Women's interpretation of an abnormal result on measurement of fetal nuchal translucency and maternal serum screening for prenatal testing of Down syndrome

OBJECTIVE

To assess the effects of sociodemographic and health-provider factors on women's understanding of abnormal results on measurement of nuchal translucency (NT) and maternal serum screening (MSS), 18 months after the implementation of a policy aimed at increasing women's awareness regarding MSS.

METHODS

A representative sample of women (n = 734) who gave birth in Parisian maternity units in 1999 were asked about their understanding of an abnormal result on MSS and NT. We assessed the effects of sociodemographic and health-provider factors on the probability of women interpreting an abnormal result correctly, misinterpreting it as a definitive diagnosis, or declaring that they did not know how to interpret the result. Response rate was 92% and the analyses included multinomial models.

RESULTS

For both MSS and NT measurement, the majority of women interpreted an abnormal result correctly. However, there were substantial sociodemographic differences in the probability of women interpreting an abnormal result correctly, and more so in the probability of their declaring not to know how to interpret the result. The probability of correct interpretations was substantially higher, and that of declaring not to know how to interpret the result substantially lower, for MSS than NT measurement. However, for several sociodemographic groups, the proportion of women who misinterpreted an abnormal result on screening as indicative of a definitive diagnosis was also higher for MSS as compared with NT measurement.

CONCLUSIONS

These findings underscore the need for additional efforts, along with alternative strategies, to inform women about the implications of prenatal screening, particularly in the case of measurement of NT.

Trends and geographic inequalities in the prevalence of Down syndrome in Europe, 1980-1999

BACKGROUND

EUROCAT is a network of population-based registries for the epidemiologic surveillance of congenital anomalies covering approximately one quarter of births in the European Union. Down syndrome constitutes approximately 8% of cases of registered congenital anomaly in Europe, with over 7000 affected pregnancies in the 15 current member states of the European Union each year. In this paper, we aim to examine trends in the live birth prevalence of Down syndrome in Europe in the light of trends in maternal age and in prenatal diagnosis.

METHODS

Descriptive analysis of data from 24 EUROCAT registries, covering 8.3 million births 1980-99. Cases include live births, stillbirths and terminations of pregnancy following prenatal diagnosis.

RESULTS

Since 1980, the proportion of births to mothers of 35 years of age and over has risen quite dramatically from 8 to 14% for the European Union as a whole, with steeper rises in some regions. By 1995-1999, the proportion of "older" mothers varied between regions from 10% to 25%, and the total prevalence (including terminations of pregnancy) of Down syndrome varied from 1 to 3 per 1000 births. Some European regions have shown a more than twofold increase in total prevalence of Down syndrome since 1980. The proportion of cases of Down syndrome which were prenatally diagnosed followed by termination of pregnancy in 1995-1999 varied from 0% in the three regions of Ireland and Malta where termination of pregnancy is illegal, to less than 50% in 14 further regions, to 77% in Paris. The extent to which terminations of pregnancy were concen trated among older mothers varied between regions. The live birth prevalence has since 1980 increasingly diverged from the rising total prevalence, in some areas remaining approximately stable, in others decreasing over time.

CONCLUSION

The rise in average maternal age in Europe has brought with it an increase in the number of pregnancies affected by Down syndrome. The widespread practice of prenatal screening and termination of pregnancy has in most of the regions covered by EUROCAT counteracted the effect of maternal age in its effect on live birth prevalence. Under the joint influences of maternal age and prenatal screening the pattern of geographic inequalities in Down syndrome live birth prevalence in Europe has also been changed.

[Prevalence and prenatal diagnosis of congenital malformations in the Parisian population: twenty years of surveillance by the Paris Registry of congenital malformations]

OBJECTIVES

To assess overall and malformation-specific trends in the prevalence, prenatal diagnosis and pregnancy termination of congenital malformations in the Parisian population.

