Home
About
About Us Our Team
Our Services
All Departments Fertility Reproductive Surgery Recurrent Miscarriage Gynaecology Services
Pricing
Consultation Fees Fertility Assessment Packages Fertility Treatment Prices Investigations costs
FAQs
Contact us
Book an Appointment Send Message

JIVA Fertility

Body weight and Fertility

Maintaining a healthy bodyweight is important when trying to conceive. Being overweight or underweight can make it harder to get pregnant and may increase pregnancy risks.

What is Body Mass Index?

Body Mass Index (BMI) is a simple way to check if your weight is in a healthy range for your height. Although it does not distinguish between fat, muscle, or bone, it is still a useful measure for assessing weight-related health risks.

Check out the NHS BMI calculator.

BMI ranges

For Caucasians:

Less than 18.5 – Underweight
18.5 - 24.9 – Healthy weight
25 - 29.9 – Overweight
30 and above – Obese

For South Asian, Chinese, Middle Eastern, Black African, and African-Caribbean individuals:

Under 18.5 – Underweight
18.5 - 23 – Healthy weight
Over 23 – Increased risk (Overweight)
Over 27.5 – High risk (Obese)

Since people from different ethnic backgrounds may have a higher risk of developing health problems at lower BMI levels, guidelines have been adjusted to reflect these risks.

How does my BMI affect fertility?

For Women:

Underweight:

Can cause irregular and infrequent ovulation or sometimes no ovulation – your periods are delayed or sometimes absent.

Overweight and Obesity:

Can cause irregular and infrequent ovulation or sometimes no ovulation – your periods are delayed or sometimes absent.
Can increase the risk of developing symptoms associated with polycystic ovary syndrome (PCOS).

Does my BMI affect the chances of getting pregnant with fertility treatment and having a healthy baby?

Yes, your BMI can impact both your chances of conceiving with fertility treatment and having a healthy pregnancy.

Impact on IVF/ICSI success

There is strong evidence that being underweight or obese can lower the success rates of IVF and ICSI treatments.

The response to ovarian stimulation is reduced, leading to fewer eggs retrieved during IVF/ICSI in women who are obese.
Women who are underweight are more likely to have lower egg quality and poor implantation rates.
Higher BMI is linked to higher miscarriage rates

Pregnancy risks with a high BMI

If you conceive with a BMI in the obese range, you are at an increased risk of pregnancy complications, such as:

Gestational diabetes (diabetes that develops during pregnancy)
High blood pressure and pre-eclampsia (which can lead to serious complications for both mother and baby)
Thrombosis (blood clots), which can be life-threatening
Increased likelihood of requiring a caesarean delivery
Increased risk of heavy bleeding (postpartum hemorrhage) after birth

Impact on baby’s health with High BMI

Children born to individuals with obesity are at an increased risk of:

Birth defects
High birth weight (macrosomia), which can lead to difficulties during birth
Obesity and metabolic disorders later in life

Should I lose weight before pregnancy?

If your BMI is in overweight or obese range, losing weight to a normal BMI range before getting pregnant can improve your chances of conception and reduce pregnancy risks.

If you are not ovulating regularly, even losing just 5-10% of your body weight can significantly help regularize ovulation.
If your BMI is over 35, additional medical assessments may be needed before fertility treatment is offered.
If your BMI is over 40, pregnancy is generally not advised until weight is reduced.

How can I optimise my weight for optimal fertility?

Eat a balanced, healthy diet – Focus on whole grains, fruits, vegetables, and lean proteins.
Stay active – Aim for 150-300 minutes of moderate exercise per week (such as brisk walking, jogging, or swimming).
Reduce portion sizes – Be mindful of calorie intake.
Avoid sugary drinks and processed foods – Choose water, homemade meals, and natural snacks.
Be aware of emotional eating – Seek support if needed.
If you feel that you have always been underweight and are struggling to gain weight OR struggling with weight loss, speak to your doctor. They may refer you to a dietitian or a weight management program or in some circumstances to bariatric specialists for discussing surgical options.

Medical conditions that can affect weight and fertility

Some health conditions can make weight management harder and impact fertility, including:

Polycystic ovary syndrome (PCOS)
Underactive thyroid (hypothyroidism)
Type 2 diabetes

If you suspect a medical condition is affecting your weight, speak to your doctor for further assessment and support.

Underweight - effects on Pregnancy

Increased risk of:

- Miscarriage

- Premature labour and birth

- Babies with low birth weight or growth restriction

How can I put on weight safely?

The best way is to get help from a qualified healthcare professional - to assess for any health conditions that may have caused weight loss

‍

A balanced diet is recommended. For JIVA Fertility patients, we have a dedicated professional Dietician-Nutritionist who will be able to provide evidence-based dietary guidance tailored to your fertility/PCOS journey. www.YourGreekDietitian.com

‍

Regular Exercise will improve your appetite - we encourage you to build muscle with strength training or yoga.

Men, Weight, and Fertility

Men with a high BMI may struggle with fertility due to:

Lower testosterone levels
Poor sperm quality
Increased risk of erectile dysfunction

Blank / Empty placeholder

Blank / Empty placeholder

At JIVA Fertility, we assess how weight affects fertility and help you take the right steps for a healthier pregnancy.
Every small step towards a healthy weight improves your chances of conceiving and having a safe pregnancy!

Come & Visit Us

New York, NY 10001

123 Main Street

Apt 4B

Contact: +123 456-7890

Los Angeles, CA 90012

456 Elm Avenue

Suite 300

Contact: +122 555-1212

Book an Appointment

Please use this form only for general enquiries or appointment requests. Do not include personal health information (PHI) in this form.

Name

Phone

Preferred Date

Please note we are open only on Monday, Tuesday and Thursdays, excluding Public holidays.

Contact Request

Message (Optional)

I understand this form is NOT for sharing personal medical or health information, and I agree to be contacted by JIVA Fertility.

Thank you for submitting your appointment request!
Our team will review your details and contact you within 24 hours (excluding weekends and public holidays) to confirm your appointment date and time.

Oops! Something went wrong while submitting the form.

This site is for information purposes only and is not a substitute for medical consultation, diagnosis, or treatment. We suggest arranging a suitable specialist appointment if you wish to discuss your medical issues.