Ultrasound screening for fetal abnormalities

Fetal structural anomalies diagnosed during the first, second and third trimesters of pregnancy using ultrasonography: a retrospective cohort study

BACKGROUND

The prevalence of congenital abnormalities in general populations is approximately 3-5%. One of the most important applications of obstetric ultrasound is in detection of fetal structural defects.

OBJECTIVE

To assess fetal structural anomalies diagnosed using ultrasound in the three trimesters of pregnancy.

DESIGN AND SETTING

Retrospective cohort study at the Mário Palmério University Hospital of the University of Uberaba (Universidade de Uberaba, UNIUBE), from March 2014 to December 2016.

METHODS

Ultrasound data at gestational weeks 11-13 + 6, 20-24 and 32-36 were recorded to identify fetal anomalies in each trimester and in the postnatal period. The primary outcome measurements were sensitivity, specificity, positive predictive value and negative predictive value for detection of fetal anomalies and their prevalence.

RESULTS

The prevalence of anomalies detected using ultrasound was 2.95% in the prenatal period and 7.24% in the postnatal period. The fetal anomalies most frequently diagnosed using ultrasound in the three trimesters were genitourinary tract anomalies, with a prevalence of 27.8%. Cardiac anomalies were diagnosed more often in the postnatal period, accounting for 51.0% of all cases. High specificity, negative predictive value and accuracy of ultrasound were observed in all three trimesters of pregnancy.

CONCLUSION

Ultrasound is safe and has utility for detecting fetal anomalies that are associated with high rates of morbidity and mortality. However, the low sensitivity of ultrasound for detecting fetal anomalies in unselected populations limits its utility for providing reassurance to examiners and to pregnant women with normal results.

Systematic review of first-trimester ultrasound screening for detection of fetal structural anomalies and factors that affect screening performance

OBJECTIVES

To determine the sensitivity and specificity of first-trimester ultrasound for the detection of fetal abnormalities and to establish which factors might impact on screening performance.

METHODS

A systematic review and meta-analysis of all relevant publications was performed to assess the diagnostic accuracy of two-dimensional transabdominal and transvaginal ultrasound in the detection of congenital fetal anomalies prior to 14 weeks' gestation. The reference standard was detection of abnormalities at birth or postmortem. Factors that may impact on detection rates were evaluated, including population characteristics, gestational age, healthcare setting, ultrasound modality, use of an anatomical checklist for detection of first-trimester anomalies and type of malformation included in the study. In an effort to reduce the impact of study heterogeneity on the results of the meta-analysis, data from the studies were analyzed within subgroups of major anomalies vs all types of anomaly and low-risk/unselected populations vs high-risk populations.

RESULTS

An electronic search (until 29 July 2015) identified 2225 relevant citations, from which a total of 30 studies, published between 1991 and 2014, were selected for inclusion. The pooled estimate for the detection of major abnormalities in low-risk or unselected populations (19 studies, 115 731 fetuses) was 46.10% (95% CI, 36.88-55.46%). The detection rate for all abnormalities in low-risk or unselected populations (14 studies, 97 976 fetuses) was 32.35% (95% CI, 22.45-43.12%), whereas in high-risk populations (six studies, 2841 fetuses) it was 61.18% (95% CI, 37.71-82.19%). Of the factors examined for their impact on detection rate, there was a statistically significant relationship (P < 0.0001) between the use of a standardized anatomical protocol during first-trimester anomaly screening and its sensitivity for the detection of fetal anomalies in all subgroups.

CONCLUSIONS

Detection rates of first-trimester fetal anomalies ranged from 32% in low-risk groups to more than 60% in high-risk groups, demonstrating that first-trimester ultrasound has the potential to identify a large proportion of fetuses affected with structural anomalies. The use of a standardized anatomical protocol improves the sensitivity of first-trimester ultrasound screening for all anomalies and major anomalies in populations of varying risk. The development and introduction of international protocols with standard anatomical views should be undertaken in order to optimize first-trimester anomaly detection. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Effectiveness and cost-effectiveness of routine third trimester ultrasound screening for intrauterine growth restriction: study protocol of a nationwide stepped wedge cluster-randomized trial in The Netherlands (The IRIS Study)

Background

Intrauterine growth retardation (IUGR) is a major risk factor for perinatal mortality and morbidity. Thus, there is a compelling need to introduce sensitive measures to detect IUGR fetuses. Routine third trimester ultrasonography is increasingly used to detect IUGR. However, we lack evidence for its clinical effectiveness and cost-effectiveness and information on ethical considerations of additional third trimester ultrasonography. This nationwide stepped wedge cluster-randomized trial examines the (cost-)effectiveness of routine third trimester ultrasonography in reducing severe adverse perinatal outcome through subsequent protocolized management.

Methods

For this trial, 15,000 women with a singleton pregnancy receiving care in 60 participating primary care midwifery practices will be included at 22 weeks of gestation. In the intervention (n = 7,500) and control group (n = 7,500) fetal growth will be monitored by serial fundal height assessments. All practices will start offering the control condition (ultrasonography based on medical indication). Every three months, 20 practices will be randomized to the intervention condition, i.e. apart from ultrasonography if indicated, two routine ultrasound examinations will be performed (at 28–30 weeks and 34–36 weeks). If IUGR is suspected, both groups will receive subsequent clinical management as described in the IRIS study protocol that will be developed before the start of the trial.

The primary dichotomous clinical composite outcome is ‘severe adverse perinatal outcome’ up to 7 days after birth, including: perinatal death; Apgar score <4 at 5 minutes after birth; impaired consciousness; need for assisted ventilation for more than 24 h; asphyxia; septicemia; meningitis; bronchopulmonary dysplasia; intraventricular hemorrhage; cystic periventricular leukomalacia; neonatal seizures or necrotizing enterocolitis. For the economic evaluation, costs will be measured from a societal perspective. Quality of life will be measured using the EQ-5D-5 L to enable calculation of QALYs. Cost-effectiveness and cost-utility analyses will be performed. In a qualitative sub-study (using diary notes from 32 women for 9 months, at least 10 individual interviews and 2 focus group studies) we will explore ethical considerations of additional ultrasonography and how to deal with them.

Discussion

The results of this trial will assist healthcare providers and policymakers in making an evidence-based decision about whether or not introducing routine third trimester ultrasonography.

Trial registration

NTR4367, 21 March 2014.

Routine prenatal ultrasound anomaly screening program in a Nigerian university hospital: Redefining obstetrics practice in a developing African country

BACKGROUND

Congenital anomalies are among the leading causes of fetal and infant morbidity and mortality worldwide. Prenatal ultrasound (US) screening has become an essential part of antenatal care in the developed world. Such practice is just evolving in the developing countries such as Nigeria. The aim of this article is to present our initial experience and demonstrate the effectiveness of a prenatal US screening program in detecting congenital malformation in a developing country.