METHODS

We used data from the Paris Registry of Congenital Malformations, which includes all births and pregnancy terminations with structural birth defects or chromosomal anomalies. Data on total and live birth prevalence were available for the period 1981-2000 and for prenatal diagnosis and pregnancy terminations for 1983-2000. Twenty malformations were selected for malformation-specific analyses due to their higher frequency and consistent definitions in different classification systems.

RESULTS

For the period 1981-2000, the overall total prevalence of malformations was 3.2%. Prenatal diagnosis rates consistently increased from 16.2% (95% CI, 13.8-18.6) of cases with malformation in 1983 to 69.1% (95% CI, 66.7-71.5) in 2000. Pregnancy terminations increased from 8.8% (95% CI, 7.0-10.8) of cases with malformation in 1983 to 30.1% (95% CI, 27.7-32.6) in 2000.

CONCLUSION

Registries of congenital malformations provide population-based data on the prevalence of malformations and their associations with other anomalies. Registry-based data can also be used to evaluate the impact of prenatal testing policies for congenital malformations.

Prenatal diagnosis of severe structural congenital malformations in Europe

OBJECTIVES

To assess at a population-based level the frequency with which severe structural congenital malformations are detected prenatally in Europe and the gestational age at detection, and to describe regional variation in these indicators.

METHODS

In the period 1995-1999, data were obtained from 17 European population-based registries of congenital malformations (EUROCAT). Included were all live births, fetal deaths and terminations of pregnancy diagnosed with one or more of the following malformations: anencephalus, encephalocele, spina bifida, hydrocephalus, transposition of great arteries, hypoplastic left heart, limb reduction defect, bilateral renal agenesis, diaphragmatic hernia, omphalocele and gastroschisis.

RESULTS

The 17 registries reported 4366 cases diagnosed with the 11 severe structural malformations and of these 2300 were live births (53%), 181 were fetal deaths (4%) and 1863 were terminations of pregnancy (43%); in 22 cases pregnancy outcome was unknown. The overall prenatal detection rate was 64% (range, 25-88% across regions). The proportion of terminations of pregnancy varied between regions from 15% to 59% of all cases. Gestational age at discovery for prenatally diagnosed cases was less than 24 weeks for 68% (range, 36-88%) of cases. There was a significant relationship between high prenatal detection rate and early diagnosis (P < 0.0001). For individual malformations, the prenatal detection rate was highest for anencephalus (469/498, 94%) and lowest for transposition of the great arteries (89/324, 27%). Termination of pregnancy was performed in more than half of the prenatally diagnosed cases, except for those with transposition of the great arteries, diaphragmatic hernia and gastroschisis, in which 30-40% of the pregnancies with a prenatal diagnosis were terminated.

CONCLUSION

European countries currently vary widely in the provision and uptake of prenatal screening and its quality, as well as the "culture" in terms of decision to continue the pregnancy. This inevitably contributes to variation between countries in perinatal and infant mortality and in childhood prevalence and cost to health services of congenital anomalies.

Risk of a Down syndrome live birth in women 45 years of age and older

OBJECTIVES

To determine the risk of a Down syndrome (DS) live birth for women 45 years of age and over.

METHODS

A meta-analysis of data from five published articles, 13 EUROCAT congenital anomaly population registers and two unpublished sources.

RESULTS

Information was available on the number of DS live births occurring amongst 13,745 live births to women 45 years of age and over. Information was also available on DS pregnancies diagnosed prenatally that were subsequently terminated. These pregnancies were adjusted for expected fetal loss to estimate the number of live births that would have occurred in the absence of prenatal diagnoses, when a total of 471 DS live births were estimated to have occurred. The risk of a DS birth did not increase for women 45 years of age and over. The average risk was 34 per 1000 births (95% CI: 31-37).

CONCLUSION

The risk of a DS live birth for women 45 years of age and over is considerably lower than has often been previously assumed. The most likely explanation is that women of this age are more likely to miscarry DS pregnancies than younger mothers.

