If a couple is healthy, sex during the fertility window (five days before ovulation and on the actual day) [1] will most likely end up in pregnancy. These indications represent the theory, but in practice, there are a few important nuances.
Day of the cycle
Scientists have studied the days of the menstrual cycle in which sex most often leads to conception. Contrary to popular belief, the highest chances are not on the day of ovulation, but two days before.
Probability of conception with a single sexual relation on different days of the cycle.
Source: American Society of Reproductive Medicine
The main issue is how to calculate ovulation. Even in women with a regular cycle, it can shift several days in one direction or another [1].
Frequency of sexual intercourse
If you are looking to conceive, it makes sense to have sex more often during the fertility window. Ideally, every one to two days; this increases the possibility of conception [1]. It is not necessary to “save sperm” in advance of the sexual act to increase the chance of conception, in fact, with prolonged abstinence, sperm motility and structure can deteriorate [2].
In terms of when to have intercourse, reproductive experts are sympathetic to couples wanting to conceive and are aware that having sex on a schedule can be challenging, so determining the fertility window and having sex on a specific schedule is just a recommendation.
Assisted technologies
Some health conditions don’t allow for frequent sex, or a couple may seem to have everything in check to conceive naturally but are having a hard time with it. In many such cases, doctors may suggest artificial insemination [3]. During this simple procedure, the doctor inseminates the patient with her partner’s sperm in a clinical setting the day before ovulation. If everything goes as planned, conception will occur as with regular sexual intercourse, although some couples have to try a few times before becoming pregnant.
