An important new article published in the Clinical Medicine Journal discusses pregnancy complicated with coronavirus disease 2019 (COVID-19). This article provides an overview of what is currently known about this condition and current recommendations.

COVID-19, which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first emerged in Wuhan, China at the end of 2019. Since then, SARS-CoV-2 has infected over 226 million worldwide and caused the deaths of over 4.6 million.

Study: COVID-19 in Pregnancy. Image Credit: Natalia Deriabina / Shutterstock.com

Risk factors

Pregnancy is considered a high-risk condition for COVID-19. Pregnant women are more likely to have an asymptomatic infection, which makes up 75% of infections during this period. Even among those with symptoms, cough and fever were present in approximately 40% of cases, with breathing difficulty and myalgia being present in 21% and 19% of pregnant women, respectively.

Severe COVID-19 usually occurs with infection in the second half of pregnancy, especially towards the end of the second trimester onwards. Those at greatest risk of severe COVID-19 include women who have a higher-than-ideal body mass index (BMI), those over the age of 35, and those who have chronic underlying conditions.  

Black, Asian, and minority ethnic (BAME) origins carry over their non-pregnancy risk into this condition. This increased risk is likely the result of disparities in health, healthcare, social and economic status, as well as potentially vitamin D deficiency, according to many researchers. Black women, in particular, were at five times greater risk of dying during pregnancy as compared to white women, according to the recent Mothers and Babies: Reducing Risk through Audits and Confidential Enquiries across the UK (MBRRACE-UK).

The implications of these observations include setting a separate lower threshold for hospitalization of BAME women, as well as earlier consultations with specialists of other teams while caring for these women. Overall, pregnancy should be a time for education about COVID-19 and warning women to avoid a delay in seeking medical care if they experience signs of anything beyond mild disease.

Outcomes in pregnancy

Taken together, 9% of all intensive care unit (ICU) admissions in the United Kingdom have consisted of pregnant or immediate post-partum women. One in 20 pregnant hospitalized COVID-19 patients eventually required admission to an ICU, thus indicating that pregnancy is associated with 62% higher odds of this event compared to non-pregnant women. Pregnancy with COVID-19 increases the risk of invasive ventilation by approximately 90%,

During the second wave of the COVID-19 pandemic, a higher proportion of pregnant or post-partum women of reproductive age were admitted to the ICU. It should be noted that this may have been a precautionary measure following evaluation of the clinical experiences gained during the first wave. In support of this, the maternal mortality rate was 2.2/100,000 pregnancies.

During this time, preterm birth was more common among symptomatic pregnant women with COVID-19 than others. The risk of delivery before 32 weeks gestation was almost four times higher as compared to pregnant women without COVID-19. Before 37 weeks, the risk of preterm birth in pregnant women with COVID-19 was 1.9 times higher.

Preterm delivery in approximately 80% of cases is due to medical intervention, as part of a maternal treatment protocol intended to improve the oxygenation level of the mother. This finding therefore demonstrates that pregnant women with severe COVID-19 should be treated only in facilities that can manage preterm neonates.

Diagnostic testing for COVID-19 in pregnancy

The investigators of the current study concluded that all necessary tests to confirm the main diagnosis of COVID-19, as well as other implicated conditions, should be carried out, regardless of the pregnant status, while keeping other possible explanations in mind. Imaging should be done when required.

The safety of various imaging tests was also provided in the current study, with computerized tomography (CT) scan posing the greatest risk to the mother. The risk of this scan is in the form of an increased risk of developing breast cancer at some point, with 10 mGy of radiation being increased with about a 14% higher risk. The fetal risk appears to be negligible.

Management

Asymptomatic and mild COVID-19 requires only home care, after evaluating the risk for venous thromboembolism; however, isolation should be mandated. Others should be hospitalized and isolated with multidisciplinary care.

Appropriate therapies such as tocilizumab and corticosteroids should not be denied because of pregnancy. The researchers note that despite the fall in 28-day mortality in hospitals among pregnant women during the second wave, these therapies were only used in less than 25% of women who would have otherwise benefited from them, including those who were critically ill.

Corticosteroids such as dexamethasone have been found to be very useful in reducing deaths due to COVID-19 by 20% among oxygen-dependent patients, and by 33% among those on mechanical ventilation. The choice appears to be oral prednisolone or intravenous hydrocortisone in pregnancy, given that either of these is broken down rapidly and does not readily cross the placenta.

In contrast, dexamethasone crosses the placenta with ease, and high cumulative exposure has been linked to disorders of cognition and sensory aberrations in childhood. As a result, this drug is reserved for the purpose of enhancing lung maturity in the fetus.

Post-natal care

All available data continues to show that babies are unlikely to get COVID-19 from their mothers and that these babies do not require hospital admission following birth. Given the importance of skin-to-skin contact and breastfeeding soon after birth in terms of its role in improving mental health and mother-baby bonding, the World Health Organization promotes keeping the mother-baby dyad together, irrespective of the COVID-19 status, if possible.

“Physicians should act as advocates for mothers by ensuring the baby stays with the mother or that contact time is facilitated if in the ICU setting.”

COVID-19 vaccination in pregnancy

The Joint Committee on Vaccination and Immunization recommends vaccination in both pregnant and non-pregnant women. No evidence points to any mechanism of harm for the mother or fetus throughout pregnancy and lactation.

Over 120,000 women in the United States have received a COVID-19 vaccine during pregnancy, with almost 4,000 such women having reported outcomes. The rates of adverse pregnancy events such as miscarriage, stillbirths and neonatal deaths, growth restriction, and congenital anomalies were not above the background rates, say the scientists.

The researchers clarify that the Pfizer or Moderna vaccines are preferred due to the extensive safety data available on these vaccines. The AstraZeneca vaccine should be given if the first dose has already been given successfully. Vaccine-elicited antibodies pass into the infant’s blood and into breast milk, thus protecting the baby from SARS-CoV-2.

Conclusion

While most women who contract COVID-19 during pregnancy will have a mild or asymptomatic disease, the remaining women will have a higher risk of ICU admission, invasive ventilation, and preterm birth.  

All available therapies should be used as indicated, irrespective of pregnancy, as should the vaccines. Early admission for those with more than mild symptoms and multidisciplinary therapy are key to improving outcomes in this group of patients.

Written by

Dr. Liji Thomas

Dr. Liji Thomas is an OB-GYN, who graduated from the Government Medical College, University of Calicut, Kerala, in 2001. Liji practiced as a full-time consultant in obstetrics/gynecology in a private hospital for a few years following her graduation. She has counseled hundreds of patients facing issues from pregnancy-related problems and infertility, and has been in charge of over 2,000 deliveries, striving always to achieve a normal delivery rather than operative.