Kiyotake Ichizuka

Evaluation of bidirectional transfer of plasma DNA through placenta

AbstractTo clarify the origin of cell-free fetal DNA in maternal plasma, we analyzed bidirectional transfer of plasma DNA between fetus and mother. We analyzed maternal and fetal plasma DNA obtained from 15 pregnant women at the time of Cesarean section. The subjects were five patients with preeclampsia and 10 gestational-age-matched normal controls. DNA was extracted from 1.5-ml plasma samples and the cellular fraction of maternal and umbilical blood. Seven polymorphic marker genes were analyzed. The relative concentration of fetal DNA in maternal plasma and maternal DNA in cord blood were evaluated. The relative concentration of maternal DNA in fetal circulation (median, 0.9%; range, 0.2–8.4%) was significantly lower than that of fetal DNA in maternal blood (14.3%, 2.3–64%), with P=0.007. The relative concentration of maternal DNA in fetal blood was not affected by preeclampsia. These findings indicate that cell-free DNA is unequally transferred through the placenta. The structural characteristics of the placenta suggest that the majority of cell-free fetal DNA in maternal plasma is derived from villous trophoblasts.

Predisposing factors for massive hemorrhage during Cesarean section in patients with placenta previa

To investigate whether maternal history and ultrasound findings can be predictors for massive hemorrhage during Cesarean section in patients with placenta previa and adherence of the placenta.

Limitations of conservative treatment for repeat Cesarean scar pregnancy

delineate the level of fusion, connecting vessels and fetal contour (Figure 3). One week later, repeat scans by 3D transvaginal ultrasonography confirmed the diagnosis of conjoined twins. After counseling, the patient opted to terminate the pregnancy. After evacuation, two separate bodies and two separate upper and lower extremities were noted. The location of the conjoined site could not be identified on gross inspection of the abortus because the embryos had been destroyed during the evacuation procedure. Early diagnosis of conjoined twins is crucial for determining subsequent management and possibly decreasing maternal morbidity (evacuation vs. hysterotomy). Specific sonographic findings of conjoined twins examined during the first trimester include inseparable fetal bodies despite manipulation of the uterus with a transvaginal probe or prolonged continuous scanning, bifid appearance of the embryo, single yolk sac3, and a single umbilical cord with more than three vessels. Recently, some reports4–8 have described early diagnosis of conjoined twins by 3D ultrasound imaging combined with power Doppler, computed tomography and magnetic resonance imaging. In this case, prenatal diagnosis of conjoined twins was established by transvaginal 2D ultrasonography and power Doppler. However, 3D imaging with surfacerendering provided clearer images of the characteristic features of ischiopagus twins and helped the parents to understand the complex anomalies present in their fetuses. Furthermore, it improved our diagnostic confidence to provide adequate early intervention.

Velamentous cord insertion into the lower third of the uterus is associated with intrapartum fetal heart rate abnormalities

To evaluate the accuracy of sonographic identification of the site of umbilical cord insertion (CI) at 18–20 weeks of gestation, to compare the sensitivities for detection of a velamentous cord insertion (VCI) secondary to a CI into the anterior, posterior or fundal wall, and to compare the intrapartum complications secondary to VCI into the upper, middle or lower third of the uterus.

