EP06.05: Did women's hepatitis B status affect their uptake of invasive prenatal diagnosis after a positive conventional aneuploidy screening?

Abstract

Use of invasive prenatal diagnosis (IPD) in hepatitis B surface antigen (HBsAg)-positive women carries a potential risk of vertical transmission especially when the viral load is high. The objective of the present study is to investigate HBsAg-positive women's uptake of invasive prenatal diagnosis (IPD) after a positive conventional aneuploidy screening. We hypothesis that more HBSAg-positive than- negative women would choose cell free DNA (cfDNA) testing to avoid IPD and its potential risk of vertical transmission. We retrospectively reviewed the women's choice on further testing after a positive conventional aneuploidy screening in our centre from August 2010 to July 2014. HBsAg status was checked routinely in all pregnant women. All women with a positive aneuploidy screening result were counselled by maternal fetal medicine team. With the use of descriptive statistics and Chi-square test, we compared their choice between HBsAg-positive and -negative women. Of 1398 screen positive women, 78 (5.6%) were HBsAg carriers. Of these carriers, 38.5%, 38.5%, 15.4% and 7.7% opted for chorionic villus sampling (CVS), amniocentesis, cfDNA and no further testing respectively. The corresponding figures for non-carriers were 43.2%, 31.2%. 20.0% and 5.6% respectively. The differences were not significant (p=0.3978). There was also no difference in the miscarriage rate between HBsAg-positive and -negative women (1.3% vs 1.0%, p=0.7401). In the present study, screen positive women's choice on the use or method of IPD was not affected by HBsAg status. Women should be adequately counselled on the potential risks of vertical transmission after an IPD.