Sonographic Diagnosis of Velamentous and Marginal Placental Cord Insertion

Abstract

Routine second trimester ultrasound (US) examinations include an assessment of the umbilical cord given its vital role as a vascular conduit between the maternal placenta and fetus during fetal development. Placental cord insertion abnormalities can be identified during prenatal US screening and are increasingly recognized as independent risk factors for various complications during pregnancy and delivery. The purpose of this pictorial review is to illustrate examples of velamentous and marginal placental cord insertion with an emphasis on how to differentiate their morphology using color Doppler US.

Vasa previa: Perinatal outcomes in singleton and multiple pregnancies

“…According to the image of VP by color Doppler ultrasound, VP was diagnosed as follows: Type 1 VP, in which there was a single placental lobe and the fetal vessels run freely through the membranes over the cervix or within 2 cm from the internal cervical os; Type 2 VP, in which the vessels were connected between lobes of a placenta with multiple lobes over the cervix or within 2 cm from the internal cervical os (8,12); Type 3 VP, in which fetal vessels were boomerang orbit and without velamentous insertion nor bilobed/accessory placenta (9).…”

Placental and Umbilical Cord Anomalies Diagnosed by Two- and Three-Dimensional Ultrasound

“…This abnormality is present in 1.5% of singleton pregnancies [ 59 ]. It is associated with several unfavorable perinatal outcomes, such as fetal growth restriction, placenta praevia, placental abruption, fetal heart abnormalities during labor, emergency Cesarean section, preterm labor, low Apgar scores, admission to the NICU and neonatal death, as the velamentous vessels can be compressed during uterine contractions and fetal movements [ 43 , 60 ]. The risk factors associated with this condition include bilobate/succenturiate placenta, ART, multiple gestation and a prior history of abnormal placental cord insertion [ 59 ] ( Figure 18 , Figure 19 , Figure 20 , Figure 21 and Figure 22 ).…”

“…Marginal umbilical cord insertion is another anomaly, in which the umbilical cord is inserted into the placental margin within 2.0 cm [ 44 , 60 ]. It is present in 6.3% of singleton pregnancies and presents much lower chances of complications than velamentous cord insertion [ 60 ] ( Figure 23 ).…”

“…Furcate umbilical cord insertion is a condition where the umbilical vessels separate before they insert into the placental plate and lose their Wharton’s jelly [ 59 , 60 ]. It is present in 0.1% of pregnancies and is considered a variant not well distinguished from velamentous cord insertion [ 59 , 60 ] ( Figure 24 ).…”

Ultrasound evaluation of a bilobed placenta with ‘battledore cord insertion’ — a report of an unusual case

“…In such a situation, the cord insertion site is too close to the placental margin (usually defined as < 2 cm, although some references define it as < 1 cm). A marginal cord insertion, also known as a battledore placenta, may confer a slight increase in the risk for adverse pregnancy outcomes like placental abruption, placenta previa, preterm labor, fetal distress and intrauterine growth restriction [2][3][4]. A bilobed placenta with abnormal cord insertion is even less common.…”