Concentration of maternal biochemical markers: Complications during pregnancy and their effect on the detection of trisomy 21 in the first trimester, by combined test (study carried out at a private clinic in CDMX) Biochemical markers and complications during pregnancy

Abstract

Aneuploidies are alterations that affect the number of chromosomes. Historically, a combination of markers has been used that includes: maternal age, concentrations of biochemical markers and ultrasonographic markers during pregnancy, as well as screening in the first trimester in order to detect Trisomy 21 (T21).
Objective:
To identify if biochemical markers such as Pregnancy Associated Placental Protein A (PAPP-A) and Beta human Chorionic Gonadotropin (β-hCG) are altered by complications during pregnancy and if this leads to an increased risk of developing T21 in pregnant women with healthy babies (combined test).
Material and method:
Retrospective, observational and cross-sectional study, included 73 pregnant women. Anthropometric data from the mother and the newborn were collected. A combined test was performed in the 1st trimester and biochemical markers were recorded in maternal serum (β-hCG AND PAPP-A) and ultrasonographic markers [Nuchal Translucency (NT)]. In addition, the evaluation of Cell-Free Fetal DNA (cffDNA) in peripheral blood was performed to identify aneuploidies and a pathological study of the placenta.
Results:
In the group of patients with intermediate risk for T21, there was a higher prevalence of complications during pregnancy [fetal growth restriction (4.5%), preterm labor (4.5%), miscarriage (9.09%) and death (9.09%). In the same way, patients with intermediate risk presented a higher prevalence of placental alterations such as calcifications, atrophy, congested dilated vessels, hemorrhage, hematomas, Chorioangioma, extravasation of erythrocytes and villus infarcts.

Conclusions:
The development of placental alterations and the presence of complications in pregnancy could modify the peripheral blood concentrations of β-hCG and PAPP-A, and alter the results of the combined test for T21.