Morning sickness is a common physiological phenomenon during pregnancy, typically appearing from weeks 5-6 and tending to decrease after the first three months. Common symptoms like nausea, vomiting, fatigue, bloating, and insomnia can occur at any time of day.

Dr. Do Khac Khanh, of the Obstetrics and Gynecology Center at Tam Anh General Hospital Hanoi, indicated that many women with IVF pregnancies often experience severe, prolonged morning sickness that significantly impacts their daily lives. The reasons may be related to the characteristics of the pregnancy and the expectant mother's psychological state.

Fluctuating pregnancy hormone levels are a primary factor contributing to severe morning sickness in IVF expectant mothers. This is due to the rapid increase in pregnancy hormones, especially estrogen and beta-human chorionic gonadotropin (hCG). After successful embryo transfer, hCG levels in IVF pregnant women often rise quickly, higher than in natural pregnancies. hCG is considered a main factor causing nausea and vomiting due to its impact on the brain's vomiting center and the central nervous system.

Women undergoing IVF pregnancy often need to supplement with estrogen and progesterone hormones during the initial weeks to support embryo implantation and maintain the pregnancy. The combination of high endogenous hormones and supplementary hormones means the body does not adapt quickly, leading to severe morning sickness. Many IVF expectant mothers use oral, injectable, or vaginal progesterone for many weeks, sometimes throughout the first three months of pregnancy. Progesterone relaxes smooth muscles, slows gastrointestinal motility, causing bloating, loss of appetite, nausea, and gastroesophageal reflux.

Pregnant women monitoring their pregnancy at the Obstetrics and Gynecology Center. Illustration: Tam Anh General Hospital

Multiple pregnancies are more common with IVF, which has a higher rate of twin or multiple births compared to natural pregnancies. In multiple pregnancies, hCG and estrogen levels often increase many times more than in singleton pregnancies, causing frequent nausea and vomiting. Expectant mothers may vomit multiple times a day, eat poorly, lose weight, and in some cases, require hospitalization for fluid replacement due to severe morning sickness. Additionally, the uterus growing faster in multiple pregnancies also increases pressure on the stomach and esophagus, easily causing acid reflux, heartburn, and prolonged nausea.

Maternal health and underlying conditions also play a role. Women who become pregnant through IVF often belong to the group with long-term infertility, possibly accompanied by underlying medical conditions such as endocrine disorders, polycystic ovary syndrome, endometriosis, or thyroid dysfunction. These factors make the body more sensitive to changes during pregnancy, including morning sickness. Some IVF expectant mothers undergo the procedure at an older age than average, resulting in poorer physiological adaptability and a digestive system more prone to disorders, making morning sickness symptoms more pronounced.

Psychological factors are another contributor. After a long journey of infertility treatment, many women become pregnant with feelings of anxiety, stress, and fear of miscarriage. Stress can activate the autonomic nervous system, increasing feelings of nausea, loss of appetite, and fatigue. Limited physical activity and prolonged bed rest to maintain the pregnancy also slow down the digestive process, contributing to worsening nausea and bloating.

Dr. Khanh noted that severe morning sickness does not mean an abnormal fetal development. Conversely, many studies have recorded that high hCG levels and noticeable morning sickness can be a sign of good fetal development, with the placenta increasing the secretion of certain hormones like beta-hCG and estrogen into the mother's blood. However, if an expectant mother is sensitive and experiences excessive morning sickness leading to severe, uncontrollable nausea and vomiting, possibly resulting in weight loss, debility, or dehydration, affecting her health and mental state, she should seek medical attention.

To alleviate morning sickness, expectant mothers should divide meals into smaller portions throughout the day, avoid an empty stomach, limit greasy or spicy foods, and drink enough water. Expectant mothers should also get adequate rest, maintain a comfortable mental state, and engage in gentle physical activity such as walking or yoga.

Trinh Mai