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Just the facts. COVID 19 and Pregnancy - Bliss and Baby Co

Just the facts. COVID 19 and Pregnancy

Research Update for August 27, 2021

by Evidence Based Birth®

Numbers Update from 
Johns Hopkins University

As of August 27, 2021, there are more than 214 million confirmed and probable cases of COVID-19 around the world, with more than 4.4 million total deaths. The U.S. has both the highest number of total cases (38 million) and the highest cases from the past 28 days (3.6 million). The other countries with highest 28-day case rates are India (1 million), Iran (1 million), Brazil (837,000), and the United Kingdom (832,000).

The Johns Hopkins COVID-19 Dashboard now has a counter that tracks total and 28-day vaccine doses administered around the world. There have been more than 5 billion vaccine doses administered, with 1.1 billion taking place in the past 28 days. Global vaccine inequities continue to be an issue—while the U.S. administered its first doses 8-9 months ago and is beginning to provide boosters, people in many other countries are just now getting their first doses or do not yet have access.

Readers who live in the U.S. may find the covidestim website helpful. This epidemiology project contains state and county-level maps and graphs (using data from Johns Hopkins) that depict infection rates (per 100,000), total number of infections, the reproduction number, and percent ever infected. The graphs can be helpful for detecting after infections have peaked in a local surge (however, hospitalizations may continue to increase after a peak). The covidestim website is a joint project from researchers at Yale School of Public Health, Harvard T. H. Chan School of Public Health, and Stanford Medicine.

FDA Vaccine Approval Update

On August 23, 2021, the FDA issued full approval of Pfizer’s COVID-19 vaccine, replacing the emergency authorization that was issued in December 2020. Some researchers and public health professionals think that full approval may decrease vaccine hesitancy. In a June 2021 poll, the Kaiser Family Foundation found that 31% of unvaccinated people said they would be more likely to receive a vaccine once one receives full FDA approval. NPR also reports that full approval may make it easier for employers, school systems, and the military to issue vaccine mandates.

Research on the Delta Variant in Pregnancy

global health warning has been issued in response to a new study, carried out by the National Institute for Health Research (NIHR) and the University of Oxford, that shows increasing severity of COVID-19 infection in pregnant people hospitalized with the Delta variant-particularly in those who are unvaccinated (Vousden, 2021).


  • This study, released as a preprint version, reviewed the medical records of 3,371 pregnant people admitted to the hospital due to active COVID-19 infection from the beginning of the pandemic through July 11, 2021.During the first wave of infection, 24% of hospitalized pregnant people had moderate to severe symptoms.
  • During the Alpha variant wave, 36% of hospitalized pregnant people had moderate to severe symptoms. So far, 45% of pregnant people admitted with the Delta variant have had moderate to severe symptoms
  • In February 2021, as vaccines became more widely available for pregnant people living in the United Kingdom, vaccination status was added to the data collected for this study. Of the 742 pregnant people admitted to the hospital with COVID-19 since February 2021, 738 (99.5%) were unvaccinated. Four participants who were admitted to the hospital with COVID-19 had received 1 dose of vaccine, and none of the hospitalized pregnant patients were fully vaccinated.
  • The NIHR stated that pregnant people hospitalized with the Alpha variant were more likely to require respiratory support, develop pneumonia and be admitted to the intensive care unit (ICU) as compared to those infected during the first wave.
  • Those with the Delta variant were at an even higher increased risk for respiratory support, pneumonia, and ICU admission. So far, the rate of infants admitted to the neonatal intensive care unit (NICU) has remained relatively stable.
  • In response to this worrying rise in severity of infection for unvaccinated pregnant people, the Chief Midwifery Officer of England is urging expectant parents to receive COVID-19 vaccination as soon as possible.

New Research on Vaccination during Pregnancy

An upcoming article, to be published in the American Journal of Obstetrics and Gynecology, followed 1,328 pregnant people who gave birth at St. George’s University Hospitals in London from March 2021 through July 2021. The purpose of this study was to evaluate vaccine safety and outcomes data during pregnancy. Please note that because this data is not officially published yet, there may be slight changes because of peer review or other updates (Blakeway, 2021).

  • Out of the 1,328 people who gave birth, 141 had received at least one dose of the vaccine and 1,187 were completely unvaccinated. We do not have data on how many participants were fully vaccinated. Almost all vaccinated people (85.8%) received their vaccine in the third trimester of pregnancy. Most (90.8%) received an mRNA vaccine (Moderna or Pfizer), and 9.2% received a viral vector vaccine (Astra Zeneca). All three vaccines are two-dose regimens.
  • The vaccinated and unvaccinated groups had similar rates of adverse outcomes such as stillbirth, fetal abnormalities, postpartum hemorrhage, cesarean section, and neonatal or intensive care unit admission.
  • Younger study participants were less likely to have received the vaccine, as well as those of lower socio-economic status and non-white ethnicity. There was a higher rate of vaccination in participants with Type I or Type II diabetes, possibly because this group became eligible for vaccination earlier in the study. The researchers concluded that this study has important implications for improving vaccine uptake by identifying facilitators and barriers to vaccination (AJOG).
  • One limitation of this study is that not everyone enrolled was eligible to receive a vaccine until June 2021 (some participants became eligible in April, and others in May). Another, related limitation is that the median time from vaccination to giving birth was only about one month—most vaccines were given in the third trimester of pregnancy. Additionally, those that had been fully vaccinated before pregnancy were excluded from the study. It is also important to note that this is a small sample size of pregnant, vaccinated people (141 total). More research on first and second trimester vaccination, longer-term outcomes following vaccination at any time in pregnancy, and a larger sample size is needed for continued study.
  • Note from EBB: For more information on vaccination in pregnancy, please see below:
    • We discussed the v-safe vaccine pregnancy registry at length in the May 25, 2021, edition of this newsletter, available at our COVID-19 resource page here.
    • As of August 23, 2021, the CDC notes that 153,400 people in the U.S. indicated they were pregnant in the v-safe app at the time of their COVID-19 vaccination, and more than 5,000 had enrolled in the official v-safe vaccine pregnancy registry.
    • We’ve seen some people on social media become confused by the difference between VAERS (a reporting system that is only used by people who experience potential adverse effects; although it can be helpful for identifying potential safety issues, it cannot be used to determine risk/benefit percentages), v-safe (a health checker app) and the v-safe vaccine pregnancy registry (a study that people are enrolled in after they are vaccinated during pregnancy, and has the capability to determine safety, potential benefits, and the absolute risk of adverse effects). The first study from the v-safe vaccine pregnancy registry was published in the New England Journal of Medicine (and discussed in our May 2021 newsletter).
    • To learn more about v-safe and the v-safe vaccine pregnancy registry, visit the CDC website here.
    • To read the newest pre-print analysis of the CDC v-safe pregnancy registry (that includes study data from more than 2,500 people vaccinated before 20 weeks of pregnancy), click here.

