Current status of percutaneous umbilical cord blood sampling in Japan

New challenges of fetal therapy in Japan

Aim

To review new challenges of fetal therapy in Japan after the establishment of four existing fetal therapies as standard prenatal care with National Health Insurance coverage over the past 20 years.

Methods

Reported studies and our current research activities related to four fetal therapies newly performed in Japan were reviewed.

Results

Fetoscopic endoluminal tracheal occlusion (FETO) for congenital diaphragmatic hernia (CDH) aims to occlude the trachea using a detachable balloon to promote lung growth. Following the recent successful completion of an international randomized controlled trial for CDH, in which we participated, FETO is offered for severe left CDH to perform balloon insertion at 27–29 weeks and removal at 34 weeks of gestation. Fetal cystoscopy (FC) for low urinary tract obstruction was introduced to overcome the demerits of vesicoamniotic shunting. FC may provide a proper diagnosis by visual observation of the urethra and physiological treatment of the posterior urethral valve. The effectiveness of open fetal surgery for myelomeningocele (MMC), direct surgery with laparotomy and hysterotomy, for ameliorating hindbrain herniation and the motor function was demonstrated, but it was also associated with substantial maternal and fetal risks. Fetal aortic valvuloplasty (FAV), ultrasound‐guided fetal aortic balloon dilation for critical aortic stenosis with evolving hypoplastic left heart syndrome may improve left heart development and maintain biventricular circulation. Feasibility and safety studies for FC, MMC open fetal surgery, and FAV are currently ongoing.

Conclusions

Clinical research on FETO, FC, MMC open fetal surgery, and FAV has proceeded with careful preparations in Japan.

A Review of Cordocentesis: Percutaneous Umbilical Cord Blood Sampling

We discuss the current indications, technical variation and procedure-related complications of percutaneous umbilical cord blood sampling (PUBS). The term PUBS is commonly used in the United States. Cordocentesis and funipuncture are equivalent terms. A needle guided by ultrasound is introduced into a blood vessel (usually the vein) of the umbilical cord to collect fetal specimen in PUBS.

We conducted a literature search in PubMed indexed journals and analyzed all related articles on PUBS and cordocentesis. We chose this subject because it is a relatively new but convenient method that has both diagnostic and therapeutic value in fetal medicine. At present the only procedure that provides direct access to fetal circulation is PUBS. The most common clinical indication for PUBS is suspected fetal anemia. Other major indications for PUBS are the diagnosis of congenital infections, cytogenetic analysis, metabolic disorders, fetal growth restriction and hematologic disorders. Therapeutic applications of cordocentesis or puncture of the umbilical cord are in utero transfusions for rhesus alloimmunization and medication administration. PUBS also provides a direct assessment of fetal thyroid function diagnosing fetal thyroid disorders and helps administer therapy in utero. 

Literature demonstrates a low incidence of complications associated with percutaneous umbilical blood sampling. For PUBS, the true complication rate related to the method of sampling remains unclear. A few cases reported complications conducted PUBS for therapeutic purposes which naturally has a higher accident rate compared to diagnostic purposes. Although life-threatening complications are rare, there are potential risks that include bleeding from the puncture site, fetal bradycardia, vertical transmission of maternal infection. Therefore, PUBS should be performed at perinatal care centers by experienced physicians and the best time is between 17 to 40 weeks of gestation. There are three methods used to approach the umbilical cord that includes direct, indirect and free puncture. Anteriorly placed placenta allows an easier approach to the umbilical cord. The danger of abruption of placenta must be kept in mind while using this technique. The number of punctures should be limited to a maximum of 3 to reduce complications. According to a case series report, the mean time required for the procedure was 4 minutes with a fall in duration seen with increased experience.