MATERIALS AND METHODS

This was a prospective evaluation of the prenatal US screenings conducted at a major referral hospital in Southwestern Nigeria. All pregnant women referred to the antenatal clinic for mid-trimester screening during the period of study were assessed.

RESULTS

Two hundred and eighty-seven pregnant women (5 with twin gestations) were presented for fetal anomaly scan during the study period. Twenty-nine anomalies (9.9%) were detected among the scanned population. Sixteen of the anomalies were followed to delivery/termination with a specificity of 93.5%. The commonest malformations were demonstrated in the genitourinary tract (34.5%) followed by malformations within the central nervous system (27.6%). Six (20.6%) of the anomalies were lethal. Five of the anomalies were surgically correctable.

CONCLUSION

Institutions and hospitals across Nigeria and other low- and middle-income countries need to develop policies and programs that would incorporate a standardized routine screening prenatal US in order to improve feto-maternal well-being and reduce the high perinatal mortality and morbidity in developing nations.

Routine ultrasound in late pregnancy (after 24 weeks' gestation)

BACKGROUND

Diagnostic ultrasound is used selectively in late pregnancy where there are specific clinical indications. However, the value of routine late pregnancy ultrasound screening in unselected populations is controversial. The rationale for such screening would be the detection of clinical conditions which place the fetus or mother at high risk, which would not necessarily have been detected by other means such as clinical examination, and for which subsequent management would improve perinatal outcome.

OBJECTIVES

To assess the effects on obstetric practice and pregnancy outcome of routine late pregnancy ultrasound, defined as greater than 24 weeks' gestation, in women with either unselected or low-risk pregnancies.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

All acceptably controlled trials of routine ultrasound in late pregnancy (defined as after 24 weeks).

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy.

MAIN RESULTS

Thirteen trials recruiting 34,980 women were included in the systematic review. Risk of bias was low for allocation concealment and selective reporting, unclear for random sequence generation and incomplete outcome data and high for blinding of both outcome assessment and participants and personnel. There was no difference in antenatal, obstetric and neonatal outcome or morbidity in screened versus control groups. Routine late pregnancy ultrasound was not associated with improvements in overall perinatal mortality. There is little information on long-term substantive outcomes such as neurodevelopment. There is a lack of data on maternal psychological effects.Overall, the evidence for the primary outcomes of perinatal mortality, preterm birth less than 37 weeks, induction of labour and caesarean section were assessed to be of moderate or high quality with GRADE software. There was no association between ultrasound in late pregnancy and perinatal mortality (risk ratio (RR) 1.01, 95% confidence interval (CI) 0.67 to 1.54; participants = 30,675; studies = eight; I² = 29%), preterm birth less than 37 weeks (RR 0.96, 95% CI 0.85 to 1.08; participants = 17,151; studies = two; I² = 0%), induction of labour (RR 0.93, 95% CI 0.81 to 1.07; participants = 22,663; studies = six; I² = 78%), or caesarean section (RR 1.03, 95% CI 0.92 to 1.15; participants = 27,461; studies = six; I² = 54%). Three additional primary outcomes chosen for the 'Summary of findings' table were preterm birth less than 34 weeks, maternal psychological effects and neurodevelopment at age two. Because none of the included studies reported these outcomes, they were not assessed for quality with GRADE software.

AUTHORS' CONCLUSIONS

Based on existing evidence, routine late pregnancy ultrasound in low-risk or unselected populations does not confer benefit on mother or baby. There was no difference in the primary outcomes of perinatal mortality, preterm birth less than 37 weeks, caesarean section rates, and induction of labour rates if ultrasound in late pregnancy was performed routinely versus not performed routinely. Meanwhile, data were lacking for the other primary outcomes: preterm birth less than 34 weeks, maternal psychological effects, and neurodevelopment at age two, reflecting a paucity of research covering these outcomes. These outcomes may warrant future research.

Spina bifida

Spina bifida is a birth defect in which the vertebral column is open, often with spinal cord involvement. The most clinically significant subtype is myelomeningocele (open spina bifida), which is a condition characterized by failure of the lumbosacral spinal neural tube to close during embryonic development. The exposed neural tissue degenerates in utero, resulting in neurological deficit that varies with the level of the lesion. Occurring in approximately 1 per 1,000 births worldwide, myelomeningocele is one of the most common congenital malformations, but its cause is largely unknown. The genetic component is estimated at 60-70%, but few causative genes have been identified to date, despite much information from mouse models. Non-genetic maternal risk factors include reduced folate intake, anticonvulsant therapy, diabetes mellitus and obesity. Primary prevention by periconceptional supplementation with folic acid has been demonstrated in clinical trials, leading to food fortification programmes in many countries. Prenatal diagnosis is achieved by ultrasonography, enabling women to seek termination of pregnancy. Individuals who survive to birth have their lesions closed surgically, with subsequent management of associated defects, including the Chiari II brain malformation, hydrocephalus, and urological and orthopaedic sequelae. Fetal surgical repair of myelomeningocele has been associated with improved early neurological outcome compared with postnatal operation. Myelomeningocele affects quality of life during childhood, adolescence and adulthood, posing a challenge for individuals, families and society as a whole. For an illustrated summary of this Primer, visit: http://go.nature.com/fK9XNa.

Measurements and planes assessed during second-trimester scans in Brazil: an online survey

OBJECTIVE

The purpose of this study was to estimate what measurements and planes are being assessed during second-trimester scan in Brazil, some characteristics from performing physicians and whether informed consent is being asked.

METHODS

Invitational e-mails were sent for all physicians registered in the database from three institutions. Participants who agreed to participate were directed to an online survey consisting 21 questions. All participants who agreed to participate and sent the online survey were included. We excluded participants who sent an incomplete survey; those who perform ≤ 10 second-trimester scans per month and those who do not work in Brazil.

RESULTS

A total of 41,847 invitational e-mails were submitted, and 467 participants were included in the final analysis. We observed a relatively low proportion of participants examining some important planes from fetal heart: only approximately 80% usually examine the five-chamber and three-vessel views and only 44.3% examine the tracheal view. Regarding the expertise of examiners, we observed that 10.7% of participants do not have any certificate acknowledged by our official institutions. Additionally, only 7.9% of the participants ask for signed informed consent before examination.

CONCLUSIONS

Specific guidelines are still missing. A relatively high proportion of second-trimester scan do not evaluate even what is suggested to be performed in a routine second-trimester scan.

