Obstetrics is one area of health care that couldn't be put on hold as COVID-19 cases surged across the country. Approximately 3.75 million births occurred in the United States in 2019, according to the Centers for Disease Control and Prevention (CDC), and UNICEF estimated that about 116 million infants worldwide would be born in the first nine months of the pandemic. Amid the unfolding COVID-19 crisis, pregnant people and their health care providers have navigated an ever-changing prenatal, birth, and postpartum care landscape, one in which scant scientific evidence and shifting recommendations and hospital policies have guided practice.

To follow is a closer look at what we know about COVID-19 and maternal health and the latest guidance on risk, breastfeeding, and vaccination. To read about the experiences of pregnant women during the pandemic, go to http://links.lww.com/AJN/A206.

COVID-19 RISKS AND DISPARITIES

Women who are pregnant and have COVID-19 appear to have a small but higher risk of severe illness and death. Jering and colleagues reported in JAMA Internal Medicine online in January that absolute rates of death and adverse events were low among a large national cohort of women hospitalized for childbirth from April to November 2020. However, they found the risk of death, venous thromboembolism, and preeclampsia were "considerably higher" in the women who had COVID-19 compared with those who didn't. These findings support those of a September 25, 2020, Morbidity and Mortality Weekly Report that examined outcomes for pregnant women admitted to the hospital with COVID-19. Almost half the women were experiencing symptoms, and among them 16.2% were admitted to an ICU, 8.5% required invasive mechanical ventilation, and 1% died. These outcomes didn't occur in asymptomatic pregnant women. The CDC reports that from January 22, 2020, to April 19, 2021, 86,488 pregnant women had COVID, 97 of whom died.

"The literature is a little bit difficult to discern whether or not pregnancy itself increases your risk, but clearly, women with critical illness have much higher risks when they're pregnant," said Catherine Y. Spong, MD, professor and vice chair of the Department of Obstetrics and Gynecology at the University of Texas Southwestern Medical Center in Dallas, during a JAMA discussion streamed live in early February.

Denise Jamieson, MD, MPH, professor and chair of the Department of Gynecology and Obstetrics at Emory University School of Medicine in Atlanta, also spoke during the discussion. "We know that there seems to be an increased risk of preterm birth among women who are infected with COVID. There may be an increased risk of stillbirth," she explained. "Basically, we know that, particularly among severely ill pregnant women, their babies don't do as well." It's believed the biggest risks for pregnant women occur when infection and illness occur closest to the time of delivery, she added.

A systematic review and meta-analysis of global maternal and fetal health revealed that outcomes have worsened during the crisis. The Lancet Global Health study, published online in late March, says there's been an increase in maternal mortality, stillbirth, ruptured ectopic pregnancies, and maternal depression. Noting significant disparities in high- and low-resource settings for some outcomes, the authors say health system failures during the crisis-not pandemic mitigation measures-may be the main reason for the higher rates of adverse outcomes: "There is an urgent need to prioritise safe, accessible, and equitable maternity care within the strategic response to this pandemic and in future health crises."

Health inequities and the maternal mortality crisis in the United States were already worsening before the COVID-19 crisis, which has disproportionately affected communities of color. A National Center for Health Statistics report published in April noted that the 2019 maternal mortality rate (20.1 deaths per 100,000 live births) was significantly higher than that of 2018 (17.4 deaths per 100,000 live births). Racial and ethnic disparities persist, with the report revealing a maternal mortality rate for Black women that is 2.5 times higher than the rate for White women. These disparities are notably higher in certain parts of the country. The Chicago Department of Public Health reported in 2019 that mortality rates for Black women were almost six times higher than those for White women.

"When you talk about maternal mortality and morbidity, this is a problem that touches all of our communities," says Representative Lauren Underwood (D-IL), a nurse. "What we've seen with the pandemic is that it has shined a bright, bright, bright spotlight on so many of these longstanding inequities and disparities, and maternal mortality is no different."

TRANSMISSION AND BREASTFEEDING

Concerns about women's health and COVID-19 risks during pregnancy have been compounded by uncertainties about the potential for mother-to-child COVID transmission. The CDC notes that infection is uncommon among infants born to women who had COVID-19 during pregnancy. In fact, research published online in JAMA Pediatrics in late January suggests pregnant women with the disease may convey natural immunity to the fetus, with an infection early in pregnancy leading to the transfer of more antibodies. The risk of transmission after birth is low, particularly when women wear masks, wash their hands, and take other precautions to prevent infection, says the CDC. Emerging research and evolving guidance on newborn care has been essential in preventing the separation of new mothers and infants, which occurred in some facilities early in the pandemic.

Approximately 84% of infants are breastfed at some point, according to the CDC's National Immunization Survey 2018-2019. Initial concerns that SARS-CoV-2 might be transmitted through breastfeeding have since been allayed. Researchers at the University of Rochester Medical Center revealed in a study published in mBio in February that they found no presence of the virus in the breast milk of women who had tested positive for COVID-19. Instead, the authors say, approximately two-thirds of the samples contained protective antibodies, supporting recommendations that women who are mildly to moderately ill should continue breastfeeding, owing to the likelihood that breast milk is protective to the infant.

