Postpartum Night Sweats: Why They Happen and When They Stop

TL;DR

• Waking up soaked in the weeks after birth is common and usually normal.
• It's driven mainly by the sharp drop in oestrogen and progesterone after delivery, plus the body shedding the extra fluid of pregnancy.
• Breastfeeding hormones can add to the pattern.
• It usually eases within a few weeks as hormones and fluid levels rebalance.
• A fever alongside the sweats, or sweats that persist for months, are reasons to contact a healthcare professional.

Many new parents are surprised to wake drenched in the first weeks after birth, often with the baby finally asleep. It's one of the more common and least talked about parts of the postpartum period, and in most cases it has a clear and reassuring explanation. Here's what's happening and roughly when it settles.

The hormone drop

During pregnancy, oestrogen and progesterone climb to high levels. Within hours to days of delivery, they fall steeply back toward baseline. Those hormones help stabilise the hypothalamus, the brain region that acts as the body's thermostat. When they drop this sharply, the thermostat becomes more reactive for a while, so small shifts in body temperature can trigger a full sweat. It's the same mechanism behind menopausal hot flushes, compressed into a shorter window.

Shedding pregnancy fluid

Pregnancy increases the body's total fluid volume substantially. After birth, the body clears that extra fluid, and sweating is one of the main routes it uses, alongside more frequent urination. This is why the sweating often feels heavy and drenching, and why it tends to be most noticeable at night when body temperature and hormones shift.

Breastfeeding and prolactin

For those who breastfeed, the hormone prolactin stays elevated, which keeps oestrogen lower for longer. That extended low-oestrogen state can prolong the sweating somewhat compared with those who don't breastfeed. It's a normal part of the same hormonal picture.

The timeline

For most people, postpartum night sweats are most intense in the first two weeks and ease over the following few weeks as hormones and fluid levels rebalance. In those who breastfeed, a milder version can linger longer, sometimes until weaning or the return of regular periods. Every recovery is different, so the exact timing varies.

Making it more comfortable

None of this needs treating in the usual sense, since it resolves on its own. A few things make it easier to live with. Breathable cotton nightwear and bedding, and a spare set within reach, save a lot of middle-of-the-night changes. A cool bedroom reduces the heat the body has to shed. Staying hydrated matters, since the body is losing fluid through the sweating. And because new-parent sleep is fragmented anyway, anything that lowers friction around the inevitable wake-ups helps. See sleep for new parents.

When to contact a professional

Postpartum sweating is usually benign, but a few signs warrant a call to a midwife, health visitor, or doctor:

• A fever, or sweats with chills, which can signal an infection such as mastitis or a womb infection
• Sweats with a rapid heartbeat, anxiety, weight loss, or a racing feeling, which can point to a thyroid problem, something that does occur postpartum
• Sweating that stays heavy for several months with no sign of easing

Postpartum thyroid changes and infections are both treatable, so it's worth getting them checked. For the wider set of night-sweat causes, see night sweats causes.

Frequently asked questions

Are night sweats normal after giving birth?

Yes. They are common and usually normal, driven by the sharp drop in oestrogen and progesterone after delivery and the body shedding the extra fluid of pregnancy.

How long do postpartum night sweats last?

They are usually most intense in the first two weeks and ease over the following few weeks. In those who breastfeed, a milder version can last longer, sometimes until weaning.

Does breastfeeding make night sweats worse?

It can prolong them. Breastfeeding keeps prolactin high and oestrogen lower for longer, which extends the low-oestrogen state behind the sweating.

When should I worry about postpartum night sweats?

Contact a professional if you have a fever or chills, a rapid heartbeat with weight loss or anxiety, or sweating that stays heavy for months. These can point to an infection or a thyroid change, both treatable.

Disclaimer

This article is for general information and education only. It is not medical advice, and it does not diagnose, treat, or prevent any condition. If you have a fever, or any concern in the postpartum period, contact your midwife, health visitor, or doctor.