Spinal dysraphism

To review the clinical features and current understanding of spina bifida with an emphasis on the Indian Scenario. Selected articles and current English language texts were reviewed. The authors experience was also reviewed and analysed. Spina bifida is a common congenital anomaly encompassing a wide spectrum of neural tube defects.It is broadly classified as spina bifida aperta and occulta. With the prenatal screening, the incidence of aperta is gradually declining, whereas the detection of occulta has increased with the advent of magnetic resonance imaging. Over the years, the understanding of pathophysiology has made a significant changein the management of these anomalies. Early detection and complete correction can significantly reduce the neurological disability. This article is an overview of spina bifida with a special emphasis on Indian scenario.

Monitoring the prenatal detection of structural fetal congenital anomalies in England and Wales: register-based study

OBJECTIVE

To provide current population-based prevalence and prenatal diagnosis rates (PND) for specified major congenital anomalies in England and Wales to enable monitoring of the Fetal Anomaly Screening Programme (FASP).

DESIGN

Secondary analysis of prospectively collected registry data.

SETTING

Seven multiple-source, population-based congenital anomaly registers, members of the British Isles Network of Congenital Anomaly Registers (BINOCAR) in 2005 and 2006.

POPULATION

2,883 births with congenital anomalies from a total of 601,545 live and stillbirths.

MAIN OUTCOME MEASURES

PND and birth prevalence of selected congenital anomaly groups/subtypes (anencephaly, spina-bifida, serious cardiac, diaphragmatic hernia, gastroschisis, exomphalos, bilateral renal agenesis, lethal/severe skeletal dysplasia, cleft lip with or without cleft palate [CL + /- P]).

RESULTS

Of the selected anomaly groups, the most frequently reported were serious cardiac (14.1 per 10,000 births [95% CI 13.0-15.2]) and CL + /- P (9.7 per 10,000 births [8.9-10.5]); the least frequent were bilateral renal agenesis and lethal/severe skeletal dysplasia (< 1.5 per 10,000 births). The PND varied for different anomalies from 53.1% (95% CI 43.5-65.2) for serious cardiac anomalies to 99.6% (95% CI 97.9-100.0) for anencephaly. Least variation in PND rates was for anencephaly (range 98.9-100%) and gastroschisis (93.5-100%); greatest variation was for serious cardiac (43.5-65.2%) and lethal/severe skeletal dysplasias (50.0-100%).

CONCLUSIONS

BINOCAR registers can, uniquely, provide contemporary data on PND and birth prevalence rates to enable monitoring of the ultrasound component of FASP at a national and regional level, allowing comparisons between populations to be made, planning of resources facilitated and assistance for parents making informed decisions on whether to enter the screening programme.

Role of first-trimester sonography in the diagnosis of aneuploidy and structural fetal anomalies

OBJECTIVE

We sought to determine the sensitivity of the first-trimester scan in the early diagnosis of aneuploidy and structural fetal anomalies in an unselected low-risk population.

METHODS

This was a retrospective chart review of all patients having first-trimester scans between 2002 and 2009. At our center, a survey of fetal anatomy is performed at the time of nuchal translucency assessment at 11 weeks to 13 weeks 6 days. A second-trimester scan is done at 20 to 23 weeks and a third-trimester scan at 32 to 35 weeks. Isolated sonographic findings of choroid plexus cysts and echogenic intracardiac foci were excluded. Lethal anomalies and those requiring immediate surgical intervention at birth were considered major structural anomalies. All scans were performed by a single sonologist certified by the Fetal Medicine Foundation. All neonates were examined at birth by a pediatrician.

RESULTS

Our study included 1370 fetuses. Six cases of aneuploidy (0.4%) were detected. The first-trimester scan detected 5 of 6 cases of aneuploidy (83%), confirmed by karyotype. There were 36 cases of structural fetal anomalies (2.6%); 20 (1.5%) were major anomalies. The first-trimester scan detected 16 of 36 (44%); 20 (56%) were identified by second- or third-trimester scans. The first-trimester scan detection rate for major structural anomalies was 14 of 20 (70%). The 5 that were missed by the first-trimester scan were detected by a second-trimester scan.

CONCLUSIONS

Our study emphasizes the importance of the first-trimester scan in the early detection of aneuploidy and structural fetal anomalies. In this small unselected low-risk population, the first-trimester scan detected 83% of aneuploidies and 70% of major structural anomalies. Our results are comparable to previously published studies from other centers and further exemplify the invaluable role of the first-trimester scan in the early detection of aneuploidy and structural anomalies in an unselected low-risk population.

Routine ultrasound in late pregnancy (after 24 weeks' gestation)

BACKGROUND

Diagnostic ultrasound is used selectively in late pregnancy where there are specific clinical indications. However, the value of routine late pregnancy ultrasound screening in unselected populations is controversial. The rationale for such screening would be the detection of clinical conditions which place the fetus or mother at high risk, which would not necessarily have been detected by other means such as clinical examination, and for which subsequent management would improve perinatal outcome.

OBJECTIVES

To assess the effects on obstetric practice and pregnancy outcome of routine late pregnancy ultrasound, defined as greater than 24 weeks' gestation, in women with either unselected or low-risk pregnancies.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (February 2008).

SELECTION CRITERIA

All acceptably controlled trials of routine ultrasound in late pregnancy (defined as after 24 weeks).

DATA COLLECTION AND ANALYSIS

All three review authors were involved in assessing trial quality and data extraction.

MAIN RESULTS

Eight trials recruiting 27,024 women were included. The quality of trials overall was satisfactory. There was no difference in antenatal, obstetric and neonatal intervention or morbidity in screened versus control groups. There was a slightly higher caesarean section rate in the screened group, but this difference did not reach statistical significance. Routine late pregnancy ultrasound was not associated with improvements in overall perinatal mortality. Placental grading as an adjunct to third trimester examination scan was associated with a significant reduction in the stillbirth rate in the one trial that assessed it. There is little information on long-term substantive outcomes such as neurodevelopment. There is a lack of data on maternal psychological effects.

AUTHORS' CONCLUSIONS

Based on existing evidence, routine late pregnancy ultrasound in low-risk or unselected populations does not confer benefit on mother or baby. It may be associated with a small increase in caesarean section rates. There is a lack of data about the potential psychological effects of routine ultrasound in late pregnancy, and limited data about its effects on both short- and long-term neonatal and childhood outcome. Placental grading in the third trimester may be valuable, but whether reported results are reproducible remains to be seen, and future research of late pregnancy ultrasound should include evaluation of placental textural assessment.

Prenatal ultrasound detection of facial clefts: a prospective study of 49,314 deliveries in a non-selected population in Norway

OBJECTIVES

To evaluate prenatal detection of facial clefts by ultrasound examination in a large non-selected population, and to study trends in detection rates over 18 years, as well as the prevalence of isolated cases and those with associated anomalies.

