In February 2020, the first patient with COVID-19 was registered in the Netherlands. COVID-19 is characterised by airway complaints, fever and a variety of other symptoms. It is caused by infection with the corona virus SARS-CoV-2. Many people worldwide have been infected with the virus, including pregnant women. We know that other virus infections can be teratogenic. For example, zika virus infection during pregnancy leads to a higher risk of microcephaly (small head circumference, associated with intellectual disability) in the unborn child. Therefore, Eurocat Northern Netherlands is collecting data about COVID-19 infections.
For all Eurocat cases born in 2020 or later, we searched the medical records of the mother and the child for information regarding COVID-19 infection during pregnancy. In our questionnaire, we also asked the mother whether she had a COVID-19 infection in the three months prior to pregnancy or during pregnancy.
At 7 October 2024, we had registered 139 cases whose mother had a COVID-19 infection just prior to or during pregnancy. In 75 cases (54%) the COVID-19 infection was not mentioned in the medical records and was only found via the Eurocat questionnaire.
The children / foetuses whose mother had a COVID-19 infection (COVID cases) had different types of congenital anomalies (Table 1). Genetic disorders occurred most frequently, followed by congenital heart defects and congenital anomalies of kidney and urinary tract (CAKUT).
Table 1 Types of congenital anomalies in COVID cases and in Eurocat NNL cases born prior to the COVID-19 pandemic
| Type of anomaly | Number of COVID cases | % COVID cases | Number of cases born in 2015-2019* | % cases born in 2015-2019 |
|---|---|---|---|---|
| Genetic disorders | 39 | 28.1% | 580 | 23.4% |
| Congenital heart defects | 30 | 21.6% | 670 | 27.0% |
| CAKUT | 29 | 20.9% | 420 | 16.9% |
| Limb anomalies | 12 | 8.6% | 480 | 19.4% |
| Oro-facial clefts | 10 | 7.2% | 170 | 6.9% |
| Total | 139 | 2480 | ||
| Cases with multiple congenital anomalies were counted in more than one anomaly subgroup * Source: https://eu-rd-platform.jrc.ec.europa.eu/eurocat/eurocat-data/prevalence_en |
||||
Overall, the pattern of congenital anomalies in COVID cases is not much different from the cases born prior to the COVID pandemic (2015-2019, Table 1). There were more genetic disorders among COVID cases, but a maternal COVID infection is not expected to result in genetic aberrations.
Most COVID-19 infections in Northern Netherlands were found in children/foetuses who were born in 2022 (82 cases). This corresponds with the peak of COVID-19 infections in Northern Netherlands.
In 36 cases, the COVID-19 infection took place during the first trimester of pregnancy, which is the most vulnerable period for the occurrence of congenital anomalies. These 36 cases had different types of anomalies and no pattern could be found. Genetic disorders were most frequently seen, which are not expected to be related to the COVID-19 infection.
The pattern of congenital anomalies in COVID cases registered in the Eurocat Northern Netherlands database (n=139, n=100 non-genetic cases) is not alarming. However, the number of cases is still relatively low and only few first trimester COVID-19 infections are registered. Therefore, Eurocat Northern Netherlands will keep monitoring COVID-19 infections and the European EUROCAT network will start an ecological study on COVID-19 and congenital anomalies. It is reassuring that most scientific studies have so far not reported an increased risk of congenital anomalies after a COVID-19 infection during pregnancy.
