The effect of chorionic villus sampling on the fraction of cell-free fetal DNA in maternal plasma.
OBJECTIVE
This study aims to assess whether the fraction of cell-free fetal DNA (cffDNA) is different at 24 h or 7 days after chorionic villus sampling (CVS), compared to subjects that do not undergo CVS.


METHODS
Pregnant women undergoing CVS for genetic testing and matched subjects undergoing first trimester combined screening alone were enrolled between 11(0/7) and 13(6/7) weeks gestation. The fractions of cffDNA were compared before the procedure, 24 h after and 7 days after between CVS patients and ultrasound-only patients.


RESULTS
Forty-five women underwent CVS and 45 had ultrasound alone. The women undergoing CVS were, on average, older (36.8 years versus 28.5 years, p=0.001) and had a higher baseline fraction of cffDNA than women in the comparison group (11.4% versus 9.8%, p=0.033). Both groups had a decrease in the mean fraction of cffDNA after 24 h. After 7 days, the trend of the mean fraction of cffDNA continued to decline in the CVS group but began to trend toward an increase in the ultrasound only group.


CONCLUSIONS
CVS does not significantly increase the fraction of cell free fetal (placental) DNA in the maternal plasma. A downward trend in cffDNA in maternal plasma is seen at 24 h and 7 days following CVS compared to baseline.
a Division of Maternal-Fetal Medicine , Department of Obstetrics and Gynecology, College of Physicians and Surgeons, Columbia University , New York , NY , USA .
Amber R
AR
Samuel
b Department of Obstetrics and Gynecology , College of Physicians and Surgeons, Columbia University , New York , NY , USA , and.
Moeun
M
Son
a Division of Maternal-Fetal Medicine , Department of Obstetrics and Gynecology, College of Physicians and Surgeons, Columbia University , New York , NY , USA .|c Department of Epidemiology , Mailman School of Public Health, Columbia University , New York , NY , USA.
Cande V
CV
Ananth
a Division of Maternal-Fetal Medicine , Department of Obstetrics and Gynecology, College of Physicians and Surgeons, Columbia University , New York , NY , USA .
Ronald J
RJ
Wapner
D000328:Adult; D015193:Chorionic Villi Sampling; D004247:DNA / Q000097:blood*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005333:Fetus; D005820:Genetic Testing / Q000379:methods; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis; D016216:Ultrasonography, Prenatal
D004247:DNA
Cell-free fetal DNA; chorionic villus sampling; fetal fraction