Factors affecting IVF success rate

Factors affecting IVF success rate

In vitro fertilization (IVF) is a medical procedure that involves fertilizing a woman’s egg with sperm in a laboratory environment then the resulting embryo is transferred to the woman’s uterus.

In vitro fertilization (IVF) is an effective treatment for infertility, although its success rate can be influenced by various factors.

This article will discuss the factors that affect the IVF success rate:

  • Age of the woman
  • BMI
  • History of previous pregnancy
  • Semen quality
  • Medical history
  • Lifestyle factors
  • Fertility clinic

What are the factors that affect the success rate of IVF treatment?


 Age of the woman 

The age of the woman is a very significant factor that influences IVF success rates. As a woman’s age increases, her chances of having a successful IVF cycle decrease. As a woman ages, the quantity and quality of her eggs and hormones for IVF often decrease.

As a result, the quality of the embryos could decrease, decreasing their chances of implantation in the uterus. The quantity and quality of eggs decline over an average of 30 years, becoming evident around the age of 40.

Insufficient ovarian reserve, poorer egg quality, egg retrieval, or fewer eggs overall may reduce a woman’s chances of becoming pregnant or producing a quality single embryo that successfully implants in the uterine wall.

The IVF success rates for women of different ages are as follows:

Percentage of live births via IVF
Under 35 55.60%
35-37 40.80%
38-40 26.80%
Over 40 7%


An elevated BMI can reduce the rate of successful implementation. When compared to patients of normal weight (BMI 18.5-24.99 kg/m2), the failure rate in implementation decreases when the BMI of females is greater than 30 (BMI > 30 kg/m2).

If IVF treatment is successfully implemented in patients with BMIs more than 40, the risk of miscarriage increases. Implementation failure and miscarriage risk are substantially higher in women with BMIs greater than 25 than in women of normal weight with the same number of harvested oocytes. Obese women required more gonadotropin stimulation cycles, but had statistically fewer oocytes for collection; the more collected oocytes, the greater the possibility of success in IVF treatment. This suggests that obesity may have an effect on oocyte quality and follicular development.

 History of previous pregnancy

Women who have previously been pregnant have a higher chance of having a successful IVF cycle than women who have never been pregnant. This is because women who have already had a pregnancy have demonstrated their ability to conceive and bring a pregnancy to birth.

 Quality of semen

Semen quality is determined by factors such as sperm concentration, percent motility, quality of motility, and sperm morphology. In IVF treatment the semen is washed and the healthy sperm are used for fertilization.

Sperm count: For successful fertility in every ejaculate the semen at least should have 15 million sperm in 1 ml, if it is lower than that the chance of pregnancy decreases.

Sperm motility: The ability of the sperm to move is its motility. Fertility tests analyze how many sperm are motile, how many sperm are motile in 1 ml of semen, how many total sperm are motile in one ejaculate, how rapidly they are moving, and the type of movement of the sperm itself. If at least 32% of the sperm travel forward, it is regarded as normal. As was previously noted, only highly motile sperm are used for IVF, and ICSI, only one healthy sperm is required.

Sperm morphology: The success of IVF can also be influenced by the sperm’s morphology, which is defined as the sperm’s shape, size, and structure. The heads and tails of the sperm are typically oval. The sperm’s tail allows it to move in the direction of the egg, and its head, which also has enzymes at its tip that can help it break through the egg’s surface, carries the genetic material. If sperm could not penetrate the egg by ICSI technic it can be injected into the egg.

DNA fragmentation: Men’s fertility may be impacted by the disorder known as DNA fragmentation. It happens when the sperm’s genetic material is harmed or abnormal. Problems with fertilization, miscarriage, or genetic abnormalities in the offspring may result from this.

