Which hormone associated with pregnancy is responsible for the feeling of bloating?

Progesterone is the hormone associated with pregnancy that contributes to the feeling of bloating. This hormone plays a critical role in preparing the body for pregnancy and maintaining the pregnancy once it has occurred. One of its primary functions is to relax the smooth muscles of the uterus to prevent contractions that could lead to miscarriage.

However, progesterone also has effects on the gastrointestinal system. It relaxes the smooth muscle of the gastrointestinal tract, which can slow down digestion and lead to increased gas production. This action can often result in a sensation of bloating and discomfort, which many pregnant individuals experience due to hormonal changes.

While estrogen, human chorionic gonadotropin, and human placental lactogen are also important hormones during pregnancy, they do not have the same direct impact on the gastrointestinal motility and the resulting feeling of bloating as progesterone does. Estrogen can influence fluid retention and changes in the body's metabolism, but it is not primarily responsible for the sensation of bloating. Human chorionic gonadotropin and human placental lactogen have roles in supporting the pregnancy, but their effects are more related to other physiological changes than to bloating specifically.