Evaluation of Routine Antepartum and Postpartum Blood Counts

Abstract & Commentary

Synopsis: Obtaining routine postpartum blood counts may not be useful.

Source: Ries A, et al. J Reprod Med 1998;43:581-585.

This retrospective study compared the admission and postpartum hematocrit determinations for a group of 770 women delivering on the authors’ obstetrical service during a six-month period. In addition, the 28-week hematocrit results were compared to the admission results to determine whether a difference in platelet concentration was noted. Ries and colleagues stratified the differences in hemoglobin concentration by type of delivery and delivery complication.

Ries et al found that there was no significant difference between the platelet concentration at the 28-week determination and the admission count.

Postpartum hematocrit concentrations were lower than those at the time of admission. However, all of the women requiring transfusion would have been identified because of complications occurring during the delivery process. These complications included such things as placenta accreta, severe pre-eclampsia with thrombocytopenia, uterine inversion, postpartum hemorrhage, acute fatty liver, broad ligament hematoma, Cesarean hysterectomy, and amniotic fluid embolus.

Among women who did not need to be transfused, women undergoing spontaneous vaginal delivery had the smallest mean decrease in hematocrit concentration, and those women having vacuum extraction had a slightly larger decrease. Forceps deliveries accounted for larger decreases than Cesarean deliveries.

Comment by Kenneth Noller, MD

This is another article that questions our "routine" practice. At many hospitals, a postpartum hemoglobin is obtained on the first post-delivery day. Ries et al rightly question whether that is a reasonable (i.e., important) determination. Based on their results, it does not seem to be.

This is not a surprising finding. Although there are occasional low hematocrits on the first postpartum day, virtually every anemia would have been expected based on some type of hemorrhage. Why then do many hospitals routinely order them? It would seem only to add expense without significant benefit. While one hematocrit determination is relatively inexpensive, there are 4 million deliveries in the United States each year, and considerable cost savings could be achieved if we could eliminate most of them. I am certainly planning to argue for cessation of this test as a routine at our hospital.

It is interesting that Ries et al also looked at platelet concentrations between 28 weeks and admission. Though they never so state in their paper, it is clear that an admission platelet concentration must be obtained before their anesthesia team will insert an epidural. I wonder how many other places also have this policy? That has not been a routine on the obstetrical services I have been involved with during the past two decades.

Although Ries et al did not do the study, I wonder how useful their routine 28-week blood count would prove to be if carefully scrutinized?