Original Article from The New England Journal of Medicine Effects on Infants of a First Episode of Genital Herpes during Pregnancy. Although genital herpes simplex virus (HSV) infections occurring during pregnancy are known to be associated with neonatal and maternal complications, their frequency and contributing risk factors are not well understood. We prospectively followed 29 patients who acquired genital herpes during pregnancy, to evaluate the perinatal effects of the infection. Brown ZA, Vontver LA, Benedetti J, et al: Effects on infants of a first episode of genital herpes during pregnancy. N Engl J Med 312:1246, 1987 5.
This article concentrates on the management issues specific to genital herpes infection during pregnancy. Although rare in the UK, neonatal herpes is a severe condition and carries a high risk of morbidity and mortality. Is this a first episode (primary infection) or a recurrence? This may be difficult to distinguish and serology may be helpful, particularly in the third trimester where it will significantly alter management. Pregnant women with untreated genital herpes during the first or second trimester appear to have a greater than two-fold risk of preterm delivery compared with women not exposed to herpes, particularly in relation to premature rupture of membrane and early preterm delivery ( 35 wk of gestation). An antiviral medicine is commonly prescribed for a first episode of genital herpes. (A first episode of genital herpes is also called a primary episode. In addition, your doctor may advise that you should take antiviral medication in the last four weeks of pregnancy to help prevent a recurrence of herpes at the time of childbirth. Antiviral medicines such as aciclovir have not been found to be harmful to the baby when taken during pregnancy. Most people who take antiviral medication get no side-effects, or only minor ones. Feeling sick (nausea), being sick (vomiting), diarrhoea, and tummy (abdominal) pain, as well as skin rashes (including photosensitivity and itching) are the most common side-effects.
The diagnosis of neonatal HSV can be difficult, but it should be suspected in any newborn with irritability, lethargy, fever or poor feeding at one week of age. In one study16 of 46 women who experienced their first episode of genital herpes during pregnancy, the cesarean section rate was significantly decreased in the women prophylactically treated with acyclovir from 36 weeks of gestation up to delivery to prevent a secondary recurrence of infection. Since the highest risk to an infant comes when the mother contracts HSV-1 or 2 during pregnancy, you can take steps to ensure that you don’t transmit herpes during this crucial time. Even women who acquire genital herpes during the first two trimesters of pregnancy are usually able to supply sufficient antibody to help protect the fetus. In addition, newly infected people – whether pregnant or not – have a higher rate of asymptomatic shedding for roughly a year following a primary episode. The second argument for vaginal delivery is that there is no practical way to detect viral shedding quickly enough to affect a delivery decision. Babies are most at risk from neonatal herpes if the mother contracts genital HSV for the first time late in pregnancy. Other factors that might affect your delivery need to be considered too before a decision can be made.
Genital Herpes In Pregnancy. Infections During Pregnancy
Many infants are exposed to acyclovir each year, and no adverse effects in the fetus or newborn attributable to the use of this drug during pregnancy have been reported. Acyclovir can be administered orally to pregnant women with first-episode genital herpes or recurrent herpes and should be administered IV to pregnant women with severe HSV infection. Experiencing these symptoms is referred to as having an outbreak or episode. Clinical manifestations of genital herpes differ between the first and recurrent outbreaks of HSV. See How does herpes infection affect a pregnant woman and her baby? Herpes infection can be passed from mother to child during pregnancy, childbirth, or in the newborn period, resulting in a potentially fatal neonatal herpes infection. Approximately two-thirds of women who acquire genital herpes during pregnancy remain asymptomatic and have no symptoms to suggest a genital HSV infection. Infants born to mothers who have a first episode of genital HSV infection near term and are shedding virus at delivery are at much greater risk of developing neonatal herpes than are infants whose mothers have recurrent genital herpes (Fig 1). Effect of serologic status and cesarean delivery on transmission rates of herpes simplex virus from mother to infant. An infected mother can pass herpes on to her baby during pregnancy or at birth, causing serious illness. This is most serious in women who have their first symptoms of herpes just before giving birth. The first time you get sores or blisters (called a herpes ‘episode’) is usually the worst. Herpes only affects a small area of skin. Although about 25 – 30 of pregnant women have genital herpes, less than 0.1 of babies are born with neonatal herpes. Recurring herpes and a first infection that is acquired early in the pregnancy pose a much lower risk to the infant. Symptoms. When genital herpes symptoms do appear, they are usually worse during the first outbreak than during recurring attacks. It usually affects the lips and, in some primary attacks, the mucous membranes in the mouth. Occasionally, the symptoms may not resemble those of the primary episode but appear as fissures and scrapes in the skin or as general inflammation around the affected area. Recurring herpes or a first infection that is acquired early in the pregnancy pose a much lower risk to the infant.
Neonatal Herpes Simplex Virus Infections
Managing genital herpes during pregnancy is very important to the health of the soon-to-be-born infant. Approximately 1 in 2000 births in America in which the mother is infected with genital herpes may result in herpes simplex virus transmission to the infant1,2, with the potential for effects on the baby as mentioned above. The greatest risk to the infant is in those pregnancies in which the mother develops her first genital herpes infection ever while pregnant2. Find out how having herpes can affect your pregnancy and how to protect your baby. The biggest concern with genital herpes during pregnancy is that you might transmit it to your baby during labor and delivery. The risk of transmission is high if you get herpes for the first time (a primary infection) late in your pregnancy.