Retained Placenta

Retained placenta is failure of expulsion of the placenta within 30 minutes of delivery with active management of the third stage, or 60 minutes with physiological management. It affects 1 to 3 percent of vaginal deliveries and is a major cause of postpartum haemorrhage; mortality is highest in low resource settings.

Causes: uterine atony with failure of separation, trapped placenta behind a closed cervix, and abnormal adherence (placenta accreta spectrum). Risk factors: previous retained placenta, preterm delivery (the incidence at 20 to 24 weeks is over 20 percent), previous uterine surgery or curettage, uterine anomalies, high parity, induction or augmentation of labour, maternal age above 30, and previous caesarean section.

• Placenta not delivered by the defined time. Bleeding may be heavy, intermittent or absent (when fully adherent). A partially separated placenta causes brisk haemorrhage.
• Failure of uterus to contract firmly; uterus remains large and soft or may be firmly contracted around a trapped placenta.
• No signs of separation: no lengthening of cord, no gush of blood, uterus not rising or becoming globular.
• Hypovolaemic shock if blood loss is significant; sepsis if retained tissue persists.
• Retained fragments after delivery: persistent postpartum bleeding, subinvolution, secondary haemorrhage, endometritis (fever, lochia offensive, uterine tenderness).

• Clinical, from the time interval and the absence of signs of separation. Check that the placenta delivered is complete (cotyledons and membranes) and note ragged edges or missing lobes.
• Assess blood loss and haemodynamic status; send full blood count, group and crossmatch, coagulation screen.
• Ultrasound if fragments are suspected after delivery: thickened endometrial echo with vascularity on colour Doppler.
• Suspect accreta if there is a previous caesarean, anterior placenta praevia, or a plane of cleavage that cannot be found at manual removal.

Immediate steps:

• Establish two large bore intravenous lines; start fluids; send blood; ensure oxytocin is given if not already (10 IU intramuscularly or 5 IU slow intravenous; infusion 40 IU in 500 mL over 4 hours). Empty the bladder.
• Controlled cord traction with the uterus supported, once, if not already tried. Do not use excessive traction (risk of uterine inversion and cord avulsion).
• Additional oxytocin 10 IU in 20 mL saline into the umbilical vein is not proven to help and is not routinely advised.
• If bleeding is heavy, do not wait for the time limit: proceed to manual removal.

Manual removal of placenta, in theatre with regional (spinal or epidural top up) or general anaesthesia, aseptic technique:

• Single dose antibiotic prophylaxis: cefazolin 2 g intravenously (or ampicillin 2 g plus metronidazole 500 mg).
• Follow the cord to the placental site, find the plane between placenta and uterine wall, separate with the side of the fingertips using a sweeping motion with the other hand on the fundus, and withdraw the whole placenta. Examine for completeness.
• Uterine massage and oxytocin infusion afterwards; consider carboprost 250 micrograms intramuscularly every 15 minutes (maximum 8 doses; avoid in asthma) or misoprostol 800 micrograms sublingually or rectally if tone is poor. Uterine relaxants (glyceryl trinitrate 50 to 100 micrograms intravenous or 400 micrograms sublingually) can be used for a trapped placenta with a constricted cervical ring.
• If no plane of cleavage is found, stop: this is placenta accreta spectrum. Do not force. Resuscitate, call senior help, and choose between hysterectomy (the usual choice with heavy bleeding), conservative surgery with resection of the adherent area and uterine repair, or leaving the placenta in situ with the cord cut short, antibiotics, and delayed interval hysterectomy or expectant resorption when bleeding is controlled and fertility is wanted. Methotrexate is not effective. Surveillance continues with weekly blood count, ultrasound and watch for infection, secondary haemorrhage and DIC for up to 6 months.

Retained fragments after delivery: ultrasound guided suction curettage or hysteroscopic resection, with antibiotics (co-amoxiclav 625 mg orally every 8 hours for 5 days) if infection is suspected.

Haemorrhage management when it occurs: massage, tranexamic acid 1 g intravenously over 10 minutes (repeat after 30 minutes if bleeding continues), crystalloid and blood replacement, intrauterine balloon tamponade, then compression sutures, uterine artery ligation and hysterectomy as needed.

Without bleeding, if the placenta is retained beyond the time limit, proceed to manual removal within 60 minutes in a prepared theatre; delayed removal beyond this increases infection and haemorrhage. Expectant observation is not appropriate.

Postpartum: monitor vital signs and blood loss; give iron; advise on recurrence (about 25 percent in the next delivery) and plan birth in a facility with theatre access.