(KXAN) — Research from Texas A&M University is expanding our understanding of how a man's alcohol consumption before conception can affect the developing fetus. Researchers already found that the father's drinking can cause birth defects associated with fetal alcohol syndrome (FAS). FAS is a condition in a child resulting from alcohol exposure while the mother is pregnant. Severity of symptoms can vary, but common physical symptoms include distinctive facial features like a flatter nose and small eyes. More serious physical effects can include a higher risk for cardiovascular and liver diseases. FAS can also cause intellectual disabilities and struggles with social skills. Texas A&M researcher finds link between father’s drinking and alcohol-related birth defects Now, researchers say the effects from alcohol can linger in a man's sperm for longer than one month, as previously believed. "What we need to do here is focus on both parents, and so we would recommend that males stop drinking three months before conception, and that women not drink at all during pregnancy," Golding said. Currently, an FAS diagnosis requires evidence that only the mother drank alcohol during pregnancy. Both parents drinking can worsen the effects. "So if you have either parent drinking individually, this is going to create a problem, say, to this level, but if both parents are drinking, it really raises the penetrance and the impact of the alcohol exposure on the developing baby," said Dr. Mike Golding, professor of physiology at the College of Veterinary Medicine at Texas A&M University. Even without the risk of FAS, Golding said pregnancy success rates with in-vitro fertilization are lower when the sperm comes from a father who drinks. "Male drinking has an absolute negative impact on pregnancy success rates, and then even staying pregnant," Golding said. While he said it's unclear if more frequent alcohol exposure is more likely to produce a child with FAS, Golding recommends staying away from alcohol when trying to conceive.