Patients selected
This is a retrospective cohort study and the patients included in this study were recruited from Xixi Hospital of Hangzhou between January 2014 and March 2018. The study was approved by the Ethics Committee of the Xixi Hospital. The data are anonymous, and the requirement for informed consent was therefore waived by Ethics Committee of Xixi Hospital of Hangzhou. CHB diagnosis was diagnosed according to the Guideline of Prevention and Treatment for Chronic Hepatitis B (2019 Update).
The inclusion criteria were as follows: (1) women aged between 20 to 40 years old; (2) confirmed pregnancy; (3) HBsAg positive and HBeAg positive (prior to seroconversion); (4) HBV DNA level ≥ 5 log10 copies/mL; or (5) viral load of > 20000 IU/mL and elevated alanine aminotransferase level (ALT, > 40 U/L). The exclusion criteria were as follows: (1) history of a child birth with immunoprophylaxis failure; (2) preterm labor; (3) co-infection with hepatitis A, C, D, E, or HIV virus; (4) fetal malformations found by ultrasound examination; and (5) treatment with HBIG during pregnancy.
Patient Grouping And Management
Treatment group (n = 128): patients received 600 mg/day LdT (orally, Novartis, Swiss) at pregestation (Group C, n = 62) and the week 28 to week 32 of gestation (Group B, n = 66). Control group (Group B, n = 101): patients received 600 mg/day LdT (orally, Novartis, Swiss) at week 24 to week 28 of gestation. LdT was stopped if the patients were in immune tolerant phase (i.e., with normal serum ALT) after one month of postpartum. LdT was continued in patients with abnormal baseline serum ALT levels (> 40 U/L).
All infants born to the enrolled women were vaccinated with 100 IU of hepatitis B immune globulin (HBIG) and 10 µg of hepatitis B vaccine within 2 hours postpartum. The second and third does of recombinant HBV vaccine were administered at 1 and 6 months of age, respectively.
Outcome Assessment
The primary outcome was the MTCT rate. The MTCT rates were compared between the treatment group and the control group. The MTCT rate was defined by HBsAg seropositivity or HBV DNA positivity at 4–7 months postpartum.
The secondary outcomes include (1) maternal HBV DNA levels before delivery; (2) maternal complications during the prenatal period, including gestational diabetes mellitus (GDM), hypertensive disorder complicating pregnancy (HDCP), intrahepatic cholestasis of pregnancy (ICP), premature rupture of membranes, hypothyroidism, postpartum hemorrhage, meconium staining of the amniotic fluid, and fetal distress; and (3) infant outcomes such as gestational age, weight, Apgar score, and birth defect rates.
Virology Tests
HBV serological markers (HBsAg, anti-HBs, HBeAg, anti-HBe, and anti-HBc) were measured using a chemiluminescent microparticle immunoassay (Architect i2000 Analyzer; Abbott Diagnostics, USA). Serum HBV DNA levels were determined using a real-time polymerase chain reaction (PCR) system (Shanghai Hongshi Medical Technology Co., LtD.), with a lower detection limit of 30 IU/mL.
Statistical Methods
Continuous variables were expressed as mean ± standard deviation (SD) and categorical values were expressed by absolute and relative frequencies. Differences of continuous data between groups were analyzed by Mann-Whitney U test or one-way ANOVA. The Chi-square test or the Fisher’s exact test was used for categorical data as appropriate. A p < 0.05 was considered statistically significant. Statistical analysis were performed using the SPSS19.0 (SPSS, Inc., Chicago, IL).