Contribution of ultrasonographic examination to the prenatal detection of trisomy 21: experience from 19 European registers

The objective of this study was to evaluate the contribution of ultrasound scanning to the prenatal detection of trisomy 21 in a large unselected European population. Data from 19 congenital malformation registers in 11 European countries were included. The prenatal ultrasound screening programs in the countries ranged from no routine screening to three ultrasound investigations per patient. Routine serum screening was offered in four of the 11 countries and routine screening on the basis of maternal age amniocentesis in all. The results show that overall 53% of cases of trisomy 21 were detected prenatally with a range from 3% in Lithuania to 88% in Paris. Ninety-eight percent of women whose babies were diagnosed before 24 weeks gestation chose to terminate the pregnancy. Centres/countries that offer serum screening do not have a significantly higher detection rate of trisomy 21 when compared to those that offer maternal age amniocentesis and anomaly scanning only. Fifty percent of trisomy 21 cases were born to women aged 35 years or more. In conclusions, second trimester ultrasound plays an important role in the prenatal diagnosis of trisomy 21. Of those cases prenatally diagnosed, 64% of cases in women <35 years and 36% of those in women >or=35 years were detected because of an ultrasound finding. Ultrasound soft markers accounted for 84% of the scan diagnoses. There is evidence of increasing maternal age across Europe with 50% of cases of trisomy 21 born to women aged 35 years or more.

Turner syndrome: Evaluation of prenatal diagnosis in 19 European registries

This study evaluated the prenatal diagnosis of Turner syndrome by ultrasound examination in an unselected population from all over Europe. Data from 19 congenital malformation registries from 11 European countries were analyzed. Turner syndrome was diagnosed in 125 cases (7.2%) in a total of 1,738 chromosome abnormalities. Sixty-seven percent of cases were detected prenatally by ultrasound examination due to the presence of congenital defects. The most frequent anomalies were cystic hygroma (59.5%) and hydrops fetalis (19%). The most frequent karyotype was 45,X (81.6%) followed by different types of mosaicism (16.8%). Significant differences in congenital defects (P = 0.0003) were observed between 45,X karyotypes and 45,X mosaicism cases. Prenatal counseling for 45,X mosaicism should take into account the expectation of a milder phenotype. In 78.6% of cases diagnosed by ultrasound examination due to congenital anomalies, the pregnancy was terminated. Prenatal detection of Turner syndrome by ultrasound examination was high in this unselected population.

Prenatal detection of rare chromosomal autosomal abnormalities in Europe

The aim of the present study was to evaluate the prenatal detection of rare chromosomal autosomal abnormalities by ultrasound (US) examination. Data were obtained from 19 congenital malformation registries from 11 European countries, between 01/07/96 and 31/12/98. A total of 664,340 births were covered and 7,758 cases with congenital malformations were recorded. Rare autosomal abnormalities were diagnosed in 114 cases (6.6%) from a total of 1,738 chromosome abnormalities. There were a wide variety of autosomal abnormalities: the most common were deletions (33 cases), duplications (32 cases), trisomies of chromosomes 8, 9, 10, 14, 15, and 16 (23 cases), and unbalanced rearrangements (19 cases). Out of these cases, 45.6% were detected prenatally by US examination due to the presence of congenital anomaly. As for the types of chromosomal anomaly, unbalanced rearrangements and deletions were the most frequently detected by US. A high percentage of cases with balanced rearrangements were associated with severe congenital anomalies. The most frequent congenital anomalies detected by US were cystic hygroma (20.6%), central nervous system defects (17.6%), cardiac defects (13.2%), and diaphragm defects (10.3%). This large series offers useful information about prenatal diagnosis by US of congenital defects associated with rare autosomal abnormalities and it provides a valuable knowledge about outcome. Fetal anomalies detected by US that were associated with rare autosomal abnormalities were significantly more frequent than those associated with common chromosomal abnormalities (45.6 vs. 34.7%). This study indicates the need to increase the detection of congenital anomalies by US.

