Fetal exposure to herpesviruses may be associated with pregnancy-induced hypertensive disorders and preterm birth in a Caucasian population

Objective To investigate the role of fetal viral infection in the development of a range of adverse pregnancy outcomes (APOs), including pregnancy-induced hypertensive disorders (PIHD), antepartum haemorrhage (APH), birthweight < 10th percentile (small for gestational age, SGA) and preterm birth (PTB). Design Population-based case-control study. Setting Laboratory-based study. Population The newborn screening cards of 717 adverse pregnancy cases and 609 controls. Methods Newborn screening cards were tested for RNA from enteroviruses and DNA from herpesviruses using polymerase chain reaction (PCR). The herpesviruses were detected using two PCRs, one detecting nucleic acids from herpes simplex virus (HSV)-1, HSV-2, Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human herpesvirus (HHV)-8, hereafter designated Herpes PCR group A viruses, and the other detecting nucleic acids from varicella-zoster virus (VZV), HHV-6 and HHV-7, hereafter designated Herpes PCR group B viruses. Main outcome measure Odds ratios and 95% CIs for specific APOs. Results For both term and PTBs, the risk of developing PIHD was increased in the presence of DNA from Herpes PCR group B viruses (OR 3.57, 95% CI 1.10-11.70), CMV (OR 3.89, 95% CI 1.67-9.06), any herpesvirus (OR 5.70, 95% CI 1.85-17.57) and any virus (OR 5.17, 95% CI 1.68-15.94). The presence of CMV was associated with PTB (OR 1.61, 95% CI 1.14-2.27). No significant association was observed between SGA or APH and exposure to viral infection. Conclusions Fetal exposure to herpesvirus infection was associated with PIHD for both term and PTBs in this exploratory study. Exposure to CMV may also be associated with PTB. These findings need confirmation in future studies.