Your Chances of Pregnancy By Age

by Jun 28, 2019

You are born with 1-2 million eggs. And guess what? That’s all you have for your entire lifetime! By your first period, the number of egg has likely already reduced down to 300,000. Only around 300 will mature and potentially lead to pregnancy.

What are your chances of pregnancy by age?

Your chance of pregnancy also can change drastically with age. Fertility typically drops with age, especially after 35. So how do you increase your chance of pregnancy at any age? Let’s look at some facts below regarding how age affects fertility.

We all know women and men at any age could have fertility problems. When factoring in health conditions, people in their 20s could be just as infertile as others in their 40s. However, age is only one factor that affects fertility. Assuming a woman has no medical conditions affecting fertility, age becomes the only remaining factor that plays a significant role in her chances of getting pregnant. In general, women reach their peak fertility at the age of 24. A gradual decline then follows until the age of 30. After 30, a steep decline of fertility starts to occur.

Fertility by age

For women in their early 20s, the chance of pregnancy is 96% if they try every month continuously for a year. From the age of 25-34, the chance is 86%. At 35 years old, you still have a 15-20% chance of pregnancy in any given month, which means 78% chance of pregnancy after a year of continuous trying. At 40, an increased amount of eggs are chromosomally abnormal. Combined with other factors such as older male partner, the chance of pregnancy drops steeply. In most women, menopause starts between the age of 40 and 60.

Miscarriage and birth defect by age

Egg quality is the major reason of reduced fertility. The chance of pregnancy changes at different ages due to the fact that egg quality is directly related to age. At age of 35, a woman might still have a lot of eggs, but an increased percentage may be chromosomally abnormal. This increases the risk of miscarriage and birth defects increase with age as well. By early 20s, about 10% of pregnancies end in miscarriage. This number increases to 12% by early 30s, 18% at age 35, and 34% by early 40s. The chance of having a special needs baby increases significantly as well, especially after 35.

Why does fertility decline?

Our eggs age with us and when eggs age, they are more likely to become chromosomally abnormal. This means there are small mistakes in DNA. Abnormal DNA can lead to cells not functioning correctly and in the case of an egg, it may not make for optimal fetal health development. Therefore, in early 20s, 90% of eggs are genetically normal. By mid 40s, <20% of eggs remain healthy. Knowing this information and how it affects your changes of pregnancy at different ages is important, however, knowing what to do with it is even more important!

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What should you do?

Know exactly when you ovulate is crucial to timing when to try conceiving. By know this, you maximize your chance of pregnancy by figuring out exactly when ovulation occurs in order to ensure sperm has the best chance of penetrating the egg. Once the egg is released from ovary, it only lives up to 24 hours, which gives you a very small window to conceive. Additionally, studies have shown that the chance of pregnancy beyond 24 hours is nearly zero [2]. For older women, the egg may even live shorter than 24 hours. Capturing the first few hours after ovulation is the key to increasing your chance of getting pregnant at any reproductive age. Mira is the only ovulation tracker that not only identifies if you are fertile or non-fertile, but also how fertile you are, by testing and plotting your actual hormone curves on Mira App via the Mira hormone analyzer. Mira detects your ovulation up to hours before your ovulation. Moreover, Mira’s hormone test is optimized towards your personal hormone pattern, avoiding any potential for missed peaks caused by irregular hormone levels and cycle lengths.

Mira Fertility Chances By Age

Staying sane is key!

At the end of the day, it’s important to keep a healthy lifestyle. While there are no proven supplements to reverse egg aging, keeping a balanced lifestyle with regular exercise, healthy diet, and lowered stress can help you not only feel better but also help you keep your spirits up as you try to conceive. Seeking help or dedicated support group is also encouraged. It can make it easier to hear other women’s stories as well as have a place for you to share yours. You can join Mira’s trying to conceive support group on Facebook.

As a last option, you may want to seek fertility treatment if you’ve been trying to conceive for at least a year without any success. As you are getting older, your chances of pregnancy drops with age even when factoring in assisted reproductive procedures. It’s best to act quickly!



  1. Number of non-growing follicles over time from Wallace, W. Hamish B.; Kelsey, Thomas W. (2010-01-27). “Human Ovarian Reserve from Conception to the Menopause”. PLoS ONE. 5 (1): e8772. doi:1371/journal.pone.0008772. PMC2811725. PMID 20111701
  2. Wilcox AJ. “Timing of sexual intercourse in relation to ovulation. Effects on the probability of conception, survival of the pregnancy, and sex of the baby”. New England Journal of Medicine. (1995) 333:1517

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