If a patient is given RhiG post partum but prior to the fetal screen (FMH) being drawn, does this affect the results of the FMH? We use Immucor reagents for the fetal screens.

No it does not as least with the Ortho kit (alba-science). The fetal screen is looking for D+ cells not anti-D. 

I understand what the test is looking for .  I wasn't sure how fast the RhiG works and if there were any D positive cells still floating around, if the Immucor kit would pick them up. I was specifically asking for input on the Immucor kit.

No, administration of RhIG should not affect the FMH Rapid Screen test. The 'Limitations' section of your package insert will contain information on what can/will cause problems.

thank you all for your input. the package insert does not address the situation of administration of RhiG prior to testing which is why I posted here. since the patient is now discharged it is a moot point.

2 hours ago, Aneg said:

thank you all for your input. the package insert does not address the situation of administration of RhiG prior to testing which is why I posted here. since the patient is now discharged it is a moot point.

With many reagents I see the limitations section of the package insert as  'no news is good news'. If something has the potential to cause a problem it will be there, especially something that might be commonly encountered.