Although you are trying for a baby, sometimes it’s best to not have sex; at least abstain for a few days before trying again. The rationale: sperm is continuously made fresh however daily ejaculation results in samples with lower amounts of sperm in each. This could make the results of the analysis look abnormal even though you are making enough sperm.
Waiting too long is not great though. Longer than 5-6 days abstinence for most men results in the number of living sperm to seem low. Why is that? Because sperm are not only being made but they also die in the ejaculate. The semen analysis measures the percentage of sperm that are living and moving and so if more are dead than alive, the sample looks bad.
Is this why my doctor said have sex every 2-3 days? In part, but the whole answer is found in the numbers. A typical “normal” number of sperm in one ejaculation is more than 48 million (ASRM). When a guy ejaculates into a woman’s vagina, many of the sperm travel through her cervix into her uterus and then down her tubes. Ejaculated sperm can live in the woman’s tubes for 2-3 days.
This means you don’t need to replenish the sperm supply every day in order to have enough around to fertilize the egg. For many couples, having sex everyday while struggling with infertility is just one more major stressor to add to the list. Keeping it casual can restore some of your sanity without lowering your odds of success, if you have a normal sperm count.
Does this mean we shouldn’t have sex every day? Not exactly, but it depends on who you ask. A small study looked at the quality of sperm rather than the quantity in samples taken daily compared to samples produced every other day. It seems that although the amount of living sperm drops with daily ejaculation, the quality of the sperm in those samples seems to be better, suggesting having sex daily is OK. This is debated so take your doctor’s advice as the final word. The take-home message is don’t over think it and just have sex.