METHODS

This prospective follow-up study from January 1987 to December 2004 was divided into two 9-year periods. The study included all registered cases of prenatally or postnatally diagnosed facial clefts in a non-selected population in Norway.

RESULTS

A total of 101 fetuses or newborns with facial clefts in a population of 49 314 deliveries were registered. The distribution of clefts was: 25 (25%) cleft lip, 52 (51%) cleft lip and palate, and 24 (24%) cleft palate (CP). No CP was detected prenatally. Cleft lip with or without cleft palate (CL(P)) was detected prenatally in 35/77 (45%) cases, with a significant increase in the detection rate from 34% to 58% between the two 9-year periods (P = 0.03). Over the whole study period CL(P) was detected at a median of 19 + 2 gestational weeks, with no change over time; altogether 24/35 (69%) cases were detected at the routine second-trimester ultrasound examination. Thirty-three of 77 (43%) cases of CL(P) and 14/24 (58%) cases of CP had associated anomalies; 12/101 (12%) had chromosomal aberrations. In 18/101 (18%) the clefts were part of a syndrome or sequence.

CONCLUSIONS

The detection rate for CL(P) improved significantly over time. Detection of CL(P) is important because nearly half the cases have associated anomalies.

Automated retrieval of standard diagnostic fetal cardiac ultrasound planes in the second trimester of pregnancy: a prospective evaluation of software

OBJECTIVE

To evaluate prospectively the performance of software that automatically retrieves, from a three-dimensional (3D) volume of the fetal chest, three diagnostic cardiac planes in the second trimester of pregnancy.

METHODS

3D static volumes of the fetal chest were acquired at the level of the four-chamber view in 72 fetuses between 18 and 23 weeks of gestation. Standardization of 3D volumes was performed in Plane A (the reference plane: four-chamber view) alone. Tomographic ultrasound imaging (TUI) was added to the display of each diagnostic plane. The left ventricular outflow plane (Cardiac plane 1: five-chamber view, aorta), the right ventricular outflow plane (Cardiac plane 2: pulmonary artery) and the abdominal circumference plane (Cardiac plane 3: abdominal circumference, stomach) were retrieved by the software from the 3D volumes and the data were analyzed to determine whether Cardiac planes 1-3 were displayed correctly in each volume.

RESULTS

The automated software displayed, in at least one TUI plane, target Cardiac plane 1 in 94.4% of volumes, target Cardiac plane 2 in 91.7% of volumes and target Cardiac plane 3 in 97.2% of volumes.

CONCLUSION

Our results validate the concept of automated sonography and its potential clinical applicability.

WITHDRAWN: Routine ultrasound in late pregnancy (after 24 weeks' gestation)

BACKGROUND

Diagnostic ultrasound is used selectively in late pregnancy where there are specific clinical indications. However, the value of routine late pregnancy ultrasound screening in unselected populations is controversial. The rationale for such screening would be the detection of clinical conditions which place the fetus or mother at high risk, which would not necessarily have been detected by other means such as clinical examination, and for which subsequent management would improve perinatal outcome.

OBJECTIVES

To assess the effects on obstetric practice and pregnancy outcome of routine late pregnancy ultrasound, defined as greater than 24 weeks gestation, in women with either unselected or low risk pregnancies.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group Specialised Register of Controlled Trials and the Cochrane Controlled Trials Register were searched.

SELECTION CRITERIA

All acceptably controlled trials of routine ultrasound in late pregnancy (defined as after 24 weeks).

DATA COLLECTION AND ANALYSIS

The principal reviewer assessed trial quality and extracted data, under supervision of the co-reviewer.

MAIN RESULTS

Seven trials recruiting 25,036 women were included. The quality of trials overall was satisfactory. There was no difference in antenatal, obstetric and neonatal intervention or morbidity in screened versus control groups. Routine late pregnancy ultrasound was not associated with improvements in overall perinatal mortality. Placental grading as an adjunct to third trimester examination scan was associated with a significant reduction in the stillbirth rate in the one trial that assessed it. There is a lack of data with regard to long term substantive outcomes such as neurodevelopment. There is a lack of data on maternal psychological effects.

AUTHORS' CONCLUSIONS

Based on existing evidence, routine late pregnancy ultrasound in low risk or unselected populations does not confer benefit on mother or baby. There is a lack of data about the potential psychological effects of routine ultrasound in late pregnancy, and the effects on both short and long term neonatal and childhood outcome. Placental grading in the third trimester may be valuable, but whether reported results are reproducible remains to be seen, and future research of late pregnancy ultrasound should include evaluation of placental textural assessment.

Automated sonography: defining the spatial relationship of standard diagnostic fetal cardiac planes in the second trimester of pregnancy

OBJECTIVE

This study defines the spatial relationship of the diagnostic planes of the fetal heart to the 4-chamber view plane in the second trimester of pregnancy as a first step in the automation process.

METHODS

Three-dimensional static volumes of the fetal chest were acquired at the level of the 4-chamber view on 75 fetuses between 18 and 23 weeks' gestation. The spatial relationship of the diagnostic cardiac planes to the 4-chamber view plane were determined for each gestational week by using rotations along the x-, y-, and z-axes and a parallel slide (millimeters) when applicable.

RESULTS

The 5-chamber view (cardiac 1 plane) was best obtained by an initial parallel slide of the reference plane (plane A) toward the fetal head followed by a rotation along the y-axis. The right ventricular outflow tract (cardiac 2) and the abdominal circumference (cardiac 3) planes were best obtained by a parallel slide only: toward the fetal head in cardiac 2 and toward the fetal abdomen in cardiac 3.

CONCLUSIONS

This study shows the spatial relationship of fetal cardiac diagnostic planes to the 4-chamber view plane in the second trimester of pregnancy in 3-dimensional volumes. Testing the clinical applicability of automated software based on these formulas is the next step.

Fetal growth and congenital malformations

OBJECTIVES

To ascertain whether the risk for congenital malformations is increased in pregnancies with deviating fetal growth, i.e. in those in which the estimated date of delivery (EDD) was postponed more than 1 week at the second-trimester ultrasound fetometry scan, or those suspected of intrauterine growth restriction at routine ultrasound fetometry in the third trimester.

METHODS

The study period was 1994-2003. We used the Swedish Medical Birth Register to identify pregnancies with appropriate data (n = 605 845). A regional ultrasound database consisting of 73 092 pregnancies was used for more detailed data and analysis of the third-trimester fetal growth. The number of congenital malformations was ascertained from three national health registers.

RESULTS

We found a moderately increased risk for any malformation in the group of fetuses in which the EDD was postponed > 1 week. The strongest effect was seen for chromosome anomalies and central nervous system malformations, including neural tube defects. In the third trimester, an increased risk for fetal malformations was found in asymmetrically vs. symmetrically growth-restricted fetuses, perhaps more strongly when adjustment of the EDD had been done at the dating scan.

