Are mobile phones and wifi safe while pregnant?

The verdict

Yes, and the UK Health Security Agency has published on it directly, which makes this one of the few environmental questions in pregnancy with a named national position behind it.

On wifi, UKHSA states that there is no consistent evidence that exposure to radio signals from wifi devices adversely affects the health of the general population. It notes the signals are very low power, typically 0.1 watt, that is 100 milliwatts, in both the user device and the router, and that the frequencies used in wifi are broadly the same as those from other radiofrequency applications such as FM radio and mobile phones.

Its conclusion is unusually direct: UKHSA sees no reason why wifi should not continue to be used, including in the education sector, and no additional action is necessary communally or individually to reduce exposure further.

What the wifi research actually looked at

This is not an opinion arrived at from first principles. The Health Protection Agency, whose functions now sit within UKHSA, carried out a systematic programme of research into wireless networks and their use in schools, including measurements of exposures from those networks.

That study supported UKHSA's view that exposures from wifi devices are small in relation to the guidelines published by the International Commission on Non-Ionizing Radiation Protection, which are the standards UKHSA recommends. It also showed that the time-averaged output power of wifi devices is generally lower than that of mobile phones, and that exposure from wifi devices is likely to be lower than from mobile phones used for voice calls, because wifi antennas tend to be further from the body during normal use.

The results were provided to the Advisory Group on Non-ionising Radiation and taken into account in its comprehensive review of the scientific evidence.

Mobile phones carry the higher exposure

Between the two, phones matter more, and UKHSA says so. It states that the highest public exposure from radio wave sources arises from mobile phones when they are used for voice calls where the device is held close to the body.

Its precautionary advice comes from the Independent Expert Group on Mobile Phones, whose recommendations were accepted by government. Two of those are worth quoting because they are frequently misrepresented. Excessive use of mobile phones by children should be discouraged. And adults should be able to make their own choices about reducing their exposure should they so wish, but be able to do this from an informed position.

Note what that is and is not. It is a statement that people may choose to reduce exposure if they want to, made explicitly to let people decide for themselves. It is not a finding of harm and it does not name pregnancy.

The practical measure UKHSA gives is simple: moving the phone away from the body, as when texting, results in very much lower exposures than if a phone is held to the head.

Base stations, masts and 5G

Masts generate more anxiety than handsets and carry far lower exposures.

UKHSA's guidance on mobile phone base stations reports measurements taken by a predecessor organisation at 118 locations across 17 base station sites, in which average exposures were found to be 50,000 times below the ICNIRP public exposure guidelines and the maximum found at any location was 500 times below them. It adds that the strength of radio waves from base station antennas falls off very quickly with increasing distance, so fields at ground level and in places normally accessible to the public are many times below guideline levels.

On 5G specifically, UKHSA notes that over the decades there has been a general trend towards increasing numbers of smaller transmitters serving smaller areas with reducing radiated powers, that many measurements continue to show public exposures well within the international guideline levels used in the UK, and that the higher frequencies proposed for 5G are not new, having been used for point-to-point microwave links and other transmitters present in the environment for many years. The ICNIRP guidelines apply up to 300 GHz, well beyond the maximum frequencies proposed for 5G.

What nobody has studied, and what that means here

It is worth being straight about the limits of this. UKHSA's statements are about the general population. There is no dedicated body of research on radiofrequency exposure in pregnancy specifically, and no health body publishes pregnancy-specific advice on phones or wifi.

That absence reads differently here than it does on, say, an untested cosmetic treatment, and it is worth explaining why. Radiofrequency exposure has been studied for decades across the whole population at exposures far higher than a router produces, and the guidelines are set with safety margins built in. The absence of a pregnancy-specific study is not the same as an unmeasured exposure.

Phone in your pocket, laptop on your bump

These are the questions people actually type, and the honest answer follows from what is above rather than from any specific study.

No body publishes a position on carrying a phone in a pocket during pregnancy or on resting a laptop on a bump. The relevant fact is UKHSA's, that exposure falls sharply with distance and that holding a device away from the body gives very much lower exposure than holding it against the head.

If you want to reduce exposure, UKHSA has explicitly said adults may choose to and told you how. Using speakerphone or headphones, texting rather than calling, and putting a laptop on a desk rather than on your lap are all zero-cost changes. None of them is recommended for pregnancy by anyone, and none of them is unreasonable.

The heat from a laptop is a separate thing

One genuine, non-radio issue worth separating out. A laptop running hard produces real heat, and resting it directly against skin for long periods causes low-grade burns in anybody, pregnant or not. That is a thermal question rather than a radio one, and it is the reason to use a desk.

The short version

UKHSA has looked at wifi and says no consistent evidence of harm and no action needed. Phones carry the higher exposure of the two, and the only precautionary advice is to hold them away from your head, offered so adults can choose for themselves. Base station exposures are tens of thousands of times below the guidelines. There is no pregnancy-specific guidance because there is nothing pregnancy-specific to say.