In conclusion, percutaneous blood sampling allows direct access to fetal circulation thus opening up new areas of prenatal diagnosis and therapy. PUBS is now a well-codified procedure. It is clear from our literature review that risks directly related to the technique are small. The indication of the procedure must be carefully chosen as the risk of complications of umbilical cord puncture is directly related to the severity of the condition. Complications such as bleeding and hematoma formation are related to duration and number of punctures which are operator-dependent. Thus, only highly trained personnel should conduct the procedure. The list of indications is extensive and growing. Nevertheless, this technique shows potential to open up new realms in the area of fetal medicine. 

Nationwide survey of intrauterine blood transfusion for fetal anemia in Japan

AIM

The present study investigated the current situation regarding intrauterine blood transfusion (IUT) for fetal anemia in Japan.

METHODS

We conducted a nationwide, multicenter, retrospective cohort questionnaire survey for cases that underwent IUT from 2011 to 2015. The questionnaire required perioperative information, indications, details of the procedure, procedure-related complications, and neonatal morbidity.

RESULTS

A total of 100 IUT procedures were performed in 66 cases at 19 institutions during the study period. The most frequent indication of IUT was complicated monochorionic diamniotic (MCDA) twins in 28 (42.4%) cases, followed by 16 (24.2%) cases of red-cell alloimmunization, and 10 (15.2%) cases of parvovirus B19 infection. IUT was performed through the umbilical cord in the vast of majority cases (92%). Bleeding from the IUT site was the most common adverse event (40%). Two cases (2%) underwent emergency cesarean section after the procedure. There were no cases of rupture of membrane or intrauterine infection after IUT. The neonatal survival rate was 77.3% in the 66 total cases and 64% in the hydrops cases. The neonatal survival rates in MCDA twins, red-cell alloimmunization, and parvovirus B19 infection were 75%, 93.8%, and 70%, respectively.

CONCLUSIONS

IUT was performed for mainly three indications in Japan: MCDA twins, red-cell alloimmunization, and parvovirus B19 infection. The incidences of severe adverse events seemed very low. The outcomes after IUT were favorable with variations in survival rates according to indications. However, further studies with long-term follow-up will be required to assess the effectiveness of IUT, especially for complicated MCDA twins.

Acute Perinatal Infection and the Evidenced-Based Risk of Intrauterine Diagnostic Testing: A Structured Review

BACKGROUND

The prevalence of perinatal infection from maternal exposure is increasing. The prevalence of acute maternal infections identifies cytomegalovirus, parvovirus B19, toxoplasmosis, and varicella as the most common organisms and in the order of frequency. Maternal informed consent and understanding is required before intrauterine testing for fetal infectious and possible genetic risk assessment.

METHODS

This structured review of the reproductive published literature focuses on the risks of amniocentesis and cordocentesis diagnostic procedure-related fetal loss rates and fetal vertical transmission (VT) rates from published infected pregnant cohorts.

RESULTS

The total postprocedure fetal loss rate for diagnostic amniocentesis procedures, in limited infectious cohorts, is 1.5% and does not appear to be increased compared to "noninfected" amniocentesis cohorts using an estimated background spontaneous fetal loss rate (no procedure) of 0.65%. The "pooled" unintended fetal loss rate is from small infected population cohorts, but can be used for counseling purposes. Postcordocentesis fetal loss risk, in an infected cohort, is not possible to estimate due to limited data. The "biological spontaneous fetal loss rate" risk with a perinatal infection (positive or negative fetal anomalies) and no diagnostic procedure before 20 weeks of gestation is reviewed. The risk of VT in acute infection cohorts as a result of the intra-amniotic diagnostic procedure is not found to be increased.

CONCLUSION

The unintended "fetal loss" rate after amniocentesis for perinatal infected cohorts is similar to that of noninfected cohorts, but the estimate is based on limited infected cohorts. There was no procedure-based risk of fetal VT in the infected cohorts, but identification of postprocedure maternal bleeding into the amniotic cavity increases the potential risk. Maternal knowledge translation and an informed consent process with risk-benefit maternal/fetal risk counseling are required prior to any diagnostic amniocentesis procedure.