(508) Assessment of stillbirth rates during the different waves of the COVID pandemic

COVID-19 became a global pandemic at the beginning of 2020 with significant morbidity and mortality. There has been a documented increase in intrauterine fetal death (IUFD) rates during the pandemic as well as placental vascular malperfusion associated with COVID infection. As the pandemic enters its third year, this study aims to analyze the rates of IUFD as they relate to the waves and variants of infection during the pandemic.

Study Design:

A retrospective cohort study was performed of IUFDs at a single community hospital from Feb. 2020 to Nov. 2021 (COVID cohort) compared to a cohort three years prior to the pandemic from Jan. 2017 to Jan. 2020. IUFD was defined by a lack of cardiac activity at 20 weeks gestational age or greater or weight ≥ 350 grams. The waves of the pandemic were defined by CDC data corresponding to dominant variants as follows: first (unsequenced, Feb. 2020-Jun. 2020), second (unsequenced, Jul. 2020-Oct. 2020), third (alpha, Nov. 2020-May 2021), fourth (delta, Jun. 2021-Nov. 2021). Retrospective chart review was performed for data collection. Demographic information was compared using t-test for continuous and chi-squared for categorical variables. Rates of IUFD were analyzed using odds ratio with 95% confidence intervals. Statistical significance was set to a p value of 0.05.

Results:

A total of 22 IUFDs were documented in the three years prior to the pandemic, and 21 in the first 22 months of the pandemic. The rate of IUFDs in the first 18 months of the pandemic was significantly greater than in the two years prior to the pandemic (2.85 vs 5.82 IUFDs per 1000 births, OR 2.04). When analyzed by waves of the pandemic, there was nearly double the rate of IUFDs during the second and third wave (4.8, 7.0, 7.5 and 3.5 per 1000 births, OR 1.71, 2.44, 2.21 and 1.63).

Conclusion:

Rates of intrauterine fetal death increased during the pandemic and progressively worsened with the dominant variant of the second and third wave. Further research is needed to assess the determinants and preventability of these fetal deaths.