Ľubušký M., Simetka O., Studnickova M., Prochazka M., Ordeltova M., Vomackova K. Fetomaternal hemorrhage in normal vaginal delivery and in delivery by cesarean section. Transfusion, 2012, 52 (9), p. 1977-1982. (IF-3,526)
ABSTRACT
BACKGROUND: The objective was to determine the
incidence and volume of fetomaternal hemorrhage
(FMH) in normal vaginal delivery and in delivery by
cesarean section. Determination of these variables
would enable optimalization of guidelines for D alloimmunization prophylaxis.
STUDY DESIGN AND METHODS: In a prospective
cohort study, a total of 3457 examinations were performed, 2413 after normal vaginal delivery and 1044
after cesarean delivery. FMH was assessed by flow
cytometry. (FMH is fetal red blood cell [RBC] volume;
fetal blood volume is double [expected fetal hematocrit
is 50%].)
RESULTS: The fetal RBC volume diagnosed in
maternal circulation after delivery ranged from insignifi-
cant FMH of not more than 0.1 mL to excessive
FMH of 65.9 mL (median, 0.7; mean, 0.78; SD, 1.48).
FMH of more than 2.5 mL (immunoglobulin [Ig] G anti-D
insufficient dose 50 mg) was observed in 1.4% (49/
3457) and excessive volumes of FMH of more
than 5 mL (insufficient dose, 100 mg) in 0.29% (10/
3457). Delivery by cesarean section presented a higher
risk of incidence of FMH of more than 2.5 mL (odds
ratio, 2.2; p = 0.004) when compared with normal
vaginal delivery. It did not, however, present a signifi-
cant risk factor for the incidence of excessive volumes
of FMH of more than 5 mL.
CONCLUSION: During normal vaginal delivery as well
as during delivery by cesarean section, FMH of less
than 5 mL occurs in the great majority of cases, and
thus for the prevention of D alloimmunization, an IgG
anti-D dose of 100 mg should be sufficient. Contrarily,
only rarely does greater FMH occur and delivery by
cesarean section does not present a risk factor.