COVID19: clinical presentation during pregnancy and impact on pregnancy outcomes. A population-based study

Principal Investigators

What is the impact of COVID-19 in mothers and fetuses? We do not have an answer to this question.

Our rationale

  • Despite most pregnancies with COVID-19 have a mild disease, there are reports of cases with severe or even fatal presentations, which create alarm among women, doctors and the society.
  • Likewise, pregnant women are highly vulnerable to the "collateral damage" of COVID-19, i.e. the long term social, wellbeing and economic consequences.
  • Because they are young, and apparently "more protected" from COVID-19, there has been a lack of attention on pregnancy.
  • This has led to lack of reliable scientific data, generating stress on women and preventing evidence-based information to inform the society, make recommendations and guide policies.
  • Therefore, there is an urgent need to have solid data on how COVID19 affects pregnancy and their child.
  • International collaboration is critical need to accelerate generation of knowledge.

What are our main questions

  • How is COVID-19 presenting in pregnant women?
    Is it worse in pregnancy like influenza? Could we predict which women are at increased risk?
  • What is the impact on pregnancy outcomes?
    Does it increase the risk of miscarriage, prematurity or fetal death?
  • How is the pandemics affecting mental well-being in pregnant women and their children?
  • Do lifestyle, socio-economic and air pollution play a role in COVID-19 in pregnancy?
  • Will the children of the "Covid generation" develop well?

To provide answers to these critical questions we have designed AN AMBITIOUS RESEARCH PROGRAMME with several lines and studies to create different cohorts.

Project design

Registries of symptomatic COVID-19 cases in pregnancy are extremely valuable to describe the disease, but normally detect the most severe end of the clinical spectrum. It is critical to do prevalence studies, i.e. study consecutive patients with and without COVID-19, to capture the asymptomatic and mild forms of COVID-19 to understand the real impact.

We are creating a large study on 3,000 pregnant women screened for COVID-19 (containing 450 cases of COVID-19) in the first and third trimester of gestation, and 3,000 non-pregnant women (300- 450 with COVID-19) of the same age.

We will describe the prevalence, the clinical presentation and the impact on pregnancy outcomes of COVID-19. This will probably be the first study describing the differences of COVID-19 in different moment of pregnancy. The results will be ready by late June 2020.

We will also study the impact of maternal nutrition, stress and the microbiome to test how they determine the susceptibility to and clinical severity of COVID-19 in pregnancy.

Finally, we will evaluate the immune response in women with different presentations of COVID-19 in collaboration with expert researchers in immunology.

Scientific objectives

With this programme we will meet important scientific goals:

  1. To describe the seroprevalence of COVID-19 infection in pregnant women in different moments of pregnancy.
  2. To describe the clinical spectrum and the perinatal outcomes associated with the disease.
  3. To compare the seroprevalence, the clinical presentation and the risk of severe forms of COVID-19 infection in pregnant women as compared with non-pregnant women matched for age.
  4. To evaluate factors associated with infection and clinical presentation, including maternal stress, nutrition, maternal microbiota, socio-economic factors and air pollution.
  5. To evaluate the immune response against SARS-CoV-2 in a subgroup of pregnant women.
  6. To evaluate the vertical transmission, the consequences in the newborns and the development of children born to COVID-19 mothers.

Data and samples

We obtain structured clinical information about the symptoms of COVID-19, the transmission of the disease in the family, questionnaires on nutrition and stress-wellbeing, and obtain biological samples:

  • Maternal nasopharyngeal swab: Real-time reverse transcription polymerase chain reaction (RT-PCR) test.
  • Maternal serum blood samples: Serology measurement of the host response to infection (IgM, IgG).
  • In women with COVID-19 we store DNA and RNA for immunological studies and collaborations with international networks investigating predisposing factors to severe COVID-19.
  • Maternal fecal and vaginal swab: Microbiota analysis.
  • Placental samples to study the effects of the infection on placenta.
  • Cord blood samples. To measure antibodies and understand if there is vertical transmission (infection of the fetus)
  • Neonatal nasopharyngeal swab (only if the mother is positive to COVID19): RT-PCR test.

Children will be followed during 1-2 years to evaluate the neurodevelopment of the "Covid-19 generation".


Crovetto F, et al. Impact of SARS-CoV-2 Infection on Pregnancy Outcomes: A Population-Based Study. Clin Infect Dis. 2021; 8 Feb:ciab104. doi: 10.1093/cid/ciab104.

Crovetto et al. Seroprevalence and presentation of SARS-CoV-2 in pregnancy. The Lancet. August 06, 2020. doi: 10.1016/S0140-6736(20)31714-1. More information.

Research team at Fundació Sant Joan De Déu (FSJD)

In collaboration with the FSJD biobank.

Research team at Fundació Clinic per la Recerca Biomèdica (FCRB)

In collaboration with the Clínic/IDIBAPS biobank (Teresa Botta and Aina Rodriguez).

Research team at Hospital Sant Pau

Who is behind this research?

BCNatal Fetal Medicine Research Center belong to Hospital Sant Joan de Deu and Hospital Clínic of Barcelona, at the University of Barcelona. We are one of groups with the largest scientific international production in our field. Over the last 10 years we have published over 450 research papers and have successfully developed large-budget research studies, including European and international projects.


The samples will be analyzed in collaboration with different centers:

  • Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS): serologies.
  • Centre de Regulació Genòmica (CRG): RT-PCRs.
  • Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC, Valencia): microbiome.
  • Integrated immunology unit Sant Joan de Déu-Clínic: immune response in a subgroup of women.

We support the international registry set up in Switzerland (COVI-Preg, Profs. D Baud and A Panchaud) and encourage all centers to register their COVID-19 cases in pregnancy. Link: