Herpes in Pregnancy Max Brinsmead MB BS Ph

Herpes in Pregnancy Max Brinsmead MB BS Ph. D May 2015

Genital Herpes 66% caused by H. simplex Type 2 l 33% associated with H simplex Type 1 l Is a latent and recurrent infection in up to 1: 5 adults l ~1: 50 women have this virus during pregnancy l But most are secondary (or recurrent) infections l Even if the woman says she has never had it before l

Neonatal Herpes 1 l Three subgroups of neonatal infection Skin, eye and mouth disease l Encephalitis only l Disseminated disease l l Disseminated disease has 80% mortality (untreated) and 30% with antiviral agents l l And 17% risk of morbidity in survivors Risk of death from skin, eye and mouth disease is 2%

Neonatal Herpes 2 l Encephalitis alone typically occurs at 10 – 28 d of age Mortality risk 6% l Morbidity risk 70% l l There are regional variations in the rate of neonatal Herpes 1: 60, 000 UK l 1: 30, 000 Europe and Japan l 1: 7500 in certain populations of the US l

Maternal Herpes l l l Primary infection can be disseminated with encephalitis, hepatitis and skin eruptions Is more common in pregnancy because of the mild immunosupression which occurs Concomitant HIV infection a real problem Most infections during pregnancy are secondary But recurrences are more common because of pregnancy-related immunosupression

Vertical Transmission of Herpes l Mostly occurs when the fetus contacts infected genital secretions But intrauterine infection and FDIU possible l Neonatal infection is also possible l l Disseminated Herpes occurs after primary maternal infection l Often l with premature delivery Secondary maternal Herpes can cause l Skin, eye and mouth disease l And sometimes isolated neonatal encephalitis l Because maternal antibodies do not protect the brain

Risk of Vertical Transmission l With maternal primary Herpes the risk of neonatal infection is 26 – 56% l With maternal secondary Herpes the risk of neonatal infection is 1 – 3% l This means that it would require 1583 Caesarean sections of patients with secondary Herpes to prevent one case of neonatal Herpes (with mortality or morbidity)

Diagnosis of Genital Herpes l l l Often unrecognised in its recurrent form Typically localised pruritis and pain Blister and ulceration PCR is a sensitive and specific test if appropriate material is collected Serum Ig. G and Ig. M can be useful in distinguishing primary and secondary infection Viral culture

Maternal Primary Herpes l l l Treat according to clinical condition Consultation with GU-Specialist desirable IV Acyclovir recommended l l But use with caution <20 weeks gestation Use blood Ig. G and Ig. M to help distinguish true primary from secondary infection CS not required if there are type specific Ig. G antibodies present CS is recommended if a primary infection is clinically diagnosed or confirmed within 6 weeks

Why Caesarean Section? A prospective study of 58, 000 women in Washington USA identified 202 of whom 117 delivered vaginally and 85 by CS. The risk of neonatal sepsis was reduced by 86% by CS but the RR confidence intervals were wide (0. 02 – 1. 12)

Maternal Secondary Herpes l l Weekly cultures are not predictive Daily Acyclovir from 36 weeks reduces the risk of A recurrence at the time of delivery l Asymptomatic virus shedding l The chance of CS l l And should be offered to women who would elect CS if there was a Herpes outbreak at the time of labour

Herpes visible at the onset of labour l l l If thought to be a secondary infection then CS is not mandatory Requires patient counselling and her choice should be respected If there are ruptured membranes then delivery should be expidated Fetal trauma should be avoided The neonatal service should be alerted

Other measures l Women who volunteer a history of genital herpes at an antenatal visit require counselling l Women with known carrier partners can be advised to take precautions against infection Or tested for HSV antibodies l l Universal serum screening will reduce both neonatal transmission and the rate of CS but is not considered cost effective l Individuals with active Herpes should not care for neonates

Any Questions or Comments? Please leave a note on the Welcome Page of this website