Examination of the placenta/placental pathology

Warning

Introduction

  • This SOP is intended to standardise the procedure for examining the placenta and membranes after birth.
  • Retained products of conception are one of the main causes of postpartum haemorrhage and infection.

Equality and diversity

NHS Borders is committed to the provision of a service that is fair, accessible and meets the needs of all individuals.

Examination of the placenta

Examination of the placenta should take place as soon as possible after delivery in a well lit area, staff must use appropriate PPE.

  • examine the cord, count the vessels in the cord and observe for the presence of true knots or thrombi
  • separate the amnion from the chorion to ensure both are present
  • ensure all cotyledons are present

Documentation of findings

Findings should be clearly documented on Badgernet – if there are concerns about completeness of a placenta it is important to inform the woman to be observant for an increase in blood loss/passing clots or signs of infection.

Investigations of placenta

A placental swab should be obtained in the following instances:

  • maternal sepsis
  • offensive smelling liquor
  • suspected chorioamnionitis
  • baby born in unexpectedly poor condition
  • in all cases of IUD

Indications for referral of placentas for pathological examination

Ensure all specimens are correctly labelled and the examination of placenta form is completed.

  • stillbirth (antepartum or intrapartum)
  • miscarriage (14+0–23+6 completed weeks’ gestation)
  • severe fetal distress defined as: pH 4.8mmol/l
  • preterm birth (less than 32+0 weeks’ gestation)
  • fetal growth restriction defined as: birthweight below 3rd centile or drop in fetal growth velocity of >2 quartiles or >50 percentiles
  • abnormal umbilical artery Dopplers (absent or reversed end diastolic flow)
  • fetal hydrops

Early onsent (<32 weeks) severe preeclampsia requiring iatrogenic early delivery
caesarean peripartum hysterectomy for morbidly adherent placenta
severe maternal sepsis requiring adult intensive care admission and/or fetal sepsis requiring ventilation or level 3 NICU admission (following swab taken from the placenta for microbiology at delivery)

  • massive placental abruption with retroplacental clot
  • monochorionic twins with TTTS.

Referral is not indicated in the following conditions as histopathological examination is unlikely to provide useful information:

  • cholestasis of pregnancy
  • ‘gritty’ placenta
  • pruritis of pregnancy
  • maternal diabetes with normal pregnancy outcome
  • hepatitis B, HIV, etc
  • other maternal disease with normal pregnancy outcome
  • placenta praevia • post-partum haemorrhage
  • polyhydramnios • rhesus negative mother with no fetal hydrops
  • history of maternal Group B streptococcus
  • maternal coagulopathy
  • maternal substance abuse
  • uncomplicated twin pregnancy
  • congenital anomaly
  • common aneuploidies
  • low grade pyrexia in labour
  • history of previous molar pregnancy

NB: To ensure a placenta is not disposed of too quickly please retain in the clean sluice in a sealed yellow bag, in the yellow placenta box (do not seal the lid), labeled with the patient’s addressograph. After 1 hour the placenta can be disposed of as normal.

 

Disposal of placenta

  • The majority of women will want the midwife to dispose of the placenta which should be done in accordance with NHS Borders policy.
  • The placenta should be placed in a yellow placenta bag then into a placenta pot and placed into a yellow waste bag.
  • If a woman wishes to take her placenta home double bag the placenta and place it in a white tub for transport home.

Editorial Information

Last reviewed: 12/05/2022

Next review date: 12/05/2025

Author(s): Brian Magowan.

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