A Retrospective Case Series Analysis of Pregnancy and COVID-19 Based on a Global Postmarketing COVID-19 Surveillance Program.

Purpose: To document and characterize COVID-19 cases involving pregnancy in the context of exposure to pharmaceutical products.

Methods: This retrospective case series analysis leveraged the Pfizer safety database containing worldwide adverse event data related to use of Pfizer products between October 1, 2019 and November 3, 2022. Selected Medical Dictionary for Drug Regulatory Activities (Version 25.0) Preferred Terms and subsequent clinical review were used to identify COVID-19 cases involving female patients who received Pfizer products during pregnancy and infants with intrauterine exposure to Pfizer products.

Findings: As of November 3, 2022, 504 pregnancy cases (426 maternal; 78 infants) were identified. Most maternal cases reported COVID-19 during the third trimester, and (when known) 52% of cases involved presentation or progression of severe COVID-19 with associated complications requiring hospitalization, and often intensive management (eg, mechanical ventilation, oxygen support) and emergent delivery. Twenty-three maternal cases were fatal; patients developed severe COVID-19 disease involving multisystem deterioration (eg, cardiopulmonary injury/decompensation, coagulopathies, septic/hemorrhagic shock) and frequently required risk-benefit decisions regarding maintaining/prolonging pregnancies to improve fetal viability while attempting to improve or stabilize maternal conditions or electing to either terminate pregnancies or induce emergent deliveries. Approximately 40% of maternal cases reported medical history involving at least one underlying condition (eg, diabetes, respiratory disorders, renal/hepatic disease, cardiac disease, obesity, autoimmune conditions) considered potentially associated with susceptibility to infection/adverse outcome of infection, or twin/triplet pregnancy, which may further complicate COVID-19 disease. Most cases with known fetal outcomes reported normal newborns including preterm/low birth weight infants, which occurred in many cases involving emergent preterm delivery due to deteriorating maternal conditions. The remaining smaller proportion of cases involved abnormal newborn/perinatal/postperinatal complications (eg, premature births, respiratory distress, alveolar damage, meconium aspiration with hypoxic-ischemic encephalopathy), intrauterine/neonatal death (due to multiple concurrent complications such as neonatal sepsis, hypoxemia/acute respiratory distress, potential cardiac damage, mucormycosis) and congenital anomaly (eg, intrauterine growth restriction in association with contracting COVID-19). Among infants tested within our dataset, 28 cases involved reference to infants who tested positive for COVID-19 infection at birth or shortly thereafter, with vertical transmission suspected only in 2 infants.

Implication: This large retrospective case series provides additional perspectives regarding potential impact of COVID-19 on pregnancy outcomes, and its characterization of this case volume may contribute to the current information landscape related to COVID-19 in pregnancy. Further studies may be warranted to confirm the generalizability of our findings to the general pregnant patient population infected with COVID-19.