How long after pregnancy does nausea typically begin?

In early pregnancy, from about the 4th to the 16th week, many pregnant women experience symptoms of morning sickness or nausea, commonly referred to as "early pregnancy reaction." This feeling can occur at any time of the day. The following describes the occurrence of pregnancy-related nausea and vomiting:

1. Timing of onset: Usually from the 4th to the 16th week of pregnancy. Most women begin experiencing symptoms at around six weeks of gestation, approximately 42 days after their last menstrual period. However, some women may feel symptoms as early as two weeks after conception, while others may not experience any symptoms throughout their entire pregnancy.

2. Causes: Mainly due to hormonal changes following implantation of the fertilized egg. The trophoblastic cells secrete human chorionic gonadotropin (hCG), and increased levels of estrogen and progesterone lead to changes in the gastrointestinal mucosal tissue, which can trigger nausea and vomiting.

3. Duration: Symptoms generally subside gradually around the 12th week of pregnancy, as hormone levels tend to stabilize by this time. However, due to individual differences, some women may experience symptoms throughout their entire pregnancy.

Feeling nauseous after pregnancy is a normal physiological phenomenon and generally not a cause for concern. If nausea and vomiting become severe, prompt medical attention is recommended.