Hyperemesis gravidarum

Nausea and vomiting are common during pregnancy and are due to a rapid increase in estrogen and beta-subunit human chorionic gonadotropin (beta-hCG) levels. Generally speaking, they appear during the 5th gestational week until they reach their peak at the 9th week and disappear between the 16th and 18th week.

Hyperemesis risk factors to take into account are:

• History of hyperemesis gravidarum in previous pregnancies.
• Nulliparity (no previous children).
• Obesity.
• Multiple pregnancy
• Molar pregnancy (a complication of some pregnancies that produces increased b-hCG).

Hyperemesis gravidarum is a rare disorder characterized by persistent, frequent (every day and several times a day) and severe nausea and vomiting that prevent the pregnant woman from eating properly. As a consequence, there is a significant weight loss (more than 5% of the initial weight), dehydration and metabolic alterations. Women with hyperemesis gravidarum do not consume enough food to provide energy to the body. Therefore, fats are used to generate energy, resulting in an accumulation of waste products (ketones) called ketosis. This can cause fatigue, bad breath and dizziness.

Dehydration from severe hyperemesis leads to increased heart rate (tachycardia) and, rarely, abnormal heart rhythms (arrhythmias).

In case of suspicion, it is important to perform a blood test and urine sediment to determine whether there is dehydration and to check for electrolyte disturbances. In addition, an obstetric ultrasound should be performed to check the condition of the fetus and to assess whether it is a multiple pregnancy or a molar pregnancy. 

The treatment of hyperemesis gravidarum depends on the severity of the symptoms. Initially, it may be treated with drugs to reduce nausea and vomiting. In some cases, hospital admission may be necessary to administer intravenous fluids and electrolytes.