Hyperemesis gravidarum is the severest form of nausea and vomiting (morning sickness) during pregnancy with incident rate of 4 per 1000 pregnancies. The persistence of nausea and vomiting causes dehydration, weight loss and keto-acidosis and in turn disrupt the serum electrolyte balance.
Therefore, Hyperemesis gravidarum is a rare complication of pregnancy and it is also called pernicious vomiting of pregnancy
Signs and symptoms of hyperemesis gravidarum
- Frequent vomiting
- Weight loss
- Postural hypotension
- Electrolyte imbalance
Causes of hyperemesis gravidarum
The actual cause of hyperemesis gravidarum is unknown but it is believed to be associated with:
- Hydatidiform mole
- Multiple pregnancy
- Previous history of unsuccessful pregnancies
It is to be noted that some women who experience this condition are likely to have a recurrence in subsequent pregnancies.
How to assess woman’s condition with hyperemesis gravidarum
- Reassure and ask the woman whether normal diet has been resumed and tolerated.
- Identify any events causing stress or anxiety because these may exacerbate any vomiting.
- Ascertain whether the nausea and vomiting are accompanied by pain; the location of any pain should be elicited.
- Check the dryness or inelasticity of her skin
- Assess the maternal weight because the mother’s weight will be less than expected for gestation.
- The pulse rate will be weak and rapid and the blood pressure will be low.
- The urine will smell of acetone, be scant and dark in colour\
- It is usual for a mother suffering from hyper emesis gravidarum to be admitted to hospital.
- Monitor the woman’s blood pressure, pulse rate and temperature at least 4-hourly.
- Measure the intake and output of fluids, including vomitus
Differential diagnosis for hyperemesis gravidarum
Proper clinical investigations must be carried out in order to rule out other conditions such as urinary tract infections (UTIs), disorders of gastrointestinal tract (GIT), or molar pregnancy because they are often associated with severe vomiting.
How to treat hyperemesis gravidarum
- Admit the woman in hospital to stabilize her and prevent further complications
- Calm and reassure her as to allay her anxiety. Pay attention to her physical needs.
- Educate her on her health condition and involve her in decision-making regarding provision of care.
- Administer intravenous infusions to rehydrate the woman and correct the electrolyte imbalance. The potassium and sodium levels will be corrected by intravenous therapy (Ringer’s lactate, or Normal saline). The infusion should be continued until hydration and electrolyte return to normal.
- Vitamin B12 (Cobalamin), vitamin B6 (Pyridoxine), and vitamin C (Ascorbic acid), folic acid and iron are prescribed to correct the anaemia.
- Give antiemetics to control the vomiting. Antiemetics safe in pregnancy include: Promethazine (Avomin), Doxylamine succinate, Prochlorperazine (compazine), Metoclopramide (Plasil or Reglan), Trimethobenzamide (Tigan), Ondansetron (Zofran), and sometimes corticosteroids such as prednisolone can be used. This is because corticosteriods have been found to be effective in treating women with hyperemesis gravidarum during first trimester of pregnancy by reducing the frequency of continuous vomiting and high-frequency vomiting.
- Once vomiting has stopped for a period of 24 hours, oral fluid may be commenced and if it is tolerated, a light diet may follow. Normal food is gradually introduced and intravenous therapy discontinued.
Complications of hyperemesis gravidarum/ pernicious vomiting of pregnancy
- If hyperemesis gravidarum is not properly managed, continual vomiting during pregnancy will cause vitamin depletions, hyponatremia, and high risk of the fetus being small for gestational age because of nutrient depletions.
- Women who are immobilized by the severity of vomiting are also at high risk of developing deep vein thrombosis due to combined effects of dehydration and immobility.
- The depleted vitamins and electrolytes can cause confusion and seizures which could subsequently lead to respiratory arrest if not properly treated.