Risk factors for cesarean section of the second twin after vaginal delivery of the first twin.

PURPOSE: To document risk factors for combined delivery, defined as unplanned cesarean section for the second twin after vaginal delivery of the first twin, particularly focusing on delivery interval between twins. METHODS: A multi-center cross-sectional study among a cohort of 5411 women with twin pregnancy experiencing vaginal delivery of the first twin in 2007-2016 at 191 tertiary referral hospitals in Japan was conducted. Primary outcome was the occurrence of combined delivery, and data were collected through the Japan Society of Obstetrics and Gynecology perinatal database. Risk factors for combined delivery were investigated using Poisson regression analysis. RESULTS: Combined delivery occurred in 235 women (5.1%) and was significantly associated with delivery interval (P < 0.001). Multivariate analysis showed women with ≥ 25 kg/m2 pre-pregnancy body mass index (BMI) and with birthweight < 1500 g of the second twin had significantly higher risk for combined delivery than women with 18.5-25 kg/m2 pre-pregnancy BMI and with birthweight ≥ 2500 g of the second twin (adjusted risk ratio (aRR) 1.72, 95% confidence interval (CI) 1.15-2.57, and aRR 2.06, 95% CI 1.14-3.72, respectively). Breech and transverse presentation of the second twin were also risk factors for combined delivery compared with cephalic presentation (aRR 3.60, 95% CI 2.67-4.85, and aRR 9.94, 95% CI 6.50-15.0, respectively). Although association of combined delivery with pre-pregnancy BMI was attenuated after adjustment by delivery interval, association with birthweight of the second twin was strengthened. CONCLUSION: Delivery interval was significantly associated with combined delivery and mediated the association between combined delivery and some other risk factors.

The Expression of MAS1, an Angiotensin (1-7) Receptor, in the Eutopic Proliferative Endometria of Endometriosis Patients.

BACKGROUND/AIM: We demonstrated that AT1 and AT2 are expressed and both pathways balance the renin-angiotensin system in endometriosis. MAS1, a specific receptor of angiotensin (1-7), opposes AT1 pathway-associated tissue remodelling. It is not known whether MAS1 has an effect on the pathogenesis of endometriosis or not. MATERIALS AND METHODS: Ovarian endometriotic tissues (endo-Ov) and eutopic endometrial tissues (endo-Em) were obtained from 29 patients with endometrial cysts. Normal endometrial tissues (cont-Em) were obtained from patients without endometriosis. Immunohistochemical staining was performed for MAS1, AT1 and AT2 in the endometriosis-associated tissues. The mRNA levels of these receptors were examined by quantitative reverse transcription PCR. RESULTS: MAS1 was immune-positive at the apical side of the glandular epithelium in the endometriotic lesions. The MAS1 mRNA levels in endo-Ov were increased significantly, irrespective of the menstrual cycle phase. The MAS1 mRNA levels were significantly higher in the proliferative-tissues of the endometriosis patients than in those of the controls. The ratio of the MAS1 to the AT1 mRNA in the proliferative tissues was increased predominantly in the endometriosis patients compared with that in the controls. CONCLUSION: High MAS1 expression in the endometrium might promote the initiation of endometriosis via migration of proliferative tissue.

Characterization of human decidual mast cells and establishment of a culture system.

BACKGROUND: Although rodent decidual mast cells (MCs) reportedly play an important role in implantation and placenta formation, the characterization of human decidual MCs has been not well clarified. The aims of this study were to investigate the distribution and characteristics of MCs in human decidua and to establish a culture system for decidua-derived MCs. METHODS: Decidual tissues were obtained from patients who underwent a legal elective abortion (6th week to 9th week of pregnancy), and decidual MCs were enzymatically dispersed. Cultured decidua-derived MCs were generated by culturing decidual cells with stem cell factor. An ultrastructural analysis of primary decidual MCs and cultured decidua-derived MCs was performed using a transmission electron microscope. Receptor and protease expression was analyzed using FACS. Histamine released from MCs was measured using enzyme immune assays. RESULTS: A larger proportion of tryptase positive(+) MCs in decidua was present on the maternal side. Both enzymatically dispersed decidual MCs and cultured decidua-derived MCs showed an FcεRIα+Kit+tryptase+chymase+ phenotype. Their granules contenting particles exhibited variable amounts of electron-lucent space separating electron-dense particles. Both enzymatically dispersed decidual MCs and cultured decidua-derived MCs released comparable amounts of histamine following FcεRI aggregation. CONCLUSIONS: The isolation method for MCs from decidua during early pregnancy and the culture system for decidua-derived MCs may enable the roles of decidual MC during pregnancy to be explored.

Effects of anti-ß2-GPI antibodies on cytokine production in normal first-trimester trophoblast cells.

AIM: The anti-ß2-GPI antibody (aß2-GPIAb) has been detected in recurrent fetal loss with strong pathogenic activity. The effects of aß2-GPIAb on cytokine production and aß2-GPIAb binding sites in first-trimester trophoblast cells were evaluated. METHODS: First-trimester trophoblast cells were cultured in 24-well tissue culture plates with immunoglobulin G (IgG) obtained from aß2-GPIAb-positive and aß2-GPIAb-negative serum. Cytokines in the cultured supernatant were measured using the suspension array system and enzyme-linked immunosorbent assays. To identify potential binding sites for aß2-GPIAb, such as toll-like receptors (TLR) 2 or TLR4, we used mouse monoclonal anti-TLR2 and/or anti-TLR4 antibodies to inhibit TLR and then measured cytokine production. RESULTS: The production of cytokines, such as interleukin-6 and interleukin-8, increased more in response to aß2-GPIAb-positive IgG than to aß2-GPIAb-negative IgG in trophoblast cells. The secretion of cytokines from trophoblast cells decreased when the TLR were blocked with mouse monoclonal anti-TLR2 and anti-TLR4 antibodies. CONCLUSION: We suspect that aß2-GPIAb might increase cytokine production by binding to TLR2 or TLR4. The increased cytokine production in response to aß2-GPIAb might play a role in the increased inflammatory response in the placenta.