Large For Dates Flashcards
What are the causes of large for dates?
wrong dates; fetal macrosomia; polyhydramnios; DM; multiple pregnnacy
What is fetal macrosomia defined as?
USS EFW >90th centile
What are the risks associated with fetal macrosomia?
labour dystocia; shoulder dystocia; PPH
What should be excluded with fetal macrosomia?
diabetes
What is polyhydramnios?
excess amniotic fluid
What are the causes of polyhydramnios?
maternal DM; fetal anomaly; monochorionic twin pregnnayc; hydrops fetalis; idiopathic
Why is common for late bookers to have wrong dates?
harder to accurately determine after the 1st trimester
What are the fetal anomalies implicated in polyhydramnios?
chromosomal; atresia; of oesophagus/duodenum/kidney
What is hydrops fetalis?
abdnormal accumulation of fluid in more than one fetal comprtaments
What are the clinical features of polyhydramnios?
abdo discomfort; prelabour rupture of membranes; preterm labour; cord prolapse
what are the clinical signs of polyhydramnia?
LFD; malpresentaiton; tense, shiny abdoment; inability to feel fetal parts
What is seen on USS with polyhydramnios?
AFI >25cm (amniotic fluid index); DVP >8cm (deepest vertical pool)
What investigations are done for polyhydramnios?
OGTT; serology- toxoplasmosis CMV; parvovirus; antibody screen; USS- fetal survey- lips, stomach
What are the risks of polyhydramnios in labour?
cord prolapse; preterm labour; PPH
When should polyhydramnios babies be induced by?
40 weeks
What is the incidence of twins?
1in 80
What is the incidence of triplets?
1 in 10,000
What race has highest risk of multiple pregnnacy?
African
What increases your chance of multiple prengnacy?
assisted conception; race; fhx; increased maternal age; parity; tall women> short women
What is a monozygotic pregnancy?
splitting of single fertilised egg
What is a dizygotic pregnnacy?
fertilisation of 2 ova by 2 sperm
What does chorionicity indicate?
1/2 placentas
What is the chorionicity of dizygous twins?
always dichorionic and diamniotic
What determines the chorionicity of monozygotic twins?
time of splitting of fertilised ovum