Their Royal Highnesses the Duchess of Cambridge and her husband, Prince William, the Duke of Cambridge, were forced to announce her pregnancy before the completion of her first trimester this past December, due to her hospitalization for hyperemesis gravidarum, a severe morning sickness. This occurs in three percent of pregnancies, and causes severe nausea and vomiting, often resulting in hospitalization for acute dehydration as it did for the Duchess. A new study published in the British Journal of Obstetrics and Gynaecology has connected this condition to multiple pregnancy complicationsÂ—but only if the symptoms initially strike during the second trimester, which is exceedingly rare. Her Royal Highness had a more typical case, with her illness striking in the first trimester. However, women who experience their first symptoms after their twelfth week are at double the risk for early onset pre-eclampsia, a potentially fatal condition that causes a spike in a pregnant woman's blood pressure and high protein levels in her urine. Early onset pre-eclampsia is a case that occurs before 32 weeks, and is associated with a higher mortality rate than cases occurring after the 32-week mark. As this will ultimately progress to eclampsiaÂ—grand mal seizures and coma during pregnancyÂ—there is no known cure for pre-eclampsia other than evacuation of the fetus. Women who experience onset of hyperemesis in their second trimester are also three times more likely to have a placental abruption, when the placenta separates from the uterine wall, and they are 39 percent more likely to have a baby small for his or her age.
The reason the timing of the Duchess's symptoms is so relevant is because the mechanisms causing hyperemesis are thought to be different at different stages of pregnancy. The condition is caused by elevated levels of the hormone human chorionic gonadotropin (hCG), and this can be caused throughout a pregnancy because a woman is carrying twins, because a woman is carrying a girl, or for unknown reasons. However, if she does not present with symptoms in the first trimester, a sudden spike in hCG in the second trimester can indicate a problem with the placenta's attachment to the uterine wall. Marie Bolin, from the Department of Women's and Children's Health at Uppsala University in Sweden, co-authored the study. She stated, "Our study found clear associations in the risk of pre-eclampsia, placental abruption and small for gestational age birth in women presenting with hyperemesis gravidarum, particularly those presenting in the second trimester. The results indicate that pregnancies with hyperemesis gravidarum in the second trimester demand an increased alertness and supervision during the pregnancy for development of any adverse outcomes associated with abnormal placentation." She added that further research is needed to determine the best course of treatment for high-risk women. John Thorp, the Deputy Editor-in-Chief of the British Journal of Obstetrics, reiterated that the condition is rare and that women presenting with symptoms in their first trimester should not be concerned.
Therefore, it is very fortunate that the Duchess of Cambridge (formerly Kate Middleton) falls into the safer realm of those who suffer from this condition. However, as the dehydration and malnutrition can still be dangerous and symptoms can persist for the duration of a woman's pregnancy, her illness should not be taken lightly. The other silver lining to this is that a public figure can sometimes raise awareness about a rare medical condition and increase understanding toward sufferers as well as enthusiasm for research, which may very well have been the reason for the rush on results of this study. It was conducted on more than one million pregnancies in the Swedish Medical Birth Register between 1997 and 2009, and looked at approximately 12,000 women who were first admitted to the hospital for hyperemesis gravidarum and their risk associations for later placental dysfunction disorders, compared to women who did not experience these symptoms.
Photo: Comrade Foot, Flickr