CONCLUSIONS

Fetuses in which the EDD differs between that calculated by the last menstrual period and that calculated by second-trimester ultrasound measurement seem to have an increased risk for congenital malformations, including chromosomal anomalies. A targeted ultrasound examination for malformation screening might be recommended for this group. A similar policy might be recommended when intrauterine growth restriction, especially of the asymmetrical type, is suspected later in pregnancy.

Trisomy 18 in neonates: prenatal diagnosis, clinical features, therapeutic dilemmas and outcome

The study aimed to analyse the clinical courses of aggressively treated neonates with cytogenetically confirmed trisomy 18, with special attention focused on the efficiency of prenatal diagnostics, associated malformations, therapeutic dilemmas and outcomes. We investigated retrospectively the data concerning 20 neonates with trisomy 18, admitted to the Neonatal Intensive Care Unit (NICU) in Katowice between January 2000 and February 2005. Their birth weights ranged from 650 g to 2400 g, mean 1812 g; gestational age ranged from 27 to 42 weeks, median 38 weeks. Intrauterine growth retardation was noticed in 90% of neonates. Trisomy 18 was suspected prenatally in 40% of cases. Most (80%) of newborns were delivered by caesarean section (92% of neonates with prenatally unrecognized chromosomal defects, 62% of neonates with trisomy 18 suspicion) and 70% of infants needed respiratory support immediately after birth. Cardiac defects were present in 95%, central nervous system malformations in 65%, severe anomalies of digestive system or abdominal wall in 25% of patients. Nine surgical operations were performed during hospitalization (4 were palliative cardiac surgeries). Six patients (30%) survived the neonatal period and were discharged from the NICU. The median survival of the neonates who died was 20 days. In 4 cases cardiac problems implicated their death; in others, deaths were attributed to multiorgan failure, prematurity and/or infection. Further improvement of efficiency of prenatal ultrasound screening for diagnosis of trisomy 18 in the fetus is necessary. A lack of prenatal diagnosis of trisomy 18 in the fetus results in a high rate of unnecessary caesarean sections in these pregnancies. Despite the aggressive treatment most neonates with trisomy 18 died during the neonatal period. The majority of deaths were attributed to cardiorespiratory and multiorgan failure. Concerning the poor prognosis, prompt karyotyping (using FISH) of clinically suspected trisomy 18 is very important, because many invasive procedures and surgeries may then be avoided.

Prenatal detection of congenital renal malformations by fetal ultrasonographic examination: an analysis of 709,030 births in 12 European countries

The study was performed to evaluate the prevalence of prenatal ultrasound diagnoses for renal anomalies in 20 registries of 12 European countries, and to compare the different prenatal scanning policies. Standardized data were acquired from 709,030 livebirths, stillbirths, and induced abortions during the study period of 2.5 years and transmitted for central analysis. At least one renal malformation was diagnosed in 1130 infants and fetuses. Prenatal diagnosis (PD) was given in 81.8% of all cases, 29% of these pregnancies were terminated. The highest detection rate was reported for unilateral multicystic dysplastic kidneys with 97% (102/105). An early diagnosis was documented for exstrophy of bladder at a mean gestational age of 18.5 weeks. Dilatations of the upper urinary tract were seen late in pregnancy at 28.3 weeks. Terminations of pregnancies (TOP) were performed in 67% (58/86) of the detected bilateral renal agenesis/dysgenesis, but only 4% of the unilateral multicystic dysplastic renal malformations (4/102). In about 1/3 of the cases, renal malformations are within the category of associated malformations, which include multiple non-syndromal malformations, chromosomal aberrations, and non-chromosomal syndromes. Renal malformations were detected in 2/3 of the associated category by the first prenatal ultrasound scan. Detection rates vary in the different countries of the European community due to diverse policies, ethical, and religious background. Countries with no routine ultrasound show the lowest rates in detection, and termination of pregnancy. Prenatally detected renal malformations should result in a careful examination for further anomalies. Prenatal ultrasound fulfills the needs of screening examinations and is a good tool in detecting lethal and severe renal malformations.

The accreditation of ultrasound practices: impact on compliance with minimum performance guidelines

OBJECTIVE

To determine the effectiveness of the American Institute of Ultrasound in Medicine (AIUM) accreditation program in improving compliance with standards and guidelines for the performance of obstetric and gynecologic ultrasound examinations.

METHODS

Scores of case studies of accreditation applications were compared with their respective scores at the time of reaccreditation 3 years later. To account for the element of time, scores of applications that recently completed first-time accreditation were also compared as a control group.

RESULTS

Individual obstetric case studies, as well as the average of all obstetric and gynecologic case studies, showed highly significant improvement with the reaccreditation application when compared with the initial accreditation application 3 years earlier (all P <.001). The proportion of practices successfully meeting obstetric and gynecologic AIUM accreditation requirements improved significantly with reaccreditation (obstetric, 57.3% for accreditation compared with 86.6% for reaccreditation; gynecologic, 60% for accreditation compared with 91.9% for reaccreditation; P <.001). Furthermore, reaccreditation scores were significantly higher than scores of recent first-time applications for obstetric case studies as well as scores of the average of obstetric and gynecologic case studies (all P <.05).

CONCLUSIONS

Our study confirms that practices that sought and received ultrasound accreditation were able to improve the scores of case studies and compliance with published minimum standards and guidelines for the performance of obstetric and gynecologic ultrasound examinations when reevaluated 3 years after the initial application scores. This improvement should translate into an enhancement of the quality of ultrasound practice.

Prenatal diagnosis of Down syndrome: ten year experience in the Israeli population

Second trimester maternal serum biochemical markers, introduced between 1990 and 1995, were supplemented with new ultrasound methods at 14-16 weeks and first trimester biochemical markers between 1995 and 2000. This study evaluated the effectiveness of a Down syndrome (DS) prevention program among the Israeli Jewish population between 1990 and 2000. We collected data on the total number of prenatal tests performed on Israeli Jewish women, DS cases detected prenatally and DS livebirths in Israel during these years. We also studied the use of the newer screening tests in 1990, 1992, and 2000. Between 1990 and 1995, use of chromosomal studies for DS in this population increased from 11.3% to 21.6% and the percentage of cases detected prenatally from 53% to 70%. However, between 1996 and 2000, even with the new screening methods, the utilization rate remained similar (20.7% and 19.8%, respectively) and the percentage detected prenatally decreased to 61% in 2000. The total cost per case detected increased from $47,971 US dollars in 1990 to $75,229 US dollars in 1992, and to $190,171 US dollars in 2000. Between 1990 and 1995, improvement in the percentage of cases detected prenatally was associated with a significant increase in the amniocentesis rate-both are attributed to the introduction of second trimester maternal serum biochemical marker tests. Unexpectedly, the introduction between 1995 and 2000 of new genetic methods to assess the DS risk did not improve the percentage detected or reduce the amniocentesis rate, and was accompanied by an increased cost per case detected.

