Study Findings

We just published our first paper from this study, and we wanted to let you know what we found! We sent the summary of study findings below to all REST Study participants.


Why did we do this study?

  • Many women experience sleep problems during pregnancy. Sometimes it’s hard to sleep because of normal pregnancy symptoms like being uncomfortable or needing to use the bathroom.
  • Some pregnant women experience worse symptoms, called insomnia. Insomnia is defined as having trouble falling or staying asleep, or waking up earlier than planned. These symptoms are distressing or impairing. About 1 in 7 pregnant women experience moderate-to-severe insomnia symptoms.
  • Cognitive behavior therapy for insomnia (CBT-I) teaches skills to make the bed a place where you sleep (instead of lying awake), increase your sleep drive, increase relaxation, and recognize unrealistic beliefs about sleep. We know that CBT-I is effective for people who aren’t pregnant. We wanted to find out if CBT-I is effective for pregnant women.
  • We used a digital version of CBT-I (Sleepio), instead of in-person sessions, to make it more convenient for pregnant women to get this treatment and so that we could reach more pregnant women.

What was involved in the study?

  • You were among a group of pregnant women who were randomly assigned to get either Sleepio or treatment as usual.
  • We had a control group (treatment as usual) to give us more confidence that any improvements were due to Sleepio, and not due to the passage of time, changes during pregnancy, or something else.
  • You completed study questionnaires at the start of the study, 10 and 18 weeks later, 1 month before your due date, and at 3 and 6 months after you had your baby (or babies!).

Who participated?

  • You were 1 of 208 pregnant women who participated in this study.
  • Participants came from 29 states and 3 countries. Most participants were from California.
  • The oldest REST Study baby is now 3 years old!

What did we find?

  • Our new paper looks at the questionnaires you completed 10 and 18 weeks after starting the study.
  • At 10- and 18-weeks after the study started, women who received Sleepio experienced greater improvements in insomnia, depressive, and anxiety symptoms compared to women who received treatment as usual.
  • At 10 weeks after the study started:
    • 34% of women who received Sleepio experienced moderate-to-severe insomnia symptoms, compared with 66% of women who received treatment as usual.
    • 16% of women who received Sleepio experienced elevated depression symptoms after finishing the intervention, compared with 31% of women who received treatment as usual.
    • 2% of women who received Sleepio experienced moderate-to-severe anxiety symptoms, compared with 8% of women who received treatment as usual.
  • At 18 weeks after the study started, findings were similar, but a little weaker.

Why is this important?

  • When you were pregnant, you might have heard unhelpful things like “If you think your sleep is bad now, just wait until the baby comes!” or “There’s nothing you can do to sleep better during pregnancy!” Our study shows just the opposite – we can improve sleep during pregnancy!
  • And, improving sleep benefited mental health more generally.

What’s next?

  • We will analyze the postpartum data to see if women who received Sleepio still had better sleep and lower depression and anxiety after the birth of their baby. We will send another update when this next paper is published.
  • We are applying for a grant to study whether treating prenatal insomnia can prevent postpartum depression.

Interested in other resources?

  • Check out our sleep tips sheet at
  • Check out a self-help CBT-I book, like:
    • Quiet Your Mind and Get to Sleep, by Colleen Carney and Rachel Manber
  • Listen to a sleep meditation, such as those available at:

Want to get involved in future studies or learn about our other work? Contact me!

Email: [email protected]