Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Health & Pregnancy

Font Size

Pool Water Risky During Pregnancy


Swimmers are at great risk because they are exposed for long periods of time and because THMs can be absorbed through the skin and inhaled from the air around the pool, he says.

Studies have shown that a one-hour swim in a chlorinated pool could result in a THM dose 141 times higher than what you get taking a shower, or a dose 93 times higher than drinking a glass of tap water.

Further research is needed to understand the link between THMs and potential health risks, writes Nieuwenhuijsen. In the meantime, he calls for swimming pool owners to reduce THM levels "as far as possible ... while maintaining effective control against waterborne microbiological disease."

The other studies that Nieuwenhuijsen mentions have actually found lower levels of THMs than this study did, Bennett says.

Also, all studies of THMs have been done in Europe, he says. "We don't know whether they chlorinate the same as we do in U.S. pools, whether they maintain pools like we do."

"I see this as more of a water quality problem than a swimming pool problem," Bennett says. "If the chemical is that bad, we need to be looking at how it got into drinking water. I would be much more concerned about that."

Pregnant lifeguards at indoor swimming pools have been known to suffer from different illnesses -- like certain lung problems -- because of the continuous exposure to chlorinated water, he tells WebMD. Whether THMs are a risk for pregnant women who are not lifeguards, "I just don't know," he says. "You can't say from this study that it is."

1 | 2

Pregnancy Week-By-Week Newsletter

Delivered right to your inbox, get pictures and facts on
what to expect each week of your pregnancy.

Today on WebMD

hand circling date on calendar
Track your most fertile days.
woman looking at ultrasound
Week-by-week pregnancy guide.
Pretty pregnant woman timing contaction pains
The signs to watch out for.
pregnant woman in hospital
Are there ways to do it naturally?
slideshow fetal development
pregnancy first trimester warning signs
What Causes Bipolar
Woman trying on dress in store
pregnant woman
Woman looking at pregnancy test
calendar and baby buggy
dark chocolate squares