Miscarriage More Likely In Thin Women
Women who are very underweight before they become pregnant are 72% more likely to miscarry in the first three months of pregnancy.
Those classed as underweight had had a body mass index (BMI) under 18.5. A team from the London School of Hygiene and Tropical Medicine looked at 600 women who had miscarried and 6,000 whose pregnancies continued past 12 weeks. Their study found that eating fruit and vegetables and chocolate every day helped reduce the risk of miscarriage.
An estimated one in five pregnancies in the UK end in miscarriage, affecting around 250,000 women in the UK every year. There are many well-established risk factors, such as increased maternal age, a previous history of miscarriage, and infertility. However the causes of the majority of miscarriages are not fully understood. There are some supposed risk factors like alcohol consumption, smoking and caffeine intake but these remain unconfirmed.
The researchers looked at the diet and lifestyles of adult women. All the miscarriages had taken place since 1995, while the successful pregnancies had occurred since 1980. They took into account year of conception and a history of miscarriage.
It was found that underweight women were 72% more likely to miscarry in the first trimester. But the two-thirds of women who took vitamin supplements during early pregnancy reduced their risk by around 50%. The effect was most pronounced among those taking folic acid or iron and multivitamins containing these. Eating fresh fruit and vegetables daily or on most days was also found to halve the odds of miscarriage. Eating chocolate every day, as half the women did, also appeared to lower the risk.
Single women were at an increased risk of miscarriage and there was a 60% higher risk in women who had had a previous abortion and a 40% higher risk in those who had had IVF. "Planned" pregnancies had 40% reduced odds of miscarriage.
Those who took more than a year to conceive were twice as likely to miscarry as those who had conceived within three months. Women who suffered from nausea and sickness in the first 12 weeks were almost 70% less likely to miscarry, and the more severe the sickness, the better the odds of the pregnancy continuing.
The researchers, led by Noreen Maconochie, a senior lecturer in epidemiology and medical statistics, said:
"It is likely that advice to encourage a healthy diet and to try and reduce stress and promote emotional well-being might help women in early pregnancy, or those planning a pregnancy, reduce their risk of miscarriage."
The Miscarriage Association added:
"We speak to thousands of women who are desperate to find out why they miscarried and what they can do to prevent it happening again. While we still don't have all the answers, these findings are going to help women who want to reduce their risk of losing a baby in pregnancy."
The latest work is published in the British Journal of Obstetrics and Gynaecology.