Is it Harder to Get Pregnant With Early or Late Ovulation ?

Is it Harder to Get Pregnant With Early or Late Ovulation ?

Timing intercourse with ovulation is important, but does it matter if you ovulate early or ovulate late when trying to get pregnant?

A question that I have gotten several times is: Does early ovulation make it harder to get pregnant? or the opposite: Does late ovulation make it harder to get pregnant? 

If you are a subscriber to our blog, you know that we only deal with facts from scientific studies. A very funny thing happened when I went looking for some good studies on this topic. I couldn't find any! That's right, there were no high quality studies that I could find for this topic.

So, what did I do? I did my own study. Today I am going to tell you about FertiGenic original research.

late ovulation conception

Phases of the menstrual cycle

First, a little background. If you look in the textbooks, it will say that the length of a woman's cycle counting from the first day of her period until the first day of the next period is usually about 28 days. Most women ovulate around day 14. The time from the beginning of her period until ovulation is called the follicular phase.

Follicular phase

Women who ovulate early have a short follicular phase. Women who ovulate late have a long follicular phase.

Why is there concern about the length of the follicular phase? Some women worry that if they ovulate in a short period of time, that maybe the egg won't have time to mature properly or that the uterine lining will be too thin. Other women worry about the opposite, that if they don't ovulate until later that the egg might get too old and be of poor quality.

Ovulation timing study methods

How did I study this? I looked back at those patients in my practice that were attempting pregnancy without the use of fertility medications. We call these natural cycles. I counted the number of days from the first day of their period until an ovulation predictor test turned positive or they took an injection of a medication called hCG to trigger ovulation. I then compared those cycles in which a pregnancy occurred to those cycles in which no pregnancy occurred.

Length of follicular phase in pregnant women

Here's what I found: In those months in which a pregnancy happened, the average length of the follicular phase was 13.6 days. The shortest was 7 days and the longest was 24.

Length of follicular phase in non-pregnant women

Those cycles that pregnancy did not occur the average time of the follicular phase was 13.4 days. The shortest was 5 days and the longest was 29. As you can see the cycles where pregnancy occurred and the cycles it did not were almost identical. For some women the time it took until ovulation was fairly consistent from one month to the next. In many women however, there was a lot of variation. Some months they would ovulate early and some months they would ovulate late.

early ovulation pregnancy success

Pregnancy rate

Next I looked at the pregnancy rate. Pregnancy occurred in 25% of the natural cycles I studied. This included all of the cycles whether ovulation occurred early on time or late.

Pregnancy rate with early ovulation

If I looked only at those months with early ovulation, less than 10 days, the pregnancy rate was also 25%. 

Pregnancy rate with late ovulation

If ovulation was late or more than 18 days then the pregnancy rate was only marginally higher at 28%.

Bottom line

The time it takes for ovulation varies from one woman to the next and even in the same woman from one month to the next. The chance for pregnancy does not seem to be affected by the time of ovulation, early or late. It seems mostly the same. 

The key to achieving pregnancy is knowing when you ovulate. If you are a woman who sees a big change in your ovulation time from one month to the next, using an ovulation predictor test might be helpful.