Risk of adverse pregnancy outcome in isolated single umbilical artery diagnosed at the mid-trimester anomaly scan: a large Danish retrospective cohort study

OBJECTIVE

To examine the association of isolated single umbilical artery (iSUA) confirmed at the mid-trimester anomaly scan and adverse pregnancy outcome and congenital malformations with up to 10 years postnatal follow up.

METHODS

This retrospective cohort study included 116,501 singleton pregnancies consecutively enrolled in first trimester screening for aneuploidies and mid-trimester anomaly scan at three University Hospitals in the Capital Region of Copenhagen, Denmark.Data from the Danish Fetal Medicine Database (2008-2017) were verified by manually scrutinizing pre- and postnatal records. The main outcomes of interest were intrauterine fetal demise (IUFD), small for gestational age (SGA), preterm delivery, cesarean section and unrecognized pre- and postnatal congenital malformations.

RESULTS

In total, 775 pregnancies with iSUA were identified. Isolated SUA were associated with a significantly increased risk of IUFD (OR 4.16, 95% CI 2.06-8.44), SGA < 3^rd centile (aOR 2.41, 95% 1.85-3.14) and SGA < 10^th centile (aOR 1.84, 95% CI 1.53-2.21), but not with preterm delivery or cesarean section. The laterality of the missing artery was not associated with SGA. In total, 4.3% of pregnancies with iSUA had unrecognized congenital malformations. 1.5% with iSUA had congenital cardiovascular malformations, which were considered minor.

CONCLUSION

Isolated SUA is associated with IUFD and SGA, supporting surveillance during third trimester. If, during the mid-trimester scan, the sonographer achieves thorough, extended cardiac views and finds no additional malformation other than SUA, fetal echocardiography seems not to be needed.

Gestational weight gain in women with pre-pregnancy overweight or obesity and anthropometry of infants at birth

Objective

To examine the association of gestational weight gain (GWG) among women with pre-pregnancy overweight or obesity with infant weight and BMI z-score at birth.

Methods

This study is a secondary analysis of a randomized controlled trial including data from 208 infants at birth born by mothers with pre-pregnancy BMI between 28 and 45 kg/m² who completed the APPROACH study (randomized to a high-protein low-glycemic index diet or a moderate-protein moderate-glycemic index diet). This analysis pooled the two diet treatment groups together and data were analyzed using a linear mixed model.

Results

Limiting GWG by 1 kg was associated with lower birthweight (-16 g, P = 0.003), BMI z-score (-0.03SD, P = 0.019), weight z-score (-0.03SD, P = 0.004), and infant abdominal circumference (-0.06 cm, P = 0.039). Infants born by mothers whose GWG was ≤9 kg weighed less (122 g, 95% CI: 6-249, P = 0.040), had similar BMI z-score (0.2SD, 95% CI: -0.06 to 0.55, P = 0.120), and lower incidence of emergency cesarean deliveries (11.5% vs. 23.1%, P = 0.044) compared to infants born by mothers whose GWG was >9 kg. When women were classified into GWG quartiles, women in Q1 (GWG range: -7.0 to 3.2 kg) gave birth to smaller infants (3,420 g, P = 0.015) with lower BMI z-score (-0.5SD, P = 0.041) than women in Q2 (3.3-7.1 kg), Q3 (7.2-10.9 kg) and Q4 (11.1-30.2 kg).

Conclusions

Limiting GWG among women with pre-pregnancy overweight or obesity was associated with lower infant weight, BMI z-score, weight z-score, and abdominal circumference at birth. Moreover, GWG below the Institute of Medicine guideline of a maximum of 9 kg was associated with lower birthweight and fewer emergency cesarean deliveries.

A high-protein low-glycemic index diet attenuates gestational weight gain in pregnant women with obesity: the "An optimized programming of healthy children" (APPROACH) randomized controlled trial

BACKGROUND

Prepregnancy overweight and excessive gestational weight gain (GWG) increase the risk of complications and offspring obesity.

OBJECTIVES

We aimed to investigate the effect of a high-protein low-glycemic index (HPLGI) diet on GWG, birth weight, and risk of gestational complications in pregnant women with obesity.

METHODS

A total of 279 women with prepregnancy overweight or obesity (BMI: 28-45 kg/m2), between 18 and 45 y old, and in their late first trimester with singleton pregnancies, were randomly assigned to 1 of 2 ad libitum diets: a high-protein low-glycemic index diet (HPLGI: 25%-28% of energy from protein and glycemic index ≤ 55) and a moderate-protein moderate-glycemic index diet (MPMGI: 15%-18% of energy from protein and glycemic index ∼60). Diets were consumed from gestational week 15 and throughout pregnancy. Participants received dietary guidance by a clinical dietician 9 times to facilitate adherence.

