What Exactly Is Hyperemesis Gravidarum?

Dutchess of Cambridge, Catherine Middleton was hospitalized during her first pregnancy for a rare form of morning sickness called hyperemesis gravidarum. The illness is serious, with the key symptoms including constant nausea and vomiting, leading to serious dehydration and dangerous weight loss.

She is now pregnant with her third child and is reported to be suffering badly again.

Fortunately for Kate, hyperemesis gravidarum is treatable, thanks to the modern availability of rehydration and nutrition via IV, but there isn't a cure per se. Some women that have suffered the condition have come forward saying that they found some relief using acupuncture. Others have been offered Zofran, a medication sometimes given to patients receiving treatment for cancer, the effects of which have not been tested on fetuses. One doctor even went so far as to offer a woman an abortion if she "couldn't take it anymore." What exactly is this condition, and why is it so difficult to treat?

We reached out to four health professionals to get their take on the condition: Amy Magneson, M.D., F.A.C.O.G., assistant clinical professor at Columbia University; Ellen Chuse, a certified childbirth educator with a practice in Brooklyn, New York; and Barbara Sellers, C.N.M., a midwife practicing in New York City; and Kimber MacGibbon, RN, Director of Education and Research at the Hyperemesis Education and Research (HER) Foundation.

While it is unknown exactly why nausea and vomiting occur in pregnancy (this phenomenon is referred to by health professionals as NVP), it is thought to be connected to the increase of the pregnancy hormone Human Chorionic Gonadotropin, or HCG. "We believe that HCG is the emetogenic culprit in hyperemesis gravidarum," says Dr. Magneson. "The placenta makes it, and a woman who is very susceptible to the emetogenic effect of HCG can end up with hyperemesis." MacGibbon concurs, saying, "Nausea, in general, is still very mysterious in the medical community — there are many pathways that lead to the nausea center in the brain, meaning that a person experiencing acute nausea can have many triggers. That, along with the fact that it is unethical to do medical trials on pregnant women, has prevented us from reaching a full understanding of the condition."

While the condition is reported as extremely rare, affecting only 1 to 2 percent of pregnancies, MacGibbon argues that it is actually much more common and may affect up to 10 percent of pregnancies. "Historically, hyperemesis has not been adequately reported in medical data and records," she says. "We've found that many pregnancy-related hospitalizations that were reported as morning sickness should have actually been reported as HG."

According to Magneson, susceptibility to hyperemesis gravidarum can be predicted a few ways. First, if the mother has experienced HG in previous pregnancies, she will likely experience it in subsequent pregnancies. Secondly, the presence of a large placental mass is associated with HG, as is the case with twin pregnancies (which, according to Magneson, is why there is so much speculation that Duchess Kate is carrying twins). Third, a family history of HG, or the presence of other medical conditions, such as hyperthyroidism, can contribute to the presence of hyperemesis. While the disease had previously been thought of as having a psychological component (historically, women suffering from HG were considered to simply be seeking attention), MacGibbon stresses that HG is a real, physical condition, rather than an emotional one. That said, the condition is so physically taxing that it can take a psychological toll on the mother, so much so that she may consider termination. "In my research, I've found that one-third to one-fourth of HG pregnancies don't make it to term, either due to miscarriage or self-induced termination by the mother," MacGibbon says. "The condition is much more alarming than many people realize."

As with normal morning sickness, these severe symptoms of HG may begin to subside after the 12- or 13-week mark, but in many cases, the symptoms can last for the duration of the pregnancy — which can be traumatic for both mother and fetus.

As Magneson describes, "Hyperemesis is a magnified version of morning sickness, in which [pregnant women's] bodies have trouble distinguishing hunger for nausea. Eating doesn't make the nausea go away...they try to eat small meals, but most of the time, they cannot even keep water down. This causes dehydration and more hunger, creating a vicious cycle. Women with HG can start to lose weight — they are essentially starving." This is scary for a number of reasons, but especially dangerous for women who are already very slim at the time of conception.

Unfortunately, there isn't a one-size-fits-all, proven, fetus-safe cure for HG, there are treatments that can make a difference for many women with the condition. The priority is to make sure that the woman is adequately hydrated and replenished with electrolytes. Only once the mother is re-hydrated and properly nourished can the nausea begin to be treated. According to Chuse, the first treatments a woman might try are peppermint tea and ginger ale, acupuncture, and bed rest, while Sellers has found that simple carbohydrates and white turkey meat can be more likely to be tolerated by the mother.

MacGibbon says that for a woman with HG, none of these methods may make a difference. For these woman, an anti-nausea medication such as Zofran will be key. Some medical professionals are hesitant when it comes to the use of Zofran to treat HG; for instance, Chuse insists that it's important to note that this medication has not been tested to ensure safety for unborn babies. "When prescribing medication for pregnant women, health professionals always have to weigh the risks against the benefits, Chuse says. MacGibbon concurs, saying, "It's never ideal for pregnant women to take any kind of medication, but in the case of severe HG, it may be a matter of life and death." MacGibbon reports that no negative side effects have yet been reported by pregnant women who have used Zofran.

Despite all of the serious risks associated with HG (not to mention the plethora of women coming forward to tell their scary stories), all four health professionals have assured us that HG is treatable. The key is to recognize the symptoms early so that the mother and fetus can be properly treated before the woman gets to the point of malnourishment and dehydration.