PURPOSE:

• Shanes et al. (American Journal of Clinical Pathology) sought to identify placental pathology associated with COVID-19 infection

METHODS:

• Case control study
• Histologic evaluation of the placenta was performed
  • Cases: Placentas from pregnant women with confirmed SARS-CoV-2 infection who delivered between March 18, 2020 and May 5, 2020
  • Historical controls
    • Placental samples derived from women who had placental evaluation for maternal/fetal indications (e.g, FGR, chorioamnionitis)
    • History of melanoma | Considered a superior control because evaluation would be performed for potential metastases rather than possible confounding indication (e.g. SGA)
• Prior to April 7, only patients with moderate to severe disease were tested | Following this date, all women admitted to labor and delivery underwent testing

RESULTS:

• 16 placentas from women with COVID-19 were evaluated
• Gestational Age at delivery
  • Term deliveries (37 to 40 weeks): 14
  • 34 week delivery: 1
  • 16 week IUFD: 1
• Placental size
  • SGA: 5
  • LGA: 1
• Indication for placental exam
  • SARS-CoV-2: 13
  • Cholestasis in pregnancy and GDM: 1
  • Pregnancy-induced hypertension: 1
  • IUFD (above): 1
• Timing of COVID-19 diagnosis
  • Remote from delivery (25 to 34 weeks): 4
  • 6 to 7 days prior to delivery: 2
  • At time of admission for delivery: 10
• Clinical COVID-19 course
  • Symptomatic: 10 patients
  • Oxygen requirement: 2
  • Maternal deaths or requiring intubation: 0
  • All infants had normal Apgar scores and discharged home except for 34 week delivery who was still in NICU
• 16 week IUFD: Retroplacental hematoma | Removed from analysis of placental findings because controls were all from 3rd trimester deliveries

Placental Findings

• Placentas from COVID-19 pregnancies were more likely to have ≥1 feature of maternal vascular malperfusion (MVM) compared to
  • Melanoma controls: Odds ratio (OR) 7.3 (P = .001)
  • Other historical controls: OR 3.4 ( P = .046)
• Individual MVM features were more likely be found in COVID-19 pregnancies
  • Decidual arteriopathy vs both control groups
  • Atherosis and fibrinoid necrosis vs both groups
  • Peripheral villous infarction vs melanoma group
• Features of fetal malperfusion (FVM) were also more common in the COVID-19 placentas vs both control groups such as delayed villous maturation
• Findings associated with acute and chronic inflammation were not increased

CONCLUSION:

• MVM reflects abnormalities in oxygenation within the intervillous space and is associated with adverse perinatal outcomes, including hypertensive disorders and preeclampsia
• Despite MVM findings, only 1 patient with COVID-19 had hypertension
• The authors conclude that the changes found in the placentas from pregnant women with COVID-19

…may reflect a systemic inflammatory or hypercoagulable state influencing placental physiology

…these findings suggest that increased antenatal surveillance for women diagnosed with SARS-CoV-2 may be warranted

Learn More – Primary Sources:

Placental Pathology in COVID-19

Related ObG Topics:

SMFM Guideline Update on COVID-19 in Pregnancy

The UKOSS COVID-19 Pregnancy Registry: Update on 427 Patients Admitted to Hospital

Pregnant Women with COVID-19 and ICU Admissions