Retrospective analysis of platelet numbers and volumes in normal pregnancy and in pre‐eclampsia

Abstract

Objective To determine the distribution of platelet volumes and numbers through pregnancy, and to compare these to changes in platelet volumes and numbers in women with pre‐eclampsia. Subjects Four hundred twenty‐eight women with normal pregnancy from whom four or more platelet measurements were available were identified. 74 women with pre‐eclampsia (blood pressure 140/90 mmHg, at least 0.5g protein/24 h urine collection) from whom platelet measurements were available between 27 and 30 weeks of gestation were identified. Results Mean platelet volume and platelet number remained constant in normal pregnancies between the first trimester and the end of pregnancy. A persistent increase of 0.8 fl ( 90th centile) in mean platelet volume was found in 14 out of 15 pre‐eclamptic patients between 24 weeks and 38 weeks of gestation and in only 13 of 428 normal pregnant individuals. Platelet numbers were decreased by 50 × 109/l (i.e. to less than the 10th centile) in 12 of the 15 patients with pre‐eclampsia. 10% of the normal pregnant population showed a similar decline in platelet numbers showing that changes in platelet numbers may be a less accurate assessment of the development of pre‐eclampsia. Conclusion We suggest that longitudinal determination of platelet volumes may be of use in identifying those women at risk of pre‐eclampsia.

The determination of a reference range for new platelet parameters produced by the Bayer ADVIATM 120 full blood count analyser

“…Platelet microcytosis is a characteristic of the Wiskott^Aldrich syndrome (Thrasher et al 1998). Platelet macrocytosis is associated with Alports's syndrome (Patterson 1997) and elevated MPV with an increased risk of pre-eclampsia (Ahmed et al 1993). The MPV values for both sexes are quite close and unlikely to in£uence the di¡erentiation of microcytic or macrocytic platelets from normal.…”

“…This has made an increasing number of parameters routinely available and generated data that were not previously available. In addition to the platelet count, the mean platelet volume has been suggested as a useful parameter (Ahmed et al 1993;Howarth et al 1999). The introduction of the Bayer ADVIA TM 120 (Bayer, USA) analyser has increased the range of platelet data that can be derived during the full blood count (FBC).…”

Mean platelet volumes in babies of preeclamptic mothers

“…On the other hand, Dundar et al [22] compared preeclamptic women with normal pregnant women and showed a statistically significant increase in MPV levels just 4.6 weeks before the occurrence of preeclampsia symptoms. However, in contrast to these data, it was emphasized that MPV values may also be higher in normal pregnancies and just making a MPV screening test may be insufficient [18,19]. In conclusion, the reason for thrombocytopenia occurring in preeclamptic mothers is still unknown.…”

“…It is well known that the higher MPV seen in normal pregnancies depends on the increased platelet formation [5,6,18,19]. Despite this, researches made to compare the MPV and platelet numbers of the preeclamptic mothers with normal pregnancies have shown different results.…”

Platelet Count and Platelet Indices at Various Stages of Normal Pregnancy in Smoking and Non-Smoking Women

“…The MPV remained stable until 35 weeks gestation and rose dramatically thereafter. Ahmed et al (15) studied the MPV in healthy pregnants. This quantity remained constant between the first trimester and the end of normal pregnancy.…”