Effect of the Low Molecular Heparin Therapy on Foetal DNA Level in Non-Invasive Prenatal DNA Screening

Study Objective: To evaluate the effect of low molecular heparin (LMH) therapy on non-invasive prenatal DNA screening (NIPS) for chromosomal pathologies. Study Design: cross-sectional study. Materials and Methods. We have examined two groups of pregnant women: group I included 49 patients with constantly low foetal DNA (twice lower than 4%) selected out of 1,505 women examined at Kulakov National Medical Scientific Centre of Obstetrics, Gynaecology and Perinatal Medicine of the Ministry of Health of Russia during the last 2 years. 17 women were administered LMH and 32 women did not receive it. Group II included 113 pregnant women with a normal foetal DNA fraction (at least 4%), that were selected randomly out of patients who were examined during the same period. 56 pregnant women were administered LMH and 57 were not. Next Generation Sequencing was used as an NIPS method. In order to determine the foetal DNA level, we amplified DNA loci with single nucleotide polymorphisms. Study Results. In group I (low foetal DNA fraction), where no LMH therapy was initiated, median values were 3.5% (3.2–3.8%); if LMH was administered, these values made 3.6% (3.4–3.9), while in group II — 7.7% (6.1–9.5%) and 7.9% (6.0–10.5%), respectively; no significant differences (p = 0.29 and p = 0.7, respectively) were recorded in both cases. Conclusion. Use of LMH does not affect NIPS; therefore, it is not necessary to adjust the LMH therapy in pregnant women prior to NIPS. Keywords: non-invasive prenatal DNA screening, heparin, anticoagulants, low molecular heparins, habitual abortion, pregnancy complications.