Trisomies 18 and 13: trends in prevalence and prenatal diagnosis - population based study

A Risk Model for Predicting Fetuses with Trisomy 21 Using Alpha-Fetoprotein Variants L2 Combined with Maternal Serum Biomarkers in Early Pregnancy

To establish a risk prediction model and the clinical value of trisomy 21 using alpha-fetoprotein variants L2 (AFP-L2) combined with maternal serum biomarkers and nuchal translucency (NT) thickness in early pregnancy. A retrospective case–control study was conducted. The subjects were divided into the case group (n = 40) or the control group (n = 40). An enzyme-linked immunosorbent assay was used to measure the maternal serum AFP-L2 level in both groups. The AFP-L2 single-index or multi-index combined risk model was used to predict the efficiency of trisomy 21. The best cut-off value and area under the curve (AUC) were determined to evaluate the predictive efficacy of different risk models constructed by AFP-L2. The maternal serum AFP-L2 level in the case group was 1.59 (0.61–3.61) Multiple of medium (MoM), which was higher than 1.00 (0.39–2.12) MoM in the control group (P < 0.001). The free beta-human chorionic gonadotropin (free β-hCG) level and NT in the case group were significantly higher than those in the control group (P < 0.001). The pregnancy-associated plasma protein A (PAPP-A) level in the case group was lower than that in the control group (P < 0.001). The AUC of AFP-L2 in predicting trisomy 21 was 0.797. After considering the maternal serum AFP-L2 level, the AUC, detection rate (DR), positive predictive value (PPV), negative predictive value (NPV), falsepositive rate (FPR), false negative rate (FNR), positive likelihood ratio (+LR), and negative likelihood ratio (-LR) were significantly improved. In this study, PAPP-A + free β-hCG + NT + AFP-L2 and PAPP-A + free β-hCG + AFP-L2 increased the integrated discrimination improvement (IDI) and net classification improvement (NRI) of predicting fetuses with trisomy 21 (1.10% and 5.27%; 11.07% and 2.78%)  (1.10% and 5.27%; 11.07% and 2.78%), respectively, after considering the maternal serum AFP-L2 level. The maternal serum AFP-L2 level in early pregnancy had high sensitivity and specificity, and it was a good biomarker to predict fetuses with trisomy 21.

First-trimester presentation of ultrasound findings in trisomy 13 and validation of multiparameter ultrasound-based risk calculation models to detect trisomy 13 in the late first trimester

OBJECTIVES

To identify the most common ultrasound patterns of markers and anomalies associated with Patau syndrome (PS), to explore the efficacy of multiparameter sonographic protocols in detecting trisomy 13 (T13) and to analyze the influence of maternal age (MA) on screening performance.

METHODS

The project was a prospective study based on singleton pregnancies referred for a first-trimester screening examination. The scan protocol included nuchal translucency (NT), fetal heart rate (FHR), secondary ultrasound markers [nasal bone (NB), tricuspid regurgitation (TR), ductus venosus reversed a-wave (revDV)] and major anomaly findings.

RESULTS

The study population comprised 6133 pregnancies: 6077 cases of euploidy and 56 cases of T13. Statistically significant differences were found in MA, FHR, NT, absence of NB, presence of revDV, TR and single umbilical artery. Fourteen cases of T13 (25%) demonstrated no markers of aneuploidy. The best general detection rate (DR) (DR of 78.6% with an false positive rate (FPR) of 1.2%) was obtained for a cutoff of 1/300 utilizing the "NT+T13" algorithm. The logistic regression model revealed that the central nervous system (CNS) anomalies had the greatest odds ratio (of 205.4) for T13.

CONCLUSIONS

The effectiveness of the multiparameter sonographic protocol used for T13 screening showed promising results in patients older than 36 years and suboptimal results in patients between 26 and 36 years old. When screening for T13 left heart defects, CNS anomalies, abdominal anomalies, FHR above the 95th percentile, increased NT, revDV and lack of NB should receive specific attention.

