What you need to know about natural family planning, according to experts

For people who aren’t ready to get pregnant or have no desire to have children, there are a variety of contraceptives — IUDs, birth control pills and the vaginal ring, to name a few — that significantly reduce the risk of conceiving.

One alternative option — which has been sweeping TikTok for the past several months — that doesn’t require medications or devices is natural family planning, also known as the fertility awareness method. It involves the diligent tracking of your menstrual cycle and other signs of ovulation to prevent a pregnancy. But the method does require some work — namely, knowing and tracking the intimate details of your menstrual cycle.

As with any contraceptive, there are some risks and benefits to consider. Here’s what experts have to say about this hormone-free option and how effective it is.

Why do some people choose natural family planning?

There are several reasons why someone would opt for natural family planning, including because they don’t want to use a device or take hormones that seem “unnatural” to the human body. With family natural planning, you can avoid any side effects you may encounter while on a hormonal birth control method.

People may also employ natural family planning if they choose not to use birth control for religious reasons. Tracking their menstrual cycles may give women control over child planning or preventing an unwanted pregnancy. “This is a way for them to work around those rules and regulations of their religious beliefs,” says Daniel DiSabatino, an ob-gyn at Axia Women’s Health,.

The method also doesn’t cost anything — except your time. So it could be an appealing option for those who can’t afford or have regular access to other contraceptive options.

How does natural cycle birth control work?

In general, natural family planning works by tracking and looking for signs that suggest your body is in its most fertile state: ovulation. “The idea is if you can avoid having unprotected intercourse during your fertile period, you can try to avoid naturally getting pregnant,” DiSabatino tells Yahoo Life.

Tracking your menstrual cycle

There are ‌two to three signs people generally watch for, Dr. Jill Purdie, medical director of Northside Women’s Specialists, which is part of Pediatrix Medical Group, tells Yahoo Life. The most common one is keeping track of your menstrual cycle from the first day of your period. While medical textbooks say 28 days is the average cycle length, research shows that menstrual cycles vary between 21 to 35 days. To prevent pregnancy, Purdie recommends knowing when you ovulate during your menstrual cycle and avoiding any sexual intercourse during that time.

Ovulation usually starts 14 days before your next period. For example, if your cycle is consistent every 28 days, you would ovulate around day 14, making it your most fertile day. However, this is not an exact science. Women, on average, are actually fertile over a six-day window each month (the 5 days before ovulation and the day you ovulate), according to the Kaiser Family Foundation. “You have about a week, which is considered the fertile period,” says Purdie.

Ovulation times can also shift because of several factors, such as changing sleep schedules, stress or intense exercise.

Monitoring your cycle works best for people with regular menstrual cycles, as it remains fairly consistent and predictable. People with irregular cycles, however, may want to consider other signs — or other contraceptive methods.

Tracking cervical mucus

People often track their cervical mucus to predict their fertile and non-fertile days. This gel-like fluid is discharged from the cervix at varying amounts throughout the menstrual cycle. When you have your period, there’s not a lot of mucus. As you approach ovulation, you’ll likely see more discharge at the time of ovulation, showing a thin and clear film. “It’s like a sticky, egg-white-like discharge that lets people know they’re probably ovulating in the next 24 hours and to avoid having sex,” explains Purdie.

Basal body temperature charting

Another sign is checking for subtle changes in your body temperature. Using an under-the-tongue thermometer, you would take your temperature at the same time every day. “Before you eat, drink or do anything else before you get out of bed, you should take your temperature,” says Purdie. If done consistently, you’ll see patterns in your temperature that align with where you are in your menstrual cycle.

During the first half of the menstrual cycle, your temperature will stay in the normal range, typically 98.6 degrees Fahrenheit. During ovulation, your body temperature rises less than half a degree Fahrenheit and stays slightly elevated until your next period.

Is there an easier way to keep track of your cycle?

While it’s possible to track your cycle with a calendar, most people these days use a mobile app. Popular apps such as Natural Cycles and Ovia use your personal information to give an accurate prediction of when you are and are not ovulating. This includes inputting data on your cervical mucus discharge along with when you last had intercourse, cycle length and any other pertinent information.

Since temperature changes are subtle, Purdie says these apps can help graph your basal body temperature.

How effective is natural family planning?

It depends on how strictly you adhere to daily tracking of your cycle. Purdie says typical users — people who are not consistent in tracking or make a mistake in their data — have about 85% protection from pregnancy. With perfect use, she says natural cycle birth control would be around 93-95% effective.

Research on the effectiveness of this type of birth control is mixed. When done correctly, one 2013 study suggests natural family planning works 95% of the time. More recently, a 2021 study using data from the Natural Cycles app estimated a 93% effectiveness in preventing pregnancy.

The actual effectiveness of natural family planning will vary by individual. However, experts say it’s unrealistic for someone to be 100% accurate in their predictions, with the occasional human error coming into play. “It's supposed to be 14 days between the time you ovulate and the time for the beginning of your menses, but that’s not always the case,” says DiSabatino. “People can ovulate at random times and can even get pregnant during their periods.”

If tracked incorrectly, there is a risk of unintended pregnancy. Also, if natural family planning is the only form of contraception, there’s an increased risk of sexually transmitted infections.

To get to nearly 100% pregnancy prevention, both experts recommend using other contraceptives, such as IUDs, which are over 99% effective.

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