Clinical Practice Guidelines for Prenatal Aneuploidy Screening and Diagnostic Testing from Korean Society of Maternal-Fetal Medicine: (2) Invasive Diagnostic Testing for Fetal Chromosomal Abnormalities

Accelerating the momentum to achieve global elimination of hepatitis B infection: a scoping review of hepatitis B guidelines to reduce mother to child transmission

Progress towards achieving global elimination of hepatitis B virus (HBV) by 2030 remains unsatisfactory. Prevention of mother to child transmission is crucial but current Clinical Practice Guidelines (CPGs) gave diverse recommendations, creating confusion and leading to significant challenges in the practical implementation across various regions owing to global inequity. We reviewed 47 CPGs on the management of hepatitis B during pregnancy against twelve important clinical questions. Of 47 guidelines, 80.9% (38/47) supported the universal approach to HBV screening. To select women for antiviral prophylaxis, 78.7% (37/47) recommended the use of HBV DNA levels, while 31.9% (15/47) recommended the use of HBeAg. Of 37 guidelines recommending HBV DNA levels, 94.6% (35/37) recommended a viral load threshold of >200,000 IU/mL to initiate antiviral prophylaxis. Of 16 guidelines addressing the mode of delivery, 87.5% (14/16) encouraged vaginal birth. Of 30 guidelines addressing breastfeeding, 60% (18/30) recommended breastfeeding. However, controversies were found in the optimal timing of HBV disease evaluation during pregnancy and the ideal timing to stop antiviral prophylaxis after delivery. Of 36 guidelines addressing the timing to initiate antiviral prophylaxis, 25% (9/36) advised starting prophylaxis between 24 and 28 weeks, while 75% (27/36) suggested other timings or provided vague descriptions. Of 38 guidelines addressing birth-dose vaccination, 42% (16/38) emphasized the importance of "vaccination as soon as possible after birth." These deficiencies and discrepancies among CPGs could significantly impede global HBV elimination.

Effect of invasive tests during pregnancy on perinatal transmission of hepatitis B infection: a scoping review

Prenatal and intrapartum invasive tests are possible mechanisms of mother to child transmission (MTCT) of hepatitis B virus (HBV). The viral activity can affect the MTCT risk after invasive tests, but the evidence is scarce. This scoping review discussed the effects of prenatal or intrapartum invasive tests on the risk of HBV MTCT. The risk of MTCT after amniocentesis was low among hepatitis B infected pregnant individuals with negative hepatitis B e antigen (HBeAg) statuses or HBV DNA < 7 log10 IU/mL, and comparable to those that did not undergo prenatal invasive tests. Amniocentesis could increase the risk of MTCT among women with seropositive HBeAg statuses or HBV DNA ≥ 7 log10 IU/mL, but there were no MTCT among these women who received antiviral treatment. Data on CVS, cordocentesis and intrapartum invasive tests were insufficient to conclude their effects on MTCT. We also reviewed 50 international clinical practice guidelines. Most of them did not have recommendations on the management of hepatitis B infected pregnant individuals requiring prenatal or intrapartum invasive tests and significant discrepancies existed among the remaining guidelines. A workflow and two pragmatic approaches were discussed to assist clinical management. Furthermore, we would like to encourage future research to provide comprehensive data on the factors influencing the MTCT rate (such as maternal HBV DNA viral load and HBeAg status, availability and timing of neonatal birth dose immunizations, transplacental or transamniotic invasive tests, complications of the invasive tests and the use of antiviral prophylaxis).

Noninvasive prenatal diagnosis (NIPD) of non-syndromic hearing loss (NSHL) for singleton and twin pregnancies in the first trimester

BACKGROUND

Noninvasive prenatal diagnosis (NIPD) has been proven feasible for non-syndromic hearing loss (NSHL) in singleton pregnancies. However, previous research is limited to the second trimester and the application in twin pregnancies is blank. Here we provide a novel algorithmic approach to assess singleton and twin pregnancies in the first trimester.

METHODS

A 324.614 kb capture panel was designed to selectively enrich target regions. Parental haplotypes were constructed by target sequencing of blood samples from the parents and the proband. Then single nucleotide polymorphisms (SNP) within target regions were classified into four and six categories in singleton and twin pregnancy, respectively. Combining relative haplotype dosage change (RHDO) and the Bayes factor (BF), fetal fraction (FF) and fetal genotype were deduced in singleton and twin pregnancies. The pregnant women's NIPD results were validated by invasive prenatal diagnosis and Sanger sequencing.

RESULTS

Sixteen women with singleton pregnancies and one woman with a twin pregnancy were recruited. Among the 16 singleton pregnancies, NIPD was successfully applied in 15 families and the coincidence rate with invasive prenatal diagnosis was 100% (15/15). Only one family NIPD result is "no call" because the imbalance distribution of SNP sites makes it difficult to estimate recombination events. Most (13/15) of pregnant women were diagnosed in the first trimester and the earliest gestation week was the 7th week. The twin pregnancy was a dichorionic diamniotic twin (DCDA). NIPD confirmed one fetus is affected, and another is a carrier with c.299_300delAT of GJB2 gene.