Modified Delphi Study on Nursing Practice and Science in Fetal Care

OBJECTIVE

To identify essential structures, processes, outcomes, and challenges of nursing practice in fetal care and to identify research priorities for nurses in fetal care.

DESIGN

We used a modified Delphi method to achieve consensus.

SETTING

A secure online survey platform.

PARTICIPANTS

The expert panel included nurses from the Fetal Therapy Nurse Network. In addition, a multidisciplinary research jury included members of the North American Fetal Therapy Network (NAFTNet).

METHODS

We collected data in three consecutive rounds with online questionnaires that were e-mailed to panelists. We used content analysis to generate statements from an initial round of open-ended questions. Statements met consensus if 75% of the panelists ranked it as greater than or equal to 6 on a 1-to-7 Likert scale.

RESULTS

The 48 nurse panelists and 11 multidisciplinary jury members described a range of nursing processes. Consensus was reached on 96 statements related to the structure, processes, outcomes, and research priorities of nurses in fetal care.

CONCLUSION

The participants agreed that an expert fetal care nursing team is necessary to provide care to women and families during fetal diagnosis and treatment. Ideally, these nurses should coordinate care and provide direct clinical care (e.g., patient counseling) in outpatient prenatal settings and inpatient settings when fetal surgery is involved. Nurses should be supported to take on leadership roles in program development, research, quality improvement, and professional development with relevant professional organizations.

Increased prenatal detection of 22q11.2 deletion and 22q11.2 duplication after introduction of nationwide prenatal screening for trisomy 21, trisomy 13, and trisomy 18

OBJECTIVE

To evaluate time of diagnosis of 22q11.2 deletion and 22q11.2 duplication as well as trisomies 21, 13, and 18 before and after introduction of a prenatal screening program including combined first-trimester screening (cFTS) for the trisomies in Denmark in 2004.

METHOD

Cross-sectional, population-based register study employing The Danish Cytogenetic Central Register. Proportions of cases diagnosed 1998-2004 and 2005-2017 were compared before 14⁺⁰ and 22⁺⁰ weeks and birth (prenatal cases) or up to 1 or 10 years of age (postnatal cases).

RESULTS

In total, 4562 cases were included. From 1998-2004 to 2005-2017, the proportion of 22q11.2 deletion cases identified prenatally increased from 4.3% (95% CI: 0.9-12.0%) to 27.3% (21.2-34.0%), while for 22q11.2 duplication an increase from 0/6 to 26/87 (prenatal cases/all cases) was observed. Similarly, proportions of trisomies 21, 13, and 18 detected before birth increased. A greater proportion of the studied conditions was identified earlier in pregnancy, but not generally earlier in the postnatal course.

CONCLUSION

Proportions of 22q11.2 deletion and 22q11.2 duplication identified prenatally increased after introduction of a prenatal screening program not aimed specifically to identify these conditions,. A greater proportion of all cases were detected earlier in pregnancy, but not earlier postnatally, following introduction of screening.

Long-term survival of children born with congenital anomalies: A systematic review and meta-analysis of population-based studies

BACKGROUND

Following a reduction in global child mortality due to communicable diseases, the relative contribution of congenital anomalies to child mortality is increasing. Although infant survival of children born with congenital anomalies has improved for many anomaly types in recent decades, there is less evidence on survival beyond infancy. We aimed to systematically review, summarise, and quantify the existing population-based data on long-term survival of individuals born with specific major congenital anomalies and examine the factors associated with survival.

