The Effect of COVID-19 During Pregnancy on Obstetric and Neonatal Outcomes: A Retrospective Case-Control Study

COVID-19 infection during pregnancy has been associated with adverse outcomes; however, most investigations were conducted early in the pandemic. The high rates of vaccination in Western Australia during peak transmission present a unique opportunity to reassess the impact of COVID-19 infection in pregnancy.

This study aimed to investigate the impact of COVID-19 infection in pregnancy on adverse obstetric and neonatal outcomes.

The retrospective case-control study conducted at a tertiary centre in Western Australia compared COVID-19 positive and negative pregnancies from March to November 2022. Data from 404 participants (223 positive and 181 negative participants) were analysed. Bivariate and multivariate analyses, adjusted for confounders, were used to assess adverse outcomes.

COVID-19 infection was significantly associated with lower cord blood pH (p = 0.012); but no other adverse obstetric or neonatal outcomes (p > 0.05). Among COVID-19 positive cases, the timing of infection by trimester did not significantly impact adverse outcomes. However, a shorter interval between COVID-19 infection and delivery was associated with higher rates of caesarean sections (p = 0.018) and neonatal comorbidities (p = 0.007). Analysis of COVID-19 severity on outcomes was limited by the small sample size (n = 4).

COVID-19 infection during pregnancy was not associated with clinically significant adverse outcomes, likely influenced by the predominant Omicron strain and high vaccination rates. Limitations of this study included lack of universal screening and a small sample size. Notwithstanding, this study provides valuable insights that reflect the current COVID-19 landscape, underscoring the need for an updated understanding as context surrounding COVID-19 infection evolves.