Does having sex daily increase the chances of conception in a couple with no known fertility issues compared to having sex every other day?

Daily vs. Every Other Day Intercourse for Conception

For couples with no known fertility issues trying to conceive, having intercourse every day during the fertile window does not meaningfully increase conception chances compared to every other day, and either approach is effective when properly timed around ovulation.

Understanding the Fertile Window

The fertile window is approximately 6 days ending on the day of ovulation, during which conception can occur 1. The probability of conception varies significantly by day:

• 5 days before ovulation: 10% probability 1
• Day of ovulation: 33% probability 1
• After ovulation: essentially 0% probability 1

Sperm can survive approximately 1.4 days on average, with a 5% probability of surviving more than 4.4 days and only 1% probability of surviving more than 6.8 days 2. The ovum survives approximately 0.7 days 2.

Frequency of Intercourse: The Evidence

The critical factor for conception is timing intercourse within the fertile window, not the specific frequency of daily versus every-other-day intercourse 1. Among 192 pregnancies studied, conception occurred only when intercourse took place during the 6-day fertile window ending on ovulation day 1.

Key consideration: Only about 6% of pregnancies could be attributed to sperm that were 3 or more days old 1. This suggests that while sperm can survive several days, fresher sperm may be more effective—but this does not necessarily mandate daily intercourse, as every-other-day timing still ensures sperm presence throughout the fertile window.

The Challenge: Identifying Ovulation

Most women cannot accurately predict their ovulation day 3. In a study of 102 women who became pregnant:

• Only 12.7% correctly estimated their ovulation day 3
• The median difference was +2 days (range -10 to +27 days) 3
• Only 55% of estimated ovulation days fell within the actual fertile window 3
• Only 27% fell on days of peak fertility 3

Practical Recommendations

For Couples Without Fertility Issues:

Use ovulation prediction methods rather than relying on calendar calculations alone:

• Urinary ovulation tests probably increase live birth rates (RR 1.36,95% CI 1.02-1.81) compared to intercourse without ovulation prediction 4
• If the baseline chance of live birth is 16% without ovulation prediction, using urine tests increases it to 16-28% 4
• Urinary ovulation tests also probably increase pregnancy rates (RR 1.28,95% CI 1.09-1.50) 4

Intercourse Frequency Strategy:

Either daily or every-other-day intercourse during the fertile window is effective, provided you:

1. Accurately identify the fertile window using urinary LH tests 4
2. Begin intercourse 5 days before expected ovulation and continue through ovulation day 1
3. Understand that conception probability peaks on ovulation day itself (33%) 1

Important Caveats:

• Fertility awareness-based methods alone (basal body temperature, cervical mucus, calendar tracking) have insufficient evidence to demonstrate benefit over no ovulation prediction 4
• The evidence is uncertain regarding whether timed intercourse using fertility awareness methods affects stress, anxiety, or depression 4
• Cycles with sexual intercourse (regardless of timing) show characteristics suggesting higher fecundability, including longer luteal phases and less premenstrual spotting 5

Bottom Line

Focus on timing, not frequency: Ensuring intercourse occurs during the 6-day fertile window is far more important than whether you have sex daily versus every other day 1. Use urinary ovulation prediction kits to identify this window 4, as most women cannot accurately estimate ovulation without assistance 3. Both daily and every-other-day intercourse during this window provide adequate sperm presence for conception 2, 1.