This article originally appeared on VICE US.
It’s well known that people hoping to become pregnant should avoid alcohol, but the bulk of research has focused on how drinking affects the pregnant partner's ability to conceive (like how it can take longer to get pregnant or hurt your chances of having a healthy baby). But a new metanalysis published Thursday in the European Journal of Preventive Cardiology, the first ever to look into the relationship between fertility and paternal drinking, has found that whoever’s providing the sperm should say goodbye to alcohol for about six months leading up to conception.
According to the study, men’s consumption of alcohol was correlated to a greater change that their babes would be born with a birth defect, such as congenital heart disease (CHD), an abnormality in the structure of the heart that’s the main cause of perinatal death and can increase the risk of cardiovascular disease later in life. That risk significantly increased (by about 47 percent) when prospective fathers drink excessively, or consume over 375 grams of alcohol a day.
Those who actually carry the baby to term have long been scrutinized for their lifestyle choices and given a long list of health considerations that could jeopardize their pregnancy, e.g., tweak the medications you take, eat a healthier diet, get enough sleep—and, of course, don't drink. The father’s pre-conception health has historically fallen to the wayside, and, until recently, there’s been little attention paid to its role in a healthy birth. But researchers have made a push to shed light on the fact that the prospective fathers’ health, which is too often overlooked, matters. And the evidence shows their drinking habits, lifestyle choices, and pre-conception health can have just as big of an impact on the fetus’ well-being and development.
The researchers assessed 55 studies, which included 41,747 babies with CHD and 297,587 without, and discovered that the more alcohol the father-to-be reported drinking leading up to conception, the higher the risk of congenital heart disease the fetus had, so much so that having alcohol even within three months before conception was linked to a 44 percent higher risk of CHD. Binge drinking—having five or more drinks in one sitting—was associated with a 52 percent higher chance of birth defects.
CHD is one of the most common types of birth defects, affecting nearly 40,000 births in the U.S. each year. The study’s findings suggest that paternal drinking could very well have something to do with why CHD is so common in newborns.
The exact mechanism of why paternal drinking causes said birth defects is unknown, so we definitely need more research in the area. Considering past evidence, though, it may be because booze changes the shape, size, and motility of otherwise healthy sperm. It could also be because frequent exposure to alcohol literally alters the drinker's DNA, which can create health issues or pathologies that are passed down to offspring.