METHODS AND FINDINGS

Seven electronic databases (Medline, Embase, Scopus, PsycINFO, CINAHL, ProQuest Natural, and Biological Science Collections), reference lists, and citations of the included articles for studies published 1 January 1995 to 30 April 2020 were searched. Screening for eligibility, data extraction, and quality appraisal were performed in duplicate. We included original population-based studies that reported long-term survival (beyond 1 year of life) of children born with a major congenital anomaly with the follow-up starting from birth that were published in the English language as peer-reviewed papers. Studies on congenital heart defects (CHDs) were excluded because of a recent systematic review of population-based studies of CHD survival. Meta-analysis was performed to pool survival estimates, accounting for trends over time. Of 10,888 identified articles, 55 (n = 367,801 live births) met the inclusion criteria and were summarised narratively, 41 studies (n = 54,676) investigating eight congenital anomaly types (spina bifida [n = 7,422], encephalocele [n = 1,562], oesophageal atresia [n = 6,303], biliary atresia [n = 3,877], diaphragmatic hernia [n = 6,176], gastroschisis [n = 4,845], Down syndrome by presence of CHD [n = 22,317], and trisomy 18 [n = 2,174]) were included in the meta-analysis. These studies covered birth years from 1970 to 2015. Survival for children with spina bifida, oesophageal atresia, biliary atresia, diaphragmatic hernia, gastroschisis, and Down syndrome with an associated CHD has significantly improved over time, with the pooled odds ratios (ORs) of surviving per 10-year increase in birth year being OR = 1.34 (95% confidence interval [95% CI] 1.24-1.46), OR = 1.50 (95% CI 1.38-1.62), OR = 1.62 (95% CI 1.28-2.05), OR = 1.57 (95% CI 1.37-1.81), OR = 1.24 (95% CI 1.02-1.5), and OR = 1.99 (95% CI 1.67-2.37), respectively (p < 0.001 for all, except for gastroschisis [p = 0.029]). There was no observed improvement for children with encephalocele (OR = 0.98, 95% CI 0.95-1.01, p = 0.19) and children with biliary atresia surviving with native liver (OR = 0.96, 95% CI 0.88-1.03, p = 0.26). The presence of additional structural anomalies, low birth weight, and earlier year of birth were the most commonly reported predictors of reduced survival for any congenital anomaly type. The main limitation of the meta-analysis was the small number of studies and the small size of the cohorts, which limited the predictive capabilities of the models resulting in wide confidence intervals.

CONCLUSIONS

This systematic review and meta-analysis summarises estimates of long-term survival associated with major congenital anomalies. We report a significant improvement in survival of children with specific congenital anomalies over the last few decades and predict survival estimates up to 20 years of age for those born in 2020. This information is important for the planning and delivery of specialised medical, social, and education services and for counselling affected families. This trial was registered on the PROSPERO database (CRD42017074675).

Congenital Heart Disease: Prenatal Diagnosis and Genetic Associations

Importance

Congenital heart disease (CHD) is a common cause of neonatal morbidity and mortality. Several genetic abnormalities have been linked to congenital cardiac disease. When diagnosed prenatally, appropriate evaluation can help optimize neonatal outcomes.

Objective

The objective of this review is to identify appropriate prenatal genetic testing when congenital cardiac defects are identified antenatally. This review also identifies specific congenital cardiac defects that are associated with fetal aneuploidy and genetic syndromes.

Evidence Acquisition

A MEDLINE search of "genetic testing" or "microarray" and "congenital heart disease" and specific conditions reported in the review was performed.

Results

The evidence cited in this review includes case reports or case series (4) textbooks (3), systematic reviews (1), expert committee opinions (10), and 37 additional peer-reviewed journal articles that were original research or expert summaries.

Conclusions and Relevance

When CHD is identified through prenatal screening, patients should be referred for genetic counseling and offered appropriate genetic testing. Prenatal diagnosis of genetic syndromes related to CHD and close communication between obstetric, genetic, and pediatric providers can help optimize outcomes for both mother and baby.

National population-based estimates for major birth defects, 2010-2014

BACKGROUND

Using the National Birth Defects Prevention Network (NBDPN) annual data report, U.S. national prevalence estimates for major birth defects are developed based on birth cohort 2010-2014.

