Thick Placenta in Pregnancy: A Review

Area of Science:

• Perinatology
• Maternal-Fetal Medicine
• Medical Imaging

Background:

• Placental thickness on ultrasound offers insights into fetal and maternal well-being.
• A thickened placenta can signal underlying structural or physiological anomalies.

Purpose of the Study:

• To define criteria for a "thickened placenta" in medical literature.
• To review associated incidence, comorbidities, and management strategies for thickened placentas during pregnancy.

Main Methods:

• A comprehensive literature search was conducted on PubMed and Web of Science (2000-2020).
• Studies examining placental thickness, etiologies, and obstetric outcomes were selected for review.

Main Results:

• The definition of a thickened placenta varies, with thresholds often exceeding 4 cm, or 6 cm in the third trimester for placentomegaly.
• Associated conditions include maternal obesity, diabetes, preeclampsia, and fetal anomalies like Beckwith-Wiedemann syndrome.
• A thickened placenta correlates with increased adverse pregnancy outcomes, neonatal morbidity, and mortality.

Conclusions:

• Routine prenatal ultrasound for placental evaluation is recommended.
• A thickened placenta necessitates further investigation into its cause.
• While specific surveillance guidelines are lacking, serial ultrasounds and weekly antenatal testing in the third trimester are suggested.