Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons
Authors: Amena Abbas
John Nahabedian
Ruiling Liu
Ashley Judge
Gyan Chandra
Jun Ju
Tanya R Myers
Kara Polen
Christine K Olson
Dana M Meaney-Delman
Veronica K Burkel
Bicheng C Zhang
Paige L Marquez
Jennifer Linn Wilkers
Jennifer Hamborsky
Susanna Trost
Karen T Chang
Katie Arnold
Lakshmi Panagiotakopoulos
Robbie Gray
CDC v-safe COVID-19 Pregnancy Registry Team
Nicole Olgun
Emmy Tran
Alaya Koneru
Kailyn Brooks
Charise Fox
Keydra Oladapo
Margaret A Honein
Morgan Nail
Lauren Zauche
Sascha R Ellington
Youngjoo Park
Dena Cherry-Brown
Obehi Ilenikhena
Ayzsa Tannis
Kimberly Newsome
Tuyen Do
Shin Y Kim
Ellen Boundy
Sarah Zohdy
Adamma Mba-Jonas
Titilope Oduyebo
Tom T Shimabukuro
Corinne Marie Parker
Ashley N Smoots
Virginia Bowen
Emily Petersen
Lindsey Torre
Letha Thomas
Penelope Strid
Tara Brown
Charles Licata
Suzanne Gilboa
Dayna Alexander
Anne Moorman
Caitlin J Green
Julianne M Gee
Jennita Reefhuis
Janet D Cragan
Monica DiRienzo
Pedro L Moro
Meghna Alimchandani
Zanie Leroy
Stacey W Martin
Anne Hause
Cynthia Moore
Cheryl Broussard
Diana Valencia
Jennifer Hegle
Journal: New England Journal of Medicine (2021)
Discipline: CLINICAL MEDICINE
Keywords: mRNA Covid-19 vaccines; pregnancy safety; adverse outcomes; v-safe; pregnancy registry
Affiliations: From the Immunization Safety Office, Division of Healthcare Quality Promotion (T.T.S., T.R.M., P.L. Moro, L.P., P.L. Marquez, C.K.O., C.L., B.C.Z., J.M.G.), and the Arboviral Diseases Branch, Division of Vector-Borne Diseases (S.W.M.), National Center for Emerging and Zoonotic Infectious Diseases, the Division of Birth Defects and Infant Disorders, National Center on Birth Defects and Developmental Disabilities (S.Y.K., V.K.B., C.J.G., D.M.M.-D.), the Division of Reproductive Health, National Center for...

Abstract:  Background: Many pregnant persons in the United States are receiving messenger RNA (mRNA) coronavirus disease 2019 (Covid-19) vaccines, but data are limited on their safety in pregnancy. Methods: From December 14, 2020, to February 28, 2021, we used data from the "v-safe after vaccination health checker" surveillance system, the v-safe pregnancy registry, and the Vaccine Adverse Event Reporting System (VAERS) to characterize the initial safety of mRNA Covid-19 vaccines in pregnant persons. Results: A total of 35,691 v-safe participants 16 to 54 years of age identified as pregnant. Injection-site pain was reported more frequently among pregnant persons than among nonpregnant women, whereas headache, myalgia, chills, and fever were reported less frequently. Among 3958 participants enrolled in the v-safe pregnancy registry, 827 had a completed pregnancy, of which 115 (13.9%) resulted in a pregnancy loss and 712 (86.1%) resulted in a live birth (mostly among participants with vaccination in the third trimester). Adverse neonatal outcomes included preterm birth (in 9.4%) and small size for gestational age (in 3.2%); no neonatal deaths were reported. Although not directly comparable, calculated proportions of adverse pregnancy and neonatal outcomes in persons vaccinated against Covid-19 who had a completed pregnancy were similar to incidences reported in studies involving pregnant women that were conducted before the Covid-19 pandemic. Among 221 pregnancy-related adverse events reported to the VAERS, the most frequently reported event was spontaneous abortion (46 cases). Conclusions: Preliminary findings did not show obvious safety signals among pregnant persons who received mRNA Covid-19 vaccines. However, more longitudinal follow-up, including follow-up of large numbers of women vaccinated earlier in pregnancy, is necessary to inform maternal, pregnancy, and infant outcomes. 

Retracted: No

PubPeer comments:
 In your table 4 you find a spontaneous abortion incidence of **12.6% that is 104 over 827** ![file] However in the footnotes of that same table you indicate  A total of 700 participants (84.6%) received their first eligible dose in the third trimester That means that of these 700 all were pregnant at the time of injection. That means that of those 827 persons 700 were 24+ weeks pregnant at the time of their inclusion in the study. A spontaneous abortion is registered in your study as occurring before 20 weeks. That means that of those 700 there was an **incidence of 0%** of spontaneous abortion because it does not apply here. However, in the Table 4 you include those 700 women in your incidence. The true incidence should exclude that population. And thus **the real incidence is : 104 over 127 : 82%** That seems high but keeping in mind the fact that there is almost 4000 women enrolled and this preliminary concerns only the **completed pregnancies**. Imagine 4000 women starting gestation at the same time, and doing a similar study after 2 months, the only completed pregnancies would be the spontaneous aborted ones. ,