METHODS

Data from 39 U.S. population-based birth defects surveillance programs (16 active case-finding, 10 passive case-finding with case confirmation, and 13 passive without case confirmation) were used to calculate pooled prevalence estimates for major defects by case-finding approach. Fourteen active case-finding programs including at least live birth and stillbirth pregnancy outcomes monitoring approximately one million births annually were used to develop national prevalence estimates, adjusted for maternal race/ethnicity (for all conditions examined) and maternal age (trisomies and gastroschisis). These calculations used a similar methodology to the previous estimates to examine changes over time.

RESULTS

The adjusted national birth prevalence estimates per 10,000 live births ranged from 0.62 for interrupted aortic arch to 16.87 for clubfoot, and 19.93 for the 12 critical congenital heart defects combined. While the birth prevalence of most birth defects studied remained relatively stable over 15 years, an increasing prevalence was observed for gastroschisis and Down syndrome. Additionally, the prevalence for atrioventricular septal defect, tetralogy of Fallot, omphalocele, and trisomy 18 increased in this period compared to the previous periods. Active case-finding programs generally had higher prevalence rates for most defects examined, most notably for anencephaly, anophthalmia/microphthalmia, trisomy 13, and trisomy 18.

CONCLUSION

National estimates of birth defects prevalence provide data for monitoring trends and understanding the impact of these conditions. Increasing prevalence rates observed for selected conditions warrant further examination.

Trisomy 13 and 18-Prevalence and mortality-A multi-registry population based analysis

The aim of the study is to determine the prevalence, outcomes, and survival (among live births [LB]), in pregnancies diagnosed with trisomy 13 (T13) and 18 (T18), by congenital anomaly register and region. Twenty-four population- and hospital-based birth defects surveillance registers from 18 countries, contributed data on T13 and T18 between 1974 and 2014 using a common data-reporting protocol. The mean total birth prevalence (i.e., LB, stillbirths, and elective termination of pregnancy for fetal anomalies [ETOPFA]) in the registers with ETOPFA (n = 15) for T13 was 1.68 (95% CI 1.3-2.06), and for T18 was 4.08 (95% CI 3.01-5.15), per 10,000 births. The prevalence varied among the various registers. The mean prevalence among LB in all registers for T13 was 0.55 (95%CI 0.38-0.72), and for T18 was 1.07 (95% CI 0.77-1.38), per 10,000 births. The median mortality in the first week of life was 48% for T13 and 42% for T18, across all registers, half of which occurred on the first day of life. Across 16 registers with complete 1-year follow-up, mortality in first year of life was 87% for T13 and 88% for T18. This study provides an international perspective on prevalence and mortality of T13 and T18. Overall outcomes and survival among LB were poor with about half of live born infants not surviving first week of life; nevertheless about 10% survived the first year of life. Prevalence and outcomes varied by country and termination policies. The study highlights the variation in screening, data collection, and reporting practices for these conditions.

Clinical article: screening for trisomy 13 using traditional combined screening versus an ultrasound-based protocol

AIMS

To compare the screening capability of ultrasonography in detecting trisomy 13 (T13) using a multiparameter sonographic protocol (NT+) with a classical combined screening test (CST) protocol.

METHODS

The project was a prospective, multicenter study based on a nonselected mixed-risk population of women referred for a first-trimester screening examination. Each subject was offered a choice between either the gold standard, traditional combined screening test (CSG arm) or the ultrasound-based screening protocol (USG arm). General and MA-based screening performances were checked.

RESULTS

The study population comprised 20,887 pregnancies: 12,933 in the CSG arm, including 27 cases of T13, and 7954 in the USG arm, including 30 cases of T13. The DR for T13 was higher in the CSG arm than in the USG arm for all tested cutoff points: 1/50 (88.5 versus 63.3%, respectively), 1/100 (88.5 versus 70%, respectively) and 1/300 (92.3 versus 83.3%, respectively). Using the ROC curves for fixed FPRs of 3 and 5%, the T13 detection rate in our study reached 90 and 93%, respectively, in the USG arm and 92 and 96%, respectively, in the CSG arm. MA influenced the T13 screening performance in the USG arm and reduced the DR in patients <31 years. Such influence was not detected in the CSG arm.

