Study details risk in pregnancies

Tags: Pregnancy

Expectant mothers with the same severe morning sickness as the Duchess of Cambridge recently suffered are at more risk of complications if they continue to have it in the second pregnancy trimester, a study suggests.

The study suggests that having the condition in this period can lead to some placental complications - it is most common in the first 12 weeks of pregnancy and often eases off in the middle trimester.

Researchers found that women with the condition in the second trimester had a doubled risk of preterm pre-eclampsia - 0.6% of women without hyperemesis gravidarum suffered from the condition compared with 1.4% of women who did.

They also had a threefold risk of placental abruption - 0.4% compared with 1.1% - and a 39% higher risk of having a small baby.

In addition, a slightly increased risk of pre-eclampsia was discovered in women with hyperemesis gravidarum in the first trimester - those admitted to hospital before they were 12 weeks pregnant.

The study data from 1,155,033 women showed that 1.1% of them suffered from hyperemesis gravidarum before they were 22 weeks pregnant. Data on normal pregnancies was compared with that of women who had hyperemesis gravidarum in the second trimester - women admitted to hospital with the condition between 12 and 21 weeks pregnancy.

In December last year, Kate was admitted to King Edward VII's Hospital in London suffering from the rare illness, which causes severe vomiting in pregnancy.

The study in BJOG: An International Journal of Obstetrics and Gynaecology  examined data from the Swedish Medical Birth Register from 1997 to 2009, with data from 1,155,033 women showing that 1.1% suffered from hyperemesis gravidarum before they were 22 weeks pregnant.

The research found clear links in risk of pre-eclampsia, placental abruption and SGA (small for gestational age babies) birth in women with hyperemesis gravidarum, especially those in the second trimester, said study co-author Marie Bolin, based at Department of Women's and Children's Health at Uppsala University, Sweden.

Copyright Press Association 2013

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