Exercise in pregnancy lowers the odds of gestational diabetes and preeclampsia by about 40 percent in randomized trials. Yet the conversation about it is often one sentence long. Here is how to have a better one.
She is 14 weeks pregnant. Before pregnancy she ran three times a week. Now she has stopped. Nobody told her to stop. Nobody told her to keep going either. When I ask why, she says what so many women say: “I didn’t want to hurt the baby.”
That fear is the real starting point of any conversation about activity in pregnancy. Not the guideline. Not the number of minutes. The fear.
This week JAMA published a short piece on how clinicians should talk with patients about physical activity.(1) It was written for people with chronic illness, not for pregnancy.
But almost every lesson in it fits the pregnant woman in front of us better than the authors may have intended.
What we mean by activity
Physical activity is any movement that uses energy: walking to work, climbing stairs, carrying groceries. Exercise is a planned part of that, like a swim or a prenatal yoga class. The JAMA authors make a simple point. When patients hear “exercise,” many picture a gym, and the idea feels like a burden.(1) When they hear “move more in your day,” it feels doable. In pregnancy, with nausea and fatigue, that difference matters even more.
What the evidence shows
The benefit is real. A 2018 meta-analysis of randomized trials found that exercise alone in pregnancy lowered the odds of gestational diabetes, gestational hypertension and preeclampsia by roughly 40 percent each.(2) Relative numbers can mislead, so here is what that means in people. In 2021, about 83 of every 1,000 women who gave birth in the US had gestational diabetes.(3) If the trial effect held at that rate, it would fall to about 53 per 1,000. That is roughly 30 fewer women per 1,000 facing diabetes in pregnancy. Real-world effects may be smaller than in trials, but the direction is clear.
ACOG recommends at least 150 minutes of moderate activity per week for women with uncomplicated pregnancies, the same target WHO sets for all adults.(4,5) Not every woman will reach it. WHO also says any amount of activity counts.(5) That second message is the one most women need to hear first.
How to start the conversation
Ask permission. “Can we talk about staying active while you’re pregnant?” It sounds small. It tells her this is a conversation, not a lecture. Then ask what she is doing now, and what worries her. Very often the answer is fear for the baby. Name it, and answer it with facts: for a healthy pregnancy, moderate activity is safe, and it is good for both of them.(4)
Then say out loud that staying active in pregnancy is hard. Morning sickness, back pain, long workdays and other children all get in the way. The JAMA authors stress that low activity usually reflects limited time, support or ability, not a lack of will.(1) Saying so removes blame before it starts.
What not to say
Avoid fear. “If you don’t exercise, you’ll get gestational diabetes” sounds like motivation. It often works as guilt. The JAMA piece cites evidence that fear, guilt and self-criticism can push people away from activity.(1) A pregnant woman already carries plenty of worry. Frame movement as something she does for herself and her pregnancy, not as a test she is failing.
Avoid the opposite error too. “Just listen to your body” sounds kind but gives her nothing. She needs a clear, simple guide.
Give her a guide she can use
The easiest one is the talk test. She should breathe faster but still be able to hold a conversation.(1,4) If she can sing, she can go a bit harder. If she cannot speak in full sentences, she should slow down. Start low and build up. A woman who was not active before pregnancy can begin with 10 minutes of walking a day.
She also needs to know when to stop and call. ACOG lists warning signs that include vaginal bleeding, regular painful contractions, fluid leaking from the vagina, chest pain, dizziness, and calf pain or swelling.(4) Give her that list in writing. Clear stop signs make women more confident, not less.
And be honest that a small number of conditions, such as certain heart or lung diseases or preeclampsia, change the plan.(4) That is a reason to talk about activity early, not to avoid the topic.
Help it last
The behavior science in the JAMA piece applies directly. Tracking activity, with a phone or a notebook, and setting goals about the behavior rather than the outcome both help.(1) “Walk 20 minutes after dinner” is a better goal than “don’t gain too much weight.” Social support helps people keep going.(1) A walking partner, a partner who joins, or a prenatal class can do more than another reminder from us.
Finally, plan for disruption. Pregnancy has bad weeks. The best advice is simple: when a routine breaks, restart small. Five minutes is not failure. It is the restart.
Conclusion
Activity in pregnancy is not a lifestyle extra. The trials show it lowers the odds of some of the most common complications we treat. That makes the conversation part of our professional responsibility, not a courtesy. Silence is not respect for her choices. A woman cannot choose well if no one gives her the facts. My advice to colleagues: ask permission, name her fear, replace “take it easy” with the talk test, hand her the warning signs, and treat every prenatal visit as a chance to bring it up again. Each conversation can be short. It just has to happen.
If this was useful, share it with a colleague who still says “take it easy” at the first visit. And if you want more evidence without the noise, subscribe to ObGyn Intelligence.
References
1. Midtgaard J, Skou ST, Bricca A. Communicating with patients about physical activity. JAMA. 2026;336(14):1272-1273. doi:10.1001/jama.2026.6083
2. Davenport MH, Ruchat SM, Poitras VJ, Jaramillo Garcia A, Gray CE, Barrowman N, et al. Prenatal exercise for the prevention of gestational diabetes mellitus and hypertensive disorders of pregnancy: a systematic review and meta-analysis. Br J Sports Med. 2018;52(21):1367-1375. doi:10.1136/bjsports-2018-099355
3. QuickStats: percentage of mothers with gestational diabetes, by maternal age. National Vital Statistics System, United States, 2016 and 2021. MMWR Morb Mortal Wkly Rep. 2023;72(1):16. doi:10.15585/mmwr.mm7201a4
4. Physical activity and exercise during pregnancy and the postpartum period: ACOG Committee Opinion, Number 804. Obstet Gynecol. 2020;135(4):e178-e188. doi:10.1097/AOG.0000000000003772
5. World Health Organization. WHO guidelines on physical activity and sedentary behaviour. Geneva: World Health Organization; 2020.
Amos,
Very correct and important!
Regards,Joachim