Women who are trying to become pregnant may be careful of their caffeine consumption, as previous studies have shown that it increases the risk of miscarriage. A new study also looked at the caffeine intake of the father in the weeks and months prior to conception and found that mom is at an increased risk for miscarriage if dad drinks coffee.
The study, from the National Institute of Child Health and Human Development, is the first that looked at the man’s caffeine consumption as well as the woman’s. Although dozens of studies over the years have shown the health benefits of caffeine, the new study found that it was not helpful in avoiding miscarriage.
Why caffeine has any effect on miscarriage is unknown. One theory is that it could be related to how caffeine affects eggs and sperm at the genetic level, although this has had no in-depth studies. Regardless of the cause, the researchers concluded that “male preconception consumption of caffeinated beverages was just as strongly associated with pregnancy loss as females.”
“There’s something about drinking caffeinated beverages that is associated with pregnancy loss,” said lead researcher Germaine Buck Louis. “Our findings provide useful information for couples who are planning a pregnancy and who would like to minimize their risk for early pregnancy loss,” she added.
The study found that mothers who consume more than two caffeinated beverages daily during the first 7 weeks of pregnancy are also at higher risk of miscarriage.
The study compared lifestyle factors among 344 pregnant couples from the weeks before conception through the seventh week of pregnancy, using a “hazard ratio” to determine the severity of lifestyle factor that included use of caffeine. They determined that consuming more than two caffeinated drinks per day resulted in a hazard ratio of 1.74 for females and 1.73 for men, nearly identical results, meaning that the miscarriage rates were 74 percent and 73 percent higher, respectively.
The researchers note that the study results identified associations, and not causations.