CONCLUSION

This study represents the pioneering evidence in the field, demonstrating the feasibility of NIPD for NSHL in twin pregnancies. Moreover, it provides a novel and advanced diagnostic approach for families at high risk of NSHL during pregnancy, offering earlier detection, enhanced safety, and improved accuracy.

Comparative analysis of obstetric, perinatal, and neurodevelopmental outcomes following chorionic villus sampling and amniocentesis

Background

The risks of invasive prenatal tests are reported in previous studies such as miscarriage, fetal anomalies, and bleeding. However, few compare short-term and long-term outcomes between invasive tests. This study aims to investigate obstetric, perinatal, and children's neurodevelopmental outcomes following chorionic villus sampling (CVS) or amniocentesis in singleton pregnancy.

Methods

This retrospective cohort study included healthy singleton pregnancies underwent transabdominal CVS (gestational age [GA] at 10-13 weeks) or amniocentesis (GA at 15-21 weeks) at a single medical center between 2012 and 2022. Only cases with normal genetic results were eligible. Short-term and long-term neurodevelopmental outcomes were evaluated.

Results

The study included 200 CVS cases and 498 amniocentesis cases. No significant differences were found in body mass index, parities, previous preterm birth, conception method, and cervical length (CL) before an invasive test between the groups. Rates of preterm labor, preterm premature rupture of the membranes, preterm birth, neonatal survival, neonatal short-term morbidities, and long-term neurodevelopmental delay were similar. However, the CVS group had a higher rate of cervical cerclage due to short CL before 24 weeks (7.0%) compared to the amniocentesis group (2.4%). CVS markedly increased the risk of cervical cerclage due to short CL (adjusted odd ratio [aOR] = 3.17, 95%CI [1.23-8.12], p = 0.016), after considering maternal characteristics.

Conclusion

Performing CVS resulted in a higher incidence of cerclage due to short cervix or cervical dilatation compared to amniocentesis in singleton pregnancies. This highlights the importance of cautious selection for CVS and the necessity of informing women about the associated risks beforehand.

Evaluation of Fetal and Maternal Outcomes in Chorion Villus Sampling (CVS)

Background

Chorionic villus sampling (CVS) is one of the invasive diagnostic methods used to diagnose chromosomal, genetic, and metabolic diseases in the embryonic period. The use of this method is associated with maternal and fetal consequences, the most serious of which is abortion. Therefore, the present study was conducted to investigate the incidence of these consequences and the factors affecting the incidence of abortion.

Materials and Methods

A cross-sectional study was performed on 98 pregnant women with CVS indications. Maternal and fetal outcomes including abortion, vaginal bleeding, subchorionic hematoma, premature rupture of membrane (PROM), chorioamnionitis, preterm delivery, limb abnormality, fetal growth retardation, and preeclampsia were recorded.

Results

The results of the present study showed that the incidence of fetal outcomes including fetal growth failure, premature rupture of membranes, abortion, and limb abnormalities was 4.1%, 7.1%, 3.1%, and 1%, and the incidence of maternal outcomes including preterm delivery, subchorionic hematoma, preeclampsia, and hemorrhage was 14.3%, 3.1%, 6.1%, and 10.2%, respectively. In addition, a decrease in free BHCG and an increase in NT were significantly associated with the occurrence of abortion (OR: 0.11 and 4.25, respectively, P value < 0.05).

Conclusion

It should be noted that due to a long time between placental sampling and the occurrence of vaginal bleeding, premature rupture of membrane, and preterm delivery, it seems that placental sampling has no effect. In addition, only a decrease in free BHCG or an increase in NT significantly increased the chance of miscarriage.

Contribution of chromosomal microarray analysis and next-generation sequencing to genetic diagnosis in fetuses with normal karyotype

AIM

The aim of this study was to investigate the contribution of chromosomal microarray analysis (CMA) and next-generation sequencing (NGS) to genetic diagnosis in fetuses with normal karyotype who underwent invasive testing for different indications.

METHODS

The results of invasive genetic testing performed at a tertiary center between September 2020 and March 2022 were retrospectively analyzed. Indications for invasive tests were classified as fetal structural malformation, presence of soft markers, and high risk in screening tests. CMA results were classified as pathogenic or likely pathogenic (pCNVs), benign (bCNVs), and variants of unknown clinical significance (VOUS).

RESULTS

A total of 830 invasive tests were performed and aneuploidy was detected in 11.2% of the fetuses. CMA was performed in 465 fetuses with normal karyotype, and pCNVs were detected in 6.9%. pCNVs were detected in 8.2% of fetuses with structural malformations, 6.5% in soft markers, and 4.7% in high risk in screening tests. Pathogenic variants were detected by NGS in 33.8% of fetuses with bCNVs.

CONCLUSIONS

pCNVs can be significantly detected not only in fetuses with structural malformations, but also in invasive testing with other indications. NGS significantly contributes to genetic diagnosis in fetuses with structural malformations.