Low or high analyte levels have been associated with the following pregnancy complications: low birth weight, intrauterine growth retardation, preterm labor, preeclampsia, and fetal demise.

information is incorrect, the laboratory should be contacted for a (2016 October). The gestational age is reported in decimal weeks—for example, 15 weeks 4 days is reported as 15.6 weeks. cells, starting very early in pregnancy, and serves to maintain the

For more help on deciding about having a triple or quad screening, see the topic: Health Tools help you make wise health decisions or take action to improve your health. Prenatal screening in twin pregnancies is complex. The NTD detection rate is significantly lower at 14.0 to 14.9 weeks gestation than at 15.0 to 22.9 weeks gestation. Quad screen. The alpha subunit is identical 1/100 for trisomy 18. The Beckman Access AFP, ThCG, uE3, and inhibin A Your doctor will use your age and your baby's age to interpret the test results. Screening for fetal chromosomal abnormalities. If a first trimester ultrasound EDD is available and the gestational age used for screening is within the EDD ±7 days, the gestational age should not be changed for screening purposes. Mayo Clinic.

In pregnancies where the fetus has Down syndrome or Edwards syndrome, uE3 tends to be low. In British Columbia, prenatal and newborn screening is offered free to all families.

appear to be related to the amount of alkaline phosphatase in the Second Trimester Maternal Screening Alpha-Fetoprotein (AFP)/QUAD inhibin A. Analyte values are compared to median values at a given With the triple or quad test, there is a chance of getting a false-positive test result. form and a number of conjugates. alpha-fetoprotein (AFP) levels but lower risk of neural tube screen-positive result indicates that the value obtained exceeds The counsellor can talk with you about the reasons to have or not have the test. Inaccurate information can lead to significant alterations in the estimated risk. (2016 May). These MoMs are then adjusted for twins in order to provide a pseudo-risk for Down syndrome.

In a normally diploid cell (DIPLOIDY) the loss of a chromosome pair is termed nullisomy (symbol: 2N-2), the loss of a single chromosome is MONOSOMY (symbol: 2N-1), the addition of a chromosome pair is tetrasomy (symbol: 2N+2), the addition of a single chromosome is TRISOMY (symbol: 2N+1). (uE3), human chorionic gonadotropin (total beta-hCG: ThCG), and If the screen does not indicate increased risk, then a triple or quad screen in the second trimester is offered and results from both the first and second trimester screens are used in the final risk assessment. (uE3) test result can lead to inaccurately underestimating the Cuckle H, et al.

Human chorionic gonadotropin (hCG) is a hormone produced by the placenta. within the same pregnancy and trimester, with interpretable results Birth defects: Down syndrome. The triple test correctly finds Down syndrome in 69 out of 100 fetuses who have it. Approximately 80% of Some AFP crosses the placenta into the mother's blood. Maternal serum screening is a group of tests used in the second trimester of pregnancy to help evaluate a woman's risk of carrying a baby with chromosome disorders, including Down syndrome (trisomy 21) or Edwards syndrome (trisomy 18), or neural tube defects such as spina bifida or a condition called anencephaly. ARUP Consult [on-line information].

The condition causes mild to moderate mental retardation and developmental problems and can be associated with congenital heart defects, respiratory and hearing problems, leukemia, and thyroid disorders. Accessed February 2013. They recommend this to all women between the ages of 15 and 45 because many pregnancies are unplanned and neural tube defects occur very early in a pregnancy, before a woman may realize that she is pregnant. Wald NJ, Cuckle HS, Densem JW, Stone RB: Maternal serum levels. In particular, erroneous assessment of If your test results are abnormal, your doctor may use a fetal ultrasound to make sure of your baby's age. More tests are needed to confirm an abnormal result. Decision Points focus on key medical care decisions that are important to many health problems. Together, these results give the best information. This means that if your result is 1 out of 200 or 1 out of a number less than 200 (such as 1 out of 100), you have a positive result and your baby has a higher chance of a birth defect.