BD stands for “baby dance,” which is a euphemism for sexual intercourse used in online fertility and pregnancy communities. You’ll see it most often in forums, apps, and social media groups where people are trying to conceive (TTC). Someone might post “We BD’d on days 10, 12, and 14” to mean they had intercourse on those cycle days.
Why People Say “Baby Dance”
The term became popular on fertility forums partly because many platforms historically flagged or filtered more direct language about sex. It also gives people a lighthearted way to discuss something that can feel clinical and stressful when conception is the goal. You’ll find BD listed alongside dozens of other shorthand terms on sites like RESOLVE, the National Infertility Association, which maintains a glossary of common fertility acronyms.
Other abbreviations you’ll frequently see alongside BD include TTC (trying to conceive), DPO (days past ovulation), BFP (big fat positive, meaning a positive pregnancy test), BFN (big fat negative), and EWCM (egg white cervical mucus, a sign of fertility). Once you recognize a handful of these, fertility forums become much easier to follow.
When BD Timing Matters Most
The reason timing comes up so often in these communities is that conception is only possible during a narrow window each cycle. A landmark study published in the New England Journal of Medicine found that pregnancy occurred only when intercourse happened during a six-day period ending on the day of ovulation. The highest probability of conception, about 33%, came from intercourse on ovulation day itself. Five days before ovulation, the odds dropped to around 10%.
This is why you’ll see people in TTC groups obsessively tracking ovulation signs and planning when to BD. They’re trying to land intercourse within that six-day window, ideally in the final two or three days before ovulation or on ovulation day.
Using ovulation prediction kits to time intercourse does appear to help. A Cochrane review covering more than 2,000 participants found that couples who used urinary ovulation tests had pregnancy rates roughly 28% higher than those who didn’t track ovulation at all. For live births specifically, the improvement was even more notable: if the baseline chance of a live birth without tracking was 16%, using ovulation tests pushed that to somewhere between 16% and 28%.
How Often to BD During the Fertile Window
A common worry is whether having sex too frequently will “use up” sperm or lower sperm quality. The American Society for Reproductive Medicine reviewed this question and found that even daily ejaculation doesn’t reduce sperm counts or motility in men with normal semen quality. In fact, for men with lower-than-normal sperm counts, daily ejaculation was associated with the highest sperm concentration and motility.
On the flip side, going more than five days without ejaculation can actually hurt sperm counts. So the old advice to “save up” before the fertile window is counterproductive. Having sex every one to two days during the fertile window is a reasonable approach for most couples.
Lubricants Can Affect Sperm
One practical detail that rarely comes up outside fertility communities: standard lubricants can damage sperm. Most water-based lubricants contain glycerin, which penetrates sperm membranes and dissolves the tail structure that sperm need to swim. Research has shown that common brands like KY Jelly and Durex lubricants significantly reduce both sperm motility and survival, with Durex performing the worst in lab studies.
If you use lubricant while trying to conceive, look for products specifically labeled as sperm-friendly or fertility-compatible. Pre-Seed, which is glycerin-free, consistently shows the least negative effect on sperm in laboratory testing. Among non-specialty options, oil-based lubricants like petroleum jelly performed better than water-based alternatives, though they come with their own drawbacks like condom incompatibility.
When BD Becomes Stressful
Turning sex into a scheduled, goal-oriented activity takes a toll on many couples. The pressure to hit the right days can make intimacy feel mechanical, and months of negative tests compound that stress. Interestingly, research on whether timed intercourse increases measurable stress levels has been inconclusive. One trial found no significant difference in stress scores between couples using ovulation kits and those who weren’t timing intercourse at all.
That said, the lack of a measurable stress difference in a clinical trial doesn’t mean it feels easy. Many people in TTC communities openly discuss the emotional weight of “performing on schedule.” Some couples find it helpful to maintain intimacy outside the fertile window so that sex doesn’t become exclusively associated with conception attempts. Others prefer to track ovulation quietly and keep the timing flexible rather than announcing “tonight’s the night” to a partner.