WATERBIRTH SAFETY SERIES PART 2: Is Water Birth Safe for Babies?

This is probably the question behind the question.

We can talk about maternal comfort, movement, pain relief and beautiful birth experiences until the cows come home, but what most parents really want to know is:

Is water birth safe for my baby?

For healthy women with low-risk, term pregnancies who are considered suitable for water birth, the available evidence is reassuring.

NICE’s latest review found that babies born in water were actually less likely to be admitted to a neonatal unit than babies in the comparison group who were born out of water.

Large systematic reviews have also found broadly comparable neonatal outcomes between water birth and land birth.

But how can a baby be born underwater?

This is understandably the bit that can seem slightly bonkers when you first think about it.

Before birth, a baby isn’t breathing air through its lungs. Oxygen is supplied through the placenta and umbilical cord.

During a planned water birth, the baby is born beneath the water and then brought to the surface.

This is also why trained water-birth care and appropriate procedures matter.

But why doesn’t a baby breathe underwater?

This is probably the bit about water birth that sounds the strangest.

We spend our entire lives knowing that humans cannot breathe underwater, so watching a baby emerge completely submerged can produce the fairly reasonable thought:

WHY ISN’T THE BABY BREATHING?!

The answer is that, immediately before birth, the baby isn’t breathing air anyway.

Inside the womb, the lungs are filled with fluid. Oxygen comes from the placenta through the umbilical cord, rather than from air entering the lungs.

The transition from this fetal circulation to breathing with the lungs is a process — not simply a switch that gets flicked because the baby’s head has been born.

Waterbirth International describes several physiological mechanisms that normally inhibit breathing around birth, including changes in fetal breathing movements, high resistance to blood flow through the lungs before birth, and protective airway reflexes.

Then comes the really important change: exposure to air.

As the newborn comes to the surface, breathing and major circulatory changes begin the transition from receiving oxygen through the placenta to receiving it through the lungs.

In other words, being born and beginning to breathe air are related events, but they aren’t quite the same event.

This is also why a baby born in water is brought gently to the surface after birth.

And it is important not to turn fascinating physiology into the claim that a baby could never gasp underwater. If a baby becomes compromised, normal protective mechanisms may not work in the usual way. Appropriate monitoring, careful selection of pregnancies suitable for water birth, and trained maternity care therefore remain important.

The reassuring bit isn’t that babies are somehow magically capable of breathing underwater.

They aren’t.

It’s that a healthy newborn undergoing a normal water birth is making a carefully coordinated transition from placental oxygenation to breathing air.

Which, when you stop to think about it, is rather extraordinary.

Want to go deeper?

Waterbirth International has an entire teaching module on fetal breathing and neonatal transition during water birth, including the physiological mechanisms that inhibit breathing before the baby reaches the surface.

Water Birth International – Keeping Baby Safe: Fetal Breathing⁠

RCOG – Care of the Newborn and Cord During the Third Stage of Labour⁠

ACOG – Immersion in Water During Labor and Delivery⁠

Are there risks?

There are rare complications associated with water birth, and they shouldn’t be brushed under the carpet simply because we happen to like water birth.

One is umbilical cord avulsion, which we’ll look at properly in Part 3 of this series.

There is also uncertainty around extremely rare outcomes, including neonatal death, because there simply aren’t enough events in the available evidence to determine confidently whether there is a difference between birth in and out of water.

That’s not terribly satisfying, but it is scientifically honest.

And when it comes to birth, honest uncertainty is considerably more useful than false certainty.

The short answer

For appropriately selected low-risk pregnancies, current research does not suggest that water birth increases serious adverse outcomes for babies.

Individual circumstances still matter, which is why suitability for water birth should always be discussed with your maternity care provider.

Sources

NICE – Intrapartum Care: Water Birth Recommendations

NICE – Water Birth Evidence Review

2024 Water Birth Systematic Review – PubMed

Waterbirth International Research Library

General information only; individual circumstances should be discussed with your maternity care provider.