Pregnant, Postpartum, and lactating people and infants have unique needs during public health emergencies, including nuclear and radiological incidents.¹ Radiation emergencies may vary in scale and severity, and include nuclear emergencies (e.g., detonation of a nuclear weapon or improvised nuclear device), detonation of a radiological dispersal device (also known as a dirty bomb), and accidental incidents, such as nuclear power plant incidents or transportation accidents involving radioactive materials.² Exposure to radioactive materials can lead to internal contamination (through swallowing or breathing in radioactive materials) and external contamination (through radioactive dust, powder, or liquid coming in contact with hair, skin, or clothing).³

The U.S. Pandemic and All-Hazards Preparedness and Advancing Innovation Act of 2019 classifies people who are pregnant, postpartum, and lactating, and infants as populations at risk for adverse health outcomes related to emerging public health threats.¹ During and after radiation emergencies, people who are pregnant, postpartum, or lactating or have infants are advised to consult a physician to understand the extent of exposure and possible contamination⁴

Health effects from radiation emergencies depend on the type of radioactive material, dose (amount of radiation received), total time it took for that dose to accumulate, and whether there is internal or external contamination. People with radiation contamination, including women of reproductive age (WRA), can develop acute radiation syndrome (if a high radiation dose is accrued over a very short time), cutaneous radiation injury (skin injury after exposure), psychological distress, and possible cancer later in life.^2,5,6

Previous research describes the acute and long-term effects of internal or external contamination for the general adult population.^5,7 For most external radiation exposures, the radiation dose to the fetus is lower than the dose to the woman.⁸ A pregnant woman’s abdomen partially protects the fetus from radiation sources that are outside her body. If a pregnant woman swallows or breathes in radioactive materials, these may be absorbed into her bloodstream.

From the woman’s blood, radioactive materials may pass through the umbilical cord to the fetus or concentrate in areas of the mother’s body near the womb and expose the fetus to radiation. Health effects to the fetus from radiation exposure can be severe, even at radiation doses too low to make the mother sick. These health effects can include miscarriage, stunted growth, deformities, abnormal brain function, and cancer.^4,8

A fetus is most sensitive to radiation between weeks 2 and 18 of pregnancy. A fetus will become less sensitive to radiation during later stages of pregnancy. In addition, radioactive material can be passed to babies through breast milk of mothers with internal contamination, through contaminated water mixed with infant formula.⁹ And while being held and fed if their caregiver has radioactive material on their skin or clothing (external contamination). Babies may swallow or breathe in these materials while feeding and can become internally contaminated.¹⁰

The absorbed dose of radiation is measured in rad or Gray (Gy) (100 rad = 1 Gy).¹⁰ There is a dose-response effect for severity of symptoms or illness by Gy absorption with duration of exposure. For example, nausea and vomiting are unlikely to occur at low doses (≤1 Gy) but with high doses (>8 Gy) they occur 90%–100% of the time within 2 h of exposure.¹⁰

Similar trends have been documented for central nervous system dysfunction, risk of cancer, and death; the higher the absorption dose, the more likely and severe the symptom or illness.¹⁰ For example, lifetime cancer risk for low-dose exposure (≤1 Gy) is 0.06 to 8% but increases to >40% for high-dose exposure (above ≥6 Gy).¹⁰ For adults, exposures ≥8 Gy are lethal.¹⁰ For a pregnant person, health effects from radiation on the pregnancy can range from no effects to miscarriage or stillbirth—depending on magnitude and duration of exposure.^4,11 For the fetus and infants, the effects can include abnormal growth, congenital malformations, abnormal brain function, and cancer in the future.^4,11

In 2016, the CDC established a Nuclear/Radiological Training and Exercise Preparedness Program for its workforce to better prepare for and respond to a radiation emergency.⁷ To develop a radiation-knowledgeable workforce, the CDC conducted agency-wide and inter-agency preparedness exercises and workshops, created a resource library for clinicians, public health professionals, and first responders, and developed trainings for public health professionals and clinicians.^12,13

The CDC’s Division of Reproductive Health (DRH) has been active in radiation preparedness activities since 2016.¹⁴ The DRH has been engaged in the planning and execution of agency-wide and interagency emergency preparedness activities, including drills and tabletop exercises, to better prepare for and respond to needs of WRA and infants in an emergency. To optimize staff response readiness for radiation emergencies, the DRH developed and maintained subject matter expertise, and collaborated with external and internal partners to increase capacity of radiation emergency preparedness efforts.

This report provides an overview of DRH’s emergency preparedness and response activities for radiation emergencies, including development of a quick reference guide on what is known about radiation emergencies and reproductive health, and participation in preparedness activities.

To strengthen the DRH’s nuclear and radiation preparedness activities and inform internal resource development, increase preparedness to develop messaging, or answer questions from the general public during radiation emergencies, the DRH developed the Radiation Emergency Quick Reference Guide to provide information about the needs of pregnant, postpartum, and lactating people, and infants during a radiation emergency.

