There was a “striking increase” within the variety of circumstances of fetal situs inversus at two Chinese obstetric facilities after the zero-COVID insurance policies have been lifted within the nation, researchers reported.

From January via July of this yr, the incidence of situs inversus — a uncommon congenital situation during which visceral organs are reversed from their regular positions — was over 4 instances as excessive because the imply annual incidence from 2014 via 2022 on the two facilities, which weren’t in the identical area, reported Shan Bian, PhD, of Tongji University in Shanghai, and colleagues.

Overall, 56 circumstances of fetal situs inversus — 52 circumstances of situs inversus totalis and 4 circumstances of partial situs inversus — have been recognized in the course of the first 7 months of 2023, with incidence peaking in April, they famous in correspondence printed within the New England Journal of Medicine.

Cases have been recognized through routine ultrasonography at a gestational age of about 20 to 24 weeks, with no change having been made in diagnostic protocol or doctor coaching.

“Although vertical transmission of SARS-CoV-2 is debated, fetal infection early in gestation could hypothetically affect visceral lateralization; alternatively, SARS-CoV-2-mediated maternal inflammatory responses might indirectly affect left-right organizer function and impair visceral lateralization,” Bian and co-authors wrote.

A surge in COVID infections after zero-COVID insurance policies have been lifted in China started in early December 2022, peaking round December 20 and ending in early February 2023, they famous. The surge is estimated to have affected 82% of the inhabitants there.

“While these initial observations are, of course, interesting, it is important to note that this is merely an observation, not a firm association or causation,” Katherine Kohari, MD, a maternal-fetal drugs specialist at Yale Medicine in New Haven, Connecticut, instructed MedWeb page Today in an e mail.

“There may be other reasons for the increase in the incidence seen in the population,” she mentioned. “Additionally, there were no increased rates of situs inversus during other time periods during which there were presumably high rates of COVID-19 infection, namely in 2020. We also do not know if the patients whose fetuses were diagnosed with situs inversus also had COVID-19 infection in pregnancy.”

“Therefore, the association would need to be further explored in a peer-reviewed research publication with more detail regarding the pregnancy exposures in each of the diagnosed cases as compared to health controls,” she added. “Even then, causation would be challenging to prove.”

Bethany Stetson, MD, a maternal-fetal drugs specialist at Northwestern University Feinberg School of Medicine in Chicago, echoed this sentiment, noting, “I think this is definitely very early stage. We don’t have a lot of the information that we would like.”

At the identical time, any time there is a rise in a start defect, “it warrants further investigation,” she instructed MedWeb page Today, including that it “never hurts to bring this up for other centers.”

Stetson additionally mentioned it was a major leap to say this particular remark is immediately associated to lifting zero-COVID insurance policies.

Both Stetson and Kohari pointed to well-known viral hyperlinks to a variety of fetal abnormalities, however to not situs inversus, although they mentioned that the latter shouldn’t be past the realm of risk.

“I am not aware of any viruses associated with the development of situs inversus in the fetus,” Kohari mentioned. “There are other viral infections that are known to cause abnormalities of fetal development, so it is plausible that the COVID-19 virus could also cause fetal abnormalities, but there is [significant research] that still needs to be done to further explore this association.”

As for prognosis, Stetson mentioned that many individuals with situs inversus certainly have a standard life expectancy. However, there’s at all times a priority and a have to search for some other findings that will also be current, resembling congenital coronary heart defects, she added.

Kohari famous that, “generally, if a true mirror image exists, then most people with this diagnosis do very well. Sometimes this diagnosis is made incidentally. However, there are variations of this arrangement that may be more associated with functional and anatomic problems.”

The examine authors additionally confused that no conclusions may very well be made concerning causality. At the identical time, they mentioned that their observations “suggest a possible relationship between SARS-CoV-2 infection and fetal situs inversus that warrants further study.”

“Further analysis is necessary to verify that genetic abnormalities in primary ciliary dyskinesia-related genes that may not have been detected during prenatal genetic screening did not contribute to the incidence of these cases and to assess the potential contribution of environmental factors,” they wrote. “It is notable that situs inversus diagnoses remained extremely rare despite the increase in incidence at our centers after the SARS-CoV-2 surge.”