March 25, 2016
Women seeking to become pregnant might be wise to lay off the caffeine – and encourage their male partners to do the same.
Women are more likely to miscarry if they and their partner drink more than two caffeinated beverages per day in the weeks leading up to conception, according to a study released Thursday by researchers at the National Institutes of Health and Ohio State University.
The study similarly found women who consume more than two caffeinated beverages each day during the first seven weeks of pregnancy also are more likely to miscarry.
The researchers compared lifestyle factors, including caffeine consumption, among 344 pregnant couples from the weeks before they conceived through the seventh week of pregnancy. They used a "hazard ratio" to determine the severity of a lifestyle factor.
Consumption of more than two caffeinated beverages per day resulted in nearly an identical hazard ratio for both females (1.74) and males (1.73). By comparison, the hazard ratio for women over 35 years old was 1.96.
"Our findings also indicate that the male partner matters too," Dr. Buck Louis said in a statement. "Male preconception consumption of caffeinated beverages was just as strongly associated with pregnancy loss as females'."
The study was not designed to prove cause and effect, but simply identified associations.
Earlier studies found caffeine consumption by women during the early pregnancy period increased the risk of miscarriage. But researchers said those studies failed to rule out whether consumption contributed to pregnancy loss or was a sign of an unhealthy pregnancy.
The earlier findings could have resulted from a healthy pregnancy rather than caffeine consumption interfering with a pregnancy, researchers said.