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Prenatal Acetaminophen And Masculinity

July 28th, 2017

Prenatal Acetaminophen And Masculinity

Prenatal Acetaminophen And Masculinity

Most people don’t pay much attention to symptoms of common cold or headaches and don’t usually seek any treatment for the management of these minor symptoms. To be honest, in most cases there is no need to take these minor ailments seriously as there are so many over-the-counter analgesic options that can alleviate your symptoms in no time.

Tylenol appears to be an ultimate escape out and most people in US manage their cold and headaches symptoms with self-medications. The fact that it contains the active ingredient known as acetaminophen (which relieves pain in pregnancy as well) can create a potential problem. According to a latest research, the use of acetaminophen in pregnancy is not considered healthy for expecting mothers especially those who are pregnant with baby boys.

Impact Of Prenatal Acetaminophen On Masculinity

According to a study that was published in the peer-reviewed journal Reproduction, investigators explored the impact of acetaminophen on fetuses of mouse and concluded that:

  • Male mouse fetus is at significant risk of developing long-term complications if exposed during pregnancy
  • There are some negative effects on the masculinity as well

The past researches have proposed that the production of testosterone can be highly suppressed by maternal consumption of acetaminophen especially if mother is pregnant with male fetuses. This can contribute to changes in the development of brain and reproductive system. What is testosterone? It is a hormone that is actively involved in the development of male reproductive system as it is responsible to manifest the male characteristic traits. It also takes part in promoting fat distribution, sexual drive, increased mass of bones and muscles and sperm and RBCs (red blood cells) production.

The past researches based on rodents revealed that suppressed testosterone levels can elevate the chances of malformation of testicles in newborns. However, the recent study suggests that there are several other risks in association with suppressed level

Pain Killers And Testosterone Image

s of testosterone which may bring about behavioral changes in adult males.

The leading author of the study Prof. Andres Hay-Schmidt, a member of Department of Neuroscience and Pharmacology in aDenmark University, at the time of study claimed that acetaminophen is a potential inhibitor of masculinity.

The study was carried out by administering a moderate dose of acetaminophen to the pregnant mice (which was nearly equivalent to the dose that most pregnant women are recommended to take). The leading author and team evaluated and assessed the behavior of male rodents and studies:

  • Their combativeness towards other male rodents
  • Mating ability
  • Behavior in marking territory

The results revealed that the male rodents born to the rodent mothers who were administered acetaminophen behaved poorly in all three aspects. It also affected the urinary behavior. The affected male rodents also displayed poor ejaculation and intromission.

The findings of the study also supported the earlier findings of studies based on rodent’s brains. Prof. Hay-Schmidt also reported that the cerebral level of certain hormones declined significantly in male rodents, affecting the region of brain, which controls sexual drive. The neurons in the ‘sexually dimorphic nucleus’, an area in anterior hypothalamus, were evidently reduced to half.

The study proposes that prenatal use of acetaminophen does not only affect the levels of testosterone (which can result in improper development of masculine traits) but it also causes diminished libido. Based on the findings, the researchers suggest that the expecting mother should consult the doctor prior to taking a pain reliever. The researchers believe that the prenatal effects of acetaminophen require further investigation in order to establish its safe and effective use.


  • Dean, A., Mungall, W., McKinnell, C., & Sharpe, R. M. (2013). Prostaglandins, masculinization and its disorders: effects of fetal exposure of the rat to the cyclooxygenase inhibitor-indomethacin. PloS one, 8(5), e62556.
  • Fisher, B. G., Thankamony, A., Hughes, I. A., Ong, K. K., Dunger, D. B., & Acerini, C. L. (2016). Prenatal paracetamol exposure is associated with shorter anogenital distance in male infants. Human Reproduction, 31(11), 2642-2650.

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