Women with hyperemesis gravidarum who take antihistamines to help them sleep are significantly more likely to experience adverse pregnancy outcomes, including low-birth weight babies and premature births, according to a study.
Women with this condition considering taking such medications should know the risks, the studys lead author, Marlena Fejzo, an assistant professor of research in obstetrics and gynecology at UCLA, said in a news release.
The cause of hyperemesis gravidarum is unknown, and the symptoms are intense; the continuous nausea and vomiting can be so violent that women in the study reported suffering from detached retinas, blown eardrums, cracked ribs and torn esophagi, Fejzo said. The symptoms can last for several months or the entire pregnancy.
“It was surprising to find the link between antihistamines and adverse outcomes as these are over-the-counter medications that are used commonly by women with HG during pregnancy,” said Fejzo, who noted she had undiagnosed HG during her first pregnancy and nearly died during her second, losing the baby at 15 weeks gestation.
“Women and their healthcare providers should be aware of the risk for adverse outcomes when deciding which medications to take to treat their HG symptoms.”
The six-year study, published June 10 on the website of the European Journal of Obstetrics & Gynecology and Reproductive Biology, compared pregnancy outcomes in 254 women with HG who were sick enough that they needed treatment for dehydration with intravenous fluids to 308 women who had normal or no morning sickness during pregnancy. Fejzo said women with HG had four times the risk of adverse outcomes. Such a link has been shown in several previous studies.
The researchers then compared women with HG who suffered adverse outcomes to women with HG who had good outcomes. They then looked at more than 35 medications and treatments commonly used by women with HG to determine whether any were linked to bad outcomes. She found that antihistamines, such as those in Unisom and Benadryl, were taken by more than 50% of HG patients who experienced adverse outcomes.
Fejzo also found that the medications were reportedly effective in less than 20% of the women who took them.
“Some doctors will suggest that their HG patients take Unisom to help them sleep through their nausea,” Fejzo said. “Our findings show not only that the use of antihistamines is linked with adverse outcomes, but also that theyre not effective. Women with HG should be aware of that so they can make educated decisions on how to treat their HG symptoms.”
Fejzo said HG is diagnosed in 0.2% to 2% of pregnant women, although rates are higher in China. She said much more work needs to be done to study the short- and long-term outcomes of medication use during pregnancy. Furthermore, “we desperately need support for research into HG to determine its cause so that medications can be designed that are safe and effective,” Fejzo said.
Read the study abstract: http://www.ejog.org/article/S0301-2115%2813%2900218-2/abstract.