Association between fetal sex and pregnancy outcomes among women with twin pregnancies: a multicenter cross-sectional study.

PURPOSE: To examine the frequency and to what extent fetal sex is associated with pregnancy outcomes among twin pregnancies, stratified by chorionicity. METHODS: This registry-based multicenter cross-sectional study was conducted using the Japan Society of Obstetrics and Gynecology perinatal database between 2007 and 2016. The sample population was restricted to women with twin pregnancies. The main pregnancy-related outcomes included preterm birth, very preterm birth, extremely preterm birth, preeclampsia, twin-to-twin transfusion syndrome (TTTS), and selective intrauterine growth restriction (s-IUGR). Birth weight, small for gestational age (SGA), and fetal death were also investigated. RESULTS: The primary analysis was performed based on 37,953 women, including 23,804 women with dichorionic diamniotic (DD) twins and 14,149 women with monochorionic diamniotic (MD) twins. Women with male/male DD twins had a significantly higher risk of preterm birth (adjusted risk ratio [aRR]: 1.07, 95% confidence interval [CI]: 1.03-1.10) and a lower risk of preeclampsia (aRR: 0.74, 95% CI: 0.62-0.88) than women with female/female DD twins. Women with male/male MD twins also had a significantly higher risk of preterm birth (aRR: 1.06, 95% CI: 1.04-1.09) than women with female/female MD twins. Risks of preeclampsia, TTTS, and s-IUGR did not differ by sex among MD pregnancies. Male SGA risk was significantly higher among male/male twins than among male/female DD twins. Among MD twins, risks of SGA and fetal death were significantly higher in male/male fetuses. CONCLUSIONS: This study demonstrated significant associations between fetal sex and several pregnancy outcomes in twin pregnancies, some of which differed by chorionicity.

Clinical outcomes in pregnant women with coronavirus disease 2019 in a perinatal medical centre in Japan: a retrospective study of the first 1 year of the pandemic.

In this retrospective study, we analysed clinical and demographic data from the medical records of 31 pregnant women with coronavirus disease 2019 (COVID-19) who were treated at our hospital between April 2020 and April 2021. The most common symptom was a fever; ∼10% of patients were asymptomatic. One patient with rapidly worsening pneumonia needed a Caesarean Section at 30 weeks and was admitted for intensive care. Twelve patients received perinatal care in our hospital (10 live births, one stillbirth, and one artificial abortion). Six patients delivered vaginally; the others delivered via caesarean section. Two patients had complications, including severe hypertensive disorders and preeclampsia. All patients recovered from COVID-19. Severe acute respiratory syndrome coronavirus 2 was not detected in the placenta, umbilical cord, cord blood, amniotic fluid, vaginal fluid, or breast milk in any patient. There were no neonatal adverse outcomes. The possibility of transmitting the coronavirus to pregnancy-related samples was low.IMPACT STATEMENTWhat is already known on the subject? COVID-19 has been affecting different countries in diverse ways, and the incidence, mortality, and morbidity rates of patients with COVID-19 vary widely by country or region and race. These differences in results may reflect racial differences and differences in national health care systems. Moreover, the information about the perinatal outcomes of pregnant women with COVID-19 and their newborns from Japan is limited.What do the results of this study add to what is known? We described the perinatal outcomes of 31 Japanese pregnant women with COVID-19 who were managed safely in a perinatal medical centre in Tokyo Japan, during the first 1 year of the pandemic.What are the implications of these findings for clinical practice and/or further research? Severe pneumonia and perinatal complications may occur, although no maternal and neonatal deaths were observed for COVID-19-positive pregnant women in our facility. Therefore, it is important to prevent this infection during pregnancy with the provision of effective medical care.

Tacrolimus treatment saved a rho-incompatible pregnancy.

A Rho-incompatible pregnancy induces anemia in the fetus and can ultimately lead to fetal hydrops and intrauterine fetal death. A patient who had experienced recurrent implantation failures following a first successful delivery finally succeeded in achieving a second pregnancy via the use of tacrolimus. The second pregnancy was Rho-incompatible. During the course of the pregnancy, the treatment with tacrolimus was continued because the patient's T helper type 1 (Th1) cell population remained at a high level following the achievement of pregnancy. The dose was increased during pregnancy because of the elevated Th1 cell count at 28-week gestation. Tacrolimus maintains a stable state of pregnancy while simultaneously suppressing the production of anti-D antibodies. Using tacrolimus, we succeeded in resolving the infertility and inhibition of antibody production in this case of an alloimmunized pregnancy.

Differences in pregnancy complications and outcomes by fetal gender among Japanese women: a multicenter cross-sectional study.

The association between fetal gender and rare pregnancy complications has not been extensively investigated, and no studies have examined this association in Japanese women. Thus, we used a large Japanese birth registry database to investigate the extent to which fetal gender affects various pregnancy outcomes. We analyzed 1,098,268 women with a singleton delivery with no congenital anomaly at 22 weeks or later between 2007 and 2015. Women carrying a male fetus had a significantly higher risk of placental abruption (adjusted risk ratio [aRR] 1.15, 95% confidence interval (CI) 1.10-1.20)], preterm delivery (aRR 1.20, 95% CI 1.19-1.22), instrumental delivery (aRR 1.27, 95% CI 1.26-1.29), and cesarean delivery (aRR 1.01, 95% CI 1.00-1.02). In contrast, they had a significantly lower risk of preeclampsia (aRR 0.92, 95% CI 0.89-0.94), placenta accreta (aRR 0.90, 95% CI 0.85-0.96), atonic hemorrhage (aRR 0.95, 95% CI 0.93-0.96), and maternal blood transfusion (aRR 0.95, 95% CI 0.92-0.99). Our findings demonstrate a significant association between fetal gender and various pregnancy complications and delivery outcomes among Japanese women.

Ultrasonographic assessment of fetal thyroid in Japan: thyroid circumference and distal femoral and proximal tibial ossification.

PURPOSE: The present study established a nomogram of fetal thyroid circumference (FTC) and the appearance timing of fetal distal femoral and proximal tibial ossification to assess fetal thyroid function in Japan. METHODS: Between April 2015 and July 2019, normal pregnant women at our hospital were recruited for the study. FTC was measured by the automatic ellipse outline and plotted against gestational age (GA). Fetal distal femoral and proximal tibial ossification measurements were obtained with standard electronic calipers from outer-to-outer margins (> 1 mm as the presence of ossification). RESULTS: A total of 199 pregnant women were examined. FTC increased logarithmically to GA. A nomogram of FTC was expressed by a logarithmic formula: [Formula: see text]. The respective 5-95th percentiles of FTC at each GA were 20.2-36.2 mm at 22 weeks, 25.0-44.8 mm at 26 weeks, 29.2-52.3 mm at 30 weeks, and 32.9-59.0 mm at 34 weeks. The fetal distal femoral epiphysis was not visualized before 30 weeks, but was visualized in 100% of fetuses after 35 weeks of gestation. The fetal proximal tibial epiphysis was not visualized before 33 weeks, but was visualized in 73.7% of fetuses at 37 weeks of gestation. CONCLUSION: We generated a GA-dependent FTC nomogram for Japanese fetuses. We also confirmed the appearance timing of fetal distal femoral and proximal tibial ossification to assess bone maturation. These assessments may be very useful for evaluating fetal thyroid function in Japan.