A Multicenter Cohort Study on the Adverse Effects Evaluation After Messenger RNA COVID-19 Vaccination Among Pregnant Healthcare Employees in Penang General Hospitals

Introduction: The year 2020 saw the emergence of novel severe acute respiratory
syndrome coronavirus 2 (SARS-CoV-2), which became a great threat to public health
worldwide. The exponential spread of the disease with millions of lives lost worldwide saw
the emergence of an accelerated vaccine development with emergency approval from
well-known regulatory bodies such as the US Food and Drug Administration, followed
by widespread vaccine deployment despite a paucity in safety profile data. This issue
becomes even more pronounced when it involves expectant mothers considering the
possible undesirable effect toward the unborn child.
Method: This was a retrospective cohort study which was conducted at six general
hospitals in the state of Penang, Malaysia. All the pregnant employees who have
consented to take the mRNA COVID-19 vaccine and participate in this study were
monitored from the time of their first vaccination and up to 28 days after they delivered
their babies.
Results: All the participants had adequate maximum vertical pocket (MVP) and no
obvious anomalies or detection of intrauterine growth restriction (IUGR) were detected
during the second trimester. However, one subject was reported to have miscarried
during the second trimester. The reported mean neonate birth weight was 3.0 kg with
the mean Apgar score of 8.8 and 9.8 at 1 and 5min, respectively. Approximately seven
(5.8%) neonates were reported to be small for their gestational age. Another three (2.5%)
neonates were reported to have anomalies.
Conclusion: As a whole, the inference that can be made from this study is that mRNA
COVID-19 vaccine appears to be safe in pregnant women regardless of the trimester as
the findings did not show obvious safety warning signs.