OB Guideline 29: Placental Pathology Evaluation

The decision to submit the placenta to the hospital’s Department of Pathology for gross and microscopic examination should be based upon a reasonable likelihood that such an examination will:

• Facilitate the diagnosis of birthing person-fetal conditions associated with adverse outcomes
• Provide information salient to, or allow prognosis for, future pregnancies and their outcomes

The American College of Obstetricians and Gynecologists (ACOG) offers no formal guidelines recommending placental examination based on specific clinical conditions with the exception of stillbirth¹. ACOG regards placental examination as “an essential component” of stillbirth evaluation. Some clinicians have advised that all placentas be submitted to pathology for examination;^2,3 however, there is a lack of consensus for routine examination.

Conditions for Placental Examination

Individual judgment is warranted concerning the appropriateness of submitting the placenta, with as much umbilical cord as is feasible, for pathologic evaluation. Consider submitting the tissue for any level of concern. Consider placental examination under the following non-exclusive list of birthing person or fetal clinical conditions:

1. Birthing Person Conditions
   • Poorly-controlled diabetes
   • Acute hypertension/preeclampsia
   • Prematurity (< 37 weeks)
   • Infections associated with congenital anomalies
   Do not send for Itrahepatic Cholestasis of Pregnancy (ICP) or Cholestasis
2. Peripartum Conditions
   • Eemperature greater than 100.4º F (intrapartum)
   • Suspected or proven infection
   • Bleeding, of magnitude beyond “show” (e.g., suspected abruption placenta, placenta previa, vasa previa)
   • Oligohydramnios or polyhydramnios
   • Postpartum hemorrhage
3. Fetal/Neonatal Conditions
   • Stillbirth (antenatal, or intrapartum) or neonatal death in the delivery or operating room
   • Multiple births (specifically monochorionic and discordant dichorionic pregnancies)
   • All major or minor congenital anomalies
   • Fetal growth restriction
   • Hydrops fetalis or an edematous placenta
   • Meconium (thin or thick), noted on admission or occurring in labor
4. Immediate Neonatal Course
   • Apgar scores of 5 or less at 5 minutes
   • Suspected neonatal infection
   • Suspected encephalopathy
   • Cord pH< 7.1
5. Gross Placental Anomalies

1. Management of Stillbirth: Obstetric Care Consensus No, 10. Obstet Gynecol. 2020;135(3):e110-e132. Reaffirmed 2025. doi:10.1097/AOG.0000000000003719
2. Salafia CM, Vintzileos AM. Why all placentas should be examined by a pathologist in 1990. Am J Obstet Gynecol. 1990;163(4 Pt 1):1282-1293. doi:10.1016/0002-9378(90)90708-f
3. Roberts DJ, Baergen RN, Boyd TK, et al. Criteria for placental examination for obstetrical and neonatal providers. Am J Obstet Gynecol. 2023;228(5):497-508.e4. doi:10.1016/j.ajog.2022.12.017