Search results
Results From The WOW.Com Content Network
Cell-free fetal DNA (cffDNA) is fetal DNA that circulates freely in the maternal blood. Maternal blood is sampled by venipuncture. Analysis of cffDNA is a method of non-invasive prenatal diagnosis frequently ordered for pregnant women of advanced age. Two hours after delivery, cffDNA is no longer detectable in maternal blood.
The Unity test uses NGS technology to look for Rh alleles (genes) in the cell free fetal DNA in the maternal bloodstream. In healthy pregnancies, at least 5% (fetal fraction) of the cell free DNA in the maternal bloodstream comes from the fetus (placenta cells shed DNA into the maternal bloodstream).
An ultrasound showing an embryo measured to have a crown-rump length of 1.67 cm and estimated to have a gestational age of 8 weeks and 1 day. Crown-rump length (CRL) is the measurement of the length of human embryos and fetuses from the top of the head (crown) to the bottom of the buttocks (rump).
Fetal hemoglobin, or foetal haemoglobin (also hemoglobin F, HbF, or α 2 γ 2) is the main oxygen carrier protein in the human fetus. Hemoglobin F is found in fetal red blood cells , and is involved in transporting oxygen from the mother's bloodstream to organs and tissues in the fetus.
Fetal antigen status can be tested as early as 15 weeks by PCR of fetal cells. [12] CVS is possible as well to test fetal antigen status but is not recommended. CVS carries a higher risk of fetal maternal hemorrhage and can raise antibody titers, potentially worsening the antibody effect. [12]
It is estimated that less than 1ml of fetal blood is lost to the maternal circulation during normal labour in around 96% of normal deliveries. [1] [2] The loss of this small amount of blood may however be a sensitising event and stimulate antibody production to the foetal red blood cells, an example of which is Rhesus disease of the newborn.
Presentation of twins in Der Rosengarten ("The Rose Garden"), a German standard medical text for midwives published in 1513. In obstetrics, the presentation of a fetus about to be born specifies which anatomical part of the fetus is leading, that is, is closest to the pelvic inlet of the birth canal.
The fetal circulation is composed of the placenta, umbilical blood vessels encapsulated by the umbilical cord, heart and systemic blood vessels. A major difference between the fetal circulation and postnatal circulation is that the lungs are not used during the fetal stage resulting in the presence of shunts to move oxygenated blood and ...