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The happy news for the British monarchy is that Kate Middleton, the duchess of Cambridge, is with child—a potential heir to the throne. Sadly, the royal isn't having an easy go of her first pregnancy.
Middleton has been diagnosed with hyperemesis gravidarum (HG), which is a dangerous type of morning sickness. HG affects anywhere between 0.2 to 2 percent of all pregnant women in developed countries. The disease is associated with nausea and vomiting so severe that women can suffer from post-traumatic stress disorder as a result.
Scientific American spoke with Marlena Fejzo, a geneticist at the University of California, Los Angeles, David Geffen School of Medicine. Fejzo developed HG during her own pregnancy. Now she hopes to find the genes responsible for the most severe cases of HG. Fejzo explains what is known about this condition and its impact on pregnant women.
[An edited transcript of the interview follows.]
What is morning sickness?
General morning sickness is just a feeling of nausea and some vomiting in the first trimester of pregnancy. ("Morning") is a misnomer; there can be nausea and vomiting at any time of the day and even during the night.
How common is it?
Well, at least 70 percent of women have some sort of nausea and vomiting in the first trimester. It's a spectrum, so it can range from just feelings of nausea where you don't feel like eating something all the way to the extreme end of the spectrum, which is hyperemesis gravidarum.
What is hyperemesis gravidarum?
Hyperemesis is defined as nausea and vomiting that's persistent and prolonged and associated with a more than 5 percent weight loss. That's inability to perform your regular, daily routine due to nausea and vomiting.
There can be fainting. We have women who are vomiting so hard that they get rib fractures or their retina detaches. They can blow out their eardrums. They can get esophageal tears. We have women whose nails have fallen off due to malnutrition.
You can get Wernicke's encephalopathy, which is a thiamine deficiency that leads to a neurological disorder. It's generally seen in alcoholics because when you drink a lot you also have a problem with your brain absorbing thiamine. You get this inability to walk straight and mental confusion, and it can also end up in death of the baby and the mother.
How many people get this disease?
It's generally quoted between 0.2 and 2 percent of women. That could be an underestimate because it's often not diagnosed. Worldwide, I've seen it go all the way to 10 percent. There's (an academic) paper in Shanghai, China, that says 10 percent of women are hospitalized for HG.
How long does HG generally last?
Twenty-two percent of women have HG lasting through term. And most of them resolve around 20 weeks.
What are the consequences for the child? How dangerous is this?
Babies born from HG pregnancies are more likely to be low birth weight, small for gestational age and born prematurely.
Mothers who had severe nausea were more likely to have children with attention problems. Babies exposed to severe nausea in utero tend to have lower task persistence and attention problems. We found that adults who were exposed to HG in utero are more likely to have emotional and behavioral disorders—a 3.6-fold increased risk.
What causes HG? Why does it affect some so profoundly, but not others?
We are trying to find the cause of HG; we found that the number-one risk factor besides having a previous pregnancy (with HG) is having a sibling with HG. We know that there is likely to be a genetic component, and we're trying to find the predisposing genes. Once we find that, hopefully we can find the cause. It's likely to be something involved in hormone metabolism, but that's just speculation at this point.
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19 Comments
Add CommentHow is this condition treated?
Reply | Report Abuse | Link to thisI had this and was prescribed Zofran. It was the only way I could function. It took away the extreme nausea. It was horrible. I could not get up without the medication.
Reply | Report Abuse | Link to thisI'm so sorry. My husband took that medicine when he had throat cancer. It is an awfully expensive med, for one thing!
Reply | Report Abuse | Link to thisI suppose that the Duchess of Cambridge can afford it, but I am surely sorry to hear that she is so unwell. It will probably pass soon. I hope so, anyway.
I am sure she will be fine. Come someday in June, Hubby will hear those immortal words, 'You, did this to me.' And child and mother will be fine.
Reply | Report Abuse | Link to thisJune? I heard those words in the first trimester.
Reply | Report Abuse | Link to thisMethodic doubts: As SciAm usually doesn't pay attention to pregnancies, funerals, and sentimental journeys of people in the class that keep tabloids and pink press workers and entrepreneurs alive and well, and SciAm is doing this with the so called "British princes", I'd like knowing: a) If the USA is or is not a Republic. b) If the USA broke apart with the Britons in the last part of the 18th Century. c) If there's a reason that can be confessed for the policy many seem having, of introducing the British "royalty" as the most "royal", most "cute", most "in", most "legitimate" and most "respectable" among the many countries that believe their political system is a "monarchy". Salut +
Reply | Report Abuse | Link to thisOne fact (or hypothesis) about HG (and morning sickness generally) is that the hormone levels of pregnant woman spike to 100 to 1000 times normal (estrogen and progesterone). It is said, this is sudden and massive change in hormones is the precipitating cause.
Reply | Report Abuse | Link to thisIf you don't have anything to say, say nothing.
Reply | Report Abuse | Link to thisHopefully, this will mean we will never be hearing from you again.
Good luck with that. Some people just love to complain.
Reply | Report Abuse | Link to thisAre our lives really so dull and flat and empty that we need these Royal British Cinderella stories to make our lives worth living? How sad! I, for one, couldn't care less about the Duchess'pregnancy,her morning sickness or her wardrobe.
