Hiccups can occur during pregnancy, but they do not have any direct impact on the fetus. Although they may be uncomfortable for the expectant mother, hiccups are a normal bodily function and not a cause for concern. Hiccups occur due to the diaphragm muscle contracting involuntarily, which has no effect on the developing baby. It is important for pregnant women to stay hydrated and maintain a healthy lifestyle, but hiccups do not pose any risk to the fetus.