Predicting Your Chances Of Getting Pregnant With IVF
Predicting Your Chances Of Getting Pregnant With IVF
When predicting your chances of getting pregnant with IVF, there are different factors to consider such as ovarian factors, sperm factors, medical factors etc. Many other fertility factors also play a role and affect the impact of other factors and so should be considered when predicting your fertility and your personal probability of IVF success.
Ovarian Reserve: Your ovarian egg supply, also called your ovarian reserve, is one fertility factor which can be estimated using two blood tests: your FSH level on Day 3 and your AMH level. A low FSH and a high AMH suggest that your ovarian reserve may be good. Your doctor may already use these lab results to determine an appropriate starting dose of ovarian stimulation medications for your IVF cycle. Some doctors also use antral follicle count, an ultrasound measure of the number of small follicles in the ovaries, which is also an estimate of your ovarian reserve.
Previous Response To Gonadotropin Medications: If you have had IVF before, your previous response to gonadotropin medications is another ovarian fertility factor that is predictive of how well you might do in a subsequent IVF cycle. For instance, an older patient may have a better than expected probability of pregnancy if her ovarian reserve tests and previous ovarian IVF stimulation history indicate that she typically produces the optimal number of mature eggs for IVF, without needing extra-large doses of IVF medications. On the other hand, a younger patient may have a poorer than expected chance of success with IVF if she requires large doses of medication and recovers average or below average number of eggs.
Sperm Count: Your partner’s sperm number and sperm quality are significant fertility factors we consider when predicting whether IVF will work for you. Total motile sperm count is one indicator of male infertility that impacts your chances of successful IVF. Motile sperm are those sperm that have the ability to swim. This is a critical function for the fertilization of an egg. The total motile count refers to the total number of swimming sperm in the ejaculate.
When sperm count and motility are extremely low, intracytoplasmic sperm injection(ICSI) is often used to manually inject each egg with one sperm. Total motile sperm count persists as a powerful predictor for success with IVF in our prediction model, even when ICSI is used. That suggests that this factor may be correlated with other sperm quality factors that are not revealed in the semen analysis.
If you had an IVF cycle before, the number and quality of your embryos is considered in our IVF prediction tests to calculate your probability of pregnancy in your next cycle. Embryo quality is typically determined by a scoring system based on embryo appearance and how well the embryos meet their developmental milestones. For instance, do you have mostly high scoring blastocysts on Day 5 of culture? This scenario bodes well for IVF success.
In fact, if you produce many high quality embryos, your doctor may recommend transferring just one embryo, because you are at higher risk of multiples. On the other hand, if you make very few embryos that reach the blastocyst stage on Day 5, other factors may weigh in more heavily in predicting your chances of success. Advanced prediction tests, developed and tested against data from thousands of IVF cycles, can help make this prediction.
No single fertility factor is predictive. Multiple factors (both positive and negative, specific to each of us) must be analyzed to arrive at a more personalized prediction of pregnancy with IVF.
OTHER MEDICAL FACTORS
Body Mass Index (BMI): Your body mass index (BMI) is a calculation of your weight and height. Although many research studies report that a BMI value either above or below the normal range (18.5-24.9) is sub-optimal for fertility, the exact impact of your BMI on your IVF success is specific to how you fare on other factors that we discussed previously (see previous posts). If your BMI is over 24.9, there’s no need to panic. Overall, it may have less impact than suggested by research that is based on group averages, especially if the complete reproductive profiles of patients have not been analyzed.
Some general concepts hold true. Having an abnormally low BMI (being underweight) is a negative factor, because your body may not have the required energy reserves for the extra metabolic needs of a healthy pregnancy. If you have a high BMI and are overweight or obese, you may develop a hormonal imbalance that interferes with normal ovulation and egg maturation- two negatives for fertility.
Obesity: Obesity may reduce the number of eggs your doctor can retrieve during your egg retrieval for technical reasons. In an obese patient, the ovaries may be located up higher into the abdomen, making it more difficult to reach every possible egg with the retrieval needle. Likewise, the ultrasound image of the ovaries may be blurry due to extra fatty tissue surrounding the ovaries. Both of these factors together may reduce the number of mature eggs collected at retrieval, which reduces the number of embryos for transfer, ultimately reducing your chance of pregnancy with IVF.
Diabetes, Thyroid Problems, Cardiac Disease: Chronic health conditions, such as diabetes, thyroid problems, or cardiac disease, can further affect your fertility.
Smoking: Smoking has a negative impact, because it reduces the quality of the eggs you produce, making them more resistant to fertilization. For example, a young woman with good ovarian reserve test results, no chronic medical conditions, a normal BMI, and a partner with good sperm quality may have a lower probability of success with IVF than expected if she smokes, based on the relative impact of each of these factors on her overall fertility.
The benefit of using statistical modeling for fertility factors is that the fertility factors you have (your ovarian reserve, your response to gonadotropins, your previous IVF history, your partner’s sperm count, your BMI and your history of smoking) can all be analyzed together to create your personal probability of pregnancy with IVF. What this means is that using analysis that is primarily based on age and/or just one or two other factors to predict whether IVF may work for you can under-or overestimate your chances, compared to a more personalized and comprehensive analysis of your unique combination of fertility factors. IVF prediction test results can add an important piece of the puzzle to help your doctor when counseling you about whether to start, continue or stop IVF treatments.