How likely are you to get pregnant if your last intercourse was 3, 4 or even 5 days before ovulation?
You probably know that natural conception must take place immediately after ovulation. When a mature egg cell is released from one of your ovaries, it must be fertilized within 24 hours, perhaps even less. If it isn’t, it dies, and your chances of pregnancy are lost in that cycle.
However, sperm cells can survive inside your body for several days and still be able to fertilize the egg. Therefore, it is possible to get pregnant from intercourse that took place a few days before ovulation.
Your chances of becoming pregnant are definitely highest when you are able to have intercourse right before ovulation. But unfortunately, perfect timing isn’t always possible. So what are your actual chances to conceive, if your last intercourse was three or more days before ovulation?
About the fertile window
The fertile window, or your fertile period, is made up of those days in your cycle when pregnancy is possible. According to FertilityFriend.com, a fertility charting service, the theoretical fertile window is six days long: The five days before ovulation plus the day of ovulation itself.
In a textbook 28-day cycle with ovulation on cycle day 14, the fertile window would therefore span from day 9 to day 14 of the cycle. Intercourse on any of these days could result in pregnancy.
However, your chances of conceiving are far from equal on each of these days. In an analysis of more than 100,000 fertility charts on their website, FertilityFriend.com found that 94% of women who became pregnant had intercourse on at least one of the last two days before ovulation, or on the ovulation day itself.
To optimize your chances of conceiving, FertilityFriend.com therefore recommends having intercourse during a three-day fertile window, which includes your ovulation day and the two previous days.
That being said: If the charts that were analyzed had mostly accurate information about intercourse patterns, 6% of the pregnancies resulted from intercourse three or more days before ovulation.
That’s a modest probability, but it’s not nonexistent.
Intercourse timing and chances of conception
Several teams of medical researchers have studied the relationship between intercourse timing and chances of conception.
In one study from 2000, published in Demographic Research, B. Colombo and G. Masarotto included a comparison of the results of previous studies (see table below).
In most cases, Day 0 (the “reference day”) corresponds to the last day with a low basal body temperature. This is the most likely ovulation day. Day -5 therefore means five days before ovulation, -4 means four days before ovulation and so forth.
|Days||Schwartz et al (1979)||Schwartz, MacDonald & Heuchel (1980)||Bremme (1981)||Weinberg et al (1998)||Wilcox, Weinberg & Baird (1998)||Colombo & Masarotto (2000)|
It won’t be a surprise that all the studies showed the best chances of conception when intercourse took place on the day of ovulation and the two previous days (days 0, -1 and -2).
But some studies found conception rates as high as 14-16% from intercourse four days before ovulation, and up to 10% five days before ovulation. Even intercourse as much as six or seven days before ovulation was reported to have resulted in pregnancy!
Other fertility factors matter
Do keep in mind that these figures are statistical averages in large study populations. Your and your partner’s age, health, intercourse frequency, and many other factors may give you better or poorer odds than these averages.
As an example, consider the following graph from an analysis of the data from the Colombo and Masarotto study, published in Human Reproduction (Oxford Journals). Here, the woman’s age is taken into account:
For all age groups, intercourse two days before ovulation gave the highest success rates. But among those who had intercourse on that specific day, women aged 19-26 were almost twice as likely to conceive as women aged 35-39.
In conclusion: If your last intercourse in this cycle was 3, 4 or 5 days before ovulation, don’t give up hope quite yet – but don’t get your hopes up too much either. Pregnancy is possible, but not likely. And in future cycles, having intercourse closer to ovulation will greatly increase your chances of getting pregnant.