BMI for IVF | Does Weight Affect Fertility | The Evewell Advice - The Evewell
Fertility advice

How weight can affect fertility

Being both under and overweight can have a huge impact on fertility. We asked nutritional therapist, Neema Savvides to look into this subject and break down the impact of weight on fertility.

Neema Savvides

Low weight and fertility

Being both under and overweight can have a huge impact on fertility.  If you are underweight (a BMI of 18.5 or less), you may have trouble getting pregnant, as your body may stop producing oestrogen.  This can cause irregular menstrual cycles or even cause ovulation to stop altogether.  Being malnourished can lead to poor quality eggs and you may not be able to support a developing baby in the uterus.

Obesity and fertility: weight and IVF success

A BMI in the obese range can also make it difficult to get pregnant.  The higher the number of fat cells you have, the more oestrogen you produce, which can affect ovulation and cause irregular cycles.  It can also lower your chances of conceiving with certain fertility treatments such as IVF. Even with regular ovulatory cycles, overweight women have lower pregnancy rates than women of normal weight.

Other health conditions associated with obesity can also impact pregnancy such as insulin resistance, thyroid disease and diabetes.

Obesity and pregnancy

Being overweight during pregnancy can have its own health complications as it increases the risk of other health problems. It can lead to:

– High blood pressure during pregnancy (gestational hypertension)

– Gestational diabetes (diabetes that starts during pregnancy): This can also cause low blood sugar in the infant, and may result in larger babies being produced (which can pose complications for the mother during the birthing process)

– Increased risk for C-sections and postpartum haemorrhage

– Premature babies

– Large or small for the gestational age babies

– Congenital birth defects

– Risk of obesity for children themselves in later life

– Elevated blood pressure as a child

– Increased risk of diabetes for the baby

Obesity and fertility have been linked to:

– Lower pregnancy rates

– Lower live birth rates per cycle (IVF)

– Higher rates of miscarriage in ART and spontaneous conception

From a male perspective, it’s just as important to maintain a healthy weight, as research has shown obesity affects testosterone and other important hormone needs for reproduction.  Obesity has been linked to lower sperm counts and lower sperm motility than those of a healthy weight.

To find out what you should be eating to increase fertility, please read our guide on the fertility diet.

We are here to help! If you are worried about how your weight may affect your fertility, please get in touch. We can put you in touch with our nutritionist or we can book you for a consultation with one of our expert fertility doctors, who will be able to give you the guidance you need.

Give us a call on 020 3964 0950 or email us at

13th May 2020 – Nutritional Therapist, Neema Savvides

For advice, regular tips and support, connect with us

Through our newsletter

On Social Media