Hyperemesis Gravidarum

Severe Morning Sickness

Pregnant women with morning sickness, nausea
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When you think of pregnancy symptoms, one of the most common thoughts will be of morning sickness. However, about 1 in 300 pregnant women every year will experience and extreme form of this called Hyperemesis Gravidarum, which by definition is the loss of at least 5% of the total body weight. Many of these women are admitted to the hospital for treatment, and it's unclear how many are not reported and treated as outpatients.

A recent study suggests that if women have sickness severe enough to be hospitalized, such as a case of hyperemesis, then she is more likely to have a girl than a boy. 56% of mothers who were hospitalized in early pregnancy had girls, compared to the 44% who had boys. Hospitalization in the later stages of pregnancy did not show this correlation.

You might be wondering how it's determined if your nausea falls into this category. Generally when women experience hyperemesis gravidarum you will see a weight loss of 5% or greater, intractable vomiting, disturbed nutrition, retinal hemorrhage, and potentially renal and liver damage.

Other than the vomiting and nausea the mother might also experience very sensitive olfactory sensations, bad taste in the mouth, shivering, difficulty reading (from dehydration and changes to the eye), and delayed gastric emptying. Other complications are rare, however it has been noted that there is an increased incidence of gall bladder problems during and after pregnancy.

Treatment can include the following:

When medications are discussed there are several that can be used.

Sometimes simple antihistamines are used. Vitamin B6 has also shown great benefit to women suffering from hyperemesis. There are also herbal and other preparations that have been tried with varying success, like powdered ginger.

The decision to use medication can be a difficult one, and it is not a decision that should be made lightly. However, when the potential benefits of the medication outweigh the potential risks of the medication to the mother or the baby, as in some cases of hyperemesis that haven't responded to other treatments, medication may be the appropriate treatment.


Obstetrics: Normal and Problem Pregnancies. Gabbe, S, Niebyl, J, Simpson, JL. Fifth Edition.

The cause of this is not known exactly, but it's believed to be related to the hormones of pregnancy.

  • Human Chorionic Gonadotropin (hCG): This is usually blamed because the rise in hCG often parallel the onset of the hyperemesis
  • Progesterone: This hormone relaxes smooth muscle, which can delay or halt peristalsis.
  • Estrogen: Since this can increase your olfactory sensitivity it has been reported to possibly increase nausea and vomiting.
  • Cortisol: This rises, but is it due to the stress or the hyperemesis?
  • Prostaglandins: This may suppress cortisol and progesterone maternally, and influence the pattern of hyperemesis.

    Thankfully most cases will subside by about 17 weeks gestation, although at 35 weeks approximately 5% of the population is still reporting problems. One Australian study showed that 20% of women still experienced problems at term.

    Generally these babies do not suffer ill effects. Although it is difficult to separate the effects of the hyperemesis and the decreased weight gain and electrolyte imbalance. There is cause for concern when certain medications are used to control the vomiting. Therefore ensure that your practitioner is current with the literature and treatments for hyperemesis. Preterm labor and low birth weight are the two major concerns with babies born to mothers with hyperemesis.

    It used to be believed that this was purely mental and that the mother was trying to reject the pregnancy for whatever reason. Science has now shown us that there is much more to hyperemesis than a mental state. Women who experience this suffer not only physically but mentally. The stress and strain of being ill and potentially hospitalized have numerous mental and physical effects on a woman. This is particularly true because women probably have the belief that pregnancy will be a joyous time in their lives. Support from the other areas of their lives is vital to the treatment of hyperemesis.

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