Couples trying to have an IVF baby could be damaging their chances if they drink just a bottle of wine between them each week.
That's the finding from a new study which shows that six units of alcohol a week for both partners cuts the chance of a live birth by a quarter.
I don't want to come across like an alcoholic here but that's not very much booze at all. It hardly seems worth it.
Indeed, doctors are now saying couples may be best off "playing it safe" and not drinking at all if they want to give themselves the best chance of conceiving through IVF.
And it's not just women who should lay off the drink - men should give it a rest too, according to the research.
The US study, which was presented at a fertility conference in Atlanta, looked at more than 2,500 couples.
Men and women who had the equivalent of two strong pints of beer or two large glasses of wine a week, or more, "significantly reduced their likelihood of pregnancy".
It cut women's chances of getting pregnant by 18.
Predictably, the odds get worse the more you drink.
Women who had between one and nine units of white wine a week were 24 more likely to fail to implant the IVF embryo.
Men who drank a beer every day reduced their chances of a live birth by 30 more likely to have a failed implantation.
Tony Rutherford, of the British Fertility Society, told the BBC: "This is further evidence to suggest that alcohol does have an impact and that those women who try for a baby should think about their lifestyle choices."
He said eggs and sperm take at least three months to develop in the body so smoking, alcohol and excess weight can affect chances of conception in that period.
"It may be that if you are trying for a baby with IVF and want to maximise your chances of success, you may want to 'play safe' and not drink at all," he said.
The study looked at couples going through IVF but doctors say this advice may also apply to couples trying to conceive naturally.
Did you stop drinking when you were trying for a baby? Do you think it makes a difference?