Terbutaline During Pregnancy: Safety Warnings Explained

What does the evidence say about terbutaline during pregnancy?

1. FDA's petition response found no approved terbutaline indication for preterm labor, described only limited value for brief intravenous use, and concluded that prolonged maintenance use lacked consistent benefit. Maternal blood and cord measurements in a small series showed transfer but did not establish birth-outcome safety. 1
2. The current terbutaline injection label says the medicine is not approved for preterm labor, should not be used longer than 48 to 72 hours, and should not be used for maintenance in an outpatient or home setting. Reported maternal events include death, arrhythmia, pulmonary edema, and myocardial ischemia. 2
3. The current oral tablet label states that oral terbutaline is contraindicated for acute or maintenance uterine-contraction suppression and repeats the boxed warning about serious maternal cardiovascular events and death. Its approved role is respiratory, not obstetric maintenance. 3
4. A double-blind trial randomized 52 women with singleton pregnancies and arrested suspected preterm labor to a terbutaline pump or saline pump. Time to delivery was 29 versus 28 days, with P=.78, and preterm and neonatal outcomes did not differ. The small trial was not powered for rare harms. 4
5. A systematic review found only two small randomized pump trials totaling 94 participants, plus biased nonrandomized and observational evidence. It rated evidence of benefit as low, found no long-term child outcomes, and concluded pump use should be limited to research settings. 5

Is terbutaline safe in each trimester?

• First trimester. Terbutaline is not a routine first-trimester pregnancy medicine for uterine contractions. If it was prescribed for asthma or another approved respiratory reason, confirm the indication and inhaled or oral plan with the prescriber rather than applying preterm-labor warnings without context.
• Second trimester. Symptoms suggesting preterm labor in the second trimester need urgent obstetric assessment. Terbutaline should not be started, extended, or delivered by a home pump to suppress contractions; any brief inpatient use requires monitoring and an individualized reason.
• Third trimester. When clinicians consider a short inpatient course for uterine contractions, the label limits prolonged use and warns about maternal tachycardia, arrhythmias, pulmonary edema, myocardial ischemia, hyperglycemia, and low potassium. It does not establish one duration as risk-free.