Clinical consequences of poor placentation II

1) Dating problems 2) Constitutional 3) Environmental problem 4) Placental insufficiency

• Chromosomal abnormalities (e.g. Trisomy 18, Triploidy) • Congenital infections (e.g. Rubella, CMV) • Genetic syndromes (e.g. Russell-Silver syndrome) • Teratogens (e.g. Fetal alcohol syndrome, Drug abuse) • Maternal problem (e.g. Cyanotic CHD)

Placenta function is nutrient and gas exchange • Poor function will lead to: • Slowing of growth • Hypoxaemia – Hypoxia – Asphyxia • Stillbirth • Ultrasound used to find evidence of • Placental dysfunction • Fetal response to the dysfunction

Risk factor • Previous history • Positive uterine arterial Doppler screen • Abnormal placental echo-texture • AC below the 5th centile Doppler changes can be noted in a pregnancy with poor placental insufficiency things we can note: Poor placentation Increased umbilical PI (Pulsatility index) Redistribution Decompensation

Clinical – Symphysis-fundal height One trial with 1639 women was available • Antenatal detection of small babies was lower in the fundal height group (28%) than abdominal palpation (48%) • No evidence of improved outcome • Serial Ultrasound biometry • Uterine artery Doppler screening

Diagnosis, fetal response and monitoring is well characterized • Pathophysiology and natural history is understood

• Increased PI in Umbilical artery is abnormal. • Deliver for reversed EDF > 32 weeks • Deliver for absent EDF > 34 weeks • MCA Dopplers not needed if Umbilical artery Dopplers are normal.

Increased PI in Umbilical artery is abnormal. Consider delivery. • Normal Umbilical artery PI alone is not enough. • MCA Dopplers needed even if Umbilical artery Dopplers are normal. Consider delivery if MCA PI < 5th centile.