Women trying to get pregnant should avoid drinking even moderately in the two weeks before their period starts, according to a new study out of the US.
The study, published on Wednesday in leading reproductive health journal Human Reproduction, investigated the link between alcohol intake and the probability of conceiving during a menstrual cycle.
Examining more than 400 women aged between 19 and 41, researchers found that drinking more than six drinks a week during any phase of the menstrual cycle was linked with a reduced probability of conception.
However drinking as little as three to six drinks a week during the last two weeks of the menstrual cycle was also linked with a reduced chance of conception.
"If we assume that a typical, healthy, non-drinking woman in the general population who is trying to conceive has approximately a 25 percent chance of conceiving during one menstrual cycle, then out of 100 women approximately 25 non-drinkers would conceive in a particular cycle, about 20 moderate drinkers would conceive and only about 11 heavy drinkers would conceive," explained lead researcher Dr Kira Taylor from the University of Louisville School of Public Health and Information Sciences.
"But the effect of moderate drinking during the luteal phase is more pronounced and only about 16 moderate drinkers would conceive."
Heavy drinking during the ovulatory part of the cycle was also associated with a significant 61 percent reduced odds of becoming pregnant. However, the researchers stress these are all estimates and should be treated with caution.
Heavy drinking was defined as more than six alcoholic drinks a week, moderate drinking was three to six drinks a week, and binge drinking was defined as four or more drinks on a single day.