Prenatal diagnosis of dysmorphic syndromes by routine fetal ultrasound examination across Europe

OBJECTIVES

Ultrasound scan in the mid-trimester of pregnancy is now a routine part of prenatal care in most European countries. The objective of this study was to evaluate the prenatal diagnosis of dysmorphic syndromes by fetal ultrasound examination.

METHODS

Data from 20 registries of congenital malformations in 12 European countries were included in the study.

RESULTS

There were 2454 cases with congenital heart diseases, 479 of which were recognized syndromes, including 375 chromosomal anomalies and 104 syndromes without chromosomal anomalies. Fifty-one of the 104 were detected prenatally (49.0%). One hundred and ninety-two of 1130 cases with renal anomalies were recognized syndromes, including 128 chromosomal anomalies and 64 syndromes without chromosomal anomalies; 162 of them (84.4%) were diagnosed prenatally, including 109 chromosomal anomalies and 53 non-chromosomal syndromes. Fifty-four of the 250 cases with limb defects were recognized syndromes, including 16 chromosomal syndromes and 38 syndromes without chromosomal anomalies; 21 of these 54 syndromes were diagnosed prenatally (38.9%), including 9 chromosomal syndromes. There were 243 cases of abdominal wall defects including 57 recognizable syndromes, 48 with omphalocele and 9 with gastroschisis; 48 were diagnosed prenatally (84.2%). Twenty-six of the 187 cases with diaphragmatic hernia had recognized syndromes, including 20 chromosomal aberrations and 6 syndromes without chromosomal anomalies. Twenty-two of them (84.6%) were detected prenatally. Sixty-four of 349 cases with intestinal anomalies were recognized syndromes; 24 were diagnosed prenatally (37.5%). There were 553 cases of cleft lip and palate (CL(P)) and 198 of cleft palate (CP) including 74 chromosomal anomalies and 73 recognized non-chromosomal syndromes. Prenatal diagnosis was made in 51 cases of CL(P) (53.7%) and 7 of CP (13.7%). Twenty-two of 188 anencephalic cases were syndromic and all were diagnosed prenatally. Of 290 cases with spina bifida, 18 were recognized syndromes, and of them 17 were diagnosed prenatally. All 11 syndromic encephaloceles were diagnosed prenatally.

CONCLUSIONS

Around 50% of the recognized syndromes which are associated with major congenital anomalies (cardiac, renal, intestinal, limb defects, abdominal wall defects and oral clefts) can be detected prenatally by the anomaly scan. However the detection rate varies with the type of syndrome and with the different countries' policies of prenatal screening.

Psychological impact of the detection of soft markers on routine ultrasound scanning: a pilot study investigating the modifying role of information

OBJECTIVES

To determine the impact on maternal anxiety of detecting a soft marker, and the association between anxiety and the information given during the scan.

METHODS

Routine 20-week fetal anomaly scans were audiotaped in the obstetric ultrasound unit of a London teaching hospital, across a four month study period. The study sample comprised 28 pregnant women: 14 in whom a soft marker was detected and a comparison group of 14 women in whom no marker was identified. Telephone interviews were conducted within one week of the scan, at 30 weeks' gestation, and one month after the birth of their children. The main outcome was anxiety, assessed using a standardized scale. Information provided during the scan was coded from transcripts.

RESULTS

In the week following the scan, women with soft markers had clinically significant levels of anxiety. At 30 weeks' gestation and one month post-partum their levels were within the normal range. Women who were told during their scan that their baby would probably be all right, compared with women not told this, were significantly less anxious and worried about their baby.

CONCLUSIONS

Results from this small longitudinal study suggest that the detection of soft markers on routine prenatal ultrasound causes considerable short-term anxiety for women and that providing reassurance during the scan may prevent some of this anxiety.

Impact of prenatal diagnosis on livebirth prevalence of children with congenital anomalies

The objectives of this study were to describe the impact of prenatal diagnosis on the birth prevalence of congenital anomalies over 21 years (1979-1999) in a well defined population in northeastern France (13,500 births per year). The material for this study came from the analysis of data from multiple sources on births and terminations of pregnancy after prenatal diagnosis of congenital anomalies in 279,642 consecutive pregnancies of known outcome. The study period was divided into three subgroups 1979-1988, 1989-1993 and 1994-1999. Between 1979-1988, 1989-1993 and 1994-1999, prenatal detection of congenital anomalies increased, respectively, from 12.0% to 25.5% and to 31.7%. Termination of pregnancy (TOP) increased in the same proportions during the three time periods. However, the increase of TOP was much higher for chromosomal anomalies than for nonchromosomal congenital anomalies. The birth prevalence of Down's syndrome fell by 80% from 1979-1988 to 1994-1999. Sensitivity of prenatal detection of congenital anomalies and TOPs were lower for isolated cases (only one malformation present in the fetus) than for multiple malformations in the same fetus. Sensitivity varied with the type of malformations: it was high for neural tube defect (79.7%) and urinary anomalies (50.7%) and low for congenital heart defects (16.4%). In conclusion, the introduction of routine prenatal diagnosis has resulted in a significant fall in the birth prevalence of children with congenital anomalies. However, this fall varied with the types of congenital anomalies.

The accuracy of antenatal ultrasound in the detection of facial clefts in a low-risk screening population

OBJECTIVES

To evaluate the accuracy of prenatal ultrasound in the detection of facial clefts in a low-risk screening population and to report on the outcome of these pregnancies.

DESIGN

We retrospectively reviewed antenatal ultrasound records from the obstetric ultrasound department, postnatal records from the regional craniofacial unit and autopsy reports of fetuses over 16 weeks' gestational age from the regional pathology department over a 5-year period (1993-97). Cross-referencing between the three data sets identified all cases of facial clefts.

RESULTS

Out of 23 577 live and still births, 30 had facial clefts; four were excluded from the study. Of the remaining 26 cases, 10 had associated major anomalies. There were 19 live births and seven terminations. Six of the seven terminations had other major abnormalities. Our detection rate for cleft lip and palate was 93% and the detection rate for isolated cleft palate was 22%. Isolated cleft lip was detected in 67% of cases. The overall detection rate for facial clefts was 65%.

CONCLUSION

From our results and a review of the literature it is clear that before standards can be set we need to define which facial clefts are sonographically demonstrable. Our data provide information for effective counseling and setting of standards for clinical practice.

