Trisomy 21 was not detected prenatally in many fetuses in which there were additional structural anomalies. The prenatal detection rate was 43% (38/88).

Twenty‐seven cases of trisomy 21 were terminated; the termination rate of the prenatally detected trisomy 21 pregnancies was 84% (27/32), excluding miscarriages and cases with no option of termination. Since 2004 this was performed in week 12. Click the topic below to receive emails when new articles are available. This website also contains material copyrighted by 3rd parties. If you do not receive an email within 10 minutes, your email address may not be registered, If improvement of the detection rates of trisomy 21 is desired, additional programs are necessary, such as first‐trimester ultrasound examinations.

13. The study population comprised a non‐selected population in a geographically well defined area consisting of the city of Trondheim and eight surrounding municipalities. 1997;1(2) © 1997. Spectrum of congenital heart defects and extracardiac malformations associated with chromosomal abnormalities: results of a seven year necropsy study. In our total population, most cases were detected by ultrasound imaging. Two of the 26 women had an early ultrasound examination at a median of 13 + 2 gestational weeks (one had a previous history of miscarriage and the other of triploidy). , , , University of New Mexico Health Sciences Center, Ultrasound findings associated with trisomy 21 may be divided into 2 groups. However, it did not have any impact on detection rates of trisomy 21 at the second‐trimester routine ultrasound examination in our study. First trimester serum tests for Down's syndrome screening. In seven of these cases, the ultrasound examination was repeated, but trisomy 21 was not suspected. The use of ultrasound imaging to examine the fetus in the second trimester led to the detection of both structural anomalies, such as duodenal atresia and atrioventricular septal defects, and the identification of soft markers that have been associated with trisomy 219-14. However, structural anomalies were found in 29/39 (74%) cases postnatally. The case at 16 weeks was referred for a history of trisomy 21, and poor visualization was noted.

Soft markers are sonographic findings that do not in themselves cause any adverse outcomes. 2001;17 (5): 442-4. Our data can be considered as a reference standard for population screening for trisomy 21 based solely on maternal age and second‐trimester ultrasound imaging. 5. Trisomy 21: Major Malformations And Screening Indicators . ... About 95% of the time, Down syndrome is caused by trisomy 21 and the child has three copies of chromosome 21 in all cells. Antenatal screening of Down syndrome (and other less common aneuploidies) should be available as a routine component of antenatal care.

You will receive email when new content is published. Some 86% (43/50) of all women with undetected trisomy 21 were aged less than 38 years; 7/50 (14%) were 38 years of age and above. Data from the ultrasound examinations were stored in an electronic database. The distribution and outcome of detected and undetected trisomy 21 fetuses are shown in Figure 1. Ischemic Stroke May Hint at Underlying Cancer, Topol: US Betrays Healthcare Workers in Coronavirus Disaster, The 6 Dietary Tips Patients Need to Hear From Their Clinicians, Trisomy 21: Major Malformations And Screening Indicators. More recently, Nyberg et al. Published by John Wiley & Sons, Ltd. Tennstedt C, Chaoui R, Körner H et-al. Three had suspicious ultrasound findings at the second‐trimester routine ultrasound scan, leading to karyotyping between 15 and 22 weeks. With a 5% false‐positive rate, screening by a combination of maternal age and fetal NT identifies 75–80% of fetuses with trisomy 21 and other major chromosomal abnormalities19-21. IUFD, intrauterine fetal death; TOP, termination of pregnancy. Nuchal translucency: thickness depends on the size of the fetus (CRL), but in general it is considered abnormal if >3 mm. A national standardized protocol for the second‐trimester ultrasound examination was used. Summary of all prenatally detected and undetected trisomy 21 cases in the non‐selected population of 49 314 births. For the last 6‐year period from 1999 to 2004 we have complete electronic registration of hospital visits, and in this period 13 trisomy 21 infants were delivered. Advanced maternal age as an indication for karyotyping contributed only 14% of the detected cases, underscoring the inefficiency of such a screening program. All material on this website is protected by copyright, Copyright © 1994-2020 by WebMD LLC. Other studies reporting on the effectiveness of routine ultrasound examination for prenatal detection of trisomy 21 in non‐selected populations have shown large variations in detection rates. According to the World Health Organization (WHO), the approximate worldwide incidence is approximately 1 in 700-1,000live births ref.

