April 2023

Factors Determining IVF Success - Part 1

In-vitro fertilization (IVF)  is a technique that has been around for half a century now, and GYNEM clinic’s professionals have been part of it for over three decades. The methods used in the IVF process have advanced a lot since the first successfully born in-vitro baby in 1978. Initially, the success rates used to be relatively low - less than 10%, while today, the IVF successful outcomes are close to 50% in women younger than 35 years [1]. There are more than 8 million babies born through this method in the world today.

IVF is a complex fertility treatment involving different steps and stages, and quite a few factors play a role in its success. The degree of a positive outcome depends on the conditions listed here:


Partners Age 

This is one of the most critical aspects that can determine the positive result of achieving a pregnancy and giving birth to a healthy baby. 

Women’s bodies are most fertile from their late teens to their early 30s. Unfortunately, the decline in female reproductive abilities speeds up after age 35. This fact doesn’t mean that after turning 35, it is impossible to conceive. However, the facts, according to The Society of Reproductive Technology, are that IVF success rates decline fast from 

  • 40.8% in women aged 35 to 37, 
  • to 26.8% in women aged 38 to 40, 
  • and down to less than 7% in women of 42 and older.[2]


The father's age also plays a role, as a study published in the American Journal of Obstetrics and Gynecology has found. Researchers have discovered that the unsuccessful IVF pregnancy rate increased by 11% with every additional year of paternal age, especially in men over 51 [3]. 




Previous pregnancies 

Having experienced a successful pregnancy in the past increases the chances of an IVF with a favorable outcome. Being pregnant and giving birth before are indicators that your body is receptive and able to carry a child.

On the other hand, if you have gone through multiple miscarriages and suffered fertility-related problems, you may expect to encounter a more difficult IVF treatment. 


Eggs, sperm, and embryo quality 

The quality, as well as the quantity of the eggs, sperm, and embryo, are closely related to the age factor. As you age, there will be fewer eggs in your ovaries, which lessens the chance of a positive result from IVF. 

In cases where the male partner is experiencing infertility issues or has lower-quality sperm, creating a more significant number of viable embryos will be difficult. As a consequence, this may mean a reduced chance of pregnancy. 


Certain fertility problems 

Negatively impacting the success of the IVF process are issues like fibroid tumors, uterine abnormalities, dual infertility, and ovarian dysfunction. 

However, IVF treatment can overcome a lot of fertility problems. The critical aspect is not to wait too long before you look for treatment. So, if you are experiencing difficulties conceiving, do not postpone; book your appointment with an IVF specialist today. 

The IVF process can also be impacted by the execution of a controlled ovarian stimulation protocol; the recipient uterine's receptivity; the IVF embryo transfer; and the lifestyle led by the patent of this treatment. You can find more information on these factors in Part 2 of the article “Factors that Determine IVF Success”. 



  1. Eskew, A. M. (2017, June 1). A History of Developments to Improve in vitro Fertilization. PubMed Central (PMC). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6140213/
  2. National Summary Report. (n.d.). https://www.sartcorsonline.com/rptCSR_PublicMultYear.aspx?ClinicPKID=0
  3. Klonoff-Cohen, H., & Natarajan, L. (2004). The effect of advancing paternal age on pregnancy and live birth rates in couples undergoing in vitro fertilization or gamete intrafallopian transfer. American Journal of Obstetrics and Gynecology, 191(2), 507–514. https://doi.org/10.1016/j.ajog.2004.01.035