Mothers' knowledge of screening for trisomy 21 in 1999: a survey in Paris maternity units

OBJECTIVE

To assess mothers' knowledge of screening tests for trisomy 21.

STUDY DESIGN

Interview of all women who had recently delivered a healthy child and were present in 15 Paris maternity units during one of the two non-consecutive days in June 1999 (N = 734).

RESULTS

Two-third said that they had access to a nuchal translucency measurement (NTM) and to maternal serum screening (MSS), and 16% to amniocentesis. Thirty-eight percent of the women who had NTMs and 69% of those who had serum screening said that they had been informed of the need for amniocentesis if the results were abnormal. Among the women who had amniocentesis, 20% did not know the risk of miscarriage and 41% had not been informed about the possibility of terminating the pregnancy if trisomy 21 was diagnosed.

CONCLUSIONS

Mothers' knowledge about the screening tests for trisomy 21 remains fragmentary. Providing comprehensive information about all these tests should be considered in early pregnancy so that women can make informed choices.

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.

Counselling following the Prenatal Diagnosis of Klinefelter Syndrome: Comparisons between Geneticists and Obstetricians in Five European Countries

Objective: To describe and compare the information obstetricians and geneticists in five European countries report they would give following the prenatal diagnosis of Klinefelter syndrome. Methods: 388 obstetricians and 269 geneticists from Germany, the Netherlands, Portugal, Spain and the UK completed a brief questionnaire assessing two variables: the information they reported providing to parents following the prenatal diagnosis of Klinefelter syndrome (categorized as positive or negative); and their perceptions of the quality of life with the condition. Results: Geneticists were more likely than obstetricians to report providing more positive than negative information about Klinefelter syndrome than equal amounts of positive and negative information or more negative than positive information about the condition (excess positive information). Regardless of specialty, the information that health professionals reported providing was predicted by their perceptions of the quality of life with the condition, and the country from which they came. Those perceiving quality of life as greater were more likely to provide an excess positive information, as were health professionals from Germany and the UK. Conclusions: These results suggest that the information parents across Europe receive after the prenatal diagnosis of Klinefelter syndrome varies according to the specialty and country of the health professionals consulted, and their perceptions of quality of life with the condition. This variation seems to reflect personal, cultural and professional differences between health professionals. Copyright 2002 S. Karger AG, Basel

[Medical termination of pregnancy for fetal anomaly: the patient's point of view]

OBJECTIVES

To analyze the patient's point of view concerning pregnancy termination for fetal anomaly.

METHODS

A questionnaire concerning the different steps of medical termination of pregnancy was given to 103 women on day 2 after termination.

RESULTS

Most women thought that they were the ones who should make the decision (67%). Complete information prior to the procedure was greatly appreciated (81%). Physical pain remained one of the main concerns for patients given Dilapan. 94% of the women had epidural anesthesia before induction. Various mourning patterns were observed. Only 41% of the women wished to see their baby after termination; there was a correlation with age of pregnancy and social environment. Psychological assistance involved the entire team and a consultation with a pedopsychiatrist (81%). The most painful moment was the moment when breaking the new of the fetal anomaly.

CONCLUSION

The women were very much in need of expressing their sorrow very soon after the event. Team work and lack of rigidity in care taking enhances the expression of individual resources, both by the medical team and the patients. Three points were highlighted by the patients.--the desire to participate in the decision making;--the importance of in-depth information on technical aspects of the procedure;--initial new breaking is recognized as a major trauma.

