Mpox Considerations for People Who Are Pregnant or Breastfeeding

Mpox and pregnancy

Data regarding monkeypox virus (MPXV) infection in pregnancy are limited. It is unknown if pregnant people are more susceptible to MPXV or if infection is more severe in pregnancy. MPXV can be transmitted to the fetus during pregnancy or to the newborn by close contact during and after birth. Adverse pregnancy outcomes, including spontaneous pregnancy loss and stillbirth, have been reported in cases of confirmed mpox during pregnancy. Preterm delivery and neonatal mpox have also been reported. The frequency and risk factors for severity and adverse pregnancy outcomes are not known.

By comparison, smallpox, a disease caused by a similar orthopoxvirus (variola virus) that was eradicated in 1980, has more severe manifestations than mpox and is associated with more severe illness during pregnancy and risk for adverse pregnancy outcomes.

Signs and symptoms

The signs and symptoms of MPXV infection in people who are pregnant appear similar to those in non-pregnant people with MPXV infection, including prodromal symptoms (e.g., fever, headache, lymphadenopathy, malaise, sore throat and cough) and rash.

The case-finding approach to a patient with suspected mpox is the same for pregnant and non-pregnant people.

During pregnancy:

• The cause of fever may be difficult to differentiate from other infections, such as intra-amniotic infection (chorioamnionitis), until the rash appears.
• Rash in a person who is pregnant and has risk factors for mpox needs to be differentiated from dermatoses of pregnancy, including polymorphic eruption of pregnancy (also known as pruritic urticarial papules and plaques of pregnancy).
• Patients with rashes initially considered characteristic of more common infections (e.g., varicella zoster or sexually transmitted infections) should be carefully evaluated for a characteristic mpox rash (see images), and diagnostic testing should be considered, especially if the person has epidemiologic risk factors for MPXV infection.
• Co-infections of MPXV and sexually transmitted infections (STIs) and HIV have been reported and the presence of an STI does not rule out mpox, so a broad approach to testing is encouraged.

Treatment

While most non-pregnant adults with an MPXV infection experience mild illness and recover spontaneously, pregnant, recently pregnant, and breastfeeding people should be prioritized for medical treatment if needed. This is because of the probable increased risk of severe disease during pregnancy, risk of transmission to the fetus during pregnancy or to the newborn by close contact during and after birth, and risk of severe infection in newborns.

Treatment for mpox should be offered, when indicated, to people who are pregnant, recently pregnant, or breastfeeding. The risks and benefits of treatment should be discussed with the patient using shared decision-making.

Close monitoring for severe disease and pregnancy complications is important. The decision to treat and monitor a pregnant person as an outpatient or in the inpatient setting should be individualized.

Tecovirimat (also known as TPOXX or ST-246)

Following consultation with CDC, if treatment is indicated, tecovirimat should be considered the first-line antiviral for people who are pregnant, recently pregnant, or breastfeeding. Tecovirimat is an antiviral medication that is FDA-approved for the treatment of human smallpox disease caused by variola virus in adults and children. However, its use for other orthopoxvirus infections, including mpox, is not approved by the FDA. Therefore, CDC holds a non-research expanded access Investigational New Drug (EA-IND) protocol (sometimes called "compassionate use") that allows for the use of tecovirimat for primary or early empiric treatment of non-variola orthopoxvirus infections, including mpox, in adults and children of all ages.

Information about the impact of tecovirimat on reproductive development is limited to animal studies. No specific fetal effects were observed in these studies in which subject animals were administered oral tecovirimat at levels approximately 23 times higher than the recommended human dosage. It is not known if treatment with tecovirimat during pregnancy prevents congenital mpox.

There are no human data on the effect of tecovirimat on milk production, the presence of the drug in human milk, or the effects on breastfed children; information is limited to animal studies. Tecovirimat was present in breast milk in animal studies in which subject animals were administered oral tecovirimat at levels approximately 23 times higher than the recommended human dosage. It is not known if levels of tecovirimat expressed in breastmilk are sufficient for treatment of a breastfeeding child with mpox. As such, if indicated, breastfeeding children with mpox should be treated independently.

Tecovirimat use allowed under the EA-IND protocol is intended to be used in concert with CDC guidance for treatment of mpox.

Cidofovir and Brincidofovir

Although cidofovir and brincidofovir have been considered as alternative antiviral therapies to treat mpox, animal studies showed evidence of teratogenicity. As such, these medications should not be used to treat mpox in people who are in the first trimester of pregnancy. It is not known if cidofovir and brincidofovir are present in breast milk, so they should not be used in people who are breastfeeding due to the potential for serious adverse reactions in the breastfeeding infant.

Vaccinia Immune Globulin Intravenous (VIGIV)

Animal reproduction studies have not been conducted with vaccinia immune globulin intravenous (VIGIV); therefore, it is not known whether VIGIV can cause fetal harm when administered during pregnancy or whether it can affect future fertility. However, immune globulins have been widely used during pregnancy for many years without any apparent negative reproductive effects. The risks and benefits of VIGIV administration should be assessed for each individual patient. It is not known whether VIGIV is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when VIGIV is administered to a person who is breastfeeding.

