women on in vitro fertilization-embryo transfer outcome.

PROBLEM: To investigate whether antithyroid antibodies (ATAs) affect the pregnancy outcome in euthyroid women undergoing in vitro fertilization‐embryo transfer (IVF‐ET).

Ovarian hyperstimulation syndrome complicating a spontaneous singleton pregnancy: A case report

It has been known that most cases of ovarian hyperstimulation syndrome (OHSS) are associated with the use of exogenous gonadotropins to induce multiple ovulation. However, OHSS is infrequently associated with a spontaneous ovulatory cycle, usually in the case of multiple gestations, hypothyroidism, or polycystic ovarian syndrome. We report a case of severe OHSS in a spontaneously pregnant woman with no underlying disease.

The Immunotherapy during in vitro Fertilization and Embryo Transfer Cycles in Infertile Patients with Endometriosis

Objective: To investigate if the immunotherapy with corticosteroids would improve the pregnancy rate in infertile patients with endometriosis who undergo in vitro fertilization and embryo transfer (IVF‐ET).

Pyridostigmine cotreatment for controlled ovarian hyperstimulation in low responders undergoing in vitro fertilization–embryo transfer

OBJECTIVE To investigate the effect of pyridostigmine, an acetylcholinesterase inhibitor, as cotreatment for controlled ovarian hyperstimulation (COH) in low responders. DESIGN Randomized, double-blind, placebo-controlled study. SETTING A reproductive medicine unit in a university hospital. PATIENT(S) Seventy infertile women with a history of low ovarian response to COH using a GnRH agonist as part of a long stimulation protocol in previous IVF-ET cycles. INTERVENTION(S) Sixty milligrams of pyridostigmine or placebo was administered orally twice daily from the first day of COH until the day of hCG injection in patients undergoing IVF-ET cycles. MAIN OUTCOME MEASURE(S) In vitro fertilization results, pregnancy outcome, and serum and intrafollicular concentrations of GH and insulin-like growth factor-1. RESULT(S) Pyridostigmine cotreatment was associated with significant decreases in the amount of gonadotropins and the duration of stimulation required. The clinical pregnancy rate was higher in the pyridostigmine group, but this difference was not statistically significant (25.7% vs. 11.4%). The serum GH level on the day of hCG injection was significantly higher in the pyridostigmine group than in the placebo group. Follicular fluid concentrations of GH and insulin-like growth factor-1 were significantly higher in the pyridostigmine group. CONCLUSION(S) This study suggests that pyridostigmine cotreatment for COH could affect the serum and intrafollicular GH and insulin-like growth factor-1 concentrations and, hence, improve the ovarian response to COH and the results of IVF in low responders undergoing IVF-ET.

The Effect of Epidermal Growth Factor on the Preimplantation Development, Implantation and Its Receptor Expression in Mouse Embryos*

Objective: To investigate the influence of epidermal growth factor (EGF) on preimplantation development, implantation, and expression of epidermal growth factor receptor (EGFR) itself in mouse embryos.

Role of actin filaments in the hatching process of mouse blastocyst

Hatching has been suggested to occur as a result of protease-mediated lysis and the blastocoele tension. However, even if rupturing is initiated at multiple sites, interestingly only a single site is used for escape. This implies that there are several mechanisms involved in hatching. In this study, the involvement of actin filaments in mouse embryo hatching was examined. We treated mouse embryos with cytochalasin B for 12 h or 24 h at the morula, middle blastocyst, expanded blastocyst, lobe-formed blastocyst and hatching blastocyst stages, and measured the amount and distribution of actin filaments using a confocal microscope. At morula, middle blastocyst, lobe-formed blastocyst and hatching blastocyst stages embryonic development was completely arrested by cytochalasin B. However, when transferred to cytochalasin-B-free medium, the embryos resumed development and escaped the zona pellucida. In the expanded blastocysts development was almost completely inhibited by cytochalasin B, but rupturing occurred in some embryos. However, development stopped completely at the ruptured stage. Distribution of actin filaments was prominent at rupturing and hatching sites regardless of cytochalasin B treatment. The amount of actin filaments was prominent at hatching embryos compared with other developmental stages of embryos. These actin filaments were distributed intensively between the trophectodermal cells, and formed locomotion patterns. Taken together, these results suggest that not only tension and lytic enzymes are required to rupture, but the activity of actin filaments may have a crucial role in the process of hatching.

Relationship between Endometrial Estrogen and Progesterone Receptors, and Sonographic Endometrial Appearance in the Preovulatory Phase

Objectives:  The purpose of the present study is to evaluate the relationship between endometrial concentrations of estrogen receptor (ER) and progesterone receptor (PR), and sonographic endometrial findings in the preovulatory phase of menstrual cycle.

Clinical Usefulness of Basal FSH as a Prognostic Factor in Patients Undergoing Intracytoplasmic Sperm Injection

Objective: To determine if basal serum follicle stimulating hormone (FSH) level could be a prognostic factor of the clinical outcome in intracytoplasmic sperm injection (ICSI) cycles in the couples with male factor infertility

Effect of Population Density on the Early Post‐Implantation Mouse Embryo Growth in vitro

Objective: To investigate the relationship between embryo population density and embryo development in vitro.