Are hot flashes a sign of labor?

Bottom lineNo - hot flashes and sweats are common in late pregnancy because of hormones, higher blood volume, and a faster metabolism, but they are not a reliable sign of labor; the real signs are regular strengthening contractions, your waters breaking, and a bloody show, so call your midwife or OB when those start.

Not reliably. Feeling suddenly hot, flushed, or sweaty is common in late pregnancy, and some women do report waves of heat in the days before labor - but hot flashes are not a recognized sign that labor is starting, and midwives do not use them to judge whether you are in labor.

Why late pregnancy makes you feel hot

By the third trimester your blood volume has increased by around 50 percent, your metabolic rate is higher, and pregnancy hormones affect how your body regulates temperature. Add a baby radiating heat from the inside and it is entirely normal to feel flushed and sweaty with no labor in sight. Hormone swings near the end of pregnancy may add hot flushes for some women, which is why the idea circulates - but it is anecdote, not an established labor sign.

The real signs labor is starting

• Regular contractions that grow stronger, longer, and closer together (unlike Braxton Hicks, they do not ease when you rest or change position)
• Your waters breaking - a gush or steady trickle of fluid
• A "show" - the mucus plug coming away, sometimes blood-tinged
• Persistent lower back ache or period-like cramping that builds
• Sometimes loose stools or a sudden urge to nest

When to call your midwife or OB

Call when contractions are regular (for example every 5 minutes, lasting about a minute), when your waters break (even without contractions), or before 37 weeks if you have any of these signs. Call urgently for bright red bleeding, fluid that is green or brown, reduced baby movements, or a severe headache with vision changes - and mention fever specifically, because feeling hot with a true fever needs checking, not watching.

Hot flashes alone, with none of the signs above, are almost always just late pregnancy being late pregnancy.

Related: due date calculator