Prenatal diagnosis versus first-trimester screening of trisomy 21 among pregnant women aged 35 or more

Abstract Objective: To compare the policy of prenatal diagnosis versus first trimester screening of trisomy 21 among pregnant women of advanced age. Methods: A retrospective study was conducted on patients aged ≥35 divided in two groups: patients who requested first trimester combined test and only in case of screen-positive result underwent invasive testing (group A); patients undergoing chorionic villous sampling or amniocentesis as first investigation (group B). The following outcome variables were compared: antenatal detection of trisomy 21, occurrence of trisomy 21 at birth, miscarriage rate, hospitals' costs. Results: 4527 women were included. Of these, 534 (11.80%) underwent T21 screening whereas 3993 (88.20%) requested primary invasive testing. In group A, 64 combined test were positive (11.99%) and 8 trisomy 21 cases were diagnosed (1.50%); the loss of euploid fetuses after invasive procedure was 4.55% (2/44). No false-negative case was observed. In group B 57 cases of trisomy 21 were diagnosed (1.43%), and pregnancy loss rate of chromosomally normal fetuses was 0.45% (17/3806). The estimated cost was, respectively, 67.720€ for the primary screening versus 1.996.500€ for direct prenatal diagnosis. Conclusion: First trimester screening of trisomy 21 is highly accurate and cost saving among women ≥35

Risk of Fetal Loss in Pregnancies Undergoing Midtrimester Amniocentesis after Inconclusive Chorionic Villus Sampling

Objective: To estimate the procedure-related risk of miscarriage in pregnancies undergoing amniocentesis (AC) following inconclusive results for a chorionic villus sampling (CVS). Methods: This was a multicentric retrospective cohort study of patients in which both CVS at 11-13 weeks' gestation and AC at 16-22 weeks were performed between January 1st, 2008, and July 31st, 2017. The primary outcome measure was pregnancy loss prior to 24 weeks gestation; the secondary one was intrauterine demise after 24 weeks. Results: A total of 287 patients underwent transabdominal CVS and AC. Nine patients were lost at follow-up; therefore, the analysis was conducted on a population of 278 patients (275 singletons and 3 dichorionic twin pregnancies). AC was performed because of placental mosaicism (93.6%), failure of direct/semidirect preparation of trophoblastic cells (3.2%), or targeted genetic testing after the diagnosis of an anomaly in the second trimester (3.2%). In continuing pregnancies, there were no fetal losses prior to 24 weeks' gestation. Two intrauterine demises (including 1 fetus with multiple anomalies and growth restriction) in the third trimester were recorded. Conclusion: Patients undergoing midtrimester AC because of an inconclusive result of CVS can be reasonably reassured that in general the risk of miscarriage and fetal loss following the procedure is very small

Attitudes of women of advanced maternal age undergoing invasive prenatal diagnosis and the impact of genetic counselling

Despite the increasing availability and effectiveness of non-invasive screening for foetal aneuploidies, most women of advanced maternal age (AMA) still opt for invasive tests. A retrospective cross-sectional survey was performed on women of AMA undergoing prenatal invasive procedures, in order to explore their motivations and the outcome of preliminary genetic counselling according to the approach (individual or group) adopted. Of 687 eligible women, 221 (32.2%) participated: 117 had received individual counselling, while 104 had attended group sessions. The two groups did not differ by socio-demographic features. The commonest reported reason to undergo invasive tests was AMA itself (67.4%), while only 10.4% of women mentioned the opportunity of making informed choices. The majority perceived as clear and helpful the information received at counselling, and only 12.7% had doubts left that, however, often concerned non-pertinent issues. The impact of counselling on risk perception and decisions was limited: a minority stated their perceived risk of foetal abnormalities had either increased (6.8%) or reduced (3.6%), and only one eventually declined invasive test. The 52.6% of women expressed a preference toward individual counselling, which also had a stronger impact on perceived risk reduction (P=0.003). Nevertheless, group counselling had a more favourable impact on both clarity of understanding and helpfulness (P=0.0497 and P=0.035, respectively). The idea that AMA represents an absolute indication for invasive tests appears deeply rooted; promotion of non-invasive techniques may require extensive educational efforts targeted to both the general population and health professionals