We assessed what is known about the effects of nuclear and radiological emergencies on WRA based on published literature and existing web resources, and used our guiding principles for addressing the needs of pregnant people as a framework.^14,15 Detailed methods about the development of the Radiation Emergency Quick Reference Guide for WRA are described in the Table 1.

We adapted our guiding principles for addressing the needs of pregnant people into six questions specific to the needs of WRA and infants during radiation emergencies: (1) Are people who are pregnant more susceptible to the effects of nuclear radiation exposure, such as an increased risk for severe illness or death? (2) Are people who are pregnant at increased risk for pregnancy complications and adverse pregnancy outcomes after a radiation emergency? (3) Are there special considerations for treatment, prophylaxis, and/or interventions for people who are pregnant, postpartum, and lactating? (4) Are exposed WRA at increased risk for negative long-term health outcomes such as cancer or infertility? (5) Are infants with exposure in utero at increased risk for death, disability, or severe illnesses? (6) Are there infant feeding considerations for exposed postpartum and lactating people?^14,15

We searched MEDLINE, Embase, CINAHL, and Scopus databases to identify relevant literature published from January 1950 to March 2022. Search strategy included terms related to nuclear accidents, radiation exposure, radiation effects, pregnancy, and birth. We limited our review to English language, original research, case reports, review articles, and government websites or reports.

We reviewed over 3800 articles, and excluded literature about medical/radiation therapy, nuclear medicine procedures, and radiation exposure of pregnant health care workers (Fig. 1). A total of 200 articles on WRA and their infants were included from the literature search. In addition, we scanned more than 20 government websites and reports to supplement results from our literature search to add to the quick reference guide.

The purpose of the quick reference guide is to highlight select references addressing the six major WRA questions, including pregnant, postpartum, and lactating people (15–49 years), and infants. These questions were adapted from our previously published guiding principles for assessing potential and emerging threats to WRA during emergencies.

We added two questions related to infant considerations after exposure that include feeding during emergencies and long-term outcomes of infants exposed in utero.^14,15 The results of the literature review include the following number of articles per question: are pregnant women more suceptible to nuclear radiation (n = 1); are pregnant women more likely to have pregnancy complications (n = 26); special treatment considerations for WRA and infants (n = 0); long-term outcomes after radiation exposure for WRA (n = 14); increased risk of disability, illness, or death for people with in utero radiation exposure (n = 155); and infant feeding considerations (n = 15).

Of these, a total of 38 articles and eight governmental websites are highlighted to address the six questions on the potential exposure risk to WRA and infants. These 38 articles were selected to highlight the outcomes of interest among WRA, including people who are pregnant, postpartum, and lactating, or infants because they discussed an original finding, provided an estimated level exposure, summarized two or more outcomes, and/or had a large sample size. Whenever needed, we supplemented information from eight governmental websites for populations of interest.

As part of the CDC’s Training and Exercise Preparedness Program, the DRH has collaborated with staff across CDC programs to design and implement preparedness and response training and exercises. In 2017, the CDC participated in the Gotham Shield Exercise, which included both a weeklong full-scale emergency simulation and brief half-day tabletop exercises, beginning with an alert of a nuclear-radiological incident.

This exercise simulated emergency response operations to detonation of a nuclear device in a large U.S. city in Federal Emergency Management Agency (FEMA) Region II. During the 4 days of the exercise, the CDC simulated activities focused on the following objectives: (1) assessing the CDC’s ability to activate staff and equip the CDC Incident Management System for a nuclear incident; (2) verify information flow plans, policies, and procedures during a nuclear radiological incident; (3) assess the CDC’s ability to share timely information with relevant partners; and (4) assess the ability to identify and report on the status of CDC assets and personnel in a region affected by a nuclear-radiological incident.

Trained response team members from DRH were actively engaged, responding to hypothetical scenarios introduced throughout the course of the exercise. Activities included estimating the number of pregnant people in the affected area using DRH Pregnancy Estimator, responding to national inquiries relating to the health of maternal and infant populations, developing emergency risk communication messages, and providing technical expertise to support early surveillance activities.⁴³

This active engagement allowed the CDC to optimize DRH staff capacity for radiation emergency responses, practice the application of reproductive health subject matter expertise to management of nuclear-radiological emergencies, identify gaps in data to inform guidance for people who are pregnant, postpartum, or lactating, and better streamline processes and procedures for responding to public health needs of people who are pregnant, postpartum, or lactating during a radiation emergency.

The DRH has continued collaborating with interdisciplinary staff (e.g., clinicians, epidemiologists, data managers, health communicators, and health physicists) across the agency to address the needs of WRA, including people who are pregnant, postpartum, or lactating, and infant health populations, during a radiation emergency.

Nearly 5 years later, the CDC participated in the 2022 Cobalt Magnet exercise. Cobalt Magnet was a full-scale simulation of a Radiological Dispersal Device in FEMA Region VI, enabling response personnel to practice protecting public health and safety, providing emergency relief to affected populations, and restoring essential services. The 4-day exercise was held May 16–20, 2022. More than 30 local, state, and federal agencies, and hospitals were involved in the exercise.

