OB Titer

[LisaMarie 2]

How many times should a titer be repeated for an OB patient, especially if the titer is considered undetectable or 0. 
if it’s critical like anti-K.  what is the approach in that case.  

[Malcolm Needs ★ 4,688]

In the UK, we either titre (anti-K, or other Kell-related antibodies) or quantify (anti-D and/or anti-c) every four weeks to 28 weeks of gestation, and then every two weeks until delivery.  All other antibodies are only monitored from when they were first detected (probably at booking) at 28-weeks of gestation, unless the titre is particularly high.

In all cases, however, if a known antibody specificity is NOT detected in an antibody screen, where, of course, the cognate antigen is expressed, then it is not worth performing the titre at all.  It is just a waste of time, money and reagents.  In such cases, however, we would perform the antibody screen over the time periods as described above.

[AMcCord 1,223]

We get specimens for titers monthly for all OB patients with clinically significant alloantibodies. As Malcolm says, if the antibody screen is negative for a patient with an historic alloantibody it is pointless to order a titer.

Once the titer rises to the point that it is considered 'critical', the patient is followed by other means and we no longer receive specimens/orders for titers. These patients are almost always being seen by specialists at that point and those providers determine what is ordered or not ordered.

[LisaMarie 2]

Thanks. Very helpful