There are some factors that can contribute to DNA fragmentation, including:

  • Age: DNA fragmentation tends to increase with age.
  • Smoking: Smoking can damage sperm DNA.
  • Exposure to environmental toxins: Exposure to certain chemicals and pollutants can also damage sperm DNA.
  • Infections: Some infections, such as chlamydia, can damage sperm DNA.
  • Medications: Some medications, such as chemotherapy drugs, can also damage sperm DNA

Lifestyle factors

Lifestyle factors can impact the success rate of IVF. Here are some lifestyle factors that can influence the outcome of IVF treatment:

Smoking: smoking has a deleterious impact on fertility in both men and women. Women who smoke have a larger chance of miscarriage than nonsmokers and the rate of live birth drops. Mothers who smoked were found to be more frequently associated with unplanned miscarriage with normal fetal karyotype than with abnormal fetal karyotype, implying that the harmful effects of carbon monoxide and nicotine might be the primary factors causing harm.

One of the most detrimental effects of cigarettes on the fetus is that carbon monoxide reduces the fetus’s oxygen levels, and nicotine’s vasoconstriction reduces the mother’s appetite, resulting in fetus malnutrition. Furthermore, cigarette poisons may have a deleterious impact on corpus luteum production and embryo implementation. A high quantity of cotinine, one of the nicotine metabolites, can reduce the amount of ova retrieved.

Not only does smoking damage women’s fertility, but it also harms men’s fertility. According to studies, smoking can reduce sperm count in men.

Stress level: There is limited evidence regarding the impact of stress on the success rate of IVF. Some studies have found that stress does not impact IVF outcomes, while others have found a decrease in the success rate of IVF with high levels of stress. It is advisable to remain calm and avoid stressful environments in order to prevent panic to increase the chance of pregnancy.

Sleep: Quality sleep is essential for reproductive health. Poor sleep has been linked to a decreased chance of a successful IVF cycle.

Diet: A healthy diet is important for reproductive health and can contribute to successful IVF outcomes. Eating a balanced diet that is rich in essential vitamins and minerals, as well as limiting processed foods, alcohol, and caffeine can help improve the success rate of an IVF cycle.

Exercise: Regular exercise has been linked to improved fertility and increased IVF success rates.

Medical history

To increase your chances of success, please supply us with a full summary of your medical history. Uterine abnormalities such as adenomyosis and endometriosis, as well as blood-clotting problems and thyroid issues, can all have an impact on conception rates. Furthermore, disease and cancer therapies such as chemotherapy and radiation therapy can have an impact on the health of your eggs.

Fertility clinic 

The fertility clinic that you choose can also affect your IVF success rate. Some clinics have higher success rates than others, so it is important to do your research and choose a clinic with a good track record. It is important to choose a  clinic to be up-to-date.


 There are a number of things that you can do to increase your chances of a successful IVF cycle:

  • Get regular exercise and eat a healthy diet. This will help you to maintain a healthy weight and overall health, which can improve your chances of success.
  • Avoid smoking and excessive alcohol consumption. These habits can damage your fertility and reduce your chances of success.
  • Manage stress levels. Stress can have a negative impact on your fertility, so it is important to find ways to manage stress in your life.
  • Take supplements. Some supplements, such as CoQ10 and DHEA, have been shown to improve IVF success rates.
  • Be patient. IVF is a complex procedure, and it can take time to achieve success. It is important to be patient and persistent throughout the process.

If you are considering IVF, it is important to talk to your doctor about your individual factors and how they may affect your chances of success. With careful planning and preparation, you can increase your chances of achieving your dream of parenthood.

Here are some additional tips to increase your chances of IVF success:

  • Choose a reputable fertility clinic with a good track record.
  • Work with a qualified and experienced medical team.
  • Follow your doctor’s instructions carefully.
  • Be realistic about your expectations.
  • Stay positive and hopeful.

IVF is a complex procedure, but it can be a very successful treatment for infertility. By following the tips above, you can increase your chances of achieving your dream of parenthood.

If you have any questions, please don’t hesitate to contact our IVF team by clicking here, at any time you want.



Kupka, M. S., Dorn, C., Richter, O., Felberbaum, R., & van der Ven, H. (2003). Impact of reproductive history on in vitro fertilization and intracytoplasmic sperm injection outcome: evidence from the German IVF Registry. Fertility and Sterility, 80(3), 508-516. https://doi.org/https://doi.org/10.1016/S0015-0282(03)00760-X