Pregnant and Overweight?

Pregnant and Overweight

Pregnant and Overweight ? Read about the issues of going through a pregnancy when overweight and what you can do to improve your health and have a healthy baby. It’s not as if anyone intends to be overweight or obese. There are many factors that affect a person’s weight but being pregnant and overweight or obese can increase the risk of complications both for the pregnancy and the baby.

PLEASE NOTE: Dr Penman is not a specialist in nutrition, and this blog post is for information only. If you are concerned about your weight and the effect it may have on your pregnancy and scans, please contact your GP who will be able to refer you to the right specialist. 


Being Overweight/Obese In The Western World

In Western countries 28% of pregnant women are overweight and 11% are obese. In the UK 33% of pregnant women are overweight, 23% of pregnant women are obese. That’s a whopping 56% of pregnant women are over the recommended BMI for their height.

The Risks Of Being Pregnant And Overweight/Obese

There are added risks being pregnant and overweight/obese. Obesity is a condition characterized by excess of body fat and a BMI over 30. Being overweight is an added stress on the body and, when coupled with a pregnancy, can add in significant complications such as pre-eclampsia, hypertension, diabetes and thromboembolism. For more information on these conditions, please visit Pregnancy Complications. It can also raise the risk of fetal abnormalities.

How Does Being Overweight Affect My Baby Scans? 

Position of baby pregnant and overweightBaby scans work by sending high frequency sound waves through the abdomen and through the uterus. The sound waves bounce off the baby and the echos then return to the probe and are turned into images on the scan monitor.

A raised BMI of the mother means the body fat between the uterus and over the belly is raised, which means the ultrasound sound waves have much more body tissue to travel through. This results in the echo coming back weaker, so the images received lack detail and look fuzzy, making the fine details difficult to observe.

Not only do images of your baby come back fuzzy, but this makes checking for chromosomal abnormalities and performing an early gender scan (between 11-13 weeks) much more difficult.

Concerns For The Fetal Medicine Specialist: 

When the fetal medicine specialist, a consultant such as Dr Penman, scans a lady with a raised BMI, he has a number of concerns :

  • Low scan image quality; it is harder to assess the wellbeing of the baby and the structures that are forming and is almost always impossible to achieve 3D and 4D images with mothers with a BMI over 35.
  • Time for the appointment; a certain amount of time is allocated for baby scans. This is usually much more time than is required, ensuring that no one is kept waiting beyond their appointment time. However, it takes a lot longer to scan a mother with a raised BMI, particularly if the BMI is over 39.
  • Number of appointments; more appointments are needed because of the difficulty in scanning.

Managing The Appointment:

Dr Penman is a very experienced fetal medicine consultant and does his best to check the baby is healthy and developing properly when the mother has a raised BMI.

Dr Penman is very aware of high-running emotions of parents when considering their baby’s health, and does his best to ensure that all his measurements and checks are accurate as is possible, explaining them thoroughly before the appointment ends.




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This is interesting! I hadn’t thought through that to get a good image you needed to have less body fat. I’m on the chubby side myself, so it’s good to hear that Dr Penman is considerate and sympathetic to the parents’ feelings.


I never would have thought that having a higher BMI than usual would make it harder to get good scan pictures. But, I went to have a Nuchal Scan with Dr Penman last week, and he was absolutely lovely – I didn’t feel embarrassed to be a bigger lady and having a scan. Thank you, Dr Penman!