What are the risks during a dilation and curettage (D&C)?

Risks During Dilation and Curettage (D&C)

The primary risks during D&C include uterine perforation (0.9%), bleeding (0.8%), false passage (0.8%), and infection, with an overall intraoperative complication rate of approximately 1.9%. 1

Immediate Intraoperative Complications

Uterine Perforation

• Perforation occurs in approximately 0.9% of procedures, most commonly at the fundus (94% of perforations) rather than the cervix 1
• Risk factors that significantly increase perforation risk include:
  • Retroverted uterus (independent risk factor, P=.008) 1
  • Postmenopausal status (independent risk factor, P=.003) 1
  • Nulliparity (independent risk factor, P=.03) 1
• Endoscopists performing fewer than 500 diagnostic procedures are four times more likely to cause perforation than experienced colleagues 2
• Catastrophic complications can occur: intestinal prolapse through uterine perforation requiring bowel resection has been documented, even in tertiary centers 3

Hemorrhage and Vascular Injury

• Severe hemorrhage occurs in approximately 0.1% of D&C procedures 1
• False passage (creating an abnormal tract) occurs in 0.8% of cases 1

Cervical and Vaginal Trauma

• Cervical laceration: rare (0.02% in large series) 1
• Vaginal laceration: 0.06% of procedures 1
• Cervical tears are an acknowledged complication of the procedure 4

Post-Procedure Complications

Infection Risk

• Fever >100.4°F (38°C) with pelvic pain and purulent discharge indicates endometritis 5
• Risk increases with retained products of conception and prolonged procedure time 5
• Foul-smelling vaginal discharge suggests endometritis or other infection 5

Incomplete Evacuation

• Presents as continued bleeding or persistent symptoms 5
• May require repeat procedure, particularly when initial endometrial biopsy has a false-negative rate of approximately 10% 2

Asherman Syndrome

• Intrauterine adhesions can develop following D&C 4

Long-Term Reproductive Risks

Preterm Birth in Subsequent Pregnancies

• D&C increases the risk of subsequent preterm birth with odds ratio of 1.29 (95% CI 1.17-1.42) for birth <37 weeks 4
• Risk escalates for very preterm birth: OR 1.69 for <32 weeks and OR 1.68 for <28 weeks 4
• Multiple D&Cs compound the risk: OR 1.74 (95% CI 1.10-2.76) for preterm birth <37 weeks 4
• Spontaneous preterm birth risk: OR 1.44 (95% CI 1.22-1.69) 4

Critical Warning Signs Requiring Immediate Attention

Hemorrhage Indicators

• Soaking through more than one pad per hour for 2 consecutive hours 5
• Blood clots larger than a quarter, suggesting incomplete evacuation or uterine atony 5
• Syncope or dizziness indicating significant blood loss 5

Infection Indicators

• Fever >100.4°F with increasing pelvic tenderness and discharge (classic triad) 5
• Persistent bleeding beyond 1-2 weeks (normal bleeding decreases gradually) 5

Perforation Indicators

• Severe abdominal pain unrelieved by prescribed medication may indicate perforation or infection 5

Risk Mitigation Strategies

Hysteroscopic guidance significantly reduces perforation risk, particularly when dilating narrow cervical canals 6. The technique involves:

• Dilating external os only to 2-7mm with Hegar dilator 6
• Passing 7-mm rigid hysteroscope under direct visualization through internal os 6
• Using minigrasping forceps under hysteroscopic vision if smallest dilator cannot pass 6

Special Clinical Contexts

Diagnostic Accuracy

• Office endometrial biopsy has 10% false-negative rate; negative biopsy in symptomatic patients requires fractional D&C under anesthesia 2
• Hysteroscopy helps evaluate for lesions like polyps in patients with persistent undiagnosed bleeding 2

High-Risk Anatomical Situations

• Patients with transabdominal cerclage can undergo D&C safely using osmotic dilators for cervical preparation, with one minor complication reported in 19 procedures 7