4D Ultrasound Scans Reveal Not So Surprising Effects of What Smoking Does To a Fetus

by Andy Peloquin

smoking during pregnancy

There is no two ways about it: smoking is bad for your health. Every health and wellness website cautions you to quit smoking. Every doctor tells you the same thing that you’ll find in every book on pregnancy: you have to stop smoking in order to keep your baby healthy.

The truth is that smoking has horrible effects on your health–before, during, and after pregnancy. It can cause high blood pressure, an increased risk of cardiovascular disease, pulmonary problems, reduced blood flow, and so many more health problems. But the threat is even higher during the months of pregnancy when a fetus is growing inside of you.

The Effects of Smoking on Babies

A team of researchers at Durham University conducted a study into the effects of smoking on unborn babies(1), and the results will blow your mind!


To examine the effects, the researchers gathered 4D ultrasound scans taken of unborn fetuses at four times in their growth–between 24 and 36 weeks. 80 scans were taken of 20 different fetuses. Of those 20 fetuses scanned via ultrasound, 16 belonged to mothers who did not smoke and 4 belonged to mothers who consumed an average of 14 cigarettes a day.

Upon examining the 4D ultrasound scans, the researchers discovered that the babies of the smoking mothers appeared to be grimacing as their mother was in the process of smoking a cigarette. For fetuses at this stage of gestation, the amount of mouth movement involved in this grimacing was much higher than normal. This means that mothers who smoke are affecting their baby’s health and development. Worst of all, the baby knows that something is wrong. Smoking causes your unborn baby to suffer even before they are born.

These findings have led the researchers to believe that smoking can negatively affect not just the mother’s health, but also the fetal nervous system. The fetal nervous system controls the movements of the fetus in-utero. Smoking can cause the nervous system to develop at a different rate–often more slowly–than normal.

According to a study published in June of 2014(2), smoking affects an infant’s ability to process speech. Smoking affected the brain physiology of the babies, which led to an increased risk of developmental problems. Prenatal exposure to tobacco and nicotine is one of the worst things you can do for your baby!

A few more effects of prenatal exposure to tobacco include:


And don’t think that the exposure to nicotine ends when you give birth! Even smoking after pregnancy can cause the nicotine and tobacco to be passed to the little one via your breast milk(3).

The truth is that smoking is going to have HORRIBLE consequences for the baby–both during and after pregnancy. As the mother, it’s in your best interest to quit smoking for the duration of your pregnancy and all through breastfeeding.


  • [1] https://onlinelibrary.wiley.com/doi/10.1111/apa.13001/abstract
  • [2] https://www.researchgate.net/publication/6379144_Smoking_during_pregnancy_affects_speech-processing_ability_in_newborn_infants
  • [3] https://onlinelibrary.wiley.com/doi/10.1111/j.1651-2227.2004.tb03023.x/abstract