Global study launched to evaluate effects of COVID-19 variants and vaccination in pregnancy

Less than a year after three papers reporting the main results of the INTERCOVID Study were published in leading medical journals (see below), the University of Oxford is this week launching the second round of the largest global study comparing COVID-19 in pregnancy with pregnant women without the infection. The updated aims of this large multinational effort are to: 1) Evaluate the effect of the new variants of the virus on pregnant women and newborns and 2) Quantify the effect of vaccination on the complications described during pregnancy and the neonatal period.

Despite the growing body of evidence regarding the dangers of COVID-19 during pregnancy – higher risk of maternal death, preeclampsia/eclampsia, severe infections, intensive care unit admissions, preterm births, and severe neonatal complications – and the efficacy and safety of COVID-19 vaccines during pregnancy, countries have been recording alarmingly low rates of vaccination among this high-risk group. Little is known, however, about the impact during pregnancy of new variants of the virus, such as Omicron. The researchers aim to fill that gap as quickly as possible because without large-scale, peer-reviewed research, the impact should not be underestimated.

José Villar, Professor of Perinatal Medicine at the University of Oxford, who co-led INTERCOVID, says: 'The effects of COVID-19 in pregnancy have been underestimated and insufficiently studied. Pregnant women were not even included in vaccine trials, which has allowed unscientific, scary “information” to be widely disseminated; hence, they are under-vaccinated. The effect of the new variants in pregnancy is unknown. We are launching the second global effort to address this unacceptable situation. Over a 4 month period across 40 medical institutions worldwide, we will be studying 1,500 pregnant women diagnosed with COVID-19 and 3,000 concomitant pregnant women with no evidence of COVID-19. The results are expected to be ready in May 2022.'

A similar methodology to the first INTERCOVID Study will be used. The researchers will be recruiting women who have tested positive to the virus at any stage of pregnancy. The women and their newborns will be followed until hospital discharge to quantify the risks associated with the exposure. For each pregnant woman who has tested positive (confirmed by either PCR, lateral flow or LAMP test), two pregnant women who have never been diagnosed with COVID-19 will be recruited as the control group. Vaccination records, including the number, types and timing of vaccines, will also be collected.

Aris Papageorghiou, Professor of Fetal Medicine at the University of Oxford, who co-led INTERCOVID, says: 'The INTERCOVID Study is driven by a large, global team of dedicated clinicians and scientists. Working together at the start of the pandemic, the team rapidly collected evidence from across the world on the potentially devastating effects of COVID-19 in pregnancy – information that has influenced vaccine policy internationally. In this extension to the INTERCOVID Study, the same team will now assess the effect of different SARS CoV 2 variants, as well as vaccines, on maternal and newborn outcomes.'

Stephen Kennedy, Professor of Reproductive Medicine at the University of Oxford, who co-led INTERCOVID, says: 'The INTERCOVID Study is another example of the extraordinary contribution the University of Oxford has made towards fighting this pandemic. Our specific focus on the effects of COVID-19 on mothers and babies is essential given the continuing hesitancy about the need for vaccination both before and during pregnancy.'

The full paper, 'Maternal and Neonatal Morbidity and Mortality Among Pregnant Women With and Without COVID-19 Infection: The INTERCOVID Multinational Cohort Study', can be read in JAMA Pediatrics.

The full paper, 'Preeclampsia and COVID-19: results from the INTERCOVID prospective longitudinal study', can be read in the American Journal of Obstetrics and Gynecology.   

The full paper, 'Diabetes mellitus, maternal adiposity, and insulin dependent gestational diabetes are associated with COVID-19 in pregnancy: the INTERCOVID study', can be read in the American Journal of Obstetrics and Gynecology.