A major Danish study found that people with epilepsy – especially men – are significantly less likely to have children compared with those without epilepsy. The likelihood of parenthood is even lower among individuals with epilepsy and a concurrent psychiatric disorder. Further research is needed to understand why having epilepsy is associated with a lower chance of having children. A researcher involved in the study emphasises the importance of determining whether the reduced chance of having children among people with epilepsy reflects a conscious decision or is influenced by factors such as the condition itself or medical treatment.
If you have epilepsy, you are much less likely to have children than people without epilepsy. This is the key finding of a new study in Denmark in which researchers analysed birth statistics among more than 2.5 million people with and without epilepsy.
The study reveals that the chances of having children are especially low among people with focal epilepsy, those with a comorbid psychiatric disorder and men with epilepsy.
According to the lead author of the study, further investigation is needed to understand why people with epilepsy are less likely to have children.
“Previous research has shown that people with epilepsy tend to have fewer children than those without epilepsy – but our study provides additional insights. We identified specific subgroups of people with epilepsy in which very few have children. This knowledge could be valuable for individuals with epilepsy, since it may raise awareness that certain subgroups face a lower probability of parenthood. It may also prompt reflection on the possible reasons behind this trend and highlight any need for support or guidance in relation to family planning,” explains Josefine Klakk, PhD Fellow, National Centre for Register-based Research, Aarhus University, Denmark.
The research has been published in Neurology.
Data on 2.5 million people
People with epilepsy are less likely to have children, but the underlying reasons remain unclear, and the researchers aimed to address this gap with their new study.
To achieve this, they gathered data from a broad range of registers, including the Danish Civil Registration System, the National Patient Register, the Danish Psychiatric Central Research Register and the Danish Medical Birth Register.
The data included all residents in Denmark who turned 15 years of age between 1982 and 2021 and who had lived in Denmark for at least five years prior to their 15th birthday.
The study included data on 2,593,097 individuals, of whom 49% were female and 46,243 individuals were diagnosed with epilepsy.
Significantly less likely to have children
This study reveals that people with epilepsy have a markedly and statistically significantly lower chance of having a child.
Men with epilepsy have a 41% lower likelihood of having children compared with men without epilepsy, and the corresponding figure for women is 28%.
The probability of having two, three, four or more children also differs. However, as the number of children increases, the disparity between people with and without epilepsy attenuates as does the difference between men and women.
Men with epilepsy have a 46% probability of being childless at 45 years versus 31% for women with epilepsy. For people without epilepsy, the figures are 23% for men and 14% for women.
“We found substantial differences, both in comparison to people without epilepsy and in absolute numbers. Particularly striking is the lower probability of having children among men with epilepsy compared with their female counterparts,” says Josefine Klakk.
Differences between types of epilepsy
Analysing individuals with different types of epilepsy revealed that people with focal epilepsy (seizures originating in a specific area of the brain) have a lower probability of having children than those with generalised epilepsy (seizures originating in both hemispheres).
Women with focal epilepsy had a 39% reduced probability of having children versus 28% for women with generalised epilepsy.
For men, the corresponding figures were 49% and 43%.
“Interestingly, the sex-specific difference was greater in generalised epilepsy than in focal epilepsy. The reasons for this remain unclear, but it may stem from differences in the underlying causes of each type of epilepsy – which could also influence the opportunities to have children,” notes Josefine Klakk.
Psychiatric comorbidity increases the likelihood of childlessness
The study also highlights that psychiatric comorbidity is associated with the likelihood of having children.
Men with epilepsy and a psychiatric disorder had a 70% lower probability of having children than men with neither. For women, the corresponding figure was 49%.
Men with epilepsy had a 41% lower probability of having children overall but 32% lower excluding those with a psychiatric disorder.
These findings suggest that psychiatric comorbidities may partly explain why people with epilepsy are less likely to have children.
In addition, individuals with epilepsy and a comorbid developmental disorder had an exceptionally low likelihood of being a parent – more than 90% lower than that of people without epilepsy.
“It is not surprising that people with developmental disorders have fewer children, but this is important to keep in mind when interpreting the results. Many individuals with, for example, developmental disorders also have epilepsy, and they contribute to the reduced likelihood of having children among people with epilepsy,” explains Josefine Klakk.
Timing of diagnosis matters
As part of the study, researchers examined whether a higher number of abortions or stillbirths among people with epilepsy could help to explain their lower likelihood of having children.
However, the findings revealed only a modest increase in the probability of abortion (4%) and stillbirth (40%), which is insufficient to account for the lower likelihood of having children among people with epilepsy.
Josefine Klakk explains that combining live births, stillbirths and abortions does not explain why women with epilepsy are less likely to have children.
Finally, the researchers found that being diagnosed with epilepsy between 10 and 19 years of age had the least influence on the probability of having children.
According to Josefine Klakk, this is particularly interesting, since people diagnosed during adolescence often have a genetic form of epilepsy.
“One might assume that genetic epilepsy would be more severe and more strongly affect the likelihood of having children – but our findings do not support this hypothesis,” Josefine Klakk adds.
Further research needed
According to Josefine Klakk, these findings should serve as a basis for further research in this area.
She emphasises that men and women with epilepsy should have the same right to have children as everyone else. If they want to have children but are unable to, society has a role in addressing this and ensuring that they receive the necessary support.
Future research could explore why men with epilepsy have a lower chance of having children than women with epilepsy. For instance, could this result from how medical treatment for epilepsy affects the spermatogenesis, or whether genetic factors, social conditions or behavioural aspects influence the association?
Furthermore, many unanswered questions remain about how different types of epilepsy affect the chance of having children.
“One interesting finding is that men with genetic types of epilepsy have a lower chance of having children than women with genetic types of epilepsy. This could influence the transmission of epilepsy-related genes to future generations. Although many questions remain unanswered, our research adds important nuances to understanding reproduction among people with epilepsy – providing a basis for further exploration,” concludes Josefine Klakk.
