From the Guidelines
To maximize conception chances after detecting a luteinizing hormone (LH) surge, you should have sex 1 day after the LH surge is detected, as this timing is supported by the most recent and highest quality evidence. The LH surge typically occurs about 24-36 hours before ovulation, and having intercourse during this window places sperm in the reproductive tract when the egg is released 1. Since sperm can survive for up to 5 days in the female reproductive tract while an egg is only viable for about 24 hours after ovulation, timing intercourse just before ovulation optimizes your chances of conception.
Key Considerations
- The timing of insemination is one of the most important factors influencing the outcome of IUI, and LH testing is the most applied method for timing in natural cycles 1.
- In IUI in natural cycles, IUI should be performed 1 day after LH rise, as stated in the draft recommendations 1.
- Having sex every 1-2 days throughout the fertile window, which typically spans the 5 days before ovulation and the day of ovulation itself, ensures sperm are present when the egg is released.
- Some couples find that having sex every other day during the fertile window helps maintain optimal sperm quality while still providing sufficient opportunities for conception.
Evidence-Based Guidance
The evidence from the study published in Human Reproduction Update in 2018 1 supports the recommendation to have sex 1 day after the LH surge is detected. This study provides the most recent and highest quality evidence on the topic, and its findings should be prioritized when making decisions about timing intercourse to maximize conception chances.
Clinical Implications
In clinical practice, having sex 1 day after the LH surge is detected can be a simple and effective way to maximize conception chances, as it takes into account the timing of ovulation and the survival of sperm in the female reproductive tract. By following this recommendation, couples can optimize their chances of conception and reduce the stress associated with trying to time intercourse perfectly.
From the Research
Timing of Intercourse after LH Surge
To maximize conception chances, the timing of intercourse after detecting a luteinizing hormone (LH) surge is crucial. The studies suggest the following:
- Ovulation typically occurs 28-36 hours after the beginning of the LH rise or 8-20 hours after the LH peak 2.
- Most ovulations occur between 16 and 28 hours after the positive LH test is observed 3.
- Intrauterine insemination (IUI) performed 1 day after the spontaneous LH rise results in significantly higher clinical pregnancy rates compared to IUI performed 2 days after the LH rise 4.
- Delaying IUI to 38-40 hours after human chorionic gonadotropin (hCG) injection also results in improved pregnancy rates 5.
Optimal Timing for Intercourse
Based on the studies, the optimal timing for intercourse after detecting an LH surge appears to be:
- Within 24 hours after the LH surge, as this allows for the highest chances of conception 3, 4.
- Between 16 and 28 hours after the positive LH test, as this is when most ovulations occur 3.
- Around 27 hours (±2 hours) after detection of the LH rise, as this is when IUI is most effective 4.
Key Considerations
When planning intercourse after an LH surge, consider the following:
- The lifespan of gametes allows for a relatively long period for fertilization, from 8 to 31 hours after urinary LH surge detection 3.
- Daily monitoring of the rise in LH can help achieve a higher pregnancy rate per IUI cycle 4.
- The timing of IUI in a natural menstrual cycle is important, and IUI should be performed 1 day after the LH rise, rather than 2 days post-LH rise 4.