Examination of the Placenta

The placenta is a fetal organ composed of three main parts: the umbilical cord, membranes (the chorion and amnion), and the functional placental tissue (the parenchyma).

Examination of the placenta is a procedure midwives are familiar with, yet its true importance and what it reveals about maternal and neonatal wellbeing often go underexplored. Understanding these insights transforms a routine examination into informed clinical practice (SA Health 2025).

Performed as soon as possible after birth by a skilled, appropriately trained clinician, the examination of the placenta is important for understanding the intrauterine environment. It also provides a record of events that may be associated with adverse pregnancy outcomes (Ravishankar & Redline 2019).

The Normal Placenta

At term, a fresh, healthy placenta has the following characteristics:

• Approximately 20 cm in length
• Weighs about 500 to 600 grams or 1/6 of the baby's birth weight.

(Healthdirect Australia 2024a; Leyto & Mare 2022)

These measurements may vary considerably depending on factors such as:

• The mode of birth
• Timing of cord clamping
• The time elapsed between delivery and examination.

(Akhavan et al. 2022)

Why Examine the Placenta?

Examination of the placenta is important as it reflects the pathophysiology of both the mother and the fetus (Schollenberg et al. 2019). It can offer important diagnostic, prognostic and therapeutic information as well as potentially revealing information that might be relevant to future pregnancies. It may also provide vital clues regarding any potential causes of neonatal illness or death.

The Examination Technique

Examination of the placenta and membranes should take place as soon as possible after birth by a skilled clinician deemed competent by their organisation to ensure they are complete and that no further action is required before the maternal parent is discharged or transferred to the ward.

After gaining informed consent, an initial gross examination should be performed, looking at the:

• Weight
• Umbilical vessel count
• Umbilical cord length and site of attachment
• Meconium or other staining/discolouration of the membranes
• Integrity of the placental and membrane tissue
• Presence of multiple lobes
• Any abnormalities

(SA Health 2025)

Following maternal consent, all placentas demonstrating clinical indications should be submitted for pathological examination (SA Health 2025). Refer to your organisation's policies and procedures regarding the storage of the placenta prior to submitting for further investigations. You should always refer to your organisation's policies and procedures, including those that specify who is permitted to perform an examination.

The Fetal Side

The fetal surface of the placenta should have a shiny, grey, smooth, translucent appearance, allowing the colour of the underlying maroon villous tissue on the maternal side to be seen (Rao et al. 2024).

Occasionally, irregularities such as succenturiate lobes are seen. These are smaller accessory placental lobes that are separate from the main disc of the placenta (Rathbun & Hildebrand 2022).

The Membranes

The membranes consist of two layers: the amnion and the chorion (SA Health 2025).

Both need to be examined for insertion, completeness, appearance, colour, thickness, vessels, the distance to the point of rupture, and any additional surface characteristics (Royal College of Pathologists of Australasia 2025).

The Umbilical Cord

The cord is usually inserted in the centre of the fetal surface with blood vessels branching outwards. At term, the typical umbilical cord length is 55 to 60 cm, with a diameter of 2.0 to 2.5 cm (Knipe 2025).

Umbilical cord abnormalities have been implicated in a large proportion of stillbirths, and therefore, a thorough assessment of umbilical cord features is important (Avagliano et al. 2025).

The umbilical cord should be assessed for length, diameter, colour, coiling, cord insertion length and any other abnormalities (Royal College of Pathologists of Australasia 2025).

The Maternal Side

The maternal surface of the placenta is also assessed. Any abnormalities, such as areas of infarction, masses, or haematomas, should be noted, and if infection is suspected, both the fetal and maternal sides should undergo a placental swab (SA Health 2025).

It is estimated that up to 37% of placentas would qualify for further histopathological examination (Polnaszek, Clark & Rouse 2022). Conditions that would indicate a placenta should undergo further investigation include, but are not limited to:

• Poor obstetric history
• Preeclampsia
• Diabetes (including gestational, type 1 and type 2)
• History of miscarriages
• Drug or alcohol misuse
• Significant disease history
• Infants transferred to the neonatal intensive care unit
• Maternal or fetal death
• Suspected chorioamnionitis
• Suspected congenital infection
• Antepartum haemorrhage
• Preterm birth
• Intrauterine growth restriction
• Any abnormality noted in the initial examination of the placenta

(SA Health 2025)

Multiple Pregnancy

The placenta and membranes for multiple births are more complex and require careful assessment, as a variety of combinations are possible. For example:

• Monochorionic, monoamniotic twins are very rare. They have just one placenta, one pair of amnion and chorion, and two cords.
• Monochorionic, diamniotic twins have one placenta and one outer chorion, but the shiny fetal surface should have two cords, each inside its own amnion.
• Dichorionic, diamniotic twins always have two separate placental units, each with two layers of membranes, just like a singleton. They may, however, be side by side and appear to be joined at first glance.

(Raising Children Network 2024)

Retained Placenta

Retained placenta affects approximately 2 out of 100 births and occurs when the placenta is not delivered within 30 minutes of birth with active management, or within 60 minutes with natural management (Healthdirect Australia 2024b). If a retained placenta is left untreated, it can lead to severe uterine infection and life-threatening blood loss (postpartum haemorrhage) (Healthdirect Australia 2024b).

Signs of a retained placenta can include:

• Fever or chills
• Bleeding
• Blood clots
• Foul-smelling discharge

(Healthdirect Australia 2024b)

Suspicion of a retained placenta or incomplete placenta is a medical emergency and requires immediate escalation to the medical team.

Conclusion

After completing a thorough examination of all parts of the placenta, the findings should be documented clearly in the clinical record. Suspected incomplete placenta is a time-critical finding that requires urgent escalation with the treating team. Clear communication with both the parent and the multidisciplinary team ensures that any concerns are acted upon promptly, reducing the risk of serious complications, including postpartum haemorrhage and infection. You should always refer to your organisation's policies and procedures, including those that specify who is permitted to perform an examination.