Resolved but Not Forgotten: The Effect of Resolved Placenta Previa on Labor Management

Area of Science:

• Obstetrics and Gynecology
• Maternal-Fetal Medicine

Background:

• Placenta previa, diagnosed in up to 15% of pregnancies, often resolves before term.
• Limited data exists on pregnancy outcomes for women whose placenta previa resolves.

Purpose of the Study:

• To investigate if abnormal placentation, even when resolved, is linked to adverse labor outcomes.
• To determine the association between resolved placenta previa and adverse events during labor.

Main Methods:

• Retrospective study of patients diagnosed with placenta previa after the second-trimester ultrasound.
• Inclusion criteria: resolved placenta previa with the placental edge >2 cm from the internal cervical os.
• Exclusion criteria: persistent placenta previa, early resolution (<20 weeks), prior cesarean delivery, or delivery at an outside institution. Time-matched controls with normal placentation were used.

Main Results:

• Resolved placenta previa patients were older, had lower prepregnancy BMI, and were more likely to be smokers, use assisted reproductive technology, or have prior uterine surgeries.
• 10.2% of resolved placenta previa patients experienced postpartum hemorrhage, compared to 2.1% in the normal placentation group (OR=5.2, P<0.01).
• Patients with resolved placenta previa required more uterotonic medications (OR=3.4, P<0.01) but showed no difference in operative delivery rates for fetal distress.

Conclusions:

• Resolved placenta previa is associated with a significantly higher incidence of postpartum hemorrhage.
• Increased use of uterotonic agents is noted in patients with resolved placenta previa.
• Hemorrhage precautions should be considered for patients with resolved placenta previa upon admission.