Meconium and Birth – What You Need To Know
As you prepare for labour, you might be told to watch for meconium if your waters break before birth.
It’s commonly thought the sign of green-stained waters is a sign your baby is in distress and needs to be born urgently.
What is the truth about meconium and how dangerous is it? We answer those questions here.
What is meconium?
Meconium is your newborn’s first poo. As your baby is developing in your womb, they practice breathing movements and swallow the amniotic fluid. The fluid has your baby’s hair and intestinal cells in it, among other things.
Over time, the debris left in your baby’s intestine builds up into a green black tar-like substance, called meconium. By the time your baby is ready for the world outside, their entire large bowel is filled with this sticky substance.
Your baby will usually pass the meconium as their first poo within the first 12 hours after birth. Your first milk, colostrum, has a laxative effect and helps to move this substance out.
Be warned – it’s quite sticky! Many new parents have been pooped on by their baby when having skin to skin after birth and find it hard to clean off.
What happens when meconium is passed before birth?
Sometimes babies pass their first poo before they’re born (statistics vary between 5-20% of births). If this happens, their skin is often tinged a green-yellow, thanks to the greasy vernix coating.
There’s two main reasons why babies poop in the uterus:
- Their digestive system has matured
- Something has triggered a sudden compression of the cord or head.
Do babies poop when distressed?
It’s believed meconium passed before birth is a sign your baby is in immediate danger.
But this isn’t always the case. If the baby’s head or cord is compressed suddenly and quickly, it can cause their sphincter muscles to relax. The poo can be pushed out. Compression of the head and cord happens during labour and babies can have a trail of meconium following their body.
If your waters break and are stained a green-yellow then these are called meconium-stained.
Your care provider will want to check your baby’s wellbeing. This can be done by measuring their heart rate, which is a good indicator of whether your baby is happy or having a hard time in there.
Can meconium be dangerous for babies?
Babies can swallow meconium while in the womb and it won’t hurt them as it’s sterile. The biggest concern is why your baby has pooped and if they’re in any distress.
There’s also the small possibility your baby will inhale meconium into their lungs. This is called meconium aspiration syndrome (MAS).
How do babies inhale meconium?
When your baby is in your womb, they are receiving oxygen from the placenta via the umbilical cord. They don’t begin to breathe with their lungs until after birth.
Until then, your baby’s lungs are filled with amniotic fluid. The pressure of contractions pushing them out of the uterus causes this fluid to be expelled, in preparation for breathing.
If stress such as low oxygen or an infection causes your baby to gasp, they can potentially inhale fluid with meconium into their lungs.
What is meconium aspiration syndrome?
When a baby has inhaled meconium, it can block their airways, making it difficult to breathe and reduce oxygen levels.
The meconium can also irritate the airways, which also makes breathing difficult. There is also an increased chance of lung infection. The meconium can affect the special substance coating your baby’s lungs, called surfactant. Surfactant helps the lungs to expand properly when we inhale.
Only a very small number of babies born with meconium stained waters will develop meconium aspiration syndrome.
Signs of meconium aspiration
If it’s suspected your baby has inhaled meconium filled fluid during labour, your care provider will assist you to birth your baby as quickly as possible. It’s no longer recommended to suction babies once their head is born.
Your care provider will look for these signs in your baby:
- Fast or rapid breathing
- Grunting or laboured breathing
- Long gaps between breaths
- Low muscle tone, poor reflexes
- Blue colour to the skin
- Chest distended.
If your baby has inhaled meconium but is active, well and has a good heart rate, they will be unlikely to need suctioning. They will be monitored for signs of MAS for 24 hours after birth.
However, a baby that has inhaled meconium, isn’t responsive and has a low heart rate will need to be suctioned immediately after they’re born. Usually this means your baby’s umbilical cord will be clamped and cut, and they will be taken to a resuscitation table to have their airway cleared with a tube.
You can ask to leave the umbilical cord intact and your baby stays with you, This will allow your baby to receive oxygen from the cord blood while their airway is being cleared.
How is MAS treated?
After birth, babies with MAS usually need to spend some time in the hospital’s special care nursery. They can be monitored for infection and likely have antibiotics, blood tests and oxygen treatment.
Babies with severe MAS can develop pneumonia and need special care. They’re also likely to experience lung infections in their first year.
Seeing your baby in a special care nursery can be distressing. Neonatal nurses can support you to spend time and bond with your baby even while they’re in special care.
Usually most babies with MAS recover without any long-term effects.
Can you prevent meconium aspiration?
The best way to prevent meconium from being inhaled during labour and birth is to give birth in a calm environment with a supportive birth team.
Labouring women who are stressed or worried can find their contractions slow down and labour stalls. This might prompt care providers to try and get things going, leading to a cascade of interventions.
Fetal distress can be caused by any number of interventions such as artificial rupture of the waters or constant fetal monitoring.
So it’s important to ensure you have a solid support team to advocate for a positive birth experience and provide comfort in labour to avoid further stress.
Meconium can be passed by a baby who is simply just ready to be born! If you have meconium stained waters and your baby is doing well, talk to your care provider about wait and see options to avoid a labour induction which could potentially cause your baby more stress.
If you’re looking for support to have a calm, positive birth experience, consider the holistic services Nurtured Birth offers through pregnancy and birth, including massage, osteopathy and doula support. Please contact us for more information.
Image provided by Victoria Berekmeri- Adelaide Birth Photographer