Functional and histological changes in rat femoral arteries by HIFU exposure

This study was an investigation of arterial contractility in response to high-intensity focused ultrasound (HIFU) and of histologic changes to the artery with various intensities of HIFU. We constructed a prototype HIFU transducer in combination with an imaging probe that provides color Doppler imaging and Doppler velocimetry. HIFU was applied through the skin to deep femoral arteries in left thighs of Sprague-Dawley rats; color images of the blood flow were used to aim the HIFU beam. Peak intensities used were 530, 1080, 2750 and 4300 W/cm2. The duration of each HIFU exposure was 5 s. HIFU was applied to five focal spots of each leg. These focal spots were aligned with a spacing of 1.0 mm so as to form a line across the artery. Blood flow occlusion was accomplished by HIFU at an intensity of 4300 W/cm2, but the flow continued with the lower intensities. Peak systolic velocities (PSVs) of blood flow as measured by Doppler velocimetry increased in the arteries to which HIFU had been applied at 1080 and 2750 W/cm2. The increase corresponded with HIFU intensity. Exposure to HIFU at 530 W/cm2 did not change the blood flow velocity. Histologic studies have demonstrated that exposure to HIFU at 2750 and 4300 W/cm2 leads to vacuolar degeneration and destruction of elastic fibers of the tunica media of the artery. Exposure at 1080 W/cm2 led to increased PSV, but did not induce histologic changes in the vessel wall. In conclusion, the response of the artery to HIFU varied with intensity. Vascular contraction without tissue degeneration occurred at low intensity; with increasing intensity, the tissue degeneration detectable in histology reduced the vascular diameter and, finally, at high intensity, the blood flow was occluded. Although these phenomena appeared to be mainly due to thermal effects, mechanical effects might have some role, particularly on vascular contraction.

Attitudes toward non‐invasive prenatal diagnosis among pregnant women and health professionals in Japan

This study aims to assess the attitudes toward non‐invasive prenatal diagnosis (NIPD) and NIPD problems in clinical practice in Japan.

Velamentous cord insertion: significance of prenatal detection to predict perinatal complications.

In the maternal and child health statistics of Japan for 2003, perinatal deaths were most frequent in pregnant women with abnormalities of the placenta, umbilical cord, and fetal membrane. Despite advances in perinatal medicine, approximately 2% of low-risk pregnant women still require an emergency cesarean section after the onset of labor. Because it is likely that half of these cases are associated with placental and umbilical cord abnormalities, it is thought that prenatal detection of such abnormalities would reduce the number of emergency cesarean sections in low-risk women. In our previous studies, some abnormalities of the placenta and umbilical cord were associated with abnormalities of cord insertion. Furthermore, we reported that prenatal detection of velamentous cord insertion (VCI) reduced the number of emergency cesarean sections in low-risk women. In this review, we describe the prenatal detection of abnormalities of umbilical cord insertion and the management of VCI based on our current clinical data.

Placenta Increta: Postpartum Monitoring of Plasma Cell-free Fetal DNA

Antenatal prediction of abnormal adherence of the placenta to the uterine wall is very important in clinical practice because it is associated with high maternal morbidity and a high risk of mortality. We previously reported that the concentration of fetal DNA in maternal plasma is increased in cases of placenta previa, especially in patients with placenta increta and placenta accreta (1). It has been suggested that invasion of trophoblasts into the uterine muscle of these patients produces increased plasma concentrations of cell-free fetal DNA because of the destruction of trophoblasts by the maternal immune system on invasion of the uterine muscle. We earlier proposed that antenatal prediction of abnormal conditions, such as placenta increta, might be achieved by an analysis of fetal DNA in the plasma of high-risk pregnant women, including those with placenta previa and/or a previous history of uterine surgery (1). In the present report, we describe a case of placenta increta in which a small part of the placenta remained adherent despite manual removal of the placenta at the time of delivery. The patient was followed by monitoring the concentrations of plasma human chorionic gonadotropin human chorionic gonadotropin β (hCGβ) and fetal DNA (DYS14) after delivery. A 37-year-old Japanese woman, gravida 0, para 0, was admitted to Showa University Hospital …

Cord insertion into the lower third of the uterus in the first trimester is associated with placental and umbilical cord abnormalities

To assess the feasibility of detecting the cord insertion site during the late first trimester, and to investigate the possible association between perinatal complications and a cord insertion in the lower third of the uterus in the first trimester.

Analysis of placental weight centiles is useful to estimate cause of fetal growth restriction

Aim:  To establish a nomogram of placental weight at delivery and to clarify the associations among standardized placental weights and known risk factors of fetal growth restriction (FGR).