COVID before or during pregnancy may confer 2 to 3 times the risk of miscarriage

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Woman who had a miscarriage with her doctor — *ake1150sb / iStock*

A study involving nearly 27,000 pregnancies suggests that women infected with COVID-19 before or during pregnancy are at two to three times the risk for miscarriage before 20 weeks' gestation.

The University of Texas–led analysis used electronic health records to evaluate the relationship between COVID-19 and miscarriage, ectopic pregnancy, and preterm delivery from 2019 to 2023. Ectopic pregnancy occurs when a fertilized egg implants outside of the uterus, rendering it unviable.

"In early pregnancy and the periconception period, SARS-CoV-2 infection may disrupt the complex immunology of pregnancy, which shifts between the temporary immunosuppression necessary for implantation and fetal tolerance and the proinflammatory response which helps to prevent infections in mid-pregnancy," the researchers wrote.

The findings were published late last week in BMC Medicine.

Results underscore need for vaccination

Among the 25,058 pregnancies in the Southeast Texas Pregnancy and COVID Cohort, 8.3% ended in miscarriage or abortion, 6.0% of which were further classified as miscarriages, 1.5% as ectopic pregnancies, 51.7% as live births, 0.6% as stillbirths, and 37.9% as deliveries, which can mean either a live birth or stillbirth. Seventeen women died, with five due to any cause and two due to COVID-19 complications around the time of childbirth.

These findings highlight the importance of COVID-19 vaccination and post-COVID management for pregnant people and those planning a pregnancy.

Among the 22,610 singleton pregnancies with gestational age at delivery after 20 weeks, 76.7% were classified by term, with 16.7% preterm (before 37 weeks' gestation).

The overall risk of miscarriage was 6.3%. Multivariable models tied both mild and moderate-to-severe pre-pregnancy COVID-19 to miscarriage (adjusted odds ratio [aOR], 2.48 and 2.81, respectively). It also linked mild and moderate-to-severe first-trimester infection to miscarriage (aOR, 2.31 and 2.45, respectively).

Risk factors for miscarriage were increasing age, Black or Hispanic ethnicity, and more chronic conditions.

Univariate models linked COVID-19 to miscarriage, and infections 31 to 180, 181 to 365, and more than 365 days before pregnancy had similar effect sizes as no COVID-19 before pregnancy (crude odds ratio, 2.33, 2.32, and 2.75, respectively).

"These findings highlight the importance of COVID-19 vaccination and post-COVID management for pregnant people and those planning a pregnancy," the authors wrote.

CDC issues Indian Ocean travel warning over chikungunya outbreaks

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Chris Dall, MA

The US Centers for Disease Control and Prevention (CDC) is warning people planning to travel to the Region of the Indian Ocean to practice enhanced precautions against chikungunya.

The Level 2 travel notice comes in response to chikungunya outbreaks in Mauritius, Mayotte, Reunion, Somalia, and Sri Lanka. It urges travelers visiting the area to use insect repellent and wear long sleeves and pants to protect against mosquitoes, which spread the virus, and recommends vaccination. The CDC says pregnant women should reconsider travel to the area.

Spread by Aedes aegypti and Aedes albopictus mosquitoes, chikungunya causes fever, severe joint pain, rash, and fatigue. While most cases are self-limited, the disease can affect neurologic and cardiovascular systems, leading to poor outcomes, including death. Yesterday the World Health Organization said Reunion island has had more than 47,500 confirmed chikungunya cases, 12 deaths, and more than 170,000 consultations for suspected chikungunya, while Mayotte has detected its first locally transmitted cases in 19 years.

Although there are two Food and Drug Administration (FDA)-approved chikungunya vaccines, the FDA and CDC last week recommended a pause in the use of Valneva's live-attenuated vaccine (Ixchiq) in people ages 60 and older. The pause was ordered while the agencies investigate five hospitalizations for cardiac or neurologic events in older people after receiving Ixchiq.

Analysis ties resistant pathogens to 10% increase in mortality risk from bloodstream infections

News brief

Chris Dall, MA

Bloodstream infection illustration — Raycat / iStock

A study of positive blood cultures over a 5-year period found that antimicrobial resistance (AMR) was associated with a 10% relative increase in the risk of death among patients with bacteremia, Canadian researchers reported today in Clinical Infectious Diseases.

Using linked microbiologic data from 114 hospital, community, and public health laboratories in Ontario, a team led by researchers from the University of Toronto and Public Health Ontario developed a cohort of patients with positive blood cultures from 2017 through 2021. They focused their analysis on pathogens responsible for at least 150 bloodstream infections and at least 20 associated deaths, and selected antibiotics for which susceptibility results were reported in at least 10% of episodes, with a resistance proportion from 1% to 99%. The primary outcome was 30-day mortality.

A total of 83,962 bacteremia episodes caused by 30 pathogens were identified, with 11 eligible pathogen-antibiotic combinations. Overall 30-day mortality was 17.1%. The most common pathogens were Escherichia coli (30.8%), Staphylococcus aureus (17.6%), and Klebsiella spp. (10.0%). The average patient age was 70 years, and 54.9% were male.

Larger impact for commonly used antibiotics

Across the 110 pathogen-antibiotic combinations studied, any resistance was associated with a 47% increased risk of 30-day mortality (hazard ratio [HR], 1.47; 95% confidence interval [CI], 1.32 to 1.65) in unadjusted analyses. But after adjusting for age, sex, healthcare exposures, comorbidities, and co-resistance, the increased risk of 30-day mortality was 10% (HR, 1.10; 95% CI, 1.07 to 1.16). The risk was 18% higher for resistance to antibiotics commonly used for empiric treatment (HR, 1.18; 95% CI, 1.10 to 1.26).

Attributable mortality due to AMR over the study period was 896 deaths, or 1.2 per 100,000 population per year.

"These results suggest that treatment adequacy could be an important mechanism leading to AMR-associated mortality, and that the mortality burden will increase if resistance rates to our most common treatment agents increase," the study authors wrote. "Ongoing surveillance and global collaboration is needed to better document and limit the impacts of antimicrobial resistance."