Be aware that the following information describes some rare complications that some readers may find disturbing. You may choose not to read parts of this section.

Possible causes for meconium in the fluid
Possible interventions

About meconium stained fluid

Meconium stained amniotic fluid (or meconium stained 'liquor' - pronounced 'like - ore' - nothing to do with alcohol!) is when the baby opens their bowels inside the uterus, making the waters look green, yellow or brownish in colour. It occurs with about 10% of babies who are 'term' (37 to 42 weeks gestation) and is quite rare if the baby is premature baby (less than 37 weeks).

'Meconium' is the thick, dark green, sticky, tar-like substance that is passed as the baby's first bowel motion after birth. At times this can be passed before the baby is born, discolouring the waters. Caregivers often use the term 'mec' or 'mec-stained liquor' (written as 'MSL') when describing the discolouration of the waters in this way.

Meconium stained liquor is usually associated with a response from the baby to having a temporarily reduced oxygen supply at some point in time (usually during labour) or a slowly reducing level of oxygen over a period of time.

Caregivers generally interpret meconium stained liquor as one sign of the baby possibly being unwell or 'distressed' when inside the uterus. The other sign linked to what is referred to as 'fetal distress', is a lowering of the baby's heart rate (or abnormal patterns if being monitored). If meconium is seen in the waters but the heart rate is normal then the baby may be suspected, but not considered, to be distressed. If both are observed then the perception of distress is more accurate.

The other health concern of meconium stained liquor is that the baby may inhale the meconium into their lungs at birth.