Establishment of Fetal Cranial and Intracranial Structure Volume Measurements using Three-dimensional Ultrasound Imaging in a Japanese Population

The goal of this study was to establish a normogram of the intracranial structure volumes in appropriate-for-gestational age (AGA) Japanese fetuses. This was a cross-sectional and prospective study of 211 AGA fetuses. The total intracranial, cerebrum, ventricle, choroid plexus, cerebellum, cerebellar vermis, and cavum septum pellucidum volumes were measured using three-dimensional (3D) ultrasound. The fetal cranial and intracranial structure volumes significantly increased with gestational age (GA). When using the GA as an independent variable and the fetal cranial or intracranial structure volumes as the dependent variable, the best-fit equation for the fetal brain was a second-order polynomial regression equation. We herein provide the first report of fetal cranial and intracranial structure volumes and their normal growth curves in normal Japanese fetuses. Future 3D ultrasound studies of volume and other intracranial fetal structures could provide valuable information about how such changes may correlate with long-term neurodevelopment and the results may be used for comparisons with fetal growth restriction in the future

Development of a High-intensity Focused Ultrasound Exposure Device for Reducing Skin Burn Risk

High-intensity focused ultrasound（HIFU）can non-invasively irradiate inside the body. However, when used to treat fetuses, it can cause thermal burns of the mother’s abdominal wall at the skin interface. This study was carried out to determine whether a modified HIFU transducer enabling split-aperture irradiation can prevent thermal burns. Two HIFU transducers were compared: a conventional transducer using full-aperture irradiation and a modified transducer using split-aperture irradiation. The modified transducer was divided into six sectors for split-aperture irradiation and had a larger surface area and a smaller F number（focal length/aperture diameter）than the conventional transducer. HIFU was delivered to eight sites on the left and right leg of a three-month-old baby pig under general anesthesia, and the sites were assessed for thermal burning by two or more dermatologists. The same person performed all irradiations. Full-aperture irradiation with the conventional transducer caused deep dermal burns at all target sites, while split-aperture irradiation with the modified transducer caused only epidermal burns or superficial dermal burns. Split-aperture irradiation using a modified HIFU transducer with six sectors and a smaller F number reduces the severity of skin burns, and thus will improve the safety of HIFU therapy

IFPA meeting 2018 workshop report II: Abnormally invasive placenta; inflammation and infection; preeclampsia; gestational trophoblastic disease and drug delivery

Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2018 there were nine themed workshops, five of which are summarised in this report. These workshops discussed new perspectives and knowledge in the following areas of research: 1) preeclampsia; 2) abnormally invasive placenta; 3) placental infection; 4) gestational trophoblastic disease; 4) drug delivery to treat placental dysfunction

Umbilical cord insertion site in early gestation and development of placenta

Aim: To study the relation of umbilical cord insertion (CI) site in early gestation and placental development from the chorion villosum. Methods: We ultrasonically measured the distance between the internal cervical Os and the CI site (CID), the distance between the internal cervical Os and lower placenta edge (PLD), and placental thickness at early (10–12 weeks) and mid-gestation (18–20 weeks). Results: CID in early gestation (CID-Early) correlated with CID in mid-gestation (r2=0.171; P<0.01). CID-Early correlated with PLD in mid-gestation (r2=0.093; P<0.01). Thickness of chorion villosum or placenta in early gestation did not correlate with that at mid-gestation. Increasing thickness of placenta was significantly higher in long CID-Early (≥20 mm) cases than short cases (<20 mm) (P<0.05). Conclusions: The process of placental development and the placental location are affected by CI location at early gestation, and suggests that this process might be affected by poor blood supply from the low uterine segment when CI site is close to the internal cervical Os.Peer Reviewe

Evaluation of placental function using near infrared spectroscopy during fetal growth restriction

Objectives: To investigate whether a near infrared spectroscopy (NIRS) system is useful for evaluation of the placental function in cases of fetal growth restriction (FGR). Methods: Subjects included 282 delivered neonates of appropriate for gestational age (AGA) and 44 small for gestational age (SGA) babies. The measurement of the concentration of oxyhemoglobin (HbO2) and deoxyhemoglobin (HHb) was conducted using transabdominal NIRS targeting the placenta at around 20 weeks, 30 weeks and after 36 weeks of gestation and calculated tissue oxygen indexes (TOI=HbO2/total Hb). We correlated between TOIs and causes of FGR. Results: TOIs measured immediately before delivery in the SGA group with severe pre-eclampsia (79.2±3.8 (%±standard deviation (SD); P=0.002)) and placental abnormalities (78.2±3.6; P=0.043) were higher than in the AGA group (74.0±4.5). TOIs in the SGA group with umbilical cord abnormalities were lower (69.7±7.7; P=0.024) than in the AGA group. Conclusion: NIRS might provide information about blood oxygen level of the intervillous space and thus explain the cause of FGR.Peer Reviewe

Effects of maternal smoking on the placental expression of genes related to angiogenesis and apoptosis during the first trimester.

Maternal cigarette smoking is reportedly associated with miscarriage, fetal growth restriction and placental abruption, and is paradoxically associated with a decreased risk of developing preeclampsia. In the present study, we investigated the gene expression levels of villous tissues in early gestation. We compared the expression levels of the genes related to angiogenesis and apoptosis in the villous tissues obtained from smoking and non-smoking pregnant women.We collected villous tissue samples from 57 women requesting surgical termination due to non-medical reasons at 6-8 weeks of gestation. The maternal cigarette smoking status was evaluated by the level of serum cotinine and patients were divided into active smokers and non-smokers by the serum cotinine level. The placental levels of VEGFA, PGF, FLT1, HIF1A, TP53, BAX and BCL2 mRNA were quantified by real time PCR.The gene expression level of PGF and HIF1A in the active smoker group was significantly higher than that in the non-smoker group. We did not observe any significant differences in the VEGFA or FLT1 expression between the groups. In active smoker group, the gene expression levels of TP53 and BAX were significantly higher than those in the non-smoker group. The ratio of BAX/BCL2 mRNA in the active smoker group was significantly higher than that in the non-smoker group.Our findings revealed that smoking might affect the placenta during early pregnancy. Maternal cigarette smoking in early pregnancy may be associated with villus hypoxia, which may influence angiogenesis and apoptosis

Evaluation of Second-generation HIFU Systems: Less-invasive Fetal Therapy for TRAP Sequence

In this report, the second-generation high-intensity focused ultrasound （HIFU） systems were clinically evaluated for human fetal therapy in two cases of twin reversed arterial perfusion sequence. The HIFU systems comprised an improved lead zirconate-titanate transducer with an imaging phase array sector probe, a Sonachill cooling system, and three phases of HIFU exposure: a trigger pulse, a continuous heating wave, and an idle period to obtain images with the imaging probe set on the transducer. To evaluate skin surface temperature, a thermal camera was used. To evaluate vessel occlusions, blood flow was measured at fixed timings after exposures. Target vessel occlusion was achieved with HIFU in only one of the cases, but recanalization occurred the following day. Both cases were finally treated with radiofrequency ablation and one infant was successfully delivered without any complications. This case highlighted three advantages with the change to second-generation HIFU systems in human fetal therapy: the simplicity of maneuvers by reduced range of motion disturbance; the ability to observe in real time during the exposure; and a decrease in total ultrasonic output. Treatment interruption due to burns or complaints of heat sensation represented an obstruction to treatment completion. This remains an issue to be addressed in the future