Low pregnancy-associated plasma protein A level in the first trimester

Article Figures & Data

Table 1.

Current screening tools for aneuploidy involving the use of PAPP-A

TEST	MARKERS	TRIMESTER
FTS	NT, free β-hCG, PAPP-A, MA	First
IPS	NT, PAPP-A, AFP, uE3, free β-hCG or total hCG, inhibin A, MA	First and second
IPS without inhibin A	NT, PAPP-A, AFP, uE3, total hCG, MA	First and second
Serum IPS	PAPP-A, AFP, uE3, free β-hCG or total hCG, inhibin A	First and second

AFP—α-fetoprotein, FTS—first-trimester screening, hCG—human chorionic gonadotropin, IPS—integrated prenatal screening, MA—maternal age, NT—nuchal translucency, PAPP-A—pregnancy-associated plasma protein A, uE3—unconjugated estriol.

Table 2.

Definition of commonly used terms

TERM	DEFINITION
IUGR	Designates a fetus that has not reached its growth potential owing to genetic or environmental factors, with an estimated fetal weight below the 10th percentile (usually measured via ultrasound)
SGA	Designates a born infant whose weight is below the 10th percentile for its gestational age—usually the result of IUGR
Preterm labour and preterm delivery	Onset of active labour and delivery before 37 weeks’ gestation
Spontaneous abortion	The ending of a pregnancy resulting in an expulsion of the fetus before it has reached a viable gestational age of 20 weeks, typically with a weight of ≤ 500 g
Stillbirth	Fetal death after 20 weeks’ gestational age. If gestational age is unknown, it is defined by a fetal weight of > 500 g
Hypertensive disorders of pregnancy	Refers to hypertension during pregnancy. There are 3 important types: Preeclampsia—new onset of hypertension with proteinuria after 20 weeks’ gestation in a previously normotensive woman Eclampsia—development of generalized tonic-clonic seizures in a woman with preeclampsia in the absence of other neurologic conditions that can account for the seizures Chronic or pre-existing hypertension—hypertension (SBP > 140 mm Hg and DBP > 90 mm Hg) that predates pregnancy or that is present before 20 weeks’ gestation