Herpes in Pregnancy 2014

Factors which affect transmission include:

• Primary or recurrent infection in the mother
• Presence of transplacental maternal neutralising antibodies
• Duration of rupture of membranes before delivery
• Use of foetal scalp electrodes
• Mode of delivery

There is no evidence of an increased risk of spontaneous miscarriage with primary genital herpes in the first trimester or that HSV acquired in pregnancy is associated with an increased incidence of congenital abnormalities.

The neonatal risks are greatest when a woman acquires a new infection in the third trimester, particularly within 6 weeks of delivery. There is some evidence of increased perinatal morbidity and stillbirth however the data are conflicting. If a vaginal delivery ensues, the risk of neonatal herpes is very high at 41%.

Disseminated herpes is more common in preterm infants and occurs almost exclusively as a result of primary infection in the mother.

• The incidence of congenital abnormalities is not increased in the presence of recurrent genital herpes infection
• In recurrent HSV the risk of neonatal herpes is low, even if lesions are present at the time of delivery (0–3% for vaginal delivery)
• Recurrent herpes at the time of delivery may cause the localised forms of neonatal herpes: both local CNS disease and skin, eye and mouth infection
• Transplacentally acquired HSV antibodies do not prevent herpes virus spreading to the brain of the neonate

• Accounts for approximately 30% of neonatal herpes infections
• Best prognosis
• With appropriate antiviral treatment, neurological and/or ocular morbidity is <2%

• Accounts for approximately 70% of neonatal herpes infections
• Approximately 60% will present without skin, eye and/or mouth infection
• Infants with local CNS disease often present late (10 days - 4 weeks of age)
• With appropriate treatment:
• Local CNS disease - mortality ~6%, neurological morbidity 70%
• Disseminated disease - mortality ~30%, neurological morbidity 17%
• Poor outcomes have been attributed to delays between symptom onset and treatment

Neonatal infection is the result of an infection at the time of birth.

Congenital infection is due to transplacental infection in utero. This is extremely rare. It may affect the skin, eyes and CNS. There may be foetal growth restriction or foetal death.

• May present with encephalitis, hepatitis, disseminated skin lesions or a combination
• Rare in adults, although more commonly reported in pregnancy, particularly if immunocompromised
• Maternal mortality associated with this condition is high

• Increased risk of more severe and frequent symptomatic recurrences of genital herpes during pregnancy
• Increased risk of asymptomatic shedding of HSV at term
• Co-infection with HSV and HIV increases replication of both viruses - genital reactivation of HSV may increase the risk of perinatal transmission of both HIV and HSV, although this has not been realised in practice in the UK

• Refer women with suspected genital herpes for assessment by a GUM physician
• Confirm diagnosis with HSV PCR
• Complete STI screen
• Do not delay treatment whilst awaiting results - manage the woman in line with her clinical condition, using aciclovir in standard doses (usually PO, IV if disseminated)
• Inform the obstetrician - if midwifery led care refer for review with an obstetrician
• Paracetamol and topical lidocaine 2% gel offer symptomatic relief
• Providing delivery is not within the next 6 weeks, the pregnancy should be managed   expectantly and vaginal delivery anticipated
• Daily suppressive aciclovir 400 mg TDS from 36 weeks reduces HSV lesions and asymptomatic shedding at term and hence the need for delivery by caesarean

Aciclovir is not licensed for use in pregnancy but is considered safe and well tolerated. Valaciclovir and famciclovir are not recommended as first line as there is less experience with their use. See full guideline for further details.

• No additional monitoring of the pregnancy is required
• Do not delay treatment - manage the woman in line with her clinical condition using standard doses of aciclovir (usually PO, IV if disseminated)
• Continue daily suppressive aciclovir 400 mg TDS until delivery
• Recommend caesarean, particularly if episode is within 6 weeks of expected delivery
• Type-specific HSV antibody (IgG) testing is advisable to distinguish between primary and recurrent genital HSV infections
  • The presence of antibodies of the same type as the HSV isolated from genital swabs would confirm this episode to be a recurrence rather than a primary infection and elective caesarean would not be indicated
• Plan mode of delivery with assumption that all first episode lesions are primary genital herpes (this can be modified if test results later confirm a recurrence)
• Recommend discussion of serology results with a virologist or GUM physician

• Recommend caesarean to all women presenting with primary episode genital herpes lesions at the time of delivery, or within 6 weeks expected delivery date
  • Benefits of caesarean may reduce if the membranes have been ruptured > 4 hours - however, there may be some benefit even after this time interval
• Consider intrapartum IV aciclovir for the mother (5 mg/kg 8 hourly) and the neonate (20 mg/kg 8 hourly) if opting for vaginal delivery
• Although vaginal delivery should be avoided if possible, in women who deliver vaginally in the presence of primary genital herpes lesions, avoid invasive procedures

• Vaginal delivery should be offered
• Caesarean section delivery can be considered
  • The risk to the mother and future pregnancies should be set against the small risk of neonatal transmission of HSV
  • The final choice of mode of delivery should be made by the mother
• Invasive procedures may be used if required
  • They may increase the risk of neonatal HSV infection but, as background risk is small, this increase is unlikely to be clinically significant
• Manage women in accordance with standard NICE intrapartum guidelines
• There is no evidence to guide the management of women with spontaneous rupture of membranes at term
  • Expediting delivery may minimise duration of potential exposure of the foetus to HSV

Primary genital herpes in preterm prelabour rupture of membranes (PPROM):

• There is limited evidence to inform best obstetric practice
• Management should be guided by MDT discussion involving obstetricians, neonatologists and GUM physicians, and the gestation that PPROM occurred
• If the decision is made for immediate delivery then the anticipated benefits of caesarean will remain
• If initial conservative management, the mother should receive IV aciclovir (5 mg/kg 8 hourly)
• Consider prophylactic corticosteroids to reduce the implications of preterm delivery upon the infant
• If delivery is indicated within 6 weeks of the primary infection, delivery by caesarean may still offer some benefit despite prolonged rupture of membranes

Recurrent genital herpes in PPROM:

• The risk of neonatal transmission is very small and may be outweighed by the morbidity and mortality associated with premature delivery
• In cases of PPROM before 34 weeks evidence suggests expectant management is appropriate, including PO aciclovir 400 mg TDS for the mother
• After 34 weeks, manage in accordance with relevant RCOG guidelines on PPROM and antenatal corticosteroid administration to reduce neonatal morbidity and mortality - it should not be influenced by the presence of recurrent genital herpes lesions

Manage according to recommendations for all women with primary genital HSV infection.

• There is some evidence that HIV-positive women with genital HSV ulceration in pregnancy are more likely to transmit HIV infection independent of other factors
• If history of genital herpes offer daily suppressive aciclovir 400 mg TDS from 32 weeks to reduce the risk of transmission of HIV, especially if vaginal delivery is planned
  • Start at earlier gestation due to increased risk of preterm labour in HIV-positive women
• The mode of delivery should be in line with the BHIVA HIV in pregnancy guideline recommendations according to obstetric factors and HIV parameters
• There is no evidence to recommend daily suppressive treatment of HSV for HIV-positive women who are HSV-1 or -2 seropositive with no history of genital herpes

In all cases the neonatal team should be informed.