Why Pregnancy Heartburn Is Worse at Night

Why is pregnancy heartburn worse at night?

The mechanism, briefly

Two things are happening at once. The NHS and ACOG both describe indigestion and heartburn as common in pregnancy, and the usual explanation has two parts.

Hormonal. Progesterone relaxes smooth muscle throughout the body, which is useful for a growing uterus and unhelpful for the sphincter at the top of the stomach. That valve closes less firmly than it used to.

Mechanical. As the uterus grows it pushes everything upward, increasing pressure on the stomach from below. That pressure is what pushes contents past a valve that is no longer holding well.

Which is why it gets worse as pregnancy goes on, and why it is worse lying down, worse after a large meal, and worse bending over.

The fix almost everyone gets wrong

Raise your whole upper body, not your head.

The instinctive response is to stack more pillows under your head, and it tends to make reflux worse rather than better. Propping only your head bends you at the neck and compresses your abdomen, which increases the pressure pushing contents upward — exactly the wrong direction.

What works instead, in order of effectiveness:

1. Raise the head of the bed itself. Blocks or risers under the legs at the head end put your whole body on an incline. The most stable option and usually free.
2. A wedge under the mattress. Same effect, nothing to slide out of place.
3. A wedge under your shoulders. Works well, and does slide. Firm wedges and foam hold the incline better than soft fiber ones.
4. Sleeping on your left side, which some people find helps with reflux specifically because of where the stomach sits. Worth trying; it costs nothing.

You are aiming for a modest incline across your whole torso rather than being sat upright. A few inches at the head end is a meaningful change.

The non-positional things that help

• Stop eating two to three hours before bed. The single most effective non-positional change, and the hardest when you are hungry at 9pm.
• Smaller, more frequent meals rather than three large ones. Less in the stomach means less pressure.
• Drink between meals rather than with them, which keeps stomach volume lower at any one time.
• Notice your own triggers. Commonly reported ones are spicy food, fried food, citrus, tomato, chocolate, coffee and fizzy drinks — but they vary enormously between people, so your own observation beats a generic list.
• Do not lie down straight after eating, and avoid bending at the waist for a while after a meal.

Medication: ask, do not guess

There are antacid and reflux options considered appropriate in pregnancy, and your midwife, OB, GP or pharmacist can tell you which apply to you. This is worth asking about rather than suffering through, because untreated nightly reflux costs a lot of sleep and sleep is not optional.

What not to do is self-prescribe from a shelf, including remedies marketed as natural, because “available without a prescription” is not the same as “appropriate in pregnancy”.

When heartburn is not heartburn

This matters. Some things that feel like severe heartburn or upper abdominal pain in pregnancy are not digestive, and one of them is serious.

Contact your provider urgently if you have pain in the upper right abdomen or just below the ribs that is severe or persistent, especially with any of: a headache, visual changes, swelling of the face or hands, feeling generally unwell, or nausea and vomiting later in pregnancy. That combination can indicate preeclampsia, which ACOG describes as needing prompt assessment, and it is not something to treat with antacids and a wedge.

Also seek advice for: difficulty swallowing, vomiting blood or anything that looks like coffee grounds, black stools, unintentional weight loss, chest pain or pain radiating to your arm or jaw, or heartburn that is not responding to anything.

If reflux is one of several things keeping you awake, see third-trimester insomnia for the whole picture, and wedge pillows for the hardware.