Are hot tubs or baths really bad for pregnant woman?

Recently I was kicked out of a YMCA hot tub because I could not hide the fact that I was obviously  pregnant. The sign simply said that pregnant woman should avoid exposure to extreme heat, so I figured I was not doing anything risky to be in a slightly hot tub, especially as I was only dipping my legs in! Plus, I figured that I could make that call for myself as a responsible (not drunk) adult who can follow my body's signals.

Whether it was a case of a legalistic lifeguard, or an insurance matter I don't know, but in 5 pregnancies, and lots of hot tub use over the years, I am happy to say that this was a first for me.

Anyhow, it got me thinking about the subject and as usual I will probably get myself into some hot water (no pun intended:) with doctors over my opinions on the subject, but when has that ever stopped me?

So, a little background here: hyperthermia, overheating or artificial fever therapy is an ancient technique used by the Greeks and Romans, as well as in the sweat lodges of the Indians. Hippocrates, Celus, Galen and other ancient greats of medicine praised many hot water therapies for its curative properties. From the start of human existence we have utilized this healing technique of overheating for immune defense against infection, as well as detoxing. It burns out harmful bacteria, viruses and organisms that cannot survive the heat, while keeping the healthy ones alive. It even speeds up the metabolism! In the same way that fevers work, causing an artificial fever is greatly beneficial for the health!

Fevers and all overheating therapies are indeed a great medicine, and that it can help to cure many "incurable diseases". In biological clinics in Europe, artificially induced fever, mostly in the form of overheating baths, has been used successfully to treat such conditions as rheumatic diseases, skin disorders, insomnia, arthritis - and even cancer! Dr. Josef Issels has said, "Artificially induced fever has the greatest potential in the treatment of many diseases, including cancer." This remark is made by one of the leading cancer specialists in the world! (There are many studies showing increased survival from cancer among those treated with hyperthermia.)

Such giants of medical science as Nobel Prize Winner, Dr. A. Lwoff, Dr. Werner Zabel, and Dr. Josef Issels, recommend and use fever therapies extensively. Recently, a research team under the direction of Dr. David S. Muchles, from Oxford University, reported that studies confirmed what ancient physicians and biological doctors knew all along - that fever is effective in combating many diseases.

According to a Dr. Paavo Airola, Ph.D., N.D. there is "no danger for healthy people to take sauna or other steam or hot baths. . . on a regular basis as a preventive, cleansing and health-building measure, as millions of people are doing both here and in Europe." (That said, ill patient's heart conditions, his ability to perspire and his general vitality should be checked closely.)
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According to the the National Institutes of Health and the American College of Obstetricians and Gynecologists though, they discourage this wonderful therapy during pregnancy. So, why are pregnant woman banned from this health giving therapy of hot water or even steam or saunas, when it seems doubly important for them to be able to detox from the additional waste from the baby???

The reason seems obvious: The heart of the pregnant woman needs to work harder to pump blood to the skin's surface with hyperthermia, which they believe can quickly cause dehydration and dizziness or even fainting. High heat from a bath, sauna or steam room could place an extreme burden on the mother’s heart and circulation at a time when her heart is already working hard, and also consequently bring less blood to the baby they say. Some test findings do suggest an association between the use of a very hot tub or hot bath during early pregnancy and the risk of miscarriage. . .possibly because of that lacking blood.

For instance, there is some evidence that a prolonged and forced overheating (at 113 degrees Fahrenheit) of a very scared/stressed animal (rabbits) does cause the death of their 3 day embryo, those rabbits who only had 10 minutes had no ill effects even at this most susceptible stage. The study even stated that artificial fever while generally regarded as a safe form of therapy for humans even in late pregnancy, the relatively delicate and rapidly developing blastocyst at about the time of implantation seems to be most sensitive to prolonged heat.
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There are a number of flaws with this study though, (IMHO) for one thing, it's test subject was a very jumpy animal, who's heart would likely be racing and caused enough stress simply by being handled or immersed in any temperature water! (As opposed to it being calmed) Also, they were caged, with only their noses above water. Being left in this intensely stressful position for any length of time is cruel punishment and very stressful I'm sure!

 Also, unlike humans, rabbits pant and use their ears to cool off, (and do not sweat) so being too emerged, and maybe too stressed, they are likely going to feel even hotter then a human would in the tub. Without the choice of whether or not to get out if they start feeling too hot, or dizzy, these caged rabbits were in a much different boat then a human would ever choose to be in. (Other studies with humans though did seem to show an increase in early miscarriage (first 4 weeks or so) associated with increased hot tub use. . .Source)

Another issue with that test is that the average temperature of a hot tub is much below what was tested on the rabbits (113 degrees). The U.S. Consumer Products Safety Commission (CPSC) after some study on the subject recommended temperatures no higher then 104 degrees for hot tubs in the States, as a number of deaths have been caused by temperatures of over 110 degrees. Soon thereafter, Underwriters Laboratory wrote rules regarding saunas and spas. They mandated that any manufacturer of these types of devices that wished to display the Underwriters Laboratory label could not have a temperature control on their hot tub which exceeded a temperature greater than 104 degrees Fahrenheit. Therefore, in the US, unless you're using an ancient hot tub or one without a Underwriters Laboratory label, the hot tub temperature is probably safe, at least in short doses, in early pregnancy. There are still some countries, (like Japan) however, where you will find hot tubs allowing temperatures far exceeding the 104 degrees Fahrenheit limit. . .
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Unless you are purposefully trying to make yourself miserable though, no one in their right mind would intentionally get in a bath or hot tub much over 104. Most people are comfortable at 98-103 actually, according to the people polled in one study. And even if they did like it hotter, most people would feel free to get out if they felt at all light headed. . .which is very unlikely if they limited their time in there and didn't submerge themselves up to their noses like the rabbits.

So I have personally concluded that hot baths are safe in all stages of pregnancy. On the other hand, intentionally using very hot baths (104-110 or above) to cure sickness is probably best avoided in at least the early weeks of pregnancy. That being said though, I know a lady who had been doing serious hypertherapy at home when she found out she was expecting, and never had a miscarriage or side effect happen to the baby. (Unless you count being huge a side effect!)

Still though, as a precaution, I choose to take a common sense approach to the subject, using moderation and keeping hydrated before or after a bath. I am also careful to listen to my body's signals like: fatigue, lightheadedness, or dizziness. Thus I feel confident to ignore some more of the fear mongering that pregnancy is so entrenched in.

 And while I don't claim to be a medical authority on the subject, I do feel that woman have the right to make up their own mind on the subject, (even if it is to intentionally attempt to cause a miscarriage) and not be bullied into compliance about their bathing habits! Much less by a lifeguard in late pregnancy, where there is apparently no danger of a miscarriage from hypertherapy! So next time someone tells you to avoid or get out of a hot tub/bath, tell them if they know you are pregnant, (i.e. you are showing) then you are most likely way past the (slightly) risky time anyways, and they can just rest easy. . .(and mind their own business!)