CONCLUSIONS

Classic CST was more effective in detecting T13 than the ultrasound-only approach. However, the recommended cutoff of 1/50 showed unsatisfactory results for both traditional CST and the multiparameter sonographic test we proposed.

Chromosomal abnormalities: subgroup analysis by maternal age and perinatal features in zhejiang province of China, 2011-2015

BACKGROUND

Recently, the prevalence of chromosomal abnormalities (CA) increased as the increasing proportion of mothers with advanced age. We aimed to explore the prevalence of CA in relation to maternal age and perinatal features.

METHODS

A retrospective study was performed based on provincial birth defects surveillance data. The relative risk (RR) and 95% confidence interval (CI) were used to calculate maternal age-specific rates of CA. Socio-demographic characteristics of mothers and perinatal features were listed.

RESULTS

The total prevalence of CA was 6.38 per 10,000 births, which increased per 10,000 births linearly from 4.02 in 2011 to 9.13 in 2015 (x ²_line-trend =52.69, p < 0.001). During this period, the prevalence for CA per 10,000 births among women over 35 years old increased from 15.34 in 2011 to 33.82 in 2015 (x ²_line-trend =115121.6, p < 0.001). The RR for overall CA, trisomy 21(T21), trisomy 18(T18) and others in mothers 35 years or older were 6.64 (95% CI 5.55 ~ 7.93), 6.83 (95% CI 5.63 ~ 8.30), 4.06 (95% CI 2.09 ~ 7.90) and 7.54 (95% CI 4.02 ~ 14.11) respectively in comparison to mothers aged 25-29 years old. The stillbirths rate for total CA was 76.45%. T21 and T18 were strongly associated with multiple anomalies, especially congenital heart abnormalities.

CONCLUSIONS

The prevalence of CA increased as maternal age increased. Cases with CA were associated with other congenital defects and high mortality risk.

The outcomes of 31 cases of trisomy 13 diagnosed in utero with various management options

There are few reports on the prognosis of prenatally diagnosed trisomy 13 in relation to postnatal management. The aim of this study was to report on the prenatal and postnatal outcomes and postnatal management of trisomy 13 fetuses that were prenatally diagnosed at our center between 2003 and 2015. The data were retrospectively reviewed from medical records. Of the 31 cases of trisomy 13, 12 patients were diagnosed before 22 weeks of gestation, and 19 were diagnosed at or after 22 weeks of gestation. Nine families opted for termination of the pregnancy, 14 fetuses died, and 8 were born alive. Aggressive treatment was requested in two of the live births, with one patient achieving long-term survival (7 years). The other died during infancy (Day 61). One out of four who received palliative treatment is alive at two years of age with only nutrition supplementation. These three patients who achieved neonatal survival had few structural anomalies. Fetal death and early neonatal death are common in trisomy 13; however, fetuses that receive medical treatment for cases without major ultrasound abnormalities may achieve neonatal survival. Therefore, it is useful to provide comprehensive information, including precise ultrasound findings and treatment options, to parents with trisomy 13 fetuses during genetic counseling.

Communication of support and critique in Swedish virtual community threads about prenatal diagnoses of fetal anomalies

BACKGROUND

A prenatal diagnosis of a fetal anomaly involves acute grief and psychological distress. The Internet has the potential to provide virtual support following the diagnosis. The overall aim was to explore communication of support and critique in Swedish virtual community threads about prenatal diagnoses of fetal anomalies.

METHODS

Systematic searches in Google resulted in 117 eligible threads. Fifteen of these were purposefully selected and subjected to deductive content analysis.

RESULTS

The virtual support involved mainly emotional support (meaning units n = 1,992/3,688, 54 %) and was described as comforting and empowering. Posters with experience of a prenatal diagnosis appreciated the virtual support, including the opportunity to gain insight into other cases and to write about one's own experience. Critique of the decision to continue or terminate the pregnancy occurred, primarily against termination of pregnancy. However, it was met with defense.

