# Heartburn at 18 Weeks Pregnant

Source: https://www.pregnancypowerhour.com/pregnancy/symptoms/heartburn-week-18
Last updated: 2026-07-01

> At 18 weeks, heartburn might begin as your growing uterus starts to gently push upward, contributing to that familiar burning sensation, especially when you lie down.

Heartburn at 18 weeks pregnant often signals the gentle but noticeable shift in your body as your uterus begins its upward journey, subtly influencing your digestive comfort. While heartburn is a common experience for many during pregnancy, for some, this might be the week it first makes an appearance, particularly as your body adjusts to the physical changes of the second trimester. The sensation, often described as a burning feeling in your chest or throat, can be a mild but persistent reminder of the incredible work your body is doing.

This early onset of heartburn in your second trimester is typically a combination of two key factors. Firstly, the hormone progesterone, which is essential for maintaining your pregnancy, also has a relaxing effect on smooth muscles throughout your body. This includes the lower esophageal sphincter, the valve that normally keeps stomach acid from flowing back up into your esophagus. When this valve is more relaxed, it creates an easier path for stomach contents to reflux. Secondly, at 18 weeks, your uterus is growing steadily and beginning to exert a gentle upward pressure on your stomach. This physical compression can also encourage acid to move in the wrong direction, leading to that familiar burning sensation. You might find this feeling is more pronounced when you're lying flat, as gravity is no longer helping to keep stomach acid down.

Navigating these new sensations can sometimes feel a bit unsettling, especially when you're already attuned to other bodily changes, such as the [increased vaginal discharge at 11 weeks pregnant](/pregnancy/symptoms/increased-discharge-week-11) that many experience. The good news is that there are often straightforward, evidence-based options to explore for managing heartburn. Many individuals find relief with over-the-counter antacids containing calcium carbonate, like Tums or Rolaids, which are considered a safe first-line approach across all trimesters. These work by neutralizing stomach acid, offering a quick way to ease the discomfort.

If you find that antacids aren't providing enough relief, or if your heartburn is significantly impacting your comfort, there are other options to discuss with your care provider. Some people find that medications like famotidine (Pepcid), which reduces acid production, can be helpful and are considered safe. For more persistent symptoms, omeprazole and other proton pump inhibitors (PPIs) are generally considered safe for use in the second and third trimesters. Remember, every body is unique, and what works well for one person might be different for another. You get to decide which approaches feel right for you, in collaboration with your provider. Just as you might monitor your body for changes like [increased vaginal discharge at 8 weeks pregnant](/pregnancy/symptoms/increased-discharge-week-8) or [increased vaginal discharge at 12 weeks pregnant](/pregnancy/symptoms/increased-discharge-week-12), paying attention to your heartburn patterns can help you and your provider make informed decisions about the best course of action. Your provider is your best resource for your specific situation and can help you weigh the options to find calm and clear relief.