Vaccines

JYNNEOS

JYNNEOS is a live, non-replicating viral vaccine approved by the Food and Drug Administration (FDA) for the prevention of both smallpox and mpox disease. It is for use in individuals who are determined to be at high risk for smallpox or mpox.

Available human data on JYNNEOS administered to people who are pregnant are insufficient to determine if there are any vaccine-associated risks in pregnancy. Studies of JYNNEOS vaccine in animals have shown no evidence of harm to a developing fetus.

While there are no data for people who are breastfeeding, animal data do not show evidence of reproductive harm; breastfeeding is not a contraindication to receiving JYNNEOS. It is not known whether JYNNEOS is excreted in human milk. Data are not available to assess the impact of JYNNEOS on milk production or the safety of JYNNEOS in breastfed infants. However, because JYNNEOS vaccine is replication-deficient, it likely does not present a risk of transmission to breastfed infants.

JYNNEOS can be offered to people who are pregnant or breastfeeding who are otherwise eligible. The risks and benefits of JYNNEOS should be discussed with the patient using shared decision-making.

Vaccination prior to exposure and post-exposure prophylaxis

Vaccination prior to exposure or post-exposure prophylaxis should be offered when indicated to people who are pregnant or breastfeeding. The risks and benefits of vaccination should be discussed with the patient using shared decision-making.

Potential impacts for breastfeeding

Contact and breastfeeding

The benefits of skin-to-skin contact and rooming-in on breastfeeding and infant physiology are well known. However, given the risk of neonatal transmission of MPXV with close contact and potential for severe disease in newborns, direct contact between a patient in isolation for mpox and their newborn is not advised.

Separation (e.g., separate rooms) of a patient with mpox from their newborn is the best way to prevent transmission to the newborn. Full-time rooming in with a newborn is not recommended during a patient's infectious period.

The patient should be counseled about the risk of transmission and the potential for severe disease in newborns. If the patient chooses to have contact with the newborn during the infectious period, strict precautions should be taken, including the following:

• There should be no direct skin-to-skin contact.
• During contact the newborn should be fully clothed or swaddled and after contact occurs the clothing or blanket should be removed and replaced.
• Gloves and a fresh gown should be worn by the patient at all times, with all visible skin below the neck covered.
• Soiled linens should be removed from the area.
• The patient should wear a well-fitting source control (e.g., medical mask) during visit.

These precautions should be continued until criteria for discontinuing isolation have been met (i.e., all lesions have resolved, the scabs have fallen off, and a fresh layer of intact skin has formed).

Discharge planning should take into account the duration of isolation, ability to strictly adhere to recommended isolation precautions, and availability of alternative caregivers.

Patients in isolation for mpox may experience increased stress because of separation from their newborns, and postpartum depression symptoms may be worsened. Providers are encouraged to share resources with patients about coping with stress during this time.

Breastfeeding

Breast milk provides protection against many illnesses. However, given that MPXV is spread by close contact and neonatal mpox infection may be severe, breastfeeding should be delayed until criteria for discontinuing isolation have been met (i.e., all lesions have resolved, the scabs have fallen off, and a fresh layer of intact skin has formed).

Some people who are breastfeeding may need additional support from a lactation provider to initiate and maintain their milk production and avoid a breast infection while mpox lesions are healing.

It is unknown if MPXV is present in breast milk. Breast milk expressed from a patient who is symptomatic or isolated should be discarded while breastfeeding is delayed. To avoid inadvertently exposing an infant to MPXV, a healthy caregiver can feed pasteurized donor human milk or infant formula. People who are breastfeeding should talk with their healthcare provider to determine if their lesions have healed and they can resume direct breastfeeding or feed expressed breast milk.

Restricting visitors

Visitors to pregnant or postpartum patients with mpox should be limited to those essential for the patient's care and wellbeing. Use of alternative mechanisms for patient and visitor interactions, such as video-call applications, should be encouraged for any additional support.

Visitors should have no direct contact with the patient. Visitors should be informed about appropriate use of personal protective equipment (PPE) according to facility visitor policy. Visitors should be instructed to only visit the patient room and should not go to other locations within the facility, including the newborn nursery.

Infection control

Infection control practices for the care of patients who are pregnant with mpox are the same as those for patients who are not pregnant with mpox– including appropriate isolation of patients with mpox; training for healthcare personnel on maternity and newborn care units on correct adherence to infection control practices and PPE use and handling; and ensuring sufficient and appropriate PPE supplies are positioned at all points of care.

If a patient who is pregnant is diagnosed with mpox, the pediatric team should be made aware of the diagnosis to inform evaluation of the newborn.

Newborns born to people with mpox should be placed in isolation, and healthcare personnel caring for newborns born to people with mpox should also follow recommendations as specified in CDC's Mpox Infection Prevention and Control in Healthcare Settings.