Reply | Report Abuse | Link to thisHowever, if some highly regarded and well credentialed scientist can prove that the pregnancy was the result of Imaculate Conception, I'll join middle America in looking forward to and welcoming the New Messiah!
Are our lives really so dull and flat and empty that we need these Royal British Cinderella stories to make our lives worth living? How sad! I, for one, couldn't care less about the Duchess'pregnancy,her morning sickness or her wardrobe.
Reply | Report Abuse | Link to thisHowever, if some highly regarded and well credentialed scientist can prove that the pregnancy was the result of Imaculate Conception, I'll join middle America in looking forward to and welcoming the New Messiah!
Hello All: there is an evolutionary basis for many things that we interpret as abnormal...but they actually served a purpose millions of years ago, and some still until today: (1) hyperbilirubinemia, an incidence of 40-50% in neonates, occurs frequently and bilirubin is an anti-inflammatory product--useful to the newborn, except when it climbs to dangerous levels; (2) post-partum depression's evolutionary basis occured when the mother realised that there would be a new alpha male who would kill her baby---hence she would divorce herself from most of her motherly feeling and suffer the obvious depression from knowing that her baby would be killed; or if the newborn was not robust and the mother felt that it might not survive, she would save whatever resources she had (food, water) for her other offspring who had a better chance of survival and let the sickly one die; (3) lower body fat retention with cellulite (almost always in women) serves to act as a store of energy for whatever famine might approach; fat tissue also contains an abundance of aromatase, and enzyme that converts the adrenal's testosterone into estrogen----adding to her fertility. Sadly, in obese male, the same enzyme produces the same increased proportion of estrogen; (4) hyperemesis was a function of a hyperacute metabolic system that was very selective about what, if any, subtle toxins got into the mother and subsequently the baby. Obviously,this purpose is not as needed today but some women remain with minimally disturbed metabolic pathways that can produce substances that can irritate the chemoreceptor trigger zone (CTZ) in the brain's 4th ventricle (outside the blood-brain-barrier) and initiate the vomiting reflex. Thus, it's Nature's (distorted) way of protecting the mother and baby from any toxin.
Reply | Report Abuse | Link to thisJust for the record - there are a great number of we Brits who are already totally bored by this story. I wish the parents-to-be well but only in the same way as I would any other couple. I deplore the fact that, whether idiot or genius, the child of this pregnancy will eventually become head of state of my country.
Reply | Report Abuse | Link to thisAs a constitutional republican, I hope that long before this child reaches maturity we have replaced the monarchy with a president as head of state, following the Irish model of a "figurehead" president without legislative powers.
Sorry, I missed the fact that some icons are part of feelings close to the religious ones, and there is people that would react to some statements the way some muslims reacted towards Salman Rushdie's "Satanic verses". I not only have things to say, and the right to do it, but want to remind you that the true heirs of the british throne are the descentants, if there are any, of Philip II, King of Spain, who was designated heir by the only true Queen of England. We are aware that Caligula changed his horse into Consul, but truth is the truth. When starting to insult, you must remember that if you send a tennis ball, you may have back a hand grenade. Watch your step, salut +
Reply | Report Abuse | Link to thisLike I said, some people just like to complain. I did not insult, and I was not offensive. Kindly keep your hand grenades to yourself.
Reply | Report Abuse | Link to thisI do understand that people may not want to read about British monarchy, but I hope that all of those complaining about it realize that the essence of this piece was to inform about hyperemesis gravidarum. The fact that involves a member of the British royal family isn't important. The subject of the article could have been anyone "famous" who is suffering from the condition. I'm sure the good people at SciAm are aware that their publication isn't a gossip magazine, but informing the public about a medical condition shouldn't open them up to extreme scrutiny just because a famous person was used to make the article more visible. How many people would have read this piece if Kate Middleton wasn't mentioned?
Research has shown it is the iron which doctors prescribe to pregnant women that causes the mornng sickness.
Reply | Report Abuse | Link to this"The effectiveness of discontinuing iron-containing prenatal multivitamins on reducing the severity of nausea and vomitingof pregnancy."
"Avoiding iron-containing multivitamins is effective in majority".
Do you have some links to these studies? If so, that would be useful information for people.
Reply | Report Abuse | Link to thisPretty much everything I put in 'quotes' , "" , can be simply 'cut and pasted' into a search engine like Google , and voila , up should pop the reference.
Reply | Report Abuse | Link to this"The effectiveness of discontinuing iron-containing prenatal multivitamins on reducing the severity of nausea and vomitingof pregnancy."
http://www.ncbi.nlm.nih.gov/pubmed/19280488
My wife experienced this during her pregnancy. Fortunately it subsided as her pregnancy progressed but it wasn't fun to deal with (and that is just from my perspective, I'm sure it was much more horrible from her side.)
Reply | Report Abuse | Link to thisSad (only a little) but true but this story would not get near the amount of reads is the headline was "Anonymous pregnant women has HG...." Still funny how the mere mention of someone famous gets people ire up for no reason. I guess people need an excuse to troll a little.