Your money shot may be a blank. About 15 per cent of couples have trouble conceiving, and at least a third of the time the guy's sperm is at fault, according to the National Institutes of Health.
So get busy: sperm quality peaks in winter and early spring, an Israeli study found, and low-stress weekends offer your best chances of success.
Dr Ashok Agarwal, head of reproductive medicine at Cleveland Clinic, explains how four lifestyle changes can improve your baby-making odds.
Consuming foods rich in the antioxidant lycopene is one solution, Harvard scientists say. (For a quick boost, eat tomato sauce: A quarter cup has 8,500 micrograms.)
In fact, Harvard researchers found that men who worked out the most had a 33 percent higher sperm count than those who exercised the least. That's because gym time helps burn fat while boosting testosterone.
So help them out: put down the smartphone. In a Cleveland Clinic study, men who used their phones more had decreased sperm mobility, perhaps because of these phones' electromagnetic waves.
In fact, some brands can wipe out 72 per cent of your offering in 30 minutes, say researchers in Australia. Save your sperm with a blend designed for procreation.