Abstract. Brominated flame retardants (BFRs) are used to prevent combustion in consumer products. Examples of BFRs are polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA), and tribromophenol (TBP). These compounds are reported to have adverse effects on human health and endocrine disrupting effects. The purpose of this study was to identify the Japanese perinatal exposure to PBDEs, hydroxylated PBDE metabolites (OH-PBDEs), TBBPA, and TBP compared with polychlorinated biphenyls (PCBs) and hydroxylated PCB metabolites (OH-PCBs). We investigated the concentrations of these compounds in maternal blood, maternal milk, cord blood, and umbilical cords from 16 Japanese mother-infant pairs by HRGC/HRMS. PBDEs were detected in all samples of maternal blood (mean ± SD; median = 25 ± 23 pg/g; 18 pg/g wet weight), maternal milk (140 ± 220 pg/g; 59 pg/g wet weight), cord blood (4.8 ± 6.5 pg/g; 1.6 pg/g wet weight), and umbilical cords (3.1 ± 3.1 pg/g; 2.1 pg/g wet weight). The mothers were divided into two groups, a high-concentration group and a low-concentration group. The percentage of BDE-47 showed the greatest difference between the two groups. 6-OH-BDE-47, TBBPA, and TBP were detected in all umbilical cord samples (mean ± SD; median = 8.4 ± 8.1 pg/g; 8.0 pg/g, 16 ± 5.5 pg/g; 15 pg/g, and 33 ± 8.2 pg/g; 32 pg/g wet weight respectively), but not in all maternal blood or cord blood samples. These results indicate that OH-PBDEs, TBBPA, and TBP, in addition to PBDEs, PCBs, and OH-PCBs, pass through the blood-placenta barrier and are retained in the umbilical cord.

Aim Assisted reproductive technology (ART) is gaining popularity worldwide. However, it is associated with increased incidence of velamentous umbilical cord insertion (VCI) in the placenta, resulting in adverse perinatal outcomes. This study aimed to identify the risk factors that might affect the incidence of VCI in pregnancies after ART treatment. Methods We retrospectively analyzed the records of 906 singleton pregnancies via ART; all women delivered in our facility. Three ART‐related variables and infant sex were examined: (1) fertilization method (conventional in vitro fertilization or intracytoplasmic sperm injection), (2) type of embryo at the time of transfer (fresh or frozen–thawed), (3) developmental stage of embryo at the time of transfer (cleavage stage or blastocyst), and (4) infant sex (male or female). Logistic regression analysis was used to assess the impact of these variables on the incidence of VCI. Results Of 906 cases, 55 had VCI (incidence rate, 6.1%). After adjusting for potential confounders, blastocyst stage of development (adjusted odds ratio [aOR]: 4.3, 95% confidence interval [CI]: 1.9–12.7) and female sex (aOR: 2.2, 95% CI: 1.2–3.9) emerged as independent risk factors for the development of VCI. The fertilization method and type of embryo at the time of transfer did not affect the incidence of VCI. Conclusions Blastocyst stage of development and female sex pose a higher risk for developing VCI. Thus, more attention should be paid to pregnancies achieved by blastocyst and with a female fetus to detect VCI proactively and safeguard the health of both mother and fetus/neonate.

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This review discusses trends in mode of breech delivery in Japan. Recently, primary elective cesarean delivery rates for singleton breech pregnancies have markedly increased due to medical counseling and maternal requests. However, breech extraction skills should be preserved and passed on to future generations of obstetricians. Vaginal breech delivery may be considered if well-trained and full-time medical staff with experience performing breech deliveries are available and comprehensive informed consent is obtained. As specialists of obstetrics and gynecology, it may be necessary to acquire rudimentary techniques for vaginal breech delivery in order to perform fair and objective informed consent procedures regarding the mode of breech delivery.

The purpose of this study was to compare core body and brain temperatures after complete but intermittent occlusions of the umbilical cord. Thermocouple probes were placed in the parasagittal parietal cortex, ascending aorta, and jugular vein of eight near-term fetal sheep and in the maternal descending aorta. Three days later, after an initial control period, the umbilical cord was occluded for 5 min, followed by a 30-min recovery period, and this cycle was repeated 4 times. Temperature changes, blood gases, and plasma glucose, lactate and adenosine were measured. In the first occlusion period, body core temperature increased 0.12 degreesC over control, and then declined to baseline after cord release, and this pattern was repeated with subsequent occlusions. Brain temperature, however, did not increase in response to any of the cord occlusions. Plasma adenosine increased 2.4-fold during the first occlusion, but not during subsequent occlusions, despite a continuing pattern of constant brain temperature, a result which minimizes adenosine's importance as a continuing regulator of cerebral metabolism. We conclude that brain temperature fails to increase because of diminished heat production by the brain and increases in cerebral blood flow, responses which delay complete depletion of adenosine 5'-triphosphate stores in brain tissue.