CONCLUSIONS

Peer support, mainly emotional, is provided and highly appreciated in threads about prenatal diagnoses of a fetal anomaly. Critique of the decision to terminate the pregnancy occurs in virtual community threads about prenatal diagnoses, but the norm is to not question the decision. Future studies need to investigate if virtual peer support promotes psychosocial function following a prenatal diagnosis and what medium would be most suitable for these types of supportive structures.

Intrauterine death in singleton pregnancies with trisomy 21, 18, 13 and monosomy X

Summary A retrospective study from November 2004 to May 2012, conducted at the Obstetric Clinic of Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (HC-FMUSP), which included 92 singleton pregnancies with prenatal diagnosis of trisomy of chromosome 21 (T21), 18, 13 (T13/18) and monosomy X (45X), with diagnosis performed until the 26th week of pregnancy. The aim of the study was to describe the frequency and to investigate predictors of spontaneous fetal death (FD). Diagnosis (T21, n=36; T13/18, n=25; 45X, n=31) was made at a mean gestational age of 18.3±3.7 weeks, through chorionic villus biopsy (n=22,24%), amniocentesis (n=66, 72%) and cordocentesis (n=4, 4%). Major malformations were present in 45 (49%); with hydrops in 32 (35%) fetuses, more frequently in 45X [n=24/31, 77% vs. T21 (n=6/36, 17%) and T13/18 (n=2/25, 8%), p<0.001]. Specialized fetal echocardiography was performed in 60% (55/92). Of these, 60% (33/55) showed changes in heart morphology and/or function. Fetuses with T13/18 had a higher incidence of cardiac anomalies [60 vs. 25% (T21) and 29% (45X), p= 0.01]. FD occurred in 55 (60%) gestations, being more frequent in 45X [n=26/31, 84% vs. T21 (n=13/36, 36%) and T13/18 (n=16/25, 64%), p<0.01]. Stepwise analysis showed a correlation between hydrops and death in fetuses with T21 (LR= 4.29; 95CI=1.9-8.0, p<0.0001). In fetuses with 45X, the presence of echocardiographic abnormalities was associated with lower risk of FD (LR= 0.56; 95CI=0.27- 0.85, p=0.005). No predictive factors were identified in the T13/18 group. Intra- uterine lethality of aneuploid fetuses is high. Occurrence of hydrops increases risk of FD in pregnancies with T21. In pregnancies with 45X, the occurrence of echocardiographic changes reduces this risk.

Survival of children with trisomy 13 and trisomy 18: A multi-state population-based study

Trisomy 13 (T13) and trisomy 18 (T18) are among the most prevalent autosomal trisomies. Both are associated with a very high risk of mortality. Numerous instances, however, of long-term survival of children with T13 or T18 have prompted some clinicians to pursue aggressive treatment instead of the traditional approach of palliative care. The purpose of this study is to assess current mortality data for these conditions. This multi-state, population-based study examined data obtained from birth defect surveillance programs in nine states on live-born infants delivered during 1999-2007 with T13 or T18. Information on children's vital status and selected maternal and infant risk factors were obtained using matched birth and death certificates and other data sources. The Kaplan-Meier method and Cox proportional hazards models were used to estimate age-specific survival probabilities and predictors of survival up to age five. There were 693 children with T13 and 1,113 children with T18 identified from the participating states. Among children with T13, 5-year survival was 9.7%; among children with T18, it was 12.3%. For both trisomies, gestational age was the strongest predictor of mortality. Females and children of non-Hispanic black mothers had the lowest mortality. Omphalocele and congenital heart defects were associated with an increased risk of death for children with T18 but not T13. This study found survival among children with T13 and T18 to be somewhat higher than those previously reported in the literature, consistent with recent studies reporting improved survival following more aggressive medical intervention for these children. © 2015 Wiley Periodicals, Inc.

