December 16th, 2010 by Shaun Day

As the weather starts to get colder, we’re getting a lot of questions about electric blankets, and one particular question which seems to be concerning a lot of people is if they should be using an electric blanket when pregnant. Pregnancy advice websites seem to be filled with dos and don’ts on every aspect of pregnancy, but a lot of the information out there is conflicting, advice on electric blankets is no exception. We decided we needed to do more than a quick Google search before we could cut through the confusion and advice anyone on an issue as important as this one. If you’ve also got lost in the sea of opposing recommendations on this issue take a look at what we found and hopefully it will help. For more information on electric blanket safety, check out our electric blanket safety tips. So what is it that’s worrying people? The issues that seem to be concerning people are the fear that an electric blanket could raise body temperatures to levels that cause miscarriage, or that the electromagnetic fields generated by the blankets may cause birth defects or even miscarriage of your baby. What did we do to find out? We decided we really needed to look directly at the medical research, so we took a trip to the local university Library and checked out some of the most significant studies on electric blankets during pregnancy. We choose four of the most respected research projects carried out on this topic to compare. You can find the complete references to these research projects at end of this article should you wish to check the research out for your self. What we found – Body Temperature The research generally concluded that fear of harm coming to your bay due to a rise in body temperature is extremely unlikely to be caused by an electric blanket. If your body temperature rises significantly to temperatures above 39⁰c there is some risk of miscarriage or spine and nerve damage. However, this is far hotter than you are ever likely to want to have your electric blanket. If you want to be on the safe side though we do recommend you make sure you have a newer electric blanket that allows you to control the exact temperature. This is not only safer during pregnancy but also prevents your blanket from getting hot enough to cause fires or to burn your body whilst you are sleeping. What we found – Electro Magnetic Fields It seems that there is also no significant evidence of risk from electromagnetic fields for the majority of your pregnancy. However, the research findings on this are a little less straightforward and there are both risks and advantages to using an electric blanket at different stages of the pregnancy which are worth explaining in a little more depth. The four pieces of research we looked at all conducted there experiments slightly differently, typically, however, thousands of women who had recently become pregnant or were planning to become pregnant were interviewed. From these interviews, the level of electromagnetic fields the women were exposed to was determined, as well as whether or not they used electric blankets. Other factors that are known to cause problems in pregnancy such as alcohol, smoking and caffeine consumption were also taken into account. Smaller numbers of women, some who use electric blankets and some who did not were then selected at random to be monitored throughout all stages of there pregnancy. The research findings were not completely consistent; it was generally found however that women who used electric blankets on very high settings for short amounts of time. (IE quickly turning the blanket on high to warm up) were at a slightly increased risk of miss carriage particularly during the first seven weeks of pregnancy. The research also found that women who used electric blankets during the last month of there pregnancy were at a slightly increased risk of giving birth to an underweight child. However, women who used electric blankets on low settings for extended periods of time (IE keeping the blanket at a constant temperature overnight) were not exposed to particularly high magnetic fields as the blanket uses less electricity to regulate the temperature in this way. The research actually found that women who did this were at a slightly decreased risk of miscarriage. Our Recommendations: So based on this what do we recommend? In the first seven weeks the risks might be slim but when it’s your baby we’re talking about we don’t recommend using an electric blanket at this stage, this is when you’re most at risk of miscarriage from Electromagnetic fields. So instead invest in a hot water bottle or an extra thick duvet to stay warm. After this first seven weeks, there doesn’t seem to be any evidence of risk, so if you do like an electric blanket there should be no problem getting it back out again, in fact there is evidence that it can be beneficial for the baby. However, to be on the safe side keep it at a low temperature for extended amounts of time rather than putting it on high for short bursts as that will decrease the electromagnetic field generated it also ensures that you do not raise your body temperature too high or burn your self. For the last month of pregnancy it’s probably best to stop using the blanket as there is a slight risk that the baby could be born underweight and also should your water break whilst your using the blanket there could be a risk of electric shock Our most important recommendation though is not to trust any single source of information, (not even this one!) See what else you can find, try and look at two or three different sources before you make any decision, and if you come across anything new please feel free to let us know in the comments. If you’d like more details on our findings, the medical journals we used are listed below; most libraries should be able to get hold of these for you. Further Reading: A Nested Case-Control of Residential and Personal Magnetic Fields Measures and Miscarriages Published in the January 2002 edition of the journal Epidemiology by a team lead by Doctor Geraldine M. Lee, P 21 - 31 The Use of Electric Bed Heaters and the Risk of Clinically Recognized Spontaneous Abortion, Published in the July 2000 edition of the journal of Epidemiology by a team lead by Doctor Geraldine M. Lee P 406 - 415 Spontaneous Abortion and Exposure to Electric Blankets and Heated Water Beds Published in the January 1998 edition of the journal Epidemiology by a team lead by Doctor Kathleen Belanger P 36 - 42 Exposure to Electromagnetic Fields during Pregnancy with Emphasis on Electrically Heated Beds: Association with Birth weight and Intrauterine Growth Retardation Published in the May 1995 edition of the journal Epidemiology by a team lead by Doctor Michael B. Bracken P 263 - 270