6 Ways to Predict Ovulation & Get Pregnant
When you are trying-to-conceive or avoiding pregnancy, you want to know when your fertile window is. Your fertile window is the range of days around ovulation where the chances of pregnancy are possible. It sounds simple, but our cycles vary and there are many different methods to predict ovulation. To understand the best ways to predict ovulation, let’s look at how ovulation occurs.
How Does Ovulation Occur?
Ovulation occurs when an egg is released during menstruation. After release, the egg travels down the fallopian tube. It can either be fertilized by sperm or if no fertilization occurs, it causes your next period cycle. For healthy women, ovulation usually happens in the middle of their menstrual cycle. Women are born with all the eggs they have and only a small percentage of them could potentially lead to pregnancy.
Ovulation is controlled by hormone releases, which are managed by a part of the brain called the hypothalamus. It instructs the pituitary gland to secrete follicle-stimulation hormone (FSH) and luteinizing hormone (LH). The hormones also trigger certain changes to the body such as mucus properties, electrolytes inside the vagina, and saliva crystallization. After ovulation occurs, basal body temperature increases by about 0.5°F.
The Benefit of Knowing Your Exact Ovulation Day
When it comes to fertility knowledge is power. Knowing your exact day of ovulation can increase your odds of getting pregnant. Once an egg is released it is able to be fertilized for about 12 to 24 hours. You have the best chance of getting pregnant if you have intercourse during your fertile window or the six days before ovulation.
6 Ways to Predict Ovulation
So how do you predict ovulation? There are several different methods each with its own pros and cons. Take your time to find the one that is right for you.
Calendar Method For Predicting Ovulation
Without taking into account personal and inter-cycle variation, ovulation happens about 14 days before the onset of the next period. If using the calendar method of fertility tracking, you should start charting the length of your cycle and calculate the predicted date of ovulation from there.
Unfortunately, this is not always true because every woman and every cycle is different. It usually takes >1 year of continuous charting to understand the pattern of your cycle. Although this is very easy to do, it may not be the most accurate method when you really want to get pregnant or avoid pregnancy naturally.
Basal Body Temperature For Predicting Ovulation
Basal body temperature (BBT) is your body temperature at rest. It is measured the first thing in the morning, usually before you get out of bed. BBT increases about 0.5°F about 12 hours after ovulation. The egg only lives up to 24 hours after it is released from the ovaries, but sperm can survive in a woman’s uterus for 4-5 days, depending on the woman’s mucus consistency.
Therefore, the fertile window starts about 4 days before BBT surges. Given this, by the time you track the temperature surge, it is already too late to predict the entire fertile window.
Another common problem with this method is that it is easily affected by environment and health status. Since 0.5°F is a rather small change, environmental temperature change such as weather fluctuations, physical exercise, illness, or even the presence of air conditioning or electrical blankets could affect your temperature and make BBT fluctuate more than 0.5°F.
Hormone Testing For Ovulation Prediction
Luteinizing hormone (LH) surges about 24 hours before ovulation. Physiologically, LH hormone is the primary cause of ovulation. Estrogen increases about 4 days before LH surge. LH and Estrogen combined to give women the full fertile window. Aside from ultrasounds, which can only be done in the hospital, this is the most accurate method doctors use to predict ovulation. The challenge is that hormone levels significantly vary across different women and cycles. Ovulation prediction kits (OPK) determine ovulation based on a set hormone threshold, which leads to false-positive and false-negative results.
Mira is the only home tracking device that tracks your actual hormone concentration at home. Using cloud-based AI, Mira learns your cycle variability through quantitative hormone tracking. Mira’s ovulation prediction is based on your personal situation, not the population average. Mira tells you how fertile you are, instead of giving you a binary “smiley or no smiley face” answer. This helps you prepare and understand your body more accurately.
Tracking Cervical Mucus Changes to Predict Ovulation
Another common method for tracking ovulation is noting changes in cervical mucus. As ovulation approaches your cervical mucus changes from thick to thin and almost an egg-white consistency. Every woman’s cervical mucus is unique so you need to get to know your own pattern in order to accurately track changes over time.
Saliva Crystallization to Track Ovulation
This method of ovulation tracking includes looking at a sample of your saliva under a microscope. As you approach ovulation your estrogen levels increase which coincides with an increase in sodium levels. As your sodium levels go up, you can notice crystallization or ferning in your saliva. During this time if you look at a sample of your saliva under a microscope you will notice a pattern similar to a fern leaf. When you see this you know ovulation is approaching.
Tracking Changes in Vagina Electrolytes for Predicting Ovulation
Similar to the saliva crystallization method, the vaginal electrolyte method tracks changes in minerals in body fluids. This method requires a special monitor that registers electrolyte changes in cervical mucus throughout your cycle.
Unlike hormone testing, these last three methods are your body’s responses to estrogen hormone changes, which means that they are secondary indicators that might be affected by other physiological factors. These methods help you become more aware of your own body but can be easily affected by sex, food, illness, and other factors. Therefore, they may not yield the best prediction results as the primary ovulation tracking method, but they can be helpful additions to understanding your body when used together with hormone testing.
What is the Best Way to Predict Ovulation?
Ultimately, this answer depends on your personal goals. For women who are seriously trying to conceive or avoid pregnancy, we recommend hormone testing, which can adapt to personal cycle variability. Hormones are the primary cause of ovulation and if tracked correctly, can achieve similar accuracy as lab-grade tests.
If your goal is to log your period, the calendar method is easy to use, and it gives you a good countdown towards your next period so that you can prepare. The mucus and saliva methods are good for when you want to pay more attention to your body and can be helpful to use alongside hormone testing to track the correlation between your hormone changes and physical symptoms.
✔️ Medically Reviewed by Dr Roohi Jeelani, MD, FACOG and Lauren Grimm, MA
Dr Roohi Jeelani is Director of Research and Education at Vios Fertility Institute in Chicago, Illinois. Dr Jeelani earned her medical degree from Ross University School of Medicine in Portsmouth, Dominica. She then completed a residency in Obstetrics and Gynecology and a fellowship in Reproductive Endocrinology and Infertility at Wayne State University, Detroit Medical Center, where she was awarded a Women’s Reproductive Health NIH K12 Research Grant. She is board certified in Obstetrics and Gynecology. Dr Jeelani has authored numerous articles and abstracts in peer-reviewed journals, and presented her research at national and international scientific meetings. A Fellow of the American College of Obstetrics and Gynecology, Dr Jeelani is a member of the American Medical Association, the American Society of Reproductive Medicine, and the American Association of Gynecologic Laparoscopists.
Lauren Grimm is Research Coordinator at Vios Fertility Institute in Chicago, Illinois. Lauren earned her bachelor’s degree from Loyola University Chicago, where she also completed her masters in Medical Sciences. Lauren has worked alongside Dr. Jeelani for the last 3 years, authoring a number of abstracts and articles in peer-reviewed journals, and presented her research at national and international scientific conferences. Lauren will be continuing her education this fall at Rush University Medical College in Chicago, IL as an MD candidate.
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