Evaluation of bone marrow function with immature platelet fraction in normal pregnancy

Background:

Bone marrow function in pregnancy is influencing blood cell concentration of platelets. The steady state of consumption and recovery or production of platelets is essential for coagulation and bleeding prevention. Reticulated platelets are an intermediate form of thrombocytes during thrombopoesis representing platelet production. The immature platelet fraction (IPF) represents these platelets as percentage of all thrombocytes. Until now, there is little knowledge on IPF during pregnancy.

Material and Methods:

69 healthy pregnant women were included in this monocentric study. Serial blood samples of 27 women (study group 1) and single blood samples of 42 women (study group 2) were taken between 20 and 40 weeks of gestation. IPF levels and thrombocytes were quantified by a routine clinical hematology analyzer. Both two study groups were analyzed separately.

Results:

IPF levels increase between 20 and 40 weeks of gestation in both study groups. Mean values rise from 3.63% to 6.06% in study group 1 and from 4.9% to 6.01% in study group 2. Most values stay below 7 – 7.5%. Highest IPF levels were measured near term. In contrast, thrombocyte counts decrease slightly during this period.

Conclusion:

Bone marrow function is mirrored by IPF levels, which increase with gestational age in healthy pregnant women. Most values remain below 7%. More studies are needed to improve understanding of thrombocyte turnover in pregnant women with conditions involving thrombocyte changes, for example HELLP syndrome.

IPF and its prognostic impact in preeclampsia and HELLP syndrome:

Background:

Hypertensive diseases are a frequent cause of maternal and fetal morbidity and mortality. A number of parameters have been introduced to diagnose preeclampsia or HELLP syndrome at an early stage. The defined cut-offs of angiogenetic and antiangiogenetic parameters soluble fms-like thyrosine kinase (sFlt) and placental growth factor (PIGF) are approved for clinical routine. However, those parameters need complex analysis and are expensive. In contrast, the immature platelet fraction (IPF) is available in most emergency departments.

Material and Methods:

69 pregnant women were included in this monocentric study, 28 had preeclampsia, HELLP syndrome or partial HELLP syndrome fitting the Tennessee criteria (study group 1). They also met the sFlt/PIGF cut-offs suggested by Verlohren et al. 2014. Data of this group has been analyzed retrospectively. Furthermore, 42 normotensive pregnant women have been included, recruited between 20 and 40 weeks of gestation as control (study group 2). In both groups the IPF was measured, compared and statistically analyzed.

Results:

Hypertensive pregnant women show significantly higher values of IPF than normotensive pregnant women. Normotensive subjects keep mean levels below 7%, whereas hypertensive women reach values higher than 10%. In this study, we demonstrate that the increase of IPF is higher in patients with HELLP syndrome than in those with preeclampsia.

Conclusion:

IPF levels are significantly higher in women with hypertensive pregnancy complications than in normotensive pregnant women. Further study is needed to confirm our results.

No conflict of interest has been declared by the author(s).