Platelet count at term pregnancy: a reappraisal of the threshold.
OBJECTIVE
To assess the safety of a new platelet count threshold for the definition of maternal thrombocytopenia late in pregnancy.


METHODS
A platelet count was performed in 6770 pregnant women late in pregnancy and in 6103 of their newborns as well as in a control group of 287 age-matched nonpregnant healthy women.


RESULTS
The prevalence of maternal thrombocytopenia (platelet count less than 150 x 10(9)/L) was 11.6%. The mean platelet counts (248 compared with 213 x 10(9)/L) and 2.5th percentile (164 compared with 116 x 10(9)/L) were significantly higher in healthy nonpregnant women than in pregnant women. Among thrombocytopenic pregnant women, 621 (79%) had platelet counts between 116 and 149 x 10(9)/L; none (0%; 95% confidence interval 0, 0.6) had complications related to thrombocytopenia, and none of their newborns had severe thrombocytopenia (platelet count less than 20 x 10(9)/L).


CONCLUSIONS
In healthy pregnant women, a platelet count over 115 x 10(9)/L late in pregnancy does not require further investigation during pregnancy and may be considered a safe threshold.
Boehlen
F
F
Department of Internal Medicine, University Hospital, Geneva, Switzerland.
Hohlfeld
P
P
Extermann
P
P
Perneger
T V
TV
de Moerloose
P
P
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008875:Middle Aged; D010976:Platelet Count; D011247:Pregnancy / Q000502:physiology*; D011250:Pregnancy Complications, Hematologic / Q000175:diagnosis*; D012016:Reference Values; D013921:Thrombocytopenia / Q000175:diagnosis*