Heartburn and Acid Reflux

Heartburn and Acid Reflux During Pregnancy: A Complete Guide

The sensation of fire rising from the depths of the stomach to the throat after what seems like an entirely innocent dinner – a familiar picture for many expectant mothers. Heartburn, or acid reflux, is one of the most common complaints, especially in the second half of pregnancy. Although this condition can cause significant discomfort, in the overwhelming majority of cases it is a completely normal physiological phenomenon related to the remarkable changes in your body.

Why does heartburn occur? Two main “culprits”

To understand why heartburn occurs, imagine your stomach as a bag of acid sealed at the top by a muscular valve — lower esophageal sphincter (LES). Under normal conditions this valve is tightly closed and prevents acid from flowing back into the esophagus. During pregnancy two powerful factors affect this idyllic picture:

• Hormonal factor: Progesterone. This is one of the main pregnancy hormones responsible for relaxing smooth muscle. This is necessary so the uterus does not contract and can grow. However, progesterone acts indiscriminately, relaxing other muscles as well, including the LES. As a result, the valve becomes less tight, allowing stomach acid to “leak” upward more easily.
• Mechanical factor: Uterine pressure. With each week, especially in the third trimester, your uterus enlarges and begins to press on internal organs, including the stomach. This pressure literally pushes stomach contents back into the esophagus, especially when you lie down or bend over.

An additional factor is that progesterone also slows down digestive processes. Food stays in the stomach longer, increasing the likelihood of reflux. You can read about other physical changes in the body in our detailed review.

When to expect the “hottest” moments?

Heartburn can appear at any gestational age, but it most often becomes a problem in the second half of pregnancy, reaching its peak in the late weeks (30‑40 weeks) when the uterus is at its maximum size. Some women experience it daily, others only after consuming certain foods (fatty, spicy foods, chocolate, citrus). It is important to understand that this is a temporary phenomenon that usually disappears completely after delivery.

Is heartburn dangerous for the baby?

This question worries many mothers, and the answer is unequivocal: no, heartburn is completely safe for your little one. The baby is comfortably situated in the amniotic fluid and does not feel your discomfort at all. The main problem with heartburn is the deterioration of your quality of life and sleep, so it is important to know how to relieve your condition. Although this description does not contain direct recommendations, you can find them in other sections of our site, for example in the article about balanced nutrition.