Abstract
Background
Noninvasive prenatal diagnosis (NIPD) has been proven available 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.
Results
All of the recruited participants, comprising sixteen women with singleton pregnancies and one woman with a twin pregnancy, had a proband with NSHL caused by GJB2 gene or SLC26A4 gene mutations. 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. 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 in the first trimester and the earliest gestation week was the 7th week.
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. These findings significantly contribute to the scientific understanding and clinical management of hearing loss in multiple pregnancies.