BMI and Waterbirth: What You Should Know About Hospital Restrictions

Body Mass Index (BMI) and Using Water Immersion for Labor and Birth: A Lesson Learned (From the Doula’s Perspective)


small__8586461765.jpgLike many women desiring a birth without the use of narcotic or analgesic pain relief, a recent doula client of mine planned to use water immersion (ie, a "waterbirth") during labor and anticipated remaining in the tub for her baby’s birth. She chose a provider who assured her that giving birth in the water was a possibility at the facility where she planned to give birth. The providers also assured my client during the last couple of weeks of her pregnancy that her body mass index (BMI) would not prevent her from using the tub. (She knew to ask because of a prior experience at a different hospital.) However, her provider's assurance did not line up with the hospital's policy. After being admitted, she found out the hospital waterbirth policy restricts women with a BMI of greater than 40 from using the tub.


The first lesson from this story is that regardless of your overall health, it’s critical to have conversations about birth options during your pregnancy with both your care providers and either the nurse manager of the labor & delivery unit or the director of women’s services at the hospital, or both. As my client learned the hard way, everyone needs to be on the same page prior to birth so that there are no unnecessary surprises at the time of labor and birth.


Waterbirth restrictions for women will vary depending on the policy each hospital creates. In the Atlanta area, policies range from a BMI restriction of greater than 35 up to greater than 40. The rationale for this type of weight restriction is that in the event a mother is in need of medical assistance and unable to step out of the tub, staff members must be able to lift her out without the risk of back injury.


However, BMI is not necessarily a logical benchmark for this purpose. Weight in pounds will vary among women who have the same BMI. For instance, a 5’3” woman who weighs 230 lbs. has a BMI of 40.7 and a 5’7” woman who weighs 260 lbs. has the same BMI. (Thank you, seasoned Atlanta doula, Christine Strain, for making this astute observation.)


I couldn’t help but wonder if BMI is used simply because it is a gentler way to communicate the restriction than body weight. I asked Barbara Harper, founder of the nonprofit organization Waterbirth International, to comment on the subject.


“I distinctly remember the first case I heard, directly from the mother who was being refused a waterbirth,” says Harper. “Her statement was perhaps an indication of why they use this. Let me quote, ‘They told me my BMI was too high to qualify for a waterbirth. They use that made-up number because they just don’t have the balls to tell me I’m too fat!’”


Members of Harper’s organization worked together in 2007 to create a set of guidelines for tub use, which state “a pre-pregnant BMI should be in the patient records.” The group is in the process of revising the guidelines. Harper shares they are recommending the elimination of BMI restrictions across the board and expects the new guidelines will be posted to by the end of September. To read the current guidelines, click here.


What is the solution?

Whatever the criteria women may be subjected to, several questions remain. Since there are legitimate safety concerns, but policy may restrict some women unnecessarily, what is the most logical way to go about taking precaution while expanding access to waterbirth for the greatest number of women?


During her certification workshops, Harper suggests to hospital staff that they do a practice session with each mother in labor, asking her to get in and out of the tub without assistance. She also drills the nurses for emergencies by instructing them to unlock the wheels of the bed, roll it to the edge of the birth pool and have the mother stand up and then sit down on the edge of the bed. Once staff sees how simple it is to transfer from the bath to the bed, the restrictions on BMI are often removed.


Furthermore, if unexpected emergencies were to occur, a “rescue net” can be used to protect the staff from injury. The use of the net is combined with rolling the bed right next to the tub. Harper says there is no threat of back injury when the net is used properly. She has demonstrated its use in hospitals and birth centers, using nurses of different body types and strength to volunteer to test its effectiveness. Developed by midwives in the UK, the net is available in the U.S. through The cost is around $400 and it comes with an instructional DVD.


Based on this information, my client should have been allowed to experience labor in the water. The decision to give birth in the water should have been made collaboratively based on the history of her pregnancy, her overall health and activity level and any other complexities that may have developed during the labor suggesting she was no longer a candidate for giving birth in the water.


“Almost every woman should be given access to a bath during labor, as the best non-pharmacological comfort measure, as long as the baby can still be monitored closely with waterproof dopplers or telemetry,” Harper explains. “The water is the very best place for an overweight, parturient woman. She can move in the water, control her body, respond better to the movements of the baby and feel much better physically after the birth because of the buoyancy effect on her muscles and cardiovascular system.”


Recent studies indicate that labor time may increase for women with a higher BMI1, so the tub may be one of the best options to normalize the labor, shares Harper.


Expect the unexpected

Even after reconciling any issues related to BMI, there are other reasons women may be restricted from using a birthing tub. It would usually be because the attending midwife or physician determines the baby needs to be monitored more closely. (Although continuous electronic fetal monitoring (EFM) equipment which is also waterproof does exist, it may not be available. If continuous EFM is preferred, women may not be cleared to get into the tub or may be asked to leave the tub.)


There may also be issues of tub availability, inadequate support personnel to fill the tub, inadequate number of staff to attend the birthing mom, or a fast birth when there’s not enough time to fill the tub. For these reasons, women may want to take some time to include a few preferences in their birth plan to be used in the event that a labor or birth pool is not available when desired. Preferences could include asking for a room with a built-in bathtub, even if it is small, using the shower with either intermittent monitoring or waterproof telemetry, or even using a foot bath would be very soothing. Just the sound of water alone may cause labor to progress more quickly by increasing oxytocin levels.2


Every woman deserves clear information during pregnancy and it’s important that care providers who attend waterbirth make it a priority to provide it. Even if a woman is not deemed to be a good candidate for waterbirth, she should not have to be faced with this kind of uncomfortable change of plans for the first time when she’s in labor.



Jenny Bennett is a Hypnobabies childbirth educator and doula in the Atlanta area. You can visit her website at







2 Blue Mind: The Surprising Science That Shows How Being Near, In, On, or Under Water Can Make You Happier, Healthier, More Connected, and Better at What You Do, by Nichols, Wallace J.


Photo credit: HoboMama via photopin cc

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