Contribution of ultrasonographic examination to the prenatal detection of chromosomal abnormalities in 19 centres across Europe

The objective of this study was to evaluate the prenatal detection of chromosomal abnormalities by fetal ultrasonographic examination in a large database provided by 19 Registries of Congenital Anomalies from 11 European countries. This study included 1738 cases of chromosomal abnormalities, liveborn, stillborn or termination of pregnancy regardless of maternal age from a population of 664,340 births during the period 1996 - 1998. The most frequent chromosomal anomalies were Down syndrome (n=1050), trisomy 18 (n=191), Turner syndrome (n=125), trisomy 13 (n=86), and triploidy (n=56). Fetal ultrasonographic examination resulted in the prenatal detection of 37.7% of the chromosomal abnormalities, thereby resulting in a reduction of 28.6% in their prevalence at birth due to terminations of pregnancy. The detection rate by ultrasound examination varied according to local policies of prenatal diagnosis : it was lower in countries where routine scan were not performed and higher in countries in which at least one routine anomaly scan during the second trimester of pregnancy was performed. The ultrasound detection varied according to the specific chromosomal anomaly and was lowest for Klinefelter syndrome (5.7%) and highest for triploidy (78.6%). For Down syndrome it was 26.4%. Termination of pregnancy was performed in 75.9% of the cases. Among the 655 cases detected by ultrasound, the most frequent ultrasound signs by category of chromosomal abnormalities were analysed. This study shows that ultrasound screening is an important tool in the prenatal detection of chromosomal abnormalities in Europe, leading to a significant reduction in the prevalence of livebirth children with chromosomal anomalies.

The variability in the interpretation of prenatal diagnostic ultrasound

OBJECTIVES

Although prenatal ultrasound is broadly used to detect abnormal fetuses, the variability in the interpretation of second-trimester prenatal ultrasound examinations is unknown. We sought to evaluate the consistency of the interpretation of prenatal ultrasound examinations.

DESIGN

Physicians who perform prenatal ultrasound and who participate in the California Maternal Serum Expanded AFP program were asked to interpret a series of test ultrasound examinations. The series of cases was selected to include a random sample of fetal structural abnormalities, ultrasound markers that have been associated with chromosomal abnormalities, and normal cases. Interobserver agreement was evaluated using a kappa statistic for each organ system. The sensitivity and false-positive rate were calculated for detecting specific anatomic abnormalities within each organ system.

RESULTS

Of the 210 sonologists eligible for inclusion in the study, completed responses were received from 148 (70%). There was moderate to substantial agreement between physicians in reporting the presence of fetal abnormalities for all organ systems (kappa range 0.40-0.88, P < 0.001). The consistency was highest for the central nervous system (CNS), neck, and face. Within each organ system, the consistency was similar for major structural abnormalities and ultrasound markers of chromosomal abnormalities. The sensitivity ranged from 62% (95% confidence interval (CI) 58-66%) for major renal abnormalities to 91% (95% CI 88-94%) for CNS abnormalities, with corresponding false-positive rates of 7% (95% CI 6-9%) for renal abnormalities and 9% (95% CI 7-11%) for CNS abnormalities. For most organ systems, the sensitivity for detecting ultrasound markers of chromosomal abnormalities was similar to the sensitivity for detecting structural abnormalities.

CONCLUSION

There is moderate to substantial agreement in the interpretation of second-trimester prenatal ultrasound examinations. Whether the identification of specific ultrasound abnormalities and markers is overall beneficial to patients remains to be determined.

Prenatal diagnosis of fetal abnormality: psychological effects on women in low-risk pregnancies

When given an adverse prenatal diagnosis, parents are deeply shocked and experience acute grief. This review considers the psychological outcomes for parents whether they opt to terminate the pregnancy or continue, either through choice or because termination is not an option. It covers the full spectrum of malformation from treatable, through those carrying a risk of significant handicap, to lethal. It draws on two types of studies: those that are retrospective and qualitative, describing feelings and aspects of care, and those that are prospective and assess psychological state with standardized measures of grief, anxiety and depression. The relationship between psychological outcome and possible associated variables, such as individual characteristics, nature of the abnormality and obstetric factors is described and evaluated. In addition, the authors draw on both scientific and support group literature to summarize good practice for the care of parents receiving an unexpected diagnosis of fetal abnormality.

Ultrasound markers of fetal chromosomal abnormality: a survey of policies and practices in UK maternity ultrasound departments

OBJECTIVE

To evaluate the management of pregnancies where the fetus was found to have one or more sonographic markers of possible fetal chromosomal abnormality.

DESIGN

Prospective anonymous postal survey of UK obstetric ultrasound units.

MAIN OUTCOME MEASURES

The management of pregnancies where the fetus is found to have a sonographic marker of aneuploidy.

POPULATION

All 252 maternity ultrasound units in the United Kingdom.

METHODS

Postal questionnaire to the superintendent sonographer in routine maternal ultrasound departments.

RESULTS

Questionnaires were returned from 179 maternity units (71%). Of the respondents 94% offered a fetal anomaly scan at 16-20 weeks' gestation and 59% performed a dating scan at 10-14 weeks. Screening for Down syndrome was available in 99% of all maternity units. The recognition of sonographic 'soft signs' for possible fetal chromosomal abnormality varied considerably between the units. When sonographers were asked about their unit's policy regarding offering amniocentesis to women with sonographic markers, 8-78% discussed amniocentesis when the marker was isolated and 53-88% when another abnormality was found. Eighty nine percent of units documented the abnormal ultrasound findings in the hospital notes and 88% of the women were informed of the findings regardless of the intention to offer amniocentesis.

CONCLUSION

The practice of routine ultrasound examination is well established in UK, though precise policies vary. The existing wide variations in management policies possibly reflect a lack of data derived from low risk populations. There is a need to collect such data from low risk populations with known screening practices so that national guidelines to standardize practice can be formulated.

The 4 year outcome following the demonstration of bilateral renal pelvic dilatation on pre-natal renal ultrasound

There is little in the literature regarding long-term prognosis in cases of fetal pyelectasis and calyceal dilatation. The aim of this study was to correlate antenatal ultrasound findings with outcome in a large group of children, most of whom had routine antenatal mid-trimester scans. 75 babies with bilateral pyelectasis and calyceal dilatation in the pre-natal period and complete radiological and clinical data were identified over a 3 year period. Pre-natal ultrasound was correlated with results of post-natal investigation and the frequency of post-natal surgery was established. Follow-up was documented to discharge or to at least 4 years of age. Prognosis was related to the degree of pelvic dilatation, but neonatal morbidity was much more likely to be associated with pre-natal calyceal dilatation and/or hydroureter. 68% (51 of 75) of babies had insignificant abnormalities on post-natal investigation, defined as either transient fetal pyelectasis and calyceal dilatation, extrarenal pelves, or transient neonatal pyelectasis and calyceal dilatation. Five babies died in the neonatal period, all classified as either moderate or severe disease. Of the surviving 70 cases (93.3%), 27% had renal anomalies that required treatment by prophylactic antibiotics or surgery. The remaining babies were conservatively managed and followed as outpatients. One child required transplantation and a further two had a severe degree of chronic renal failure by the age of 4 years. These data will be of value in prospective counselling.

