STUDIO OSSERVAZIONALE MULTICENTRICO SUL RICORSO ALLE PROCEDURE DI VALUTAZIONE DEL RISCHIO E/O DI DIAGNOSI PRENATALE.

Multicenter observational study using the procedures for risk assessment and / or prenatal diagnosis BACKGROUND The increased use of the screening test and prenatal diagnosis is closely correlated with the perception of risk. Often the perception of risk is adjusted according to the choice, some already made, even according to their family history and socio-cultural context. The causal relationship between real and perceived risk is very difficult to determine and many factors of different nature interfere. Often the lack of knowledge and understanding prevail in generating those feelings that lead women to make unconscious choices. OBJECTIVE The aim of the study was to evaluate the factors influencing choice of invasive techniques (CVS, amniocentesis) for prenatal diagnosis (PD) in a population of women, after childbirth, that delivery in S.Gerardo Hospital (Monza) and V.Buzzi Hospital (Milano). METHOD Structured interview in an unselected population of consecutive women (after childbirth) administered by 2 trained interviewers. The interview included social variables and clinical history, type of care during pregnancy, use of screening tests, and VAS (visual analogue scale, range from 1 to 10) of perceived risk of miscarriage due to amniocentesis (using risk of 1/200), and of a child with Down Syndrome (DS) (using a risk of 1/350). Both VAS investigated the perceived risk in term of intensity and acceptability (0 least risk and least acceptable to 10 most risk and more acceptable). Statistical analysis included logistic regression, in which all variables significant at univariate were entered, with p<0.01 or 95% CI not inclusive of unit considered significant. RESULTS 60% of women underwent screening test and 22% underwent invasive procedures. At logistic regression factors affecting the choice of screening test were: to have already had at least one miscarriage (OR=2,72 p=0,0016), to have received a consulance (OR=3,13 p=0,0017), number of visits during pregnance (OR=1,29 p=0,0003), wrong knowledge about test(OR=1,83 p=0,039). At logistic regression factors affecting the choice of invasive PD were: maternal age (OR 11,58 p<.0001),to be married (OR=0,23 p=0,005) to have received a consulance (OR=3,53 p=0,001) ,to be assisted in a public service (p=0,06), considering low the risk of miscarriage after amniocentesis (p=0,08). CONCLUSIONS: The choices regarding screening test and invasive PD are influenced by type of assistance, while social variables are less involved. The counselling should consider factors involved in perceiving risks.