Battledore Placenta

A battledore placenta is a placenta in which the umbilical cord inserts at the edge of the placental disc, like the handle of a table tennis bat, instead of into its centre. It results from eccentric implantation. It matters because it is linked with growth restriction, preterm birth, a thin placenta and cord vessels that can be injured at delivery.

• Risk factors: assisted conception, multiple pregnancy, advanced maternal age, smoking, previous marginal insertion.
• The cord lacks the support of the central thick placenta.
• Most babies have a normal outcome.

Women have no symptoms. Examination is normal, and the finding comes from a scan or from inspecting the delivered placenta.

• Normal fundal height in most.
• Small for dates uterus if growth is restricted.
• Differential diagnosis: central cord insertion, velamentous cord insertion, furcate insertion, succenturiate lobe, circumvallate placenta.
• Complications: fetal growth restriction, preterm birth, abnormal cardiotocography in labour, cord avulsion at delivery, retained placenta, small for gestational age baby.

The approach is ultrasound with colour Doppler to show where the cord enters the placenta.

• Ultrasound at 18 to 22 weeks: cord insertion at the edge of the placental disc, with a vessel entering at the margin; colour Doppler confirms the vessels.
• Growth scans at 28 and 32 weeks; umbilical artery Doppler.
• Exclusion of velamentous insertion and vasa previa by colour Doppler across the membranes.
• Examination of the delivered placenta and cord to confirm the diagnosis.

The principle is growth surveillance with a normal delivery plan and careful handling of the cord.

• Supportive: reassure; avoid smoking; daily fetal movement counts; teach to attend for reduced movements.
• Pharmacological: aspirin 150 mg oral at night from 12 weeks to 36 weeks if uterine artery Doppler is abnormal or other risk factors exist; ferrous sulphate 200 mg oral 8-hourly for anaemia; betamethasone 12 mg IM twice, 24 hours apart, between 24 and 34 weeks and 6 days if preterm delivery is likely; oxytocin 10 IU IM at birth.
• Procedures: growth scans every 4 weeks from 28 weeks; delivery at 39 to 40 weeks for normal growth, earlier for growth restriction or abnormal cardiotocography; gentle controlled cord traction only with the uterus guarded, avoiding forceful traction; continuous cardiotocography in labour.
• Red flags: reduced fetal movements, falling growth centile, abnormal cardiotocography, bleeding at rupture of membranes.
• Follow-up: growth scans every 4 weeks; antenatal review every 2 to 4 weeks; placental histology after birth.