Current French practices for prenatal diagnosis of trisomy 21: a population-based study in Paris, 1992-97

The results and limitations of current French practices for prenatal diagnosis (PND) of trisomy 21 were examined, using population-based data from the Paris Registry for 1992-97 (219 000 births). Of 670 cases of trisomy 21 reported, 71.0 per cent were terminations of pregnancy (TOP). The PND rate among mothers 38 years and older, all of whom were offered amniocentesis, was 89.9 per cent. Nearly all affected births in this age class followed maternal decisions, either to refuse amniocentesis or continue the affected pregnancy. In younger mothers, the overall French prenatal screening policy (three ultrasound examinations plus serum screening from January 1997) led to an overall PND rate of 67.3 per cent; it reached 78.8 per cent in 1997. Ultrasound accounted for 73.4 per cent of diagnosed cases. Increased detection by nuchal translucency measurement is clearly visible from 1996 onward. The birth prevalence, 8.7 per 10 000 births, diminished only slightly over the study period. The increase observed in the total number of cases in 1996 and 1997, concomitant with PND practice trends, may be due primarily to earlier TOP, which precedes miscarriages that would otherwise have occurred without being recorded. Future trends in prevalence among births must be observed carefully.

Therapeutic drug use during pregnancy: a comparison in four European countries. OECM Working Group. Occupational Exposures and Congenital Anomalies

A drug utilization study was performed using data of the OECM study on Occupational Exposures and Congenital Malformations, which was conducted in six European Registries of Congenital Anomalies (two in France, two in Italy, one in Great Britain, and one in The Netherlands): the mothers were interviewed after delivery for exposures during pregnancy, including use of therapeutic drugs. The analysis of drug use considered only the 1134 control mothers of healthy newborns, and focused on the first trimester of pregnancy: 36.2% of the interviewed mothers used at least one drug (excluding vitamins and minerals) during the first trimester. This rate varied from 22.5% in Glasgow to 50.3% and 44.2% in the French centers. Anti-infectives were the most frequent drugs (12.3% of mothers), then antinauseants (10.6%), and treatments for threatened abortion (5.5%). Important variations between countries were observed, reflecting different medical attitudes towards drug use during pregnancy.

Management of the fetus with a correctable malformation in Paris maternity units: evolution 1985-1994

OBJECTIVE

To analyze the evolution of the management of delivery and neonatal care in a population of children with correctable malformations born in Parisian maternity hospitals during the period 1985-1994.

METHODS

Data were collected by the Paris Registry of Congenital Anomalies from 400,000 births recorded in Parisian maternity hospitals over a 10-year period. Chromosomal anomalies were excluded. The evolution between the first period (1985-1989) and the second (1990-1994) was analyzed for the following indicators in the management of liveborn children: place of delivery; frequency of prenatal diagnosis; transfer to intensive care units, and mortality.

RESULTS

More than 60% of the births of malformed children took place in public maternity hospitals where better management is offered. Most of them were prenatally diagnosed, except for esophageal and anorectal atresia for which the rate of prenatal diagnosis was low. For malformations with poor prognoses (diaphragmatic and abdominal wall anomalies), the rate of deliveries in public maternity hospitals reached about 90%, mostly in those with intensive care units. The evolution between the two periods was characterized by a quicker transfer to intensive care units, during the first day of life for most cases. Lethality during the first day, which was already low during the first period, decreased further. The early neonatal mortality rate decreased for cardiac anomalies, but not significantly. The prognosis remained poor for diaphragmatic anomalies: 49% of liveborn children died during the first week of life.

[Hypoglycemic complications of oral drug therapy of diabetes mellitus. 21 cases]

The authors present 21 cases of severe hypoglycaemic side effects in diabetics treated with oral sulphonylurea drugs, including two deaths. The medications involved the most frequently were glibenclamide followed by glybutamide and glicalzide. Such side effects often occur early and are unrelated to dose. The classical predisposing factors were noted : old age, renal insufficiency, hepato-cellular insufficiency, drug associations -- in particular oral anticoagulants and salicylates. The indications for such drugs in the treatment of diabetes are discussed. Their use seems doubly illogical in the case of late onset obesity diabetes since the latter is accompanied by cardiovascular complications. It is dangerous in the elderly, particularly sensitive to the risks of hypoglycaemia and in who the diagnosis of "diabetes" is too often made on inadequate grounds.