Fertility Treatment 'Calculator' May Help Predict Pregnancy After Several Tries, Study Says Researchers used IVF data from ten years in the U.K. to develop the tool.

 -- Couples who have had trouble getting pregnant and choose fertility treatments often face more uncertainty about their chances of having a baby after the process starts.

Researchers in the U.K. focused on helping couples deal with the unknown by creating an online "calculator" that uses information from past U.K. couples who have used in-vitro fertilization (IVF), over a 10-year time span. The results of their research were published today in the British medical journal, the BMJ.

The tool is designed to show the likelihood of pregnancy, based on a couple's profile, after up to six cycles of IVF, according to the study. The authors said it is meant to help people decide whether to continue IVF treatments.

"It's really important for us to set up expectation so that people can [know] if it doesn't work they are prepared for that," and can try again if they want, Dr. Brooke Rossi, reproductive endocrinologist at University Hospitals Cleveland Medical Center told ABC News.

IVF, where a woman's ovaries are stimulated to produce eggs, which are then removed, fertilized outside her body and re-implanted in the uterus as embryos, is one of the most popular options to increase the chances of pregnancy. But it can be a long and expensive process that may involve additional attempts, or cycles, as couples try to start a healthy pregnancy.

Rossi said the tool was different than many other IVF calculators because it looked at the odds of having a successful pregnancy after six cycles of IVF as opposed to a single cycle.

She pointed out that people may think a 40 percent chance of pregnancy through a single IVF cycle is low but that it is still double the monthly fertility rate -- 20 percent -- for a healthy couple. Rossi said people should remember that while a 20 percent chance every month seems low, after a year, a healthy couple has generally about an 80 percent fertility rate.

The study authors devised the "calculator" based on data from the U.K. to help people decide whether or not to continue to use IVF, according to the study. The research groups, based at University Medical Centre Rotterdam and the University of Aberdeen, wanted to develop a way to predict the chance a couple would conceive through IVF over time. To create an accurate prediction they used data collected between January 1999 and September 2008 by the Human Fertilisation and Embryology Authority in the U.K., which collects data on licensed fertility treatments.

More than 113,000 women who underwent a total of more than 184,000 IVF cycles were in the database. By looking at which women ended up giving birth after undergoing IVF treatment, they were able to come up with two models to help predict if an IVF treatment would be effective in other women.

In one model, researchers used age, how long a couple had been infertile and previous pregnancy to gauge the likelihood of a successful future pregnancy.

The second model included couples who had been through one cycle of IVF and could give information on the success of that cycle, including how many eggs were collected and if a pregnancy was achieved.

Doctors or patients can enter the age of the prospective mother, the number of years a couple has been trying to conceive, and whether they have faced any medical issues that would make pregnancy less likely, and get a percentage chance of having a baby, according to how many IVF cycles are performed. The tool can be found here.

Rossi said the calculator could be a handy tool to help fertility doctors since fertility specialists already consider many of the same variables used by the calculator when consulting a potential patient.

"Those are all things we have in our heads that we're thinking about, when we're talking to patients," she said.

Rossi clarified that while the tool may be useful no patient should rely on any single calculator to determine their fertility.

"I would never want a patient to use the population model," Rossi added, "and say 'Oh my chance is only this, I won't even talk about it with my doctor.'"

Dr. Rashmi Kudesia assistant professor in the Division of Reproductive Endocrinology & Infertility at the Icahn School of Medicine at Mount Sinai, also said the calculator could be another tool for patients to better understand their fertility.

"When it comes to fertility treatment," Kudesia said, "it's overwhelming for a lot of patients because there's a lot of ways to massage the numbers."

For couples in the U.S., however, she noted that the tool may not be quite as accurate because it's based on women in the U.K., who may have different characteristics than women in the U.S.

Dr. Lucky Sekhon is a board certified OB/GYN specializing in Reproductive Endocrinology and Infertility at the Icahn School of Medicine at Mount Sinai/ Reproductive Medicine Associates of New York program. She is a resident in the ABC News Medical Unit.