Pre-Term Labor Meds Linked to ComplicationsMar 9, 2009 | Parker Waichman LLP
A new study is revealing that preterm labor medications given to expectant mothers to prevent early births may be linked with serious complications, reports Reuters Health. The large European study was conducted in Belgium and the Netherlands.
The controversy in administering so-called “first-line” medications to stem preterm labor arises "because of inconclusive information on the relative safety of the various agents," explained Dr. Roel de Heus at University Medical Center Utrecht and associates in the British Medical Journal, said Reuters. Apparently, the majority of clinical trials conducted on preterm labor medication have only taken place with low-risk pregnancies, which, according to the researchers, does not “reflect real-world situations,” said Reuters.
The U.S. News and World Report said that doctors use tocolytic drugs to delay labor for up to two days. By doing this, some time is received to allow steroids to speed up the baby’s lung development and allow the pregnant mother to be transferred to a facility with a neonatal intensive care unit, said U.S. News and World Report, citing the study. The most popular tocolytics include beta agonists and nifedipine—a smooth muscle relaxer, which works on the uterine muscles—atosiban, and indometacin—a labor hormone inhibitor, according to the study. It safety of tocolysis to mothers and babies remains unknown, said U.S. News and World Report.
The study looked at 1920 women who were treated with a variety of medications to halt preterm labor and found 14 serious adverse events, linked to the treatment, occurred to the mothers and involved breathing difficulties, low blood pressure, heart failure, and fluid in the lungs. When drugs were combined, the incidence increased to 16 percent; four patients required intensive care treatment, said Reuters Health. "As there is no evidence that treatment with combined (drugs) is superior to single or sequential treatment, we believe that combined treatment should be discouraged," said the team, reported Reuters Health. According to U.S. News and World report, the study involved 28 hospitals; atosiban was used in 42 percent of the cases, nifedipine in 24 percent, beta agonists in 14 percent, and indometacin in eight percent.
"The real dilemma” is "whether to treat or not..., not which drug to use," said the writers of a related editorial, quoted Reuters Health, which added that after three decades of research, it remains unclear if stopping preterm labor benefits or harms the baby. "After 30 years of research, we still do not know whether tocolysis benefits the fetus, so the choice of which drug to use remains a secondary question. The real dilemma is whether or not we should treat at all," they wrote, quoted U.S. News and World Report. The prevailing theory of "keeping the baby inside longer must be a good thing" requires reevaluation, they wrote, said U.S. News and World Report.
U.S. News and World Report also noted that the team suggested that both combined and single beta agonist treatment should be discouraged for the treatment of preterm labor and suggested additional trials to study the safety and efficacy of nifedipine and atosiban.