Akira Nakashima

Implications of assisted reproductive technologies on term singleton birth weight: an analysis of 25,777 children in the national assisted reproduction registry of Japan

OBJECTIVE To evaluate the implications of assisted reproductive technologies (ART) on neonatal birth weight. DESIGN A retrospective study using analysis of covariance and multiple logistic regression analysis of the Japanese ART registry. SETTING Japanese institutions providing ART treatment. PATIENT(S) A total of 25,777 singleton neonates reaching term gestation following ART during the years 2007-2008, with 11,374 achieved through fresh embryo transfers (fresh ET) and 14,403 achieved through frozen-thawed embryo transfers (FET). INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Birth weight. RESULT(S) The mean birth weight after FET was significantly higher compared with fresh ET and all Japanese births (3,100.7 ± 387.2 g, 3,009.8 ± 376.8 g, and 3,059.6 ± 369.6 g, respectively). The risk for low birth weight in FET was significantly lower compared with fresh ET. In fresh ET, ovarian stimulations were associated with about twofold risk of low birth weight compared with natural cycle. Regarding to the duration of embryonic culture, the risks resulting from a shorter culturing time were significantly higher compared with a longer culturing time in fresh ET. CONCLUSION(S) The best method of embryo transfer for fetal growth was FET after extended culturing until blastocyst stage. However, further investigations should be performed to understand the safety of ART treatment.

The frequency of ovulation from the affected ovary decreases following laparoscopic cystectomy in infertile women with unilateral endometrioma during a natural cycle

PurposeTo evaluate the cystectomy-induced damage on the follicular growth and ovulation of an affected ovary during natural cycles.MethodsTwenty-eight infertile patients with unilateral ovarian endometriomas who underwent laparoscopic cystectomy were retrospectively evaluated. The ovulation rate of an affected ovary during natural cycles was compared before and after cystectomy in each patient, and it was also determined if ovulation from the affected ovaries resulted in pregnancy.ResultsAfter surgery, the ovulation rate was significantly lower than that before cystectomy (16.9 ± 4.5% vs. 34.4 ± 6.6%, P = 0.013). After surgery, 14 pregnancies were achieved without IVF treatment, and only 2 of them (14.3%) were achieved from an operated-side ovary. However, the pregnancy rate per ovulatory cycle of the operated-side ovary was not different from that of the intact ovary (8.8% vs. 5.8%, P = 0.750).ConclusionsLaparoscopic cystectomy is an invasive treatment in that it reduces the frequency of ovulation; however the pregnancy rate per ovulation did not deteriorate.

Optimization of a novel nylon mesh container for human embryo ultrarapid vitrification

OBJECTIVE To evaluate the efficacy of a nylon mesh container in vitrification of human embryos and to determine the optimal osmotic pressure of the initial thawing solution. DESIGN Retrospective analysis. SETTING National Center for Child Health and Development, Tokyo, Japan. PATIENT(S) Infertile patients undergoing either in vitro fertilization or intracytoplasmic sperm injection in our hospital. INTERVENTION(S) Embryos, at the cleavage stage, were cryopreserved using the vitrification method in either a plastic straw or a nylon mesh container. The embryos were thawed using an initial osmotic pressure of either 0.5 M or 1.0 M sucrose with subsequent step-wise dilution. After thawing, the embryos were transferred to the uterus. MAIN OUTCOME MEASURE(S) Survival rate of blastomeres, embryo survival rate, implantation, and pregnancy rates, cancellation rate because of embryo damage. RESULT(S) Use of nylon mesh and the 1.0 M sucrose thawing solution significantly improved blastomere survival rate (98.0 +/- 1.0%, mean +/- SEM), pregnancy rate (41.0%) and implantation rate (32.3%). CONCLUSION(S) Vitrification using a nylon mesh container and subsequent thawing in a 1.0 M sucrose solution is an easy and inexpensive method that improves the reliability of embryo cryopreservation of embryos without adverse effects on clinical outcomes.

The ratio of late-follicular to mid-follicular phase LH concentrations efficiently predicts ART outcomes in women undergoing ART treatment with GnRH-agonist long protocol and stimulation with recombinant FSH

PurposeTo establish an index to predict ART outcomes and to identify infertile patients who need LH supplementation during ovarian stimulation.MethodsSerum LH concentrations were measured during the mid- and late-follicular phase in 86 normogonadotropic infertile patients who underwent ART treatment using GnRH-agonist long protocol with recombinant-FSH. The relationships between serum LH concentrations at both time points and ART outcomes were retrospectively analyzed, and the relationships between the ratio of late-follicular to mid-follicular LH concentrations and ART outcomes were also evaluated.ResultsThere were no significant correlations between the mid- or late-follicular LH concentrations and ART outcomes. The ratio of late-follicular to mid-follicular LH concentrations <1.0 was considered the relatively LH decreased group (RD group) and ratio ≥ 1.0 was considered the relatively LH increased group (RI group). The number of usable embryos in RD group was similar to that in RI group, but the pregnancy and implantation rates in the RD group (9.7% and 5.8%) were significantly lower than those in the RI group (31.1% and 17.2%; p < 0.05).ConclusionsRelatively decreased LH concentrations during ovarian stimulation using GnRH-agonist long protocol with rec-FSH had a negative effect on ART outcomes. Therefore, the ratio of mid- to late-follicular phase LH concentrations is suggested to be an efficient index to identify patients who might benefit from LH supplementation.

Laparoscopic proximal tubal division can preserve ovarian reserve for infertility patients with hydrosalpinges

Aim:  To investigate whether laparoscopic proximal tubal division for the treatment of hydrosalpinges could preserve ovarian function.

Injury to the endometrium prior to the frozen–thawed embryo transfer cycle improves pregnancy rates in patients with repeated implantation failure

This retrospective cohort study evaluated the effectiveness of injury to the endometrium prior to the frozen–thawed embryo transfer (FET) cycle in patients with repeated implantation failure (RIF) in our clinic.

Laparoscopically-assisted transabdominal oocyte retrieval in an infertility patient with ovarian malposition

Infertility patients with malpositioned ovaries have considerable difficulty conceiving naturally because of extended fallopian tubes and ovarian malposition; such patients turn for help to assisted reproductive technology (ART) treatment. For most of these patients, ovarian malposition prevents transvaginal oocyte retrieval, so the transabdominal approach for oocyte retrieval is required. One of our infertility patients presented with ovarian malposition, and laparoscopy-assisted transabdominal oocyte retrieval was performed. We performed a Gonadotropin-releasing hormone agonist (GnRH-a) long protocol with human menopausal gonadotropin (hMG) ovarian stimulation, and used a standard transvaginal probe through the anterior abdominal wall for ovarian imaging and monitoring of the growing follicles. The patient underwent laparoscopically-assisted transabdominal oocyte retrieval—9 oocytes were recovered, and 5 were fertilized, and 2 embryos were transferred to the patient’s uterus. The patient became pregnant and a gestational sac was detectable by transvaginal ultrasonography, but she spontaneously miscarried. The patient then received several laparoscopically-assisted transabdominal oocyte retrievals and finally became pregnant following a thawed embryo transfer during a hormone replacement cycle, and now her pregnancy is going well.