Why BMI may be important for IVF outcome?

Please note that the information contained on this site was correct at the time it was posted. We are as diligent as possible in updating the information on this website. While we constantly strive to provide quality information, please be aware that there may have been subsequent changes which make the information outdated at the time you are accessing it.

What is the connection between Body Mass Index and IVF outcome?

Does BMI really play important role in the whole IVF process or it’s just a myth? Is it better when it’s lower than higher and can it really affect our fertility so much?
So you have no more doubts about this watch three experts explaining if and how body weight can influence the chances of pregnancy. 

This week experts in 3on1 #IVFANSWERS are:

  • Dr Maria Arqué – International Medical Director at Fertty International
  • Dr Natalia Szlarb – Medical Director at IVF Spain – Medical Director at IVF Spain
  • Dr Àlex García-Faura – Scientific Director of Institut Marquès

Dr Maria Arquè, Fertty International, Spain

Answer from Dr Arquè - International Medical Director

Being underweight or overweight could have a detrimental effect on the likelihood of achieving a pregnancy. Ideally, our BMI should be between 20 and 25 which is considered normal weight. We have seen that patients who are underweight or overweight might have a higher risk of miscarriages, it might be more difficult for them to achieve a pregnancy with or without IVF and in patients who undergo IVF, especially patients who are overweight or obese have higher risk of miscarriages and need bigger dose of medication for achieving the same results or same number of oocytes. The response to the medication might be more erratic and the likelihood of achieving the pregnancy is lower. Apart from that, not only from the perspective of the treatment itself, the risks during pregnancy, so what we would call obstetrics risks are higher for complications like preeclampsia, gestational diabetes, preterm delivery in all patients who do not have the ideal weight. I would like to encourage all people who are going to undergo a fertility treatment or considering getting pregnant, try to keep your BMI as healthy as possible, to try maximize the results and have a healthy pregnancy and successful outcome.


Dr Natalia Szlarb, IVF Spain

Answer from Dr Natalia Szlarb - Medical Director

BMI is very important for implantation and for pregnancy. In IVF-Spain we have a different approach: for us, it is important to generate genetically normal healthy euploid embryo of young patients. At this point BMI doesn’t matter for IVF cycle and freezing good quality embryos. Later on, when patients have their genetic material secured and frozen, before we transfer the embryo, we talk to the patient about how to optimize their BMI. At IVF-Spain we have a support group of psychologists, nutritionists as well as a personal trainer who are more then happy to guide you in your journey of losing weight.


Dr Àlex García-Faura , Institut Marquès, Spain

Answer from Dr García-Faura Scientific Director

BMI, Body Mass Index, healthy range should be between 19 and 25. Being under 19, underweight, can block spontaneous ovulation and pregnancy. Under IVF treatment, underweight can give a higher risk of hyper-stimulation and reduce the chance of implantation.
Being overweight or obese, when BMI is over 30 or higher, will also reduce the chances for ovulation and for spontaneous pregnancy. In IVF treatments a high BMI can reduce ovarian response to stimulation, it can also give us higher estrogenic levels, affecting endometrial thickness and quality for implantation. Other risks are thrombosis and thromboembolism that might require preventive use of heparin during IVF treatment and, also, during pregnancy.
Obese patients have a higher risk of diabetes, hypertension, preterm birth and low weight new-borns that might present cardiovascular problems long-life after birth.


3on1 IVFanswers - three answers to one question

Three IVF experts answering the same question.

If you need help choosing an IVF Clinic Abroad
Spare 3 minutes of your time. You will save at least a few hours.

If you are looking for an egg donation clinic abroad, use the eggdonationfriends unique patients tool – Clinic Matching Test. Our consultants will analyse your needs and choose 3 overseas clinics which match your expectations. Our database of IVF centres includes only trusted fertility clinics which have experience in providing high quality services to international patients. The suggested IVF centres will contact you directly within 3 working days. Spare 3 minutes of your time – you will save at least a few hours! Our assistance is free of charge.

Leave a Reply

Your email address will not be published. Required fields are marked *