The DRH team activated for the exercise as part of the CDC’s At-Risk Task Force, an all-hazards preparedness and response team focusing on the needs of populations with access and functional needs in emergencies, including infants and people who are pregnant, postpartum, or lactating. Specifically, DRH staff answered questions, and prepared partner e-mails, talking points, and social media risk communication messages for people who are pregnant, postpartum, or lactating; they also developed a 100-day strategic plan for surveillance of adverse outcomes among people who are pregnant, postpartum, or lactating.⁴⁴

The DRH has also supported state and regional nuclear radiation exercises. In July 2022, DRH staff supported a readiness response exercise in FEMA Region IV, both on-site and virtually. Participants from local, state, and federal agencies assisted with the exercise at a mock community reception center (CRC), which is expected to be erected after a nuclear power plant emergency and used for individual screening, evaluation, and decontamination.⁴⁴

As part of the exercise, state and local staff evaluated potentially affected people for medical treatment due to radioactive contamination, scanned individuals’ bodies and recorded the radiation contamination levels, and counseled people on potential long-term health effects. More than 150 participants underwent contamination screening, decontamination showering, and registration.

During the simulation, it was found that information on pregnancy status was not routinely collected from people arriving at the CRC, despite several scenarios where the participants actively disclosed that they were pregnant. The DRH staff provided feedback during an after-action review of the exercise to include a standard question on the screening questionnaire about pregnancy and infant feeding.

People who are pregnant, postpartum, or lactating, and infants, have unique needs and risks for adverse outcomes during radiation emergencies. Due to these unique needs and potential risks, it is critical to incorporate questions about pregnancy, lactation status, and infant feeding into any data collection effort. Information about pregnancy status (Y/N) and estimated date of delivery is needed for pregnant people.

For people with infants, information on typical infant feeding practices (breastfeeding, formula feeding, or mixed feeding) is needed. There is also a need for linked longitudinal data to provide surveillance and monitoring of pregnancy and infant outcomes after nuclear or radiological incidents.⁴⁵

The DRH collaborated across CDC on nuclear radiation activities to address the needs of WRA, including people who are pregnant, postpartum, or lactating, and infants. One of the activities included developing an internal resource guide that included six questions that staff should ask individuals who are screened during a radiation emergency. Two of the questions specifically addressed infants’ exposure and feeding. The DRH then developed activities and exercises to train inter-agency staff for radiation emergencies and incorporated this information into the resource guide.

The DRH participation in functional exercises highlighted the need for (1) clear information on what is known about pregnant people at the beginning of an emergency; (2) specific questions about pregnancy status and infant feeding practices and incorporating responses into any data collection efforts; (3) long-term monitoring of health needs and outcomes of people who are pregnant, postpartum, or lactating, and their infants; and (4) collaborations across the agency to address the special needs of these populations (e.g., working with the CDC’s Division of Nutrition, Physical Activity, and Obesity or the National Center on Birth Defects and Developmental Disabilities to highlight risks for pregnant, postpartum, and lactating people and infants).

During an emergency, WRA and people who are pregnant, postpartum, or lactating are advised to follow the same protective instructions as everyone else (e.g., shelter in place until it is safe to go outside).^8,9 If referred to a CRC for screening, it is recommended that on arrival at the facility they notify staff members that they are pregnant, postpartum, or lactating and how they are feeding their infant.^8,9 The CRC evaluation process often includes referrals for medical care.^8,9

Once safe to do so, pregnant, postpartum, or lactating people should seek medical attention to continue prenatal or postpartum care. In addition, guidance is available for infant feeding during emergencies, and specifically during radiation emergencies, that can serve as a resource to public health responders.^9,46

It is important to include reproductive health subject matter experts in planning for and response to radiation emergencies to ensure that data collection is adapted to the needs of WRA and infants. The results of our literature search found that there are unique considerations for WRA and infants after radiation emergencies. Our analysis had some limitations.

First, our search included articles only in the English language, which could introduce bias due to some incidents taking place in countries where English is not the primary language. Second, multiple studies assessed the same disaster and outcomes. Third, most studies did not have a direct measure of radiological exposure. Fourth, some studies had small sample sizes. Finally, we excluded studies that solely assessed mental health outcomes, such as anxiety or stress during or after radiation emergencies due to the complex relationship of mental health with exposure and our outcomes of interest. Further, we considered it a topic that deserves its own literature search.

Public health surveillance and research on reproductive health outcomes should be initiated as soon as possible after an incident. The Radiation Emergency Quick Guide is intended to be a resource that can be used to quickly assess the literature on the unique considerations of WRA during radiation emergencies. More information is needed for a more robust assessment of the potential impacts of radiation emergencies on pregnant, postpartum, and lactating people, and infants.

When planning and responding to nuclear emergencies, considerations for the unique needs of WRA and infants are important. The DRH will continue to support emergency planning and preparedness activities (e.g., drills, state, and federal functional exercises). We will develop and maintain subject matter expertise. We will also work collaboratively (e.g., across the CDC, federal government, and state and local partners) to develop and update tailored communication materials for different audiences on the special circumstances that nuclear and radiological emergencies pose to WRA, pregnant, postpartum, or lactating people, and infants.