Neurological Development In Toddlers After Maternal SARS-CoV-2 Infection During Pregnancy

In Utero Exposure to SARS-CoV-2 - the CRONOS registry The "COVID-19 Related Obstetric and Neonatal Outcome Study" (CRONOS) investigated the short-term effects of SARS-CoV-2 infections on mothers and their newborns during pregnancy. From April 3rd, 2020, to February 10th, 2023, data on 8,540 women and their newborns were collected, with active participation from 130 out of 686 (19%) German obstetric hospitals. The study was approved by the ethics committees of the coordinating center (UKSH Kiel, AZ: D 451/20) and each participating hospital. Information about CRONOS has been published on the German Society of Perinatal Medicine´s website, www.dgpm-online.org, and the German Clinical Trials Registry (DRKS00021208). About 2,000 women agreed to be contacted again for further follow-up.

The CRONOS-Kids study focuses on child health and will study some of the intrauterine-exposed children longitudinally. As an increased rate of placentitis with a concomitant increased risk of stillbirth and preterm delivery has been seen in infections with the Alpha and Delta variants, women with an SARS-CoV-2 infection between January 2021 and December 2021, initially recruited in the five participating university hospitals, will be contacted.

Recruiting for CRONOS-Kids On each of the five research sites, women initially participating in CRONOS will be invited via email, letter, or by phone to participate in the CRONOS-Kids study.

Unexposed children and their parents will be invited to participate via their local pediatricians.

All women will be able to book appointments at their respective hospitals via a dedicated website (http://cronos-kids.de). The management of patient contact will be conducted exclusively by non-examiners. Pseudonymization will be used.

Study instruments All children will undergo examination by personnel specifically trained for this purpose. In order to assess potential motor and cognitive deficiencies, the M-ABC-2 and the ASQ-3 will be utilised. Furthermore, social-emotional aspects will be addressed using a specific SE-test.

Questions of a general nature will address the subjects of pregnancy, birth, and social circumstances, with a view to identifying potential sources of bias with regard to developmental delays.

Potential bias To circumvent any potential bias in the study, responsibility for patient contact and examinations will be allocated to different members of the research team. Personnel conducting neurodevelopmental testing will adhere to the principles of blinding, ensuring that they remain unaware of the subjects' exposure status.

We expect a bias in the participation of highly educated and German-speaking families. This is likely to affect both the exposed and non-exposed groups.

Statistical analysis The Marburg University research team will manage data refinement. Analysis will control for potential confounders such as children´s sex, weeks of gestational age at birth, asphyxia at birth and social circumstances.

To be able to measure a mean effect in an unpaired t-test with an alpha level of 0.05 and a power of 0.8 (Cohen's d = 0.5), 64 subjects per group are required, i.e

Primary outcomes

• Motoric skills [36 to 60 months old children]: Motoric skills will be measured using the M-ABC-2 ("global rate"), as well as parental self reports in the ASQ-3 (areas: "gross motor" and "fine motor") with age-specific cut-off values.

Secondary outcomes

• Communication [36 to 60 months old children]: Communication will be measured using parental self reports in the ASQ-3 (area: "communication") with age-specific cut-off values.
• Personal-Social development [36 to 60 months old children]: Personal-social development will be measured using parental self reports in the ASQ-3 (area: "personal-social") and self reports in the social-emotional questionaire, both with age-specific cut-off values.

Sex: All, ages: 3 Years to 5 Years, accepts healthy volunteers

Inclusion Criteria:

* Toddlers (age 33 to 60 months), who were exposed (case) or not exposed (controll) with SARS-CoV-2 intrauterin.

Exclusion Criteria:

* No parental consent

• Pecks U, Mand N, Kolben T, Rudiger M, Oppelt P, Zollkau J, Dempfle A; The CRONOS registry. SARS-CoV-2 Infection During Pregnancy-An Analysis of Clinical Data From Germany and Austria From the CRONOS Registry. Dtsch Arztebl Int. 2022 Sep 5;119(35-36):588-594. doi: 10.3238/arztebl.m2022.0266. PMID 35794736