Marginal cord insertion

Marginal cord insertion, also known as a 'battledore insertion', is a type of abnormal cord insertion.

Terminology

Insertion of the umbilical cord within <2 cm from the placental margin is described as marginal cord insertion (usually defined as <2 cm ⁵ although some references define it as <1 cm ^3,6). Whereas lateral insertion of the umbilical cord >2 cm from the placental margin is described as eccentric cord insertion.

Epidemiology

The estimated incidence is at ~7% ¹ of singleton pregnancies but ~25% of twin pregnancies. Hence, it is very important to locate the umbilical cord in all patients, particularly in high-risk pregnancy.

Pathology

Associations

• intrauterine growth restriction (IUGR) / low birth weight
• monochorionic twins pregnancy
• placental abruption ¹⁰
• pre-eclampsia ¹⁰
• nuchal cord entanglement ¹⁰
• preterm birth ⁷

Some authors state that there is no increased risk ⁵.

Treatment and prognosis

Progression into a velamentous cord insertion as a result of "placental trophotropism" can be seen in later stages of pregnancy. Second-trimester marginal cord insertion can be associated with increased likelihood for low birth weight, pre-term delivery and composite adverse obstetrical and neonatal outcomes ⁸.