Kate Middleton, Duchess of Cambridge, and her husband, Prince William, recently announced that she is pregnant with the couple’s third child.
Since the duchess has struggled in the past with hyperemesis gravidarum, which causes severe nausea and vomiting and can sometimes last the entire pregnancy, we asked maternal-fetal medicine expert Dr. Hyagriv Simhan, medical director of Obstetrical Services at Magee-Womens Hospital of UPMC, about the condition.
A. This condition is an extreme manifestation of typical pregnancy nausea, which is commonly called “morning sickness.” Normal nausea starts at the beginning of pregnancy and usually ends at about 13 to 14 weeks. Hyperemesis can last much longer, but most women will feel significantly better by 20 weeks. It is characterized by vomiting, dehydration and, in some instances, malnutrition, electrolyte abnormalities and weight loss.
How common is hyperemesis gravidarum?
A. Hyperemesis complicates about 1 to 3 percent of pregnancies. In contrast, morning sickness affects about one-third of pregnant women and two-thirds of pregnant women will have at least some vomiting. Hyperemesis may run in families and recur from pregnancy to pregnancy.
What causes it?
A. Hyperemesis is thought to occur because of the brain’s response to the pregnancy hormone, hCG. Conditions where the hCG level is very high, such as in twins and triplets, can make hyperemesis more likely. Also, some women are more sensitive to hCG than others. We don’t understand why that may be, but some women experience much more severe nausea and vomiting than others, despite having a comparable hCG level. There tends to be a general perception that the nausea is in a woman’s head. It is not. It is not a minor annoyance. It is debilitating.
How is it treated?
A. Treatment of hyperemesis focuses on therapies to reduce the feeling of nausea, treatment of associated conditions (such as reflux), correction of dehydration and electrolyte abnormalities with oral or IV hydration, and nutritional replacement therapy. To alleviate the nausea, we generally start with behavioral therapy – altering food choices and timing of meals, as well as strategies like acupressure. When necessary, we move on to anti-nausea medications or to other forms of feeding, some of which avoid the stomach.
Does it affect the baby?
A. For a fetus, the only source of nutrition is its mother. And, for the mother and the fetus, nutrition is essential. The good news is that, in most instances, we can treat hyperemesis successfully.