Probability of Loss of Sac
Probability of Not Losing Sac

About the Daily Twin Miscarriage Probability Chart

This tool is still in BETA, we're still ironing out the kinks in our model.

Like the Miscarriage Graph, the Daily Twin Miscarriage Probability Graph displays the probability of a miscarriage. Where the Miscarriage Graph calculates the odds for a sigelton pregnancy, this Daily Twin Miscarriage Probability Graph for a twin pregnancy.

Using this tool you can see the day-specific odds, or calculate the odds between two points in time, by subtracting the probability associated with date from another. For example, if the model gives the probability of a miscarriage occurring on or after 4 weeks, 0 days is as 25.2%, and the probability of a miscarriage occurring on or after 4 weeks, 1 day as 24.4%, then the probability of a miscarriage occurring at exactly 4 weeks, 0 days is 25.2-24.4 or 0.8%. Probabilities in the graph are rounded to the nearest tenth of a percent, so very small probability differences between two dates may not be noticeable in the graph.

Have questions about the model or tool?

Probability models can often behave in unintuitive ways. Please feel free to reach out with any questions you might have. Below are some of the questions I most often receive.

Where does the data come from?

Philippe Tummers, Paul De Sutter, Marc Dhont, Risk of spontaneous abortion in singleton and twin pregnancies after IVF/ICSI, Human Reproduction, Volume 18, Issue 8, August 2003, Pages 1720–1723,

Why can't I add maternal information?

There's less research avaliable on the miscarriage rate of multiple pregnancies compared to singleton pregnancies. It may seem like the risk factors are the same between singleton and multiple pregnancies, but we just don't have enough data to be certain, and the model is already making a number of assumptions.

The above study only included 397 twin pregnancies and involved participants who concieved their twins through IVF/ICSI. We're already making the assumption that miscarriage rates for those women are comparable to women who concieved twins without reproductive assistence.

This website is intended for general information & entertainment purposes only. This website is not intended to be considered medical advice. I am happy to answer questions about the apps, and the mathematics behind them. I cannot answer medical questions.

Pregnant? You may enjoy our other pregnancy apps like the Miscarriage Reassurer or the Personalized Week by Week Calendar. When you are a little further along in your pregnancy, be sure to check out the Labor Probability Calculator and Labor Probability Chart.

Into Probability Distributions? You may also be interested in our Labor Probability Chart, which charts the probability of labor over time using a left skewed normal distribution.

Wanting to become pregnant? Our Time to Conception Estimator can estimate how long it may take.