Fertility

High Fertility vs Peak Fertility; What's the Difference?

Hillary Bennetts

High Fertility vs Peak Fertility; What's the Difference?

Trying to conceive can be a confusing time. In this blog, we’re looking at one aspect of the TTC journey - high fertility and peak fertility. What are high fertility and peak fertility? How are they different? Is one better than the other? Let’s take a look!

What is High Fertility?

High fertility refers to the time period of the menstrual cycle during which the ovaries generate more estrogen as a fertile egg grows. This typically happens in the five-day window before ovulation. 

This period of high fertility is also often called the “fertility window” because it is when female fertility is high, and since sperm can live in a female’s body for up to 5 days, when sperm may have an opportunity to fertilize an egg once released.

What is Peak Fertility?

Peak fertility has a shorter and more specific timeframe compared to high fertility. Peak fertility typically occurs toward the end of the five-day fertility window. It starts approximately the day before ovulation, until the day of ovulation. This is because once a developed egg is released into the fallopian tube, it is only viable for 24 hours. 

These two days in a woman’s cycle are when they have the highest chance of conceiving if they try to conceive (either via sexual intercourse or insemination).

How long does peak fertility last?

The period of peak fertility can vary by woman and by cycle. Peak fertility aligns with your LH surge, and women can have different types of LH surge patterns. Here are a few different LH surge patterns:

  • Single: This is the typical pattern that you see with one obvious LH surge. 
  • Biphasic: This looks like one LH spike, followed by a second one. 
  • Plateau: In this, LH levels rise and stay high for several days before dropping. 
  • Multiple: This pattern has two or more LH surges. 

Multiple surges can be misleading, since even if you have more than a single LH surge pattern, you still only have one “true” LH surge that triggers ovulation. However, depending on what your LH surge pattern looks like, you may get more or less peak fertility time.

High Fertility vs Peak Fertility: What’s More Important for Conception?

The likelihood of conceiving depends on several factors beyond the fertility window, including the quality of the egg and sperm. However, knowing your high fertility and peak fertility timeframes is important since your chances of conceiving are highest during periods of high and peak fertility. 

As discussed, high fertility is a longer window and peak fertility is a shorter window. Peak fertility is a part of high fertility during which you are most fertile. 

How do you know your high and peak fertility days?

So, how do you know what your high and peak fertility days are? There are a few different ways that you can track.

Ovulation calculators / period trackers

  • These online tools/calculators aim to calculate your fertile window using your period date and your average cycle length. 
  • But don’t rely solely upon them – they are only about 21% accurate because they don’t actually take your hormones into account.

Cervical mucus

  • Stating the obvious here, but the female body does some incredible things. And, one of those is changing your cervical mucus when you become more fertile.
  • As your estrogen levels rise (marking high fertility), your cervical mucus consistency becomes clear, stretchy, and watery. And when you reach peak fertility, it looks and feels like egg whites.
  • This may sound hard to rely upon, and it is – cervical mucus observation can be subjective and hard to interpret for some.

Ovulation predictor kits (OPKs)

Ovulation tests detect LH (luteinizing hormone) in your pee. LH is the hormone that surges before ovulation, so a positive result means you're about to ovulate. Ovulation usually occurs within 36 hours of a positive test.

OPKs work similarly to at-home pregnancy tests. You simply pee on an indicator strip and wait for a test line to appear. The difference between pregnancy tests and ovulation tests is that any line on a pregnancy test indicates pregnancy, whereas a test line on an ovulation test will get increasingly dark as you approach ovulation. The test line should be as dark as the control line to indicate ovulation.

OPKs work well in many cases, but you have different LH surge patterns, if your hormones fluctuate because of PCOS, or if your hormones don’t fall within the OPK threshold range, then your results may be less reliable.

FAQs

Can you have high fertility without peak fertility?

In short, yes, you can have high fertility without peak fertility. While this is not a typical case, there is a chance that an increase in estrogen does not coincide with an increase in LH levels. But this isn't always the case.

Can you have peak fertility without high fertility?

In short, yes. This can happen if your estrogen levels are low and do not rise sufficiently.

Is high fertility or peak fertility better?

Both phases are helpful for conceiving. While peak fertility marks your highest chances of conception, it only lasts a very short time. The realities of life mean that it just might not be realistic or convenient to plan to have sex in such a narrow window.

Your high fertility days might not be at the highest fertility, but they allow for more flexibility in planning your attempts at conception. Because remember, stress over timing the perfect time to have sex can also impact your chances of conception!

What to do next if you're struggling to conceive

There are many factors that can impact fertility. If you're not able to get pregnant after a year of tracking your ovulation and having intercourse on your high and peak fertility days, there might be something else going on.

At this point, reach out to your healthcare practitioner who can explore what next steps to take to help you along your fertility journey.

In addition, you can also take a look at your own diet and lifestyle to see if you and your partner can optimize anything to support fertility:

  • Engage in regular exercise.
  • Aim for 7-8 hours of sleep.
  • Focus on healthy whole foods.
  • Manage stress.
  • Consider exposure to environmental toxins (even in things like personal care products and household cleaners).
  • Support your egg and sperm health with targeted supplementation.

The journey to parenthood isn't always straightforward. Needed is here to support you along the way with trusted education and supplementation. 

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Hillary Bennetts, Nutritionist

Hillary Bennetts is a nutritionist and business consultant focusing on prenatal and postpartum health. In addition to nutrition consulting, she provides business consulting and content creation for companies in the health and wellness industry. Hillary spent almost a decade in corporate consulting before shifting gears to combine her lifelong passion for health and wellness with her business background and nutrition education.

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