Researchers Say Up to 25 Percent of Miscarriages Preventable

Having a miscarriage is one of the most traumatic events that can happen in a woman's life, and it's surprisingly common. New research by scientists in Demark suggests that about a quarter of miscarriages might be prevented by lifestyle changes. Their data was published in BJOG: International Journal of Obstetrics and Gynaecology on Wednesday.

More on Yahoo: BPA Exposure Linked to Higher Rate of Miscarriage

About 50 percent of fertilized eggs spontaneously abort-often before a woman is aware she is pregnant, usually because of chromosomal abnormalities but also from exposure to toxic agents, maternal health disorders, and illegal drug use, and other factors. In the United States, the miscarriage rate for women who know they are pregnant is between 15 and 20 percent. Researchers in Denmark wanted to determine the preventable risks of miscarriage and find out what percentage were caused by these factors.

More on Yahoo: Catholic School Teacher Fired Over Pregnancy

The research team looked at data from approximately 90,000 pregnancies that occurred between 1996 and 2002 and were tracked by a national registry. They focused on modifiable risk factors including exercise, alcohol consumption, smoking, drinking coffee, work schedule, regular heavy lifting, maternal age, and pre-pregnancy weight.

They found that that the key pre-pregnancy factors associated with lowering miscarriage risk were being a healthy weight-neither obese nor underweight-and being under 30 years old. Women who had a healthy BMI and were between 25 and 29 years old at the time of conception had a lowered risk of miscarriage by more than 14 percent. According to the data, the highest risk factors during pregnancy were alcohol consumption, lifting more than 40 pounds on a daily basis (by working as a care giver or nurse for instance), and working at night.

They reported that the overall highest risk factors associated with miscarriage were drinking alcohol during pregnancy and maternal age.

Over the last year, there has been some debate over the risk of moderate drinking during pregnancy triggered by studies on early pregnancy and alcohol consumption well as the controversial book Expecting Better by economist Emily Oster which challenged the status quo on alcohol, sushi, and coffee among other pregnancy taboos. This new study supports the continued stance of the American Congress of Obstetrics and Gynecology and the U.K Royal College of Obstetricians and Gynaecologists that avoiding all alcohol is the safest approach.

Spotlighting maternal age is also sure to spark controversy, since birth rates for women over 30 are at their highest levels since the 1960s. However, other studies confirm that the risk of miscarriage does increase with age. According to the American Pregnancy Association, women between the ages of 35 and 45 have a 25 percent of miscarriage and women over 45 have up to a 50 percent chance. "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," said Anne-Marie Nybo Andersen, senior researcher at the University of Copenhagen, in a release. The researchers also acknowledged that some factors such when you have a baby may be difficult to modify, but that they believe it is important to provide information about the "increased chances of having a successful pregnancy at a relatively young age."

Some critics of the study are pointing out that risk is not the same as cause and urge a degree of caution when it comes to interpreting the results. According to Patrick Wolfe, a professor of statistics at University College London, "The study does not establish a causal relationship between its reported risk factors and miscarriage." He added that it shouldn't be seen as "the last word" on an important and sensitive issue. "The main message from the paper," researcher Andersen clarified in a release, "is that miscarriages are a subject for prevention." Women who are planning to conceive should speak to their doctor about how to maintain a healthy lifestyle that will support their pregnancy.

Also on Shine:

Can Foods Increase Your Fertility

Pregnancy Time-Lapse Video: A Walk Through 7 States

What You Should Know About Pregnancy After 40