Understanding Retained Placenta: Definitions and Timeframes
A retained placenta occurs when the placenta fails to deliver within a specific timeframe following the birth of the baby. In the context of active management of the third stage of labor, if the placenta is not expelled within 30 minutes after delivery with uterotonics and controlled cord traction, it is classified as retained. For physiological or expectant management, the threshold is typically 60 minutes.
Three main physiological mechanisms account for this delay:
- Placenta Accreta Spectrum: Abnormal invasion of the placental villi directly into the myometrium due to a deficient decidua basalis.
- Uterine Atony: The myometrium fails to contract effectively after fetal delivery, preventing the shearing forces required to separate the placental plane.
- Hourglass Contraction: A localized spasm of the lower uterine segment traps a completely separated placenta inside the uterine cavity.
Etiology and Risk Factors in Nigerian Clinical Practice
Identifying risk factors helps midwives anticipate complicated third stages. In Nigerian maternity units, previous uterine surgery stands out as a major predisposing factor for abnormal placentation.
Review these common risk factors:
- Previous Uterine Scar: History of Caesarean sections or myomectomy increases the risk of placenta accreta.
- Grand Multiparity: Frequent high parity tires the myometrium, raising the incidence of uterine atony.
- Uterine Instrumentation: Previous dilation and curettage can damage the endometrial lining.
- Previous Retained Placenta: Women with a history of retention in an earlier birth face higher recurrence rates.
Recognizing Clinical Presentation and Postpartum Hemorrhage Risks
The classic presentation of a retained placenta involves the non-delivery of the placental mass past the accepted timeframe, often accompanied by varying degrees of vaginal bleeding. When the placenta is partially separated, open maternal blood sinuses bleed profusely because the surrounding myometrium cannot clamp down. Conversely, a totally adherent placenta may present with little immediate bleeding but poses a grave threat of sudden, catastrophic hemorrhage once manipulation or partial separation occurs.
Midwives must maintain high vigilance. Continuous observation of vital signs is mandatory because concealed bleeding or slow, steady blood loss can quickly push a postpartum woman into hypovolemic shock. Palpation of the uterine fundus often reveals a boggy, high-riding uterus if atony is present, or a contracted uterus if an hourglass ring has trapped the tissue.
Immediate Resuscitation and Pre-Procedure Preparation
Before attempting any manual removal, stabilizing the mother is paramount. Midwives must initiate emergency measures to address or prevent hypovolemic shock.
- Establish Intravenous Access: Insert two large-bore cannula needles (16G or 18G) to infuse normal saline or Ringer's lactate rapidly.
- Take Blood Samples: Send blood immediately for typing, cross-matching, and baseline hemoglobin estimation.
- Administer Fluids and Blood: Resuscitate volume aggressively while awaiting cross-matched blood if hemorrhage is active.
- Empty the Bladder: Pass a sterile indwelling urinary catheter to decompress the bladder, as a full bladder impedes uterine contraction and manual entry.
- Explain the Procedure: Briefly reassure the patient and obtain informed consent if her condition permits.
Manual Removal of Placenta (MROP) Procedure: Step-by-Step Execution
Manual removal of the placenta is a skilled intra-uterine procedure performed under strict aseptic conditions and appropriate anesthesia. The midwife or doctor introduces a gloved hand into the uterine cavity to peel the placenta off the uterine wall.
- Step 1 - Cord Traction: Grasp the umbilical cord gently and follow its course upward through the vagina and cervix into the uterine cavity.
- Step 2 - Uterine Entry: Insert the hand, formed into a cone shape, through the cervix while using the abdominal hand to support and steady the fundus from above.
- Step 3 - Locate the Plane: Locate the edge of the placenta and find the natural cleavage plane between the placental tissue and the decidua.
- Step 4 - Sweeping Action: Using the side of the hand in a gentle sideways slicing motion, separate the entire placenta from the uterine wall.
- Step 5 - Extraction: Once completely detached, grasp the placenta, withdraw your hand from the uterus, and ensure the membranes are gently teased out as well.
Aseptic Technique, Analgesia, and Bladder Care During MROP
Because manual removal involves entering the sterile uterine cavity, infection control is paramount. The procedure is painful; therefore, adequate pain relief is essential. In Nigerian clinical practice, options range from intravenous sedation with ketamine or diazepam to regional or general anesthesia depending on facility capabilities.
Aseptic precautions require scrubbing up, wearing sterile surgical gowns and long gloves, and thoroughly cleaning the perineum with antiseptic solutions. Continuous monitoring of maternal vital signs during anesthesia ensures early detection of adverse drug reactions or cardiovascular compromise.
Post-Procedure Management, Antibiotic Prophylaxis, and Uterine Monitoring
Following successful manual removal, ongoing vigilance prevents secondary complications. Midwives must administer a prophylactic dose of antibiotics, such as ampicillin and metronidazole, to guard against endometritis.
Immediate postpartum care involves:
- Uterotonic Infusion: Administer oxytocin infusion to maintain uterine contraction and prevent secondary atony.
- Fundal Checks: Monitor uterine tone and vaginal bleeding every 15 minutes for the first hour, then hourly.
- Vital Signs Monitoring: Track blood pressure, pulse, and respiratory rate to catch hidden hemorrhage early.
- Inspection of Placenta: Examine the removed placenta and membranes to ensure no residual fragments remain inside.
Complications, Red Flags, and When to Refer
While MROP is a life-saving intervention, it carries inherent risks. Midwives must remain alert to immediate and delayed complications.
- Uterine Perforation: Accidental penetration of the myometrium by fingers or instruments.
- Postpartum Hemorrhage: Continued bleeding from atony, trauma, or retained fragments.
- Puerperal Sepsis: Severe uterine or pelvic infection due to bacteria introduced during manipulation.
- Uterine Inversion: Rare but catastrophic turning inside out of the uterus.
Recognize red flags such as persistent heavy bleeding, rising pulse, falling blood pressure, severe lower abdominal pain, or foul-smelling lochia. Prompt escalation and referral to a higher-level comprehensive emergency obstetric care facility are life-saving when complications exceed primary midwifery competencies.