Women in the first trimester of pregnancy (the first three months after conception) are always advised to take medications, for anything, only if absolutely necessary. If you can avoid taking anything but your prenatal vitamins and folic acid, you’re baby will be far better off. In the first trimester the baby’s limbs are developing, organ systems are forming, and heart and brain are slowly developing into the central nervous and cardiovascular systems. If a malformation occurs, its origin is during this period.
Pregnancy is also fraught with aches, pains, bowel problems, fatigue, weight gain, and mobility limitations that beg for relief. It’s a rare pregnant women who doesn’t express how she feels physically during this nine month misery session. Sleeping problems are also a big issue during pregnancy, and lack of refreshing, deep sleep wears a woman down.
Included in the prescribing information for every medication is a short paragraph on the effects each drug has during “PREGNANCY AND LACTATION.” This information is found in the PDR, the Physicians Desk Reference, or in the drug’s package insert. The sticky wicket here is that the evaluation for this is most often done on animals and not humans. The liability one might expose oneself to by purposely giving Mrs. Smith a drug to find out how it might affect her fetus is astronomical. I honestly don’t know how this information is obtained in humans other than by accidental exposure and evaluation of the baby at birth, plus animal experimentation.
As an aside, the PDR was that 3000+ page large red or blue book the doctor looked in for details on the drug he was prescribing. It was printed annually, and I had one in each exam room, I’m my private office, and at home. I used it every day for something. The last print publication of the PDR was in 2017. It is now available online or as an app. Instead of “Physicians’ Desk Reference” it is now called the “Physicians’s Digital Reference.” I even used it for this blogpost.
For sleeping problems in pregnancy, extensive studies have shown that in the First trimester, exposure to nonbenzodiazepine sleeping pills was NOT associated with increased risk for congenital deformities. A large U.S. study of 4 million pregnancies showed “Z-drugs,” as they’re known, did NOT put pregnant women at risk for common abnormalities. Researchers could not, however, rule out a connection between Z-Drugs and a heart anomaly, tetralogy of Fallot, or neural tube defects (spinal cord and brain anomalies).
The author says this study reassures doctors and patients that “z-drugs” are safe for sleep problems during the early months of pregnancy. Z-drugs are zolpidem (Ambien), eszopiclone (Lunesta), zaleplon (Sonata), all very commonly prescribed sleep medications. I don’t think I agree with this conclusion, however. In this study, zolpidem (Ambien) was prescribed in 0.5% to 0.6% of the participants. Compared to pregnancies not taking zolpidem, there was no difference in congenital malformations seen between the two groups. It was that statistic that caused them to conclude Z-drugs were safe.
I’m a huge doubter/skeptic about this report. I think the conclusion is not as straightforward as it needs to be. Instead of a Z-drug, if a pregnant woman can’t sleep, I would tell her to take a couple of Benadryl. I seriously doubt it has any correlation to tetralogy of Fallot or spina bifida. Those are two problems that should not be scoffed at. They are serious, sometimes fatal, anomalies. I disagree completely with the cavaliers attitude toward these potentially harmful drugs.
Reference: Brooks M. “Z-drugs” for Disordered sleep in Early Pregnancy: New Safety Data Medscape 2025 December 31.
