It should be noted that the study was conducted on human tissues in the laboratory, not in people.
A group of scientists from the University of Rennes, led by Séverine Mazaud-Guittot, have found the first evidence in human ovarian tissue that exposure to ibuprofen during the first three months of fetal development results in a drastic loss of germ cells that produce the follicles from which eggs develop. The results, published in Human Reproduction, indicate that germ cells died or did not reproduce at the usual rate.
Babies are born with a finite number of follicles in the ovaries and this defines their future reproductive capacity as adults - explains Mazaud-Guittot in a statement - A sparsely stocked initial reserve will result in a shorter reproductive life, an early menopause or infertility, all of them events that occur decades later in life. We found that two to seven days of exposure to ibuprofen dramatically reduced the accumulation of germ cells in human foetal ovaries during the first trimester of pregnancy and the ovaries did not fully recover from this damage.
Dr. Mazaud-Guittot and her colleagues obtained human fetuses between 7 and 12 weeks of development from legally induced pregnancy interruptions and with the consent of the mothers. They then cultured the ovarian tissue in the laboratory and divided the samples into two groups, one was exposed to ibuprofen and the other was the control group. A total of 185 fetus samples were analyzed.
The results show that ibuprofen crosses the placental barrier. The concentration we found in the umbilical cords of fetuses from mothers who ingested 800 mg of ibuprofen two to four hours before surgery,"adds Mazaud-Guittot," is similar to the concentration that can be found in an adult's blood for the same treatment, meaning that the fetus is exposed to the same concentration as the mother. By testing concentrations that were in the range of what can be found in an adult's blood, we discovered that there were fewer cells growing and dividing, more cells dying and dramatic germ cell loss, regardless of fetal gestational age. Five days after the ibuprofen was removed, these adverse effects were not completely reversed.
Comparing both groups, the one exposed to ibuprofen, showed a 50% reduction in ovarian germ cells.
Researchers say more work needs to be done on the mechanisms of action of ibuprofen in the human ovaries and on alternative analgesics. In addition, the study has limitations in that fetal tissue was studied in the laboratory and not in a living body.
This is the first study to look at the effects of ibuprofen on ovarian tissue - concludes Mazaud-Guittot - and the first to show that ibuprofen can cross the placental barrier during the first trimester of pregnancy and expose the fetus to the drug. It's important information for midwives and obstetricians to advise mothers because each case is unique.