professionals of Lozano Blesa University Clinical HospitalWithin the group Placental pathophysiology and fetal programming from the Aragon Health Research Institute (IIS Aragon), together with those from La Vall d’Hebron in Barcelona, have participated in the study INTERCOVID 2022, which has shown that infection by SARS-CoV-2 increases the risk of complications during pregnancy and that vaccination is effective in offering protection to pregnant women.
The work, coordinated from the Oxford Universityhas been published in The Lancet. The project has been carried out in 41 hospitals in 18 countries, the two mentioned being the only participating Spanish centers. The objective is to evaluate the impact of the Omicron variant of COVID-19 during pregnancy on the mother and the fetus and also on neonates.. In April 2021, it was already confirmed that the risk of complications increased in pregnant women who were infected with SARS-CoV-2 and, on this occasion, evidence is provided on the effect of Omicron and the efficacy of vaccination against this variant.
The researchers studied 1,545 pregnant women diagnosed with the variant and 3,073 pregnant women without a diagnosis of COVID-19, of which 216 pregnant women were from the Zaragoza III Health Sector (72 with Covid-19 plus 144 controls), of which the Clinic is a reference hospital. The study was carried out between November 2021 and June 2022, during which time Omicron was considered to be predominant. The results showed that this variant during pregnancy was associated with an increase in complications, such as preterm labor, and hospital admissions. Serious symptoms appeared in 4-7% of unvaccinated women diagnosed with the Omicron variant, and it was especially high in obese or overweight women.
In particular, among women with severe symptoms, increased risk of preeclampsia (high blood pressure during pregnancy). “Unvaccinated pregnant women infected with the Omicron variant still run a significant risk of complications,” says Marta Fabre, a researcher at IIS-Aragón and a physician at the Lozano Blesa Clinical Biochemistry Service. Nerea Maiz, a specialist in the Obstetrics Service of the Vall d’Hebron Hospital and researcher of the Maternal and Fetal Medicine group of the Vall d’Hebron Research Institute (VHIR): “The study provides us with evidence on the increased risk during pregnancy due to this variant, especially among symptomatic and unvaccinated women” .
On the other hand, it was observed that vaccination offered high protection against severe symptoms of COVID-19 and against complications of pregnancy, and vaccinated women had a low risk of needing admission to intensive care units. The effectiveness of the vaccine against the development of severe symptoms in women with COVID-19 was 74% in women with the complete vaccination schedule, and reached 91% in those who had received a booster dose..“Fortunately, broad vaccination coverage has been achieved in our environment in recent years, but we must continue to insist on the benefits of receiving booster doses, in accordance with the schedule set by the health authorities”, points out Fabre. “The study clearly indicates the need for full vaccination, preferably with booster doses, to offer protection for pregnant women”, adds Corn.
Regarding the type of immunization received, mRNA vaccines (such as those of Pfizer-BioNTech and Modern) were most effective in preventing severe COVID-19 symptoms and complications for at least 10 months from the last dose. Viral-vectored vaccines (such as those for AstraZeneca y Janssen) also offered adequate protection if a booster dose had been administered. Regarding the side effects of vaccination, they were not observed in the mother or in the fetus or newborn., even having received the vaccine during pregnancy. INTERCOVID 2022 is an example of an international collaborative study that provides robust evidence to improve the health of mothers and babies around the world. The findings of this study and previous results have contributed to changing clinical practice and recommendations for pregnant women.
