Materials and Methods: This was a retrospective cohort study including all women who had cffDNA measurement as a primary or secondary screening test for chromosomal abnormalities in a screening laboratory in Iran.

Results: Totally, 481 out of 634 pregnant women (75.9%) did not develop any pregnancy complications. On the other hand, 55 pregnancies (8.7%) led to preterm delivery. Based on the results, 33 pregnant women (5.2%) gave birth to intrauterine growth restriction (IUGR) babies and 16 pregnant women (2.52%) developed preeclampsia (PE). Moreover, 15 women developed gestational diabetes. Further, 11 pregnancies resulted in abortion and 6 pregnancies led to fetal death. There was a positive association between the duration of pregnancies and the weight of the babies at birth (r = 0.362, P = 0.000). There was a statistically significant association between the increase in cffDNA level and trisomy (P = 0.000) and the decrease in cffDNA level and the incidence of PE (P=0.019).

Conclusions: The reduction of plasma cffDNA level in pregnancies led to PE and the elevation of cffDNA results in fetal trisomy. However, further studies will be required to confirm these findings.