OB/GYN

First Trimester Bleeding

1.6% ED visits (overall)

?IUP: up to 50% SAb

+FHR +bleeding: 14% SAb (Juliano, Ann EM, 2008)

>50% (up to 2/3) of SAb lost due to chromosomal abnormalities (not preventable)

We don't need to give RhoGAM for first trimester bleeding. Fetal blood volume 0.3cc, 1cc needed for alloimmunization. (Zipursky, Can Med Assoc J, 1967)

http://www.smartem.org/smartem.org/Podcast/Entries/2011/6/8_Threatened_Ab__Knowledge_is_Power.html