No evidence of fetal DNA persistence in maternal plasma after pregnancy

Abstract

Short-and long-term persistence of fetal DNA in maternal plasma has been investigated. Short-term persistence at very low concentration was detected in 47 out of 105 women within two days after delivery. Twelve out of 13 samples re-tested within three days scored negative.No long-term persistence was detected in 172 women who had previous sons or abortions. Molecular microchimerism due to circulating fetal DNA persisting from previous pregnancies should not hamper non-invasive plasma-based prenatal testing.

Monitoring of Venus transgenic cell migration during pregnancy in non-transgenic rabbits

“…The available data in literature about fetal microchimerism within same species, especially in women, are also contradictory. Numerous publications provided data about fetal microchimerism after pregnancy in women [for details, see review (Gammill and Nelson 2010)], but studies claiming no evidence for fetal DNA in maternal plasma after delivery were also published (Lo et al 1999; Smid et al 2003). Our results based on three different methods suggest that beside the prominent role of placentation, the influence of species-specific differences in pregnancy-related microchimerism cannot be ruled out.…”

Effect of labor on postpartum clearance of cell‐free fetal DNA from the maternal circulation

“…The first report studied eight patients delivered by elective CS with serial samples taken immediately postpartum, and all but one had cleared cff DNA by 2 h. The mean half-life calculated from these eight patients was 16.3 min (ranging from 4 to 30 min) (Lo et al, 1999a). A much larger investigation of postpartum persistence of fetal DNA did not report any data relating to the mode of delivery (Smid et al, 2003). In that study, 47/105 of women tested positive within 2 days of delivery.…”

“…Free fetal DNA rises in concentration following elective termination of pregnancy (Wataganara et al, 2005) and preterm labor (Leung et al, 1998), but the labor process at term does not appear to cause a rise in cff DNA concentration (Ingargiola et al, 2003). The largest study of postnatal clearance to date found that 45% of women still had detectable DNA on day 1-2 postpartum (Smid et al, 2003), but information regarding the exact time interval to testing and the mode of delivery was not reported. To our knowledge, data directly comparing clearance rates in women according to the presence or absence of labor have not been previously published.…”

“…Microchimerism due to long-term persistence of fetal cells from previous pregnancies is well established (Bianchi et al, 1996); in contrast, postnatal clearance of cff DNA is relatively rapid (Lo et al, 1999a). One notable exception in the literature suggests that cff DNA can persist for decades after pregnancy (Invernizzi et al, 2002), but this is unconfirmed in numerous other studies (Johnson-Hopson and Artlett, 2002;Benachi et al, 2003;Smid et al, 2003;Rijnders et al, 2004), and current opinion is that cff DNA pertains to the current pregnancy only. *Correspondence to: L. Hui, Department of Maternal Fetal Medicine, Royal Hospital for Women, Randwick NSW 2031, Several factors have been shown to influence the rate of clearance: maternal disease such as preeclampsia (Lau et al, 2002), and placental disease such as retained placenta (Jimbo et al, 2003).…”

Placental RNA in Maternal Plasma

“…12 Moreover, most reports have suggested that cell-free fetal DNA is unlikely to persist in maternal plasma. [12][13][14] Similar to the circulating fetal DNA, circulating fetal-derived hPL RNA has recently been shown to be cleared rapidly from the maternal plasma after delivery with the clearance half-life of 14.1 min. 11 The rapid clearance of the fetal nucleic acids suggests that prenatal diagnosis performed using fetal DNA and RNA in maternal plasma is unlikely to be susceptible to false results due to previous pregnancies.…”