A six year study of the antenatal detection of fetal abnormality in six Scottish health boards

OBJECTIVE

To assess the sensitivity of prenatal diagnosis by ultrasound and biochemical methods, to evaluate the reasons for non-detection and to make appropriate recommendations.

DESIGN

Six year observational study, during which biochemical screening for trisomy 21 was introduced and there was an increase in routine ultrasound scanning at 18-22 weeks.

SETTING

Six health boards in Scotland.

POPULATION

264,481 pregnancies, of which 862 were terminated because of fetal abnormality, and 2123 delivered with prenatally detectable major fetal abnormalities.

MAIN OUTCOME MEASURES

The prenatal detection of trisomies 13, 18 and 21, and 12 major structural abnormalities, which the average ultrasonographer with average skills using average equipment would be expected to detect.

RESULTS

Serum biochemical screening improved detection of trisomy 21 from 33% to 57%. The detection rate for the major abnormalities was 62% (815/1320) and 73% (598/818) when the trisomies were excluded. 18-22 weeks scanning yielded a 92% detection rate. Of the 505 undetected cases, 15% declined prenatal screening, 46% were unscreened because they were ineligible for testing, unbooked, booked too late or scanned too early for a diagnosis to be made, 2% had findings suspicious of a chromosomal abnormality but testing was not undertaken and 37% had a negative scan at a gestation when the abnormality was potentially detectable.

CONCLUSIONS

A policy of first trimester scanning followed by serum alpha-fetoprotein screening and additional scanning as clinically indicated is effective in detecting major structural abnormalities, but scanning at 18-22 weeks and serum biochemical screening for trisomy 21 improved the detection rates. Supervised training and adequate equipment are essential. Present prenatal diagnostic tests will not detect all abnormalities and patients must be made aware of this.

6-year experience of prenatal diagnosis in an unselected population in Oxford, UK

BACKGROUND

The benefits and harm associated with prenatal diagnosis are open to debate. We give a 6-year overview of the experience of one prenatal-diagnosis unit using a defined, unselected population.

METHODS

All congenital malformations suspected prenatally and all congenital malformations, including chromosome anomalies, confirmed at birth were identified from the local Congenital Malformation Register. All fetuses or infants of women booked for delivery at the Oxford Women's Centre who had an OX postcode and date of delivery between 1991 and 1996 were eligible for the study.

FINDINGS

725 (2%) of 33,376 babies, were judged abnormal at delivery. 396 (55%) malformed fetuses and infants had been correctly identified prenatally. 174 fetuses had a suspected abnormality identified on scan and subsequently proved to be normal. 160 (92%) of these false-positive results were attributable to the reporting of so called ultrasound soft markers. Accuracy of ultrasound diagnosis was good for structural malformations. Ultrasound soft markers were responsible for a 4% increase in detection of malformations (from 51% to 55%) and a 12-fold increase in false-positive rate (one in 2332 to one in 188). 171 pregnancies (43% of prenatally diagnosed malformed babies) were terminated because of suspected abnormality. Suspicion of abnormality in these cases was first aroused after ultrasound scan in 136 (79%); chromosome analysis because of advanced maternal age, family history, or higher risk in biochemical screening test in 25 (15%); and molecular analysis of single gene defect because of family history in ten (6%). There was a 20% reduction in prevalence of conditions compatible with survival beyond the neonatal period because of termination of such pregnancies.

INTERPRETATION

More than half of all malformed fetuses can be identified prenatally in routine practice, mostly following initial suspicion from ultrasound examination. Ultrasound soft markers lead to a small increase in detection of malformations but a large increase in false positives. Further research on the impact, including psychological, and value of markers is required to determine whether the benefits of reporting them exceeds the harm. Because methods and techniques continually change, ongoing surveillance of prenatal diagnostic services is vital.

Choosing options for ultrasound screening in pregnancy and comparing cost effectiveness: a decision analysis approach

OBJECTIVE

To compare the cost effectiveness of different programmes of routine antenatal ultrasound screening to detect four key fetal anomalies: serious cardiac anomalies, spina bifida, Down's syndrome and lethal anomalies, using existing evidence.

DESIGN

Decision analysis was used based on the best data currently available, including expert opinion from the Royal College of Obstetricians and Gynaecologists, Working Party and secondary data from the literature, to predict the likely outcomes in terms of malformations detected by each screening programme.

SETTING

Results applicable in clinics, hospitals or GP practices delivering antenatal screening.

MAIN OUTCOME MEASURE

The number of cases with a 'target' malformation correctly detected antenatally.

RESULTS

There was substantial overlap between the cost ranges of each screening programme demonstrating considerable uncertainty about the relative economic efficiency of alternative programmes for ultrasound screening. The cheapest, but not the most effective, screening programme consisted of one second trimester ultrasound scan. The cost per target anomaly detected (cost effectiveness) for this programme was in the range 5,000 pound silver-109,000, pound silver but in any 1000 women it will also fail to detect between 3.6 and 4.7 target anomalies.

CONCLUSIONS

The range of uncertainty in the costs did not allow selection of any one programme as a clear choice for NHS purchasers. The results suggested that the overall allocation of resources for routine ultrasound screening in the UK is not currently economically efficient, but that certain scenarios for ultrasound screening are potentially within the range of cost effectiveness reached by other, possibly competing, screening programmes. The model highlighted the weakness of available evidence and demonstrated the need for more information both about current practice and costs.

Prenatal screening and women's perception of infant disability: a Sophie's Choice for every mother

Prenatal screening can significantly benefit parents and the community. However, it has created a dilemma for women as it requires them to quickly decide whether to continue a pregnancy or terminate it should the test indicate a foetal abnormality. This can be psychologically traumatic for women torn between their connection to an unborn child with all its possible imperfections, and a desire to prevent its suffering as a disabled child in later life. A woman must also consider her own and her family's future welfare. Extensive research into the physical aspects of prenatal screening has not explored the meaning of the experience for women or whether termination is the most appropriate option. This article examines recent qualitative studies, concluding that women who terminate a pregnancy following prenatal screening may experience an acute grief reaction or be plagued by guilt and fear that can precipitate marital breakdown. Additionally, there is a risk that through striving to eradicate congenital disability, a community risks promoting a cult of perfectionism that may have discriminatory effects on disabled people.