Why does nausea recur in the third trimester of pregnancy?

Individuals have different constitutions, so pregnancy experiences and sensations vary widely—and these differences shape unique memories for the future. Most women experience nausea to varying degrees during the first trimester. While some may feel nauseous right up until delivery, what causes nausea to reappear in the third trimester?

Why Does Nausea Reappear in the Third Trimester?

Nausea in late pregnancy may result from hormonal fluctuations, increased gastrointestinal burden, and elevated intra-abdominal pressure. During the third trimester, pronounced hormonal changes cause relaxation of gastrointestinal smooth muscle. As the fetus grows, the digestive tract bears greater mechanical load, impairing peristalsis and gastric emptying—leading to nausea. Additionally, progressive fetal growth increases intra-abdominal pressure, which may elevate diaphragmatic tension and trigger reflexive nausea and vomiting. Poor dietary habits in late pregnancy—such as consuming raw, cold, greasy, or unhygienic foods—can also disrupt gastrointestinal function and provoke nausea and vomiting.

During pregnancy, some women frequently experience vomiting and awaken from sleep due to nausea. This phenomenon causes significant discomfort for many. In fact, eating just a few plain crackers before returning to bed can effectively alleviate this discomfort. Others suffer severe morning nausea and vomiting; for them, drinking a small amount of warm water followed by some crackers—and then resting briefly—is recommended.

Pregnant individuals are advised to maintain a light, easily digestible diet, avoid overeating, and drink plenty of water. We hope this information is helpful to you.