The termination rate among women who received their trisomy 21 diagnosis by opting for an amniocentesis for advanced maternal age was 90%, whereas it was 77% among the ultrasound‐detected trisomy 21 fetuses. However, three ultrasound examinations were offered routinely, and the estimated rate of amniocentesis in the group with advanced maternal age was between 65 and 70%. Only one of the 56 cases was not followed up at St Olavs University Hospital.

The data can be considered as a future reference standard for population screening for trisomy 21 using maternal age and second‐trimester ultrasound examination without the influence of confounding factors such as private healthcare, biochemical serum screening and first‐trimester NT measurements. In 11/50 prenatally undetected trisomy 21 cases, suspicious ultrasound findings were registered during pregnancy. However, they are seen more frequently in fetuses with an abnormality. Aitken DA, Wallace EM, Crossley JA et-al. Even so, it appears unlikely that detection rates of trisomy 21 can be improved significantly without extending our prenatal program, for example with first‐trimester NT screening in combination with biochemical tests. Six of the 22 cases detected in the second trimester did not have structural anomalies, only soft markers. Saller DN, Canick JA.

The structural anomalies diagnosed postnatally among all 50 undetected trisomy 21 neonates are listed in Table 3. 7. 2. Other studies from tertiary referral centers report detection rates of up to 91%34. Diagn. Thus, the sensitivity of such studies cannot be compared with our data, which are based on a non‐selected population.

Meta-analysis of second-trimester markers for trisomy 21. In 1987, Benacerraf et al.

In order to assess and compare the emerging techniques it is necessary to evaluate traditional practices. The ultrasound findings registered and additional structural anomalies found after birth in the 11 cases are listed in Table 4. Heart. However combined screening test is most preferred. The study period was divided into three 6‐year periods. Consequently, the ultrasound examination was responsible for the detection of 68% of all detected cases (P = 0.001).

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology. ADVERTISEMENT: Supporters see fewers/no ads, Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. Our data showed that many liveborn trisomy 21 infants required surgery or other forms of treatment and long follow‐up, resulting in considerable demands on healthcare resources and the families. In 78% (39/50) of the trisomy 21 cases, the second‐trimester ultrasound examination was described as normal. During the whole study period our amniocentesis rate was low compared with that in studies from other countries. In addition, karyotyping was offered to women who would be 38 years or older at expected term. No significant change in the detection rate was observed over the 18 years. Within the study population, 88 cases of trisomy 21 were diagnosed by either prenatal or postnatal karyotyping during the period 1987–2004. Burnout Might Really Be Depression; How Do Doctors Cope? 12. After delivery or termination of pregnancy, further prenatal and postnatal data from the pregnancy, birth and neonatal development were recorded and, if available, autopsy reports and photographs were included. 22 (3): 395-401. Apparently, an increasing rate of women then relied exclusively on early ultrasound examination without further testing. This is caused by abnormal cell division during the development of the sperm cell or the egg cell. Rumack CM, Wilson SR, Charboneau JW. Increased NT thickness has been shown to be associated with chromosomal abnormalities18. The level of significance was set at 5%. The study period was divided into three 6‐year periods: the first from 1987 to 1992, the second from 1993 to 1998, and the third from 1999 to 2004. Clin Obstet Gynecol. Ductus venosus Doppler in screening for trisomies 21, 18 and 13 and Turner syndrome at 11-13 weeks of gestation. Until 1984, advanced maternal age was the only known recognized risk factor to justify amniocentesis for fetal karyotyping. For each fetus with anomalies, video recordings, biochemical tests and karyotype were registered prospectively. The median maternal age of the women with prenatally detected cases was 36 years; 23/38 (61%) women were below 38 years of age at detection. If improvement in detection rates is desired, additional programs are necessary. This follow‐up study included all prospectively registered cases of cytogenetically confirmed trisomy 21 with a prenatal or postnatal diagnosis at St Olavs University Hospital in Trondheim during the period January 1987 to December 2004.

Maiz N, Valencia C, Kagan KO et-al.