Consequences of SARS-CoV-2 infection on pregnant women and their descendants are not well known. The Mother and Child Covid-19 study is a cohort recruiting about 1000 pregnant women and their children in Cantabria, North of Spain, during COVID-19 pandemic. This article reports the cohort profile and preliminary results as recruitment is still open. Three sub-cohorts can be identified at recruitment. Sub-cohort 1 includes women giving birth between 23rd March and 25th May 2020; they have been retrospectively recruited and could have been exposed to COVID-19 only in their third trimester of pregnancy. Sub-cohort 2 includes women giving birth from 26th May 2020 on; they are being prospectively recruited and could have been exposed to COVID-19 in both their second and third trimesters of pregnancy. Sub-cohort 3 includes women in their 12th week of pregnancy prospectively recruited from 26th May 2020 on; they could have been exposed to COVID-19 anytime in their pregnancy. All women are being tested for SARS-CoV-2 infection using both RT-PCR for RNA detection and ELISA for anti-SARS-CoV-2 antibodies. All neonates are being tested for antibodies using immunochemoluminiscency tests; if the mother is tested positive for SARS-CoV-2 RNA, a naso-pharyngeal swab is also obtained from the child for RT-PCR analysis. Children will be followed-up for one year in order to ascertain the effect that COVID-19 on their development. As of 29th July, 477 women have been recruited (212, 132 and 133 for sub-cohorts 1, 2 and 3, respectively). Eight women tested positive to SARS-CoV-2 RNA. Seven children were born from these women and all tested negative for SARS-CoV-2 RNA. Summarizing, we are recruiting a cohort of 1000 pregnant women and their neonates during the COVID-19 pandemic. Results so far show that few women were infected at delivery and no child have been affected.