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Pregnancy, Lactation, and the COVID-19 vaccine

Jan 30, 2021
Pregnancy, Lactation, and the COVID-19 vaccine
Should the pregnant patient get a COVID-19 vaccine? CDC currently cites this as a personal choice, with incorporation of the obstetrician for assistance in making the decision.

Should the pregnant patient get a COVID-19 vaccine? CDC currently cites this as a personal choice, with incorporation of the obstetrician for assistance in making the decision.Society for Maternal-Fetal Medicine indicates there is little data but that “A safe vaccine is generally considered one in which the benefits of getting it outweigh the risks. The two current vaccines are not live vaccines. There is only a very small chance that they cross the placenta, so it’s unlikely that they even reach the fetus, although we don’t know this for sure. There is no evidence at this time that the vaccines affect future fertility.” Ultimately, the Society for Maternal-Fetal Medicine calls the decision to be vaccinated a “personal choice” and asks patients to “Talk to your health care provider about a plan to get the vaccine after pregnancy.2 The American College of Obstetrics and Gynecology recommend that the vaccination not be “withheld” from pregnant women and recommend that the vaccine “should be offered to lactating individuals similar to non-lactating individuals when they meet criteria for receipt of the vaccine based on prioritization” but recommends a conversation with the treating physician and that the pregnant women consider all information available.”3

All of these organizations are shy of making a firm recommendation due to the lack of data since pregnant and nursing women were excluded from the trials but are quick to point out that pregnant women have a more severe course of COVID-19 than non-pregnant women. Specifically, there was a large study4 of 1,300,938 women identified through the National Notifiable Disease Surveillance System as laboratory positive for acute COVID-19 infection from January 22-October 3, 2020. Of these, 461,825 had information on pregnancy and 409,462 were symptomatic. The course was clearly worse for pregnant women with a 3-time greater risk of intensive care unit use (10.5 v. 3.9/1000 patients); 2.9 greater need for invasive ventilation (2.9 v. 1.1/1000 patients); 2.4 more likely to require extracorporeal membrane oxygenation (0.7 v. 0.3/1000 patients) and 1.7 times more likely to die of COVID-19 (1.5 v. 1.2/1000 patients). A separate study5 between March1-August 22, 2020, through the COVID-19-Associated Hospitalization Surveillance Network (COVID-19 Net) analyzed 598 pregnant women that were hospitalized with COVID-19 also showed more severe illness. At the time of admission 45.5% of the women were symptomatic, with that trend increased for women in their first and third trimester, 84% of whom were symptomatic. 16.2% f the 272 hospitalized, symptomatic women were admitted to the ICU, 8.5% required invasive mechanical ventilation and 2 (0.7%) of whom died.

In terms of pregnancy outcome, 458 women (76.6%) completed their pregnancies with 97.8% live births, and 2.2% pregnancy losses, in both symptomatic and asymptomatic COVID-19 patients.5 Of the pregnancy losses, 0.9% occurred at <20 weeks gestation, 1.1% occurred at >20 weeks gestation and 0.2% was at an unknown gestational age. Of the pregnancies that went to term, 87.4% were term and 12.6% were preterm (<37 weeks). Of the live births, preterm delivery occurred in 23.1% of symptomatic and 8% asymptomatic pregnant women. Of the infants born live, 2 died during hospitalization after requiring invasive mechanical ventilation, one as a complication of preeclampsia and one complicated by gestational hypertension.5

Table I: Pregnancy outcome in women hospitalized with and without COVID-19

Characteristic Pregnant Women Hospitalized with COVID-19 Pregnant Women Hospitalized for Other reasons
Intensive Care Admission4 1.1% (3 times non-COVID) 0.4%
Require Mechanical Ventilation4 0.29% (2.9 times non-COVID) 0.11%
Require ECMO4 0.07% (2.4 times non-COVID) 0.03%
Likelihood of Death4 0.15% (1.7 times noon-COVID) 0.12%

Table II: Pregnancy outcome in neonates born to women with COVID-19

Characteristic Pregnancy Outcome in COVID-19 positive, previously hospitalized patient Pregnancy Outcomes of General Population
Live Births 97.8%5 62%6
Pregnancy Losses 2.2%5 16% end in stillbirth or miscarriage and 22% end in abortion for a total of 38%6
Pregnancy Loss, <20 weeks gestation 0.9%5 10-20%7
Pregnancy Loss, >20 weeks gestation 1.1%5 1/160 (0.6%)8
Pregnancy Loss, unknown gestation 0.2%5 N/A
Term Pregnancies 87.4%5
Preterm 12.6%5 10%9
Preterm delivery in symptomatic patients 23.1%5 N/A
Preterm delivery in asymptomatic patients 8%5 N/A
Live Born infants that later died 0.4%5 N/A

In terms of neonate exposure, one study10 showed that there was no evidence of placental infection or transmission from the 64 pregnant women who tested positive for COVID-19 were to their neonates. However, transfer of immunity was also inadequate and lower than that of influenza, for example.

This is all new and there are no definite answers, only weighing risks and benefits. Multiple studies are examining these issues and are recruiting patients:






5Delahoy MJ, Whitaker M, O’Halloran A, et al. Characteristics and Maternal and Birth Outcomes of Hospitalized Pregnant Women with Laboratory-Confirmed COVID-19 — COVID-NET, 13 States, March 1–August 22, 2020. MMWR Morb Mortal Wkly Rep 2020; 69: 1347–1354.




10Edlow, AG, et al. Assessment of Maternal and Neonatal SARS-CoV-2 Viral Load, Transplacental Antibody Transfer, and Placental Pathology in Pregnancies During the COVID-19 Pandemic. JAMA Netw Open. 2020;3(12):e2030455. doi:10.1001/jamanetworkopen.2020.30455