Causes of vomiting during pregnancy | Vomiting during pregnancy

Causes of vomiting during pregnancy

The so-called pregnancy vomiting occurs particularly in early pregnancy (1st-3rd month), preferably in the morning hours. The clinical picture “Hyperemesis gravidarum” (which means “very severe vomiting during pregnancy“, see section “When do I have to go to the doctor?”) is to be distinguished from the usual morning sickness, which can be accompanied by indisposition and vomiting.

The causes of vomiting during pregnancy have not yet been sufficiently clarified. There are various theories that can be used to draw connections between nausea and the natural processes in a pregnancy. The most common assumption is that it is due to hormonal changes during early pregnancy.

The main focus is on the hormone hCG (= human chorionic gonadotropin), which has a pregnancy-maintaining function. HCG is produced as early as 24 hours after fertilization and reaches its highest concentration approximately between the 8th and 12th week. After this time, the pregnancy-maintaining hormones are produced by the placenta and at the same time nausea is reduced in the majority of pregnant women. In most women, the nausea decreases after the third month. Nausea may be more pronounced in multiple pregnancies.

Vomiting in the 1st third

Emesis gravidarum, the common pregnancy vomiting from which the majority of all expectant mothers suffer, is often limited to the first third of the pregnancy. Since the concentration of the pregnancy hormone hCG in the blood starts to decrease again at the end of the first trimester (third), the symptoms are also relieved at this time – at least this is the theory, since hCG is directly associated with vomiting. The transition from the normal form to hyperemesis gravidarum is smooth and initially difficult to differentiate.

Vomiting in the 2nd third

If the vomiting does not occur until the second trimester, it is almost certainly hyperemesis gravidarum. According to researchers, this is probably caused by too high a level of hCG and thyroxine, a thyroid hormone. The high level of these hormones in the blood probably causes severe nausea and affects the function of the placenta.

As a result, preeclampsia can develop – a syndrome in which blood pressure rises (hypertension) and increased protein excretion in the urine (proteinuria). Since the syndrome can develop into eclampsia, which is associated with seizures and coma, immediate treatment is urgently needed. Severe vomiting during the second third of the pregnancy can, in the worst case, lead to premature placental detachment, which can endanger the life of the unborn child and the mother.