Herpes simplex virus infection in pregnancy: Clinical sciences

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Introduction0:00–1:08

Herpes simplex virus, or HSV infection is a common sexually transmitted infection or STI. There are two types of this virus: HSV1 and 2.
Even though HSV1 is associated with cold sores, and HSV2 with genital ulcers, both can cause genital ulcers so presentation alone is not enough to differentiate between the two.
Determining the HSV subtype is important as it can provide information on the risk of recurrence. Now, the infection itself carries some risks.
A primary outbreak in the first trimester of pregnancy can result in neonatal chorioretinitis, microcephaly, and skin lesions, while a primary outbreak near the time of delivery significantly increases the risk for neonatal transmission.
Recurrent infections can also be transmitted to the neonate during delivery through intrapartum exposure to the virus in the maternal genital tract and can result in disseminated disease or CNS disease, with the possibility for long-term neurologic impact.When a patient presents with a chief concern suggesting HSV infection in pregnancy, start with a focused history and physical examination.

Focused H&P1:08–2:45

History might reveal a prior HSV outbreak. Additionally, the patient might have a prior documented history of positive HSV antibodies.
They might report single or multiple genital lesions, which are possibly painful. A primary outbreak typically involves multiple painful lesions, whereas a recurrent outbreak more commonly presents as a single ulcer that is mildly painful or non-painful.
Be sure to ask about prodromal symptoms that occur with recurrent infections including burning or tingling in the area where the outbreak normally occurs.
Lastly, patients might report vulvar pruritus, dysuria, or systemic symptoms such as fever, headache, or malaise. When it comes to the physical exam, the focus is on the genital area.
You might find perineal erythema and genital ulcers. Ulcers could be single and unilateral or multiple and bilateral.
Additionally, the exam might reveal tender inguinal lymphadenopathy if there is a primary infection. Now, if the patient can tolerate it, perform a speculum exam to evaluate for cervical lesions and consider testing for concurrent sexually transmitted infections and/or vaginitis if clinically indicated.
Here’s a high-yield fact! HSV is typically transmitted through direct contact and has an incubation period of 2-12 days.
Alright, if the patient has a prior history of genital herpes, we are talking about a recurrent infection. The current outbreak is treated with antiviral medication, such as acyclovir or valacyclovir.

Prior history of genital herpes2:45–4:08

Additionally, all pregnant individuals with a history of HSV require suppressive therapy with antivirals beginning at 36 0/7 weeks gestation through delivery.
Suppressive therapy not only reduces the risk of an outbreak at the time of delivery but also decreases asymptomatic shedding, reducing the risk of acquired intrapartum neonatal herpes.Finally, any patient who presents in labor with a history of HSV requires assessment for both prodromal symptoms and any active genital lesions, as these are contraindications to a vaginal delivery.
A thorough perineal, sterile speculum and visual cervical examination must be performed to assess for genital ulcers or lesions.
If there are no prodromal symptoms or lesions, the patient can continue laboring and undergo a vaginal delivery. However, if prodromal symptoms or an active lesion are present, a C-section is recommended to decrease the risk of neonatal herpes.
After delivery, notify the pediatrics team of the patient’s HSV status, so that they can properly examine the neonate for symptoms of neonatal transmission.
Okay, let’s go back and talk about patients with no prior history of genital herpes. Your next step here is to order a direct viral test on the lesion, which involves unroofing a lesion with a swab and sending collected fluid for viral culture and/or PCR-based HSV antigen detection.

No prior history of genital herpes 4:08–8:54

Additionally, obtain a type-specific serologic test to check for HSV1 and/or HSV2 antibodies. Keep in mind that If a patient reports a recent history of genital ulcers or lesions but does not currently have one, or has a clinical history that otherwise might suggest HSV, serology alone is enough.
Here’s a clinical pearl! When a direct test on a lesion is positive, it confirms the diagnosis of genital HSV infection.
Keep in mind that the type of test also matters; PCR-based testing has the highest sensitivity and specificity whereas viral culture has an overall low sensitivity, particularly 80% for primary lesions and 40% for recurrent or healing lesions.
As such, a negative result does not necessarily exclude the presence of infection, as recurrent outbreaks are less likely to yield a positive result.
Now, if both lesion test and serology are negative, repeat serologic testing in 3 to 4 weeks. If serology remains negative, consider an alternative diagnosis.
If instead, serology is positive, this means that there was a recent exposure to HSV without an outbreak. On the flip side, the lesion test might be negative with positive serology.
These patients had prior exposure but remained asymptomatic without an outbreak. In both situations, counseling is required to address the patient's positive serologic results.
As before, outbreaks are treated with antiviral medications like acyclovir or valacyclovir. You can also consider repeat direct viral testing on the lesion to determine if serologic positivity matches that of the lesion or if a non-primary first episode is instead diagnosed.
Additionally, these patients require suppressive therapy beginning at 36 0/7 weeks with antiviral medications, assessment for prodromal symptoms, and an exam assessing for active lesions when in labor as a C-section is recommended if either of these are present.
Also, alert the pediatrics team so they can appropriately monitor the infant post-delivery. Alright, let’s go back to our diagnostic tests.
If the lesion and the serologic tests are positive for the same HSV subtype, your diagnosis is a recurrent HSV infection.
Treatment consists of antiviral medication for active outbreaks, suppressive therapy at 36 0/7 weeks, and assessment for prodromal symptoms and/or active lesions while in labor, which require a c-section.
Remember to notify the pediatrics team.Here’s a clinical pearl! Recurrent infections are possible even in patients who deny any prior history of genital lesions.
This occurs when patients have an asymptomatic exposure in the past and are now having an active outbreak due to the immunosuppressed state of pregnancy.
As such, a recurrent outbreak may be the first clinically-recognized episode of genital herpes. Of note, patients with recurrent infections will often have prodromal symptoms before the appearance of a lesion and the duration of viral shedding is shorter when compared to a primary infection.
The next combination of results includes positive lesion and serology tests but for opposite subtypes. This occurs when either the patient has an HSV1 positive lesion and only HSV2 antibodies OR has an HSV2 positive lesion and only HSV1 antibodies.
Both of these scenarios represent a non-primary first episode infection. Finally, if the lesion test is positive, but serology is negative, we are talking about a primary infection.
Here’s a clinical pearl! The initial presentation of primary genital infection can be severe with multiple painful lesions, dysuria, and systemic symptoms, though some patients may also present with only mild symptoms or have no symptoms at all.
For both non-primary first episodes and primary infections, outbreak treatment involves antiviral medications like acyclovir and valaciclovir; suppressive therapy at 36 0/7 weeks; and labor evaluation including a sterile speculum exam, as well as possible C-section and notifying the pediatrics team.
Alright, as a quick recap… if a pregnant patient presents with signs and symptoms of HSV genital infection, make sure to find out if they have a history of genital herpes.

Review8:54–9:37

If they do, that’s a recurrent infection. If not, you should order a direct lesion test and serology test to make the diagnosis.
As for the treatment, the current outbreak is managed with antiviral medications. Next, initiate suppressive therapy with antivirals beginning at 36 0/7 weeks gestation through delivery.
At delivery, assess for prodromal symptoms and any active genital lesions, as these are contraindications to vaginal delivery, so your patient might need a C-section.
Finally, be sure to notify the pediatrics team.