A research team based at the University of Copenhagen explored the incidence of miscarriage in Denmark to see if there might be ways to prevent them. Their findings suggest certain lifestyle changes could prevent a substantial number of miscarriages that occur before week 22 of pregnancy. They also identified risk factors that were the most likely to cause miscarriage. Their work was recently published in the International Journal of Obstetrics and Gynaecology.

“The main message from the paper is that miscarriages are a subject for prevention,” says Anne-Marie Nybo Andersen, the lead researcher for the study. Prevention is most likely to occur when all risk factors are eliminated.

Nyobo Andersen’s team of researchers started with 91,427 pregnancies documented in the Danish National Birth Cohort for the period of 1996 to 2002. Of this number, 88,373 matched all the research criteria and were used in the study. Telephone interviews supplemented the registry data. The miscarriage rate among this study group was 3.5%.

The researchers divided the risk factors into pre-pregnancy and during pregnancy risk factors.

Pre-Pregnancy Risk Factors

  • Age — 30 years or older
  • Underweight
  • Obesity

During-Pregnancy Risk Factors

  • Alcohol consumption
  • Lifting more than 44 pounds (20 kilograms) daily
  • Night work

Other findings include:

  • If all pre-pregnancy risk factors were eliminated, the study indicates there would be 14.7% fewer miscarriages in Denmark.
  • If all during-pregnancy risk factors were also eliminated, the incidence of miscarriage would be reduced by 12.5%.
  • The risk of miscarriage was found to be highest for women in their mid-30s and older who also drink alcohol and work night shifts.

In addition to the message that prevention is possible, Nyobo Andersen says her study’s findings offer important confirmation to women and their partners that lifestyle choices do matter. The findings could also be useful in adjusting national maternity policy, workforce regulation, and in academia for pregnant students. Nyobo Andersen says, “Everybody, young men and women, as well as those who have political responsibilities should bear in mind that postponing pregnancy to the mid-30s implies a seriously increased risk of miscarriage.”

The modifiable risk factors under evaluation in the University of Copenhagen study did not include all lifestyle behaviors that promote a healthy pregnancy. For optimum health during pregnancy, women of all ages are urged to maintain a healthy body weight, eat a nutritious balanced diet, exercise regularly, and refrain from smoking or exposure to secondhand smoke at home, work, and elsewhere.

Source: Nyobo Andersen, Anne-Marie, et al. “Risk factors for miscarriage from a prevention perspective: a nationwide follow-up study (abstract).” BJOG: An International Journal of Obstetrics and Gynaecology. John Wiley & Sons, Inc. Feb 19, 2014. Web. Mar 1, 2014.