There is little data on the impact on breastfeeding of COVID-19 vaccines, but they are not believed to be transmitted to children through breast milk, and "there is little biological plausibility that the vaccine will cause harm," according to the Academy of Breastfeeding Medicine. By contrast, vaccine-generated protective antibodies may be transferred from the mother to the infant via breast milk, the group says, citing the passive protection offered by influenza and pertussis vaccines.

VACCINATION DURING PREGNANCY

The dearth of data about the impact of COVID-19 vaccines on both breastfed infants and pregnant women is because of pregnant and lactating people being excluded from the initial COVID vaccine trials-as they have been from most research studies, including those for COVID treatments. This lack of information has complicated risk assessment and sowed vaccine hesitancy. When combined with misinformation, it has also led to unfounded concerns about, for instance, vaccines causing infertility-an assertion that has no scientific support and has been widely refuted.

Expert opinion supports vaccination in women who choose it. Pregnant or breastfeeding women can be offered any of the authorized vaccines, according to the CDC. The agency acknowledges there's limited safety data in this population but says there's no evidence the vaccines cause problems in pregnancy or with the development of the placenta. The Society for Maternal-Fetal Medicine strongly recommends access to COVID-19 vaccines for people who are pregnant and lactating. The Maternal Immunization Task Force, whose members include the American College of Nurse-Midwives; the Association of Women's Health, Obstetric and Neonatal Nurses; and the American College of Obstetricians and Gynecologists (ACOG), posted a statement on ACOG's website in February supporting vaccination during pregnancy, including for the approximately 330,000 health care workers believed to be pregnant at that time. ACOG also strongly encourages women contemplating pregnancy to be vaccinated.

An article published online in March in the American Journal of Obstetrics and Gynecology offers some of the first scientific evidence of COVID-19 vaccines' efficacy in pregnant women. The authors, reporting the first data from a large cohort study examining the impact of mRNA COVID-19 vaccination on maternal antibody generation, found that vaccinated women who were pregnant and lactating had vaccine-induced antibody titers comparable to those of vaccinated women who were not pregnant. These titers were significantly higher than those seen in women who had the virus during pregnancy. In addition, the researchers report that vaccine-generated antibodies were found in umbilical cord blood and breast milk, suggesting that immunity is transferred via the placenta and during breastfeeding.

Spong said during the JAMA discussion that when talking with pregnant patients who are considering the vaccine, "It's really important that you consider the risk to the woman of COVID-19. So, in an area where there is active transmission, and she is in a high-risk group, she should certainly have access to that vaccine."

Jamieson agreed, saying she also emphasizes the "real and meaningful risks" of declining vaccination, noting that it comes down to a risk-benefit analysis: "We know the risks of being infected." Ultimately, she believes it's likely that "the benefits [of vaccination] will greatly outweigh the risks, any theoretical risks, none of which we've seen yet."

That pregnant and lactating women and their health care providers have had little scientific evidence to consider in their decisions about vaccination highlights the historical exclusion of these populations from research studies. It's a situation many have tried to change in the past few decades, most recently through the work of the Task Force on Research Specific to Pregnant Women and Lactating Women, which was established by the 21st Century Cures Act of 2016. This task force met from 2017 to 2020 and released a report last August that includes recommendations that have yet to be implemented. In the absence of data from vaccine trials, the CDC is collecting surveillance data from vaccinated pregnant and lactating people through its smartphone-based v-safe after vaccination health checker tool. As of April 19, more than 94,000 women had self-reported as pregnant via v-safe. The CDC will analyze these data to gain a better understanding of the effect of COVID vaccines during pregnancy, including details about vaccine-related symptoms and obstetric outcomes.

OPPORTUNITIES TO IMPROVE CARE

With the COVID-19 crisis spotlighting the need to improve maternal health outcomes, especially among high-risk populations, there is greater recognition that doing so requires solutions that address the social determinants of health. The Black Maternal Health Momnibus Act of 2021, says Underwood, offers a "comprehensive solution to end our nation's maternal mortality crisis." Focused on improving Black maternal health outcomes and care for vulnerable populations, the legislation seeks to address inequities in the health care system that will improve care for all pregnant people. Cosponsored by the congresswoman, the Momnibus Act was first introduced last spring and reintroduced in February. It now contains 12 bills, which have also been introduced separately and include new legislation focused on environmental threats to pregnant and postpartum women, the need to enroll women in COVID-19 vaccine trials, and education on vaccination during pregnancy. Three of the bills, focused on telehealth and veteran's and mental health, have bipartisan support, Underwood notes.

The Momnibus Act is designed to build on existing legislation, such as the American Rescue Plan Act, the COVID-19 relief package that was signed into law in March and includes an option for states to extend Medicaid coverage after women give birth. States that opt for this extension must provide women with full benefits coverage throughout their pregnancy and for a year afterward. Medicaid pays for almost half of all births in the United States, and women are currently covered for only 60 days after giving birth. Approximately half of the mostly preventable U.S. maternal deaths occur during the postpartum period, with 12% occurring from six weeks to a year postpartum.

The Momnibus Act has been endorsed by almost 200 organizations, including the American Nurses Association and the American College of Nurse-Midwives. Underwood was unequivocal when asked how nurses can support the legislation: "Everybody reading this has one congressperson and two senators. We need all three individuals to join us as cosponsors on the Momnibus. It's that simple."-Corinne McSpedon, senior editor