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; and
• 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
   • diabetes
   • hypertension
   • substance abuse
   • prematurity (less than completion of 37th gestational week)
   • post-maturity (greater than the completion of the 42nd gestational week)
2. Peripartum Conditions
   • temperature 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
3. Fetal/Neonatal Conditions
   • still birth (antenatal, or intrapartum) or neonatal death in the delivery or operating room
   • multiple births
   • 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. ACOG Obstetric Care Consensus No.10, March 2020. Reaffirmed 2022. American College of Obstetricians and Gynecologists.
2. Salafia CM, Vintzileos AM. Why all placentas should be examined by a pathologist in 1990. American Journal of Obstetrics and Gynecology. 1990;163:1282–93.
3. Langston C, et al. Guideline for examination of the placenta: developed by the Placental Pathology Practice Guideline Development Task Force of the College of American Pathologists. Archives of Pathology and Laboratory Medicine. 1997;121(5):449–76.