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. In addition, we continuously monitor the pattern of congenital anomalies of children or foetuses whose mother had a COVID-19 infection (COVID cases).
For all Eurocat cases born in 2020 or later whose parents have given permission for registration, 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 September 11th, 2025, we had registered 162 cases whose mother had a COVID-19 infection just prior to or during pregnancy. In 87 cases (54%) the COVID-19 infection was not mentioned in the medical records and was only found via the Eurocat questionnaire.
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 non-COVID cases registered by Eurocat Northern Netherlands
| Type of anomaly | N COVID cases | % COVID cases | N non-COVID cases* | % non-COVID cases* |
|---|---|---|---|---|
| Genetic disorders | 44 | 27% | 328 | 30% |
| Congenital heart defects | 30 | 19% | 220 | 20% |
| CAKUT | 28 | 17% | 122 | 11% |
| Limb anomalies | 15 | 9% | 114 | 10% |
| Genital anomalies | 14 | 9% | 85 | 8% |
| Orofacial clefts | 12 | 7% | 45 | 4% |
| Other | 9 | 6% | 118 | 11% |
| MCA | 5 | 3% | 52 | 3% |
| GI anomalies | 5 | 3% | 19 | 1% |
| Total | 162 | 100% | 1048 | 100% |
| CAKUT, congenital anomalies of kidney and urinary tract; GI, gastro-intestinal; MCA, multiple congenital anomalies; n, number * non-COVID cases concern foetuses or children who were born in 2020-2025, whose parents gave permission for registration in the Eurocat Northern Netherlands database and whose mother presumably did not have a COVID infection just prior to or during pregnancy |
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Overall, the pattern of congenital anomalies in COVID cases is not much different from the non-COVID cases born in the same time period (Table 1). Orofacial clefts and CAKUT were slightly more often seen in COVID-cases. When we looked at the specific anomalies, there was no pattern seen.
Most COVID-19 infections in Northern Netherlands were found in children/foetuses who were born in 2022 (93 cases). This corresponds with the peak of COVID-19 infections in Northern Netherlands.
In 49 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 49 cases had different types of anomalies, and no pattern could be found. Genetic disorders were most frequently seen, followed by congenital heart defects and CAKUT.
The pattern of congenital anomalies in COVID cases registered in the Eurocat Northern Netherlands database is not alarming. However, the number of cases is still relatively low and only 49 first trimester COVID-19 infections are registered. Therefore, Eurocat Northern Netherlands will keep monitoring COVID-19 infections and the European EUROCAT network is currently performing an ecological study on COVID-19 and congenital anomalies: COVICAT.
It is reassuring that most scientific studies have so far not reported a strong increased risk of congenital anomalies after a COVID-19 infection during pregnancy.
