obs and gyny

• 28 and 32 weeks.
• In ectopic pregnancy.
• When high risk of transplacental haemorrahge e.g. CVS, external cephalic version, amniocentesis, foetal blood sampling, abdo trauma.
• all surgical and medical terminations unless already known to have anti-D.
• threatened miscarriage after 12 weeks but not before.

• 10-13 weeks 5%
• 16% 0.5% (standard time)

after 10 weeks (ealier than amniocentesis). loss rate is 4%, can be used to 20 weeks were cordocentesis is then used.