ABO-incompatibility is usually mild but occasionally can cause significant hemolysis with hyperbilirubinemia. Sarici et al identified risk groups for significant hyperbilirubinemia starting at 6 hours after delivery. The authors are from Hacettepe University, Ihsan Dogramaci Children's Hospital and Gulhane Military Medical Academy in Ankara, Turkey.
Patient selection: neonate with ABO incompatibility
A neonate with significant ABO incompatibility may have:
(1) an elevated reticulocyte count
(2) a strongly positive direct antiglobulin test (DAT)
(3) a sibling with ABO incompatibility
Additional testing should include:
(1) exclusion of hemolysis due to anti-D or antibodies to other red cell antigens
(2) maternal and neonatal ABO types consistent with syndrome
(3) exclusion of other causes of hyperbilirubinemia
(4) elution of the antibody can be performed but is rarely performed
The authors identified serum total bilirubin concentrations that separated pateints into low, low-intermediate, intermediate-high and high risk groups over the range from 6 to 102 hours.
Line 1: separates low risk from low-intermediate risk groups
Line 2: separates low-intermediate from intermediate-high risk groups
Line 3: separates intermediate-high and high risk groups
|
|
6 hours
|
30 hours
|
54 hours
|
78 hours
|
|
line 1
|
3.3
|
6.5
|
9.2
|
11
|
|
line 2
|
4
|
8
|
11
|
13
|
|
line 3
|
6.5
|
12
|
15
|
17
|
estimate for line 1 equation =
= (-0.000608 * ((hours)^2) + (0.1586 * (hours)) + 2.351
estimate for line 2 equation =
= (-0.001302 * ((hours)^2) + (0.2219 * (hours)) + 2.666
estimate for line 3 equation =
= (-0.001519 * ((hours)^2) + (0.2714 * (hours)) + 5.002
The risk group can help guide decisions for discharging and treating the neonate.
