6.2 Water Immersion, Waterbirth & Non-Supine Birth Positions

Water Immersion Versus Waterbirth

The AMCB task list separates two related but distinct competencies: attends and manages waterbirth and attends and manages birth with the mother in various non-supine birthing positions. Immersion during labor and birth in water are not the same intervention and do not carry the same evidence.

Immersion During the First Stage

Evidence for water immersion during the first stage of labor is favorable and largely uncontested. Cochrane reviews report:

• Shorter first stage of labor.
• Reduced use of epidural, spinal, and parenteral analgesia.
• Higher maternal satisfaction and sense of control.
• No increase in adverse maternal or neonatal outcomes.

Warm water reduces circulating catecholamines, provides buoyancy that permits effortless position change, and delivers continuous tactile counter-stimulation to the pain gate.

Birth in Water (Waterbirth)

The evidence for delivering the infant under water is genuinely contested, and the midwife must be able to state both positions accurately.

• ACOG and the AAP conclude that immersion in the first stage may be offered, but that there is insufficient evidence of neonatal benefit from birth in water, and they recommend that birth occur on land. Their concern rests on rare but serious case reports: neonatal drowning or near-drowning, umbilical cord avulsion with neonatal hemorrhage when the newborn is lifted too quickly, and waterborne infection including Pseudomonas and Legionella.
• ACNM and the Royal College of Midwives support waterbirth as a reasonable option for appropriately selected patients under rigorous protocol with documented informed consent.

Eligibility for Waterbirth

Singleton, vertex presentation, 37 0/7 weeks or later, spontaneous or well-established labor, a reassuring fetal heart rate, clear amniotic fluid, no parenteral opioid within the preceding interval and no neuraxial analgesia, no maternal fever or infection, no bleeding beyond normal show, and no condition requiring continuous electronic monitoring.

Safe Waterbirth Protocol

1. Water temperature at or below 37.5 °C (99.5 °F), checked and documented; maternal temperature hourly. Maternal hyperthermia raises fetal temperature and metabolic demand.
2. Two attendants present at the birth and a rehearsed evacuation plan — the tub must be exitable in seconds.
3. Fetal heart rate by waterproof Doppler every 15–30 minutes in the active first stage and every 5 minutes or after every contraction in the second stage.
4. Hands off. Do not touch the fetal head, do not apply fundal pressure, and do not attempt to guide the birth. Allow the baby to be born entirely under water.
5. Bring the newborn gently but promptly to the surface, face first, without traction on the cord. Pulling the infant up too forcefully is the mechanism of cord avulsion.
6. Once the face has surfaced, it stays out of the water. Never resubmerge the newborn — the first breath abolishes the dive reflex that protected the airway during the birth.
7. Keep the newborn's body warm and largely in the water while skin-to-skin, then exit the tub for cord clamping, the third stage, and any repair.

Mandatory Exit From the Tub

Vaginal bleeding beyond show, meconium-stained fluid, any abnormal fetal heart rate, maternal fever or hypotension, shoulder dystocia, a newborn requiring resuscitation, a need for perineal repair, or maternal request.

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Non-Supine Birth Positions and Promoting Second-Stage Progress

Why Position Matters

The supine and lithotomy positions reduce the functional dimensions of the pelvic outlet, force the fetus to ascend against gravity, and add aortocaval compression. Cochrane evidence for upright versus supine positions in the second stage without an epidural shows a shorter second stage, fewer assisted vaginal births, and fewer episiotomies — balanced against a modest increase in second-degree tears and in estimated blood loss over 500 mL.

[!IMPORTANT] Nuance for epidural patients. The BUMPES trial found that in nulliparous women with a low-dose epidural, an upright position in the second stage did not improve and may worsen the rate of spontaneous vaginal birth compared with lying down. The evidence favoring upright positions comes from women without neuraxial analgesia. Individualize rather than applying one rule to everyone.

Promoting Progress in the Second Stage

• Change position every 20–30 minutes when descent is slow; the position that works is usually the next one tried.
• Verbal encouragement and responsive coaching that follows the patient's own urge outperforms counted directed pushing.
• Delayed (passive) descent for 1–2 hours is appropriate with an epidural and no urge to push.
• Use a birth stool, squat bar, rebozo, or partner support to make upright positions sustainable.
• Never apply fundal pressure. It is associated with uterine rupture, perineal and anal sphincter injury, and worsened shoulder dystocia, and it has no demonstrated benefit.