How long does it take to detect pregnancy with Natural Cycles?

Detecting pregnancy early has several benefits. For those trying to conceive, early pregnancy detection gives more options for prenatal care in the first trimester. For those who have an unplanned pregnancy and want to seek an abortion, early detection means that there are more options available to them, and also decreases the risk of complications.

In this study, the Natural Cycles Research Team partnered with external researchers to investigate how long it takes for NC° users to detect a pregnancy. The study included 20,429 Cyclers in the US who had consented to their data being used for research, and in total, 23,728 pregnancies were included in the analysis. The time to pregnancy detection was determined by analyzing how many days after their last period started a Cycler logged a positive pregnancy test.

The results showed that Cyclers on NC° Plan Pregnancy logged a positive pregnancy test on average 31.3 days after their last period started. For those using NC° Birth Control (to prevent pregnancy), pregnancy detection took longer — they logged a positive test after 35.9 days on average.

Additionally, logging more temperature data in the NC° app was linked with faster pregnancy detection. A probable explanation for this finding is that users who are more active in the app are more likely to be aware of when their period is expected and notice if they don’t get it. In addition, logging more data allows the algorithm to give more accurate period predictions and send prompts to the Cycler to take a pregnancy test. Those who logged at least 10 temperatures during the first 30 days of their cycle detected pregnancy 0.8 and 1.7 days faster on average for NC° Plan Pregnancy and NC° Birth Control respectively.

We also found that those with irregular cycles and longer cycles had a longer time for pregnancy detection, as did those with a BMI in the obese and underweight ranges (BMI over 30 or under 18). 

Overall, NC° users in this study detected pregnancy faster compared to what’s been reported in previous research, and there were also fewer instances of pregnancies detected after six-seven weeks. There are a few possible reasons for this difference. First, NC° users are actively tracking their cycle, which means that they may be more likely to notice a missed period and know if they’ve had sex on days the app has identified as fertile. Secondly, the Cyclers in this study do not represent the overall population, as the majority are White (82%) and hold a university education (86%). Lastly, the NC° app contains informational content about the menstrual cycle and sexual health, so Cyclers may be more aware of how to spot a potential pregnancy compared to the population as a whole.

This study helps shed more light on factors that can influence how long it takes to detect a pregnancy, specifically for those who use NC° to track their fertility. It also highlights the potential impact of cycle literacy on early pregnancy detection.