Unusual trend in the prevalence of trisomy 13 in mothers aged 35 and older: A population based study of national congenital anomaly data

BACKGROUND

Trisomy 13 is one of the three autosomal trisomies compatible with viability. It is associated with structural anomalies, learning disability and poor survival. Advanced maternal age is the most frequently suggested risk factor. This is a population based register study to investigate the temporal trends of trisomy 13.

METHODS

Chromosomal trisomies were reviewed by the Welsh Congenital Anomaly Register using data from 1998-2012. All pregnancy outcomes were included. Prevalence rates and trends for all cases and for cases with mothers aged below 35 years and those aged 35 years and older were plotted for trisomy 13, 18 and 21. Possible risk factors contributing to the trend in older mothers were compared in the early and late period of the study.

RESULTS

There were 124 cases of trisomy 13 over the 15 year period with 55 mothers aged 35 years and older. Overall prevalence was 2.5 per 10,000 total births. A significant declining trend in the prevalence of trisomy 13 in mothers aged 35 and older (χ(2) trend = 4.98, p=0.026) was noted. Rates for younger mothers were lower and remained stable. Prevalence of trisomy 18 and 21 in older mothers remained stable.

CONCLUSION

The unexpected declining trend in trisomy 13 in older mothers could not be explained by the risk factors examined in this study. There have been no other reports of trends in the prevalence of trisomy 13 in older mothers in recent years. There is further need for surveillance of trends in future and in other populations.

Ten Years of Experience with First-Trimester Screening for Fetal Aneuploidy Employing Biochemistry from Gestational Weeks 6+0 to 13+6

Objectives: To validate the performance of first-trimester screening for fetal aneuploidy employing blood samples drawn in gestational weeks 6-13. Methods: Prospective combined first-trimester screening for fetal aneuploidy in Denmark was validated in two large datasets: (1) a dataset from the Central Denmark Region including 147,768 pregnancies from October 2003 to October 2013, and (2) a national dataset including 220,739 pregnancies from January 2008 to August 2011. Results: For trisomy 21, the weekly median multiple of the median (MoM) increased from 0.37 in week 6 to 0.70 in week 13 (pregnancy-associated plasma protein-A), and from 0.99 in week 6 to 2.68 in week 13 (free βhCG). The overall detection rate (DR) for fetal trisomy 21 was 91.2%. Employing blood samples from gestational week 9, the DR was 97% (p = 0.05). For fetal trisomy 18, trisomy 13 and triploidy, the overall DRs after first-trimester screening were 79.5, 86 and 85%. In the national dataset, the overall DR for trisomy 21 was 86.3% ranging from 89 (weeks 9 and 10) to 80% (weeks 12 and 13). Conclusion: The results from both datasets show that blood sampling in gestational weeks 9-10 is a robust and high-performance strategy, which can be applied for routine first-trimester screening in clinical practice.

Fetal diagnostic indications for second and third trimester outpatient pregnancy termination

OBJECTIVE

To determine the frequency of diagnostic indications among women seeking to terminate pregnancies for reasons of fetal abnormality, spontaneous fetal demise, or a genetic disorder in a private outpatient clinic specializing in late outpatient abortion procedures.

METHOD

A total of 1005 women requested termination of pregnancy for reasons of genetic disorder, fetal anomaly, or fetal demise over 20 years (1992-2012). Gestational ages ranged from 12 to 39 weeks. In all cases, a documented diagnosis of fetal abnormality or fetal demise was made prior to referral. Records were reviewed to verify fetal diagnosis for all patients seeking termination of pregnancy for reasons of fetal disorder. Major complications included major unintended surgery, hemorrhage requiring transfusion, or pelvic infection.

RESULTS

Preoperative diagnoses included the following: chromosomal abnormalities (n = 378), genetic syndromes and single gene disorders (n = 30), structural anomalies (n = 494), and other conditions (n = 103). These include 26 cases of spontaneous fetal demise and nine selective terminations of one abnormal twin. The major complication rate was 0.5%.

CONCLUSIONS

The majority of diagnoses were in the categories of genetic disorder and neurologic abnormality.