\n A new study found that some girls born to mothers who took acetaminophen during pregnancy developed reproductive organ changes that could affect fertility later in life. It\u2019s a finding the study authors say should drive future research but shouldn\u2019t yet change how certain symptoms are treated during pregnancy.\n <\/p>\n
\n The new research doesn\u2019t show that acetaminophen, also known as paracetamol or Tylenol, caused the reproductive changes. Women shouldn\u2019t be \u201calarmed\u201d by the findings because the research does not establish cause and effect, study co-author Dr. Margit Bistrup Fischer said.\n <\/p>\n
\n It also does not mean pregnant women should stop taking acetaminophen if they need it, she noted, but \u201cit\u2019s definitely something we need as a society to talk about and inform pregnant women more about, so they can make an informed decision.\u201d\n <\/p>\n
\n Acetaminophen has long been known as the safest over-the-counter option to treat fever or pain during pregnancy, although doctors advise using it in moderation and only when necessary. An untreated fever can endanger both mother and fetus, possibly leading to birth defects<\/a> or miscarriage<\/a>.\n <\/p>\n \n Much more research is needed to determine whether it\u2019s the over-the-counter medicine itself causing the changes or something else, said Fischer, a postdoctoral researcher in the Department of Growth and Reproduction at the Rigshospitalet in Copenhagen, Denmark.\n <\/p>\n \n The American College of Obstetricians and Gynecologists agreed that more study is needed, saying in a statement that the findings \u201cdo not indicate that current clinical recommendations should change. Consistent with ACOG\u2019s existing guidance, acetaminophen remains one of the only safe medications that can be used during pregnancy when indicated, and patients should consult their obstetric care professional before making any changes to medication use.\u201d\n <\/p>\n \n Acetaminophen use during pregnancy became a hot-button issue last year<\/a> when President Donald Trump told pregnant women with pain or fever to \u201ctough it out\u201d and avoid acetaminophen if possible, blaming, without evidence, the medicine and certain vaccines for autism<\/a>.\n <\/p>\n \n Last year, the US Food and Drug Administration initiated a label change suggesting that acetaminophen use during pregnancy could put the fetus at risk of neurological conditions and alerted doctors<\/a> that acetaminophen use during pregnancy can be associated with a \u201cvery increased risk of autism,\u201d despite decades of evidence that it does not cause neurological problems and unsettled science<\/a> on the connection<\/a> between the medicine and autism.\n <\/p>\n \n Acetaminophen is the only over-the-counter drug that doctors and medical societies recommend pregnant people take for pain or fever, but organizations such as the American College of Obstetricians and Gynecologists<\/a> advise using it only as needed, in moderation and after patients talk to their doctors. Aspirin and ibuprofen can pose serious risks to the mother and fetus, including miscarriage<\/a>.\n <\/p>\n \n The new study focused on girls\u2019 reproductive organs and did not examine any links to autism.\n <\/p>\n \n Fischer said she wanted to conduct the new research because several experimental animal studies<\/a> showed that offspring of mothers given acetaminophen during pregnancy had smaller ovaries and fewer eggs. The medication appeared to interfere with egg formation and division in those experiments, Fischer said.\n <\/p>\n \n The new study<\/a>, published this week in the journal Human Reproduction Open, is one of the first to assess human use. The scientists enrolled 685 women in Denmark during the first trimester of pregnancy, a crucial time for fetal development, and evaluated 302 of their baby girls when they were 3 months old.\n <\/p>\n \n The pregnant women logged their acetaminophen use and submitted urine samples so researchers could measure how much of the drug was in their system.\n <\/p>\n \n The study found that girls exposed to acetaminophen in the womb had, on average, 40% smaller ovarian volume, 13% smaller uterine volume and 23% fewer ovarian follicles \u2014 the structures that contain immature eggs \u2014 compared with girls whose mothers did not use acetaminophen during pregnancy. They also showed lower levels of a hormone linked to ovarian reserve.\n <\/p>\n \n Smaller ovaries can signal that a person has fewer eggs<\/a>, which may make it harder to get pregnant. Girls are born with all the eggs they will ever have; the body cannot make more.\n <\/p>\n \n Having fewer eggs can also hasten earlier menopause<\/a>. Early menopause, defined as beginning before age 45, is a health concern because it means a prolonged absence of estrogen, a hormone that protects the brain, bones and heart.\n <\/p>\n \n However, this study captured only a snapshot in time; the researchers did not follow the girls long-term to determine future fertility.\n <\/p>\n \n In its statement, ACOG noted that the \u201cclinical significance of these findings is uncertain or unknown. The oldest participants evaluated were adolescents, and the study cannot determine whether the observed differences are associated with future reproductive outcomes such as fertility, ovulatory function, reproductive lifespan, or other measures of reproductive health.\u201d\n <\/p>\n