article_snippet: A new scientific review says ultrasound – which uses high-frequency sound waves to provide images of the foetus – could expose the foetus to unknown risks.
article_snippet: ‘Ultrasound scanning in the embryonic period is an invaluable resource in several important scenarios where the embryo is at possible risk.
article_snippet: There are presently no grounds for questioning the safety of diagnostic ultrasound in this context.
article_snippet: However, ultrasound imaging is increasingly being used without obvious medical justification and we have to be aware of the possibility of subtle long-term adverse effects, particularly in the first weeks of gestation when the embryo is potentially the most vulnerable.
article_snippet: The US Food and Drug Administration issued similar advice in December, saying excess ultrasound at any stage in pregnancy should be avoided.
article_snippet: Dr Lees said one of the possible harms might come from the slight heating effect produced by ultrasound which was more easily dissipated by the placenta after 10 weeks of pregnancy.
article_snippet: The review highlights the various types of ultrasound, including B-mode – the most commonly used form of ultrasound in obstetrics – colour and pulse wave Doppler.
article_snippet: Additionally, there has been a move to perform 3D and 4D ultrasound scans earlier in pregnancy, states the paper.
article_snippet: 4D ultrasound is ‘real time’ scanning and involves higher power outputs as the scanning time is longer, typically by several minutes, and should not be the sole purpose of souvenir images or video recordings in early pregnancy.
article_snippet: Dr Sadaf Ghaem-Maghami, chair of the RCOG’s Scientific Advisory Committee, said ‘B-mode ultrasound used for clinical reasons from conception to 10 weeks of gestation is safe and the benefits outweigh any theoretical risks.
article_snippet: We also emphasise that any healthcare professional involved in the use of ultrasound is aware of the safety principles of ultrasound.
highlights_snippet: Slight heating effect produced by ultrasound is one subtle side effect .
  