- Paracetamol is a common drug that is used for relieving pain.
- Scientists have found that taking paracetamol during pregnancy can inhibit the infant's masculinity.
- It is therefore important to deliberate before taking the medication, as it could increase the risk of malformation of the testicles in infants.
Paracetamol is a common drug used for relieving pain. However, during pregnancy it is important to think twice before taking the medication as it is capable of damaging the development of male behaviors, finds a new study from the University of Copenhagen.
Prior studies have found that the drug is capable of inhibiting the development of the male sex hormone testosterone in male fetuses. This could increase the risk of malformation of the testicles in infants.
‘Taking paracetamol during pregnancy can inhibit the development of male behavior in the child. It can reduce sex drive and aggressive behavior.’
David Mobjerg Kristensen, researcher at the Department of Biomedical Sciences and the Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, said, that a reduced level of testosterone at the fetal stage could be significant for the behavior of adult males.
"We have demonstrated that a reduced level of testosterone means that male characteristics do not develop as they should. This also affects sex drive. In a trial, mice exposed to paracetamol at the fetal stage were simply unable to copulate in the same way as our control animals. Male programming had not been properly established during their fetal development and this could be seen long afterwards in their adult life. It is very worrying."
The administered dose to the mice was very close to the dose of the pregnant women. The clinical trials are restricted to mice and the results can be the same to the humans. But, the harmful effects of paracetamol could be improper to undertake the same trials on humans.
Testosterone is the male sex hormone that helps to develop the male body and male programming of the brain. The masculine behaviors involved aggressiveness, ability to mate and the need for territorial marking.
The mice reacted significantly and more passively than normal for all the three parameters. The mice did not attack other males, were unable to mate and behaved more like female mice when it came to urinary territorial marking.
The specific effects of the lack of testosterone on the brain were studied after observing the changed behavioral patterns.
"The area of the brain that controls sex drive - the sexual dimorphic nucleus - had half as many neurons in the mice that had received paracetamol as the control mice. The inhibition of testosterone also led to a halving of the activity in an area of the brain that is significant for male characteristics." explained David Mobjerg Kristensen.
Female Fertility Affected
The research study that focused on the effect of paracetamol on masculine characteristics. However, paracetamol during pregnancy can have the potential to influence the lives of female mice.
The research team published a study showing that the female mice could have fewer eggs in their ovaries when the mothers had taken paracetamol during pregnancy. Even though paracetamol is harmful, it is not compulsory that it should never be taken during pregnancy.
David Mobjerg Kristensen, said, "I personally think that people should think carefully before taking medicine. These days it has become so common to take paracetamol that we forget it is a medicine And all medicine has side effects. If you are ill, you should naturally take the medicine you need. After all, having a sick mother is more harmful for the fetus."
The author finally concluded that pregnant women must continue to follow the guidelines that are given by the country's health authorities and could recommend people to contact their General Physician, if there is any doubt about the use of paracetamol.
- Anders Hay-Schmidt, Olivia T Ejlstrup Finkielman, Benjamin A H Jensen, Christine F Høgsbro, Jacob Bak Holm, Kristoffer Haurum Johansen, Tina Kold Jensen, Anderson Martino Andrade, Shanna H Swan, Carl-Gustaf Bornehag, Søren Brunak, Bernard Jegou, Karsten Kristiansen, David Møbjerg Kristensen. Prenatal exposure to paracetamol/acetaminophen and precursor aniline impairs masculinisation of male brain and behavior. Reproduction, 2017; 154 (2): 145 DOI: 10.1530/REP-17-0165