New Research on Pre-term birth and COVID-19 infection

A study published July 30, 2021, in Lancet Regional Health- Americas, looks at the association between COVID-19 infection and pre-term birth (Karasek, 2021).

  • In this study, researchers analyzed the California Vital Statistics birth certificate records of 240,157 live births that occurred in California between July 2020 and January 2021. In this sample, 3.7% of participants had a COVID-19 diagnosis in pregnancy. COVID-19 diagnosis was defined as either confirmed or probable. Confirmed cases were verified by a CDC lab, and probable cases were verified by a state or local lab. For analysis purposes, researchers divided pre-term birth into these categories: very pre-term birth (VPTB, or less than 32 weeks pregnant), pre-term birth (PTB, or less than 37 weeks pregnant), and early term birth (37 to 38 weeks and 6 days pregnant).
  • Researchers found a 60% relative risk increase in very pre-term birth in participants with a COVID-19 diagnosis. Additionally, there was a 40% relative risk increase in pre-term birth, and a 10% relative risk increase in early term birth in participants with a COVID-19 diagnosis.
  • Pregnant people with a COVID-19 diagnosis as well as high blood pressure, diabetes, and/or a BMI greater than 30, had even slightly higher increased rates in the pre-term and very pre-term birth categories compared to people with COVID-19 who did not have these factors.
  • In the study population, COVID-19 diagnosis rates increased across all race/ethnicity groups but was disproportionately higher among Latinx, American Indian/Alaska Native, and Native Hawaiian/Pacific Islander birthing people as well as among people with public insurance. The most striking disparity was in the Latinx study population, who represented 47% percent of the pregnant participants but 72% of the positive COVID-19 cases.
  • Researchers concluded that it is important to continue this work “to understand the full impact of COVID-19 diagnosis on pre-term birth and to address the increased prevalence of COVID-19 diagnosis in groups already facing inequities in birth outcomes as a result of structural racism” (The Lancet).


Professional Guidance

Over the past few weeks, several major organizations have revised their guidance to suggest that all pregnant people get vaccinated against COVID-19. These recommendations are in response to evidence that the Delta variant is causing more severe disease in pregnant people, as well as increasing data showing the safety and efficacy of COVID-19 vaccines in pregnancy and lactation.

  • On July 30, 2021, the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) put out a statement recommending COVID-19 vaccination for pregnant individuals. In a news release, they stated that their “recommendation in support of vaccination during pregnancy reflect evidence demonstrating the safe use of COVID-19 vaccines during pregnancy from tens of thousands of reporting individuals over the last several months, as well as the current low vaccination rates and concerning increase in cases.” You can read the full statement here.
  • The CDC also released updated guidance on August 11, 2021. This recommendation comes after a new, pre-print data analysis of the CDC’s v-safe pregnancy registry. In this, the medical records of nearly 2500 people who received an mRNA COVID-19 vaccine before 20 weeks in pregnancy were reviewed. The study found no increase in the rate of miscarriage in people who received the vaccine as compared to the general population (the miscarriage rate of those studied was 13%, and the national average is 11-16%). The research is available in pre-print form here.
  • Previous data from the CDC’s monitoring systems did not find any safety concerns for people vaccinated later in pregnancy. Per the CDC, the combination of this data, combined with the known severe risks of COVID-19 infection in pregnancy show that the benefits of vaccination outweigh the risks. You can read the CDC’s press release here.
  • On August 12, 2021, the American College of Nurse Midwives (ACNM), along with many other obstetric care provider groups, endorsed a joint ‘Statement of Strong Medical Consensus for Vaccination of Pregnant Individuals Against COVID-19’. The statement encourages vaccination considering the increasing severity of infection for pregnant people with the Delta variant. It also focuses on the increasing evidence of vaccine safety for pregnant people as well as for those wanting to conceive. You can read the statement from ACNM here.


Links to Other Research you may find Interesting:

  • The CDC published a report on new COVID-19 cases and hospitalizations in New York, by vaccination status, from May to July 2021. You can read it here. A similar report for Los Angeles County is available here.
  • A research letter titled “Short-term Reactions Among Pregnant and Lactating Individuals in the First Wave of the COVID-19 Vaccine Rollout” was published in JAMA Network Open. You can access the letter here.
  • A pre-publication research article titled, “SARS-CoV-2 Antibodies in Breast Milk After Vaccination” is available in Pediatrics, the official journal of the American Academy of Pediatrics. You can access that study here.
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