RESULTS

Out of 141 and 138 women randomly assigned to the HPLGI and MPMGI diets, 105 and 104 completed the intervention, respectively (75%). In the available case analyses, GWG was 6.8 ± 1.3 kg among women assigned the HPLGI diet and this was significantly lower, by -1.7 kg (95% CI: -2.8, -0.5 kg; P = 0.004), than the GWG of 8.5 ± 1.3 kg among women assigned the MPMGI diet. There were no significant differences between diets on major neonatal outcomes (birth weight and other anthropometric measures). The incidence of composite pregnancy complications was lower for the HPLGI than for the MPMGI diet (35.4% compared with 53.7%, respectively; P = 0.009), including cesarean delivery (15.4% compared with 28.8%, respectively; P = 0.03). There were no reported maternal, fetal, or neonatal deaths. Incidence of miscarriages (1%-2%) did not differ between groups.

CONCLUSIONS

A moderate increase in dietary protein in conjunction with a reduction in glycemic index during the last 2 trimesters of pregnancy reduced GWG and limited complications and cesarean deliveries among women with overweight or obesity.

Prenatal cardiac biometry and flow assessment in fetuses with bicuspid aortic valve at 20 weeks' gestation: multicenter cohort study

OBJECTIVE

To investigate prenatal changes in cardiac biometric and flow parameters in fetuses with bicuspid aortic valve (BAV) diagnosed neonatally compared with controls with normal cardiac anatomy.

METHODS

This analysis was conducted as part of the Copenhagen Baby Heart Study, a multicenter cohort study of 25 556 neonates that underwent second-trimester anomaly scan at 18 + 0 to 22 + 6 weeks' gestation and neonatal echocardiography within 4 weeks after birth, in Copenhagen University Hospital Herlev, Hvidovre Hospital and Rigshospitalet in greater Copenhagen, between April 2016 and October 2018. From February 2017 (Rigshospitalet) and September 2017 (Herlev and Hvidovre hospitals), the protocol for second-trimester screening of the heart was extended to include evaluation of the four-chamber view, with assessment of flow across the atrioventricular valves, sagittal view of the aortic arch and midumbilical artery and ductus venosus pulsatility indices. All images were evaluated by two investigators, and cardiac biometric and flow parameters were measured and compared between cases with BAV and controls. All cases with neonatal BAV were assessed by a specialist. Maternal characteristics and first- and second-trimester biomarkers were also compared between the two groups.

RESULTS

Fifty-five infants with BAV and 8316 controls with normal cardiac anatomy were identified during the study period and assessed using the extended prenatal cardiac imaging protocol. There were three times as many mothers who smoked before pregnancy in the group with BAV as in the control group (9.1% vs 2.7%; P = 0.003). All other baseline characteristics were similar between the two groups. Fetuses with BAV, compared with controls, had a significantly larger diameter of the aorta at the level of the aortic valve (3.1 mm vs 3.0 mm (mean difference, 0.12 mm (95% CI, 0.03-0.21 mm))) and the pulmonary artery at the level of the pulmonary valve (4.1 mm vs 3.9 mm (mean difference, 0.15 mm (95% CI, 0.03-0.28 mm))). Following conversion of the diameter measurements of the aorta and pulmonary artery to Z-scores and Bonferroni correction, the differences between the two groups were no longer statistically significant. Pregnancy-associated plasma protein-A (PAPP-A) multiples of the median (MoM) was significantly lower in the BAV group than in the control group (0.85 vs 1.03; P = 0.04).

CONCLUSIONS

Our findings suggest that fetuses with BAV may have a larger aortic diameter at the level of the aortic valve, measured in the left-ventricular-outflow-tract view, and a larger pulmonary artery diameter at the level of the pulmonary valve, measured in the three-vessel view, at 20 weeks' gestation. Moreover, we found an association of maternal smoking and low PAPP-A MoM with BAV. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Prevalence of Bicuspid Aortic Valve and Associated Aortopathy in Newborns in Copenhagen, Denmark

IMPORTANCE

The prevalence and characteristics of bicuspid aortic valve (BAV) are mainly reported from selected cohorts. BAV is associated with aortopathy, but it is unclear if it represents a fetal developmental defect or is secondary to abnormal valve dynamics.

OBJECTIVE

To determine the prevalence of BAV and BAV subtypes and to describe the associated aortopathy in a large, population-based cohort of newborns.

DESIGN, SETTING, AND PARTICIPANTS

The Copenhagen Baby Heart Study was a cross-sectional, population-based study open to all newborns born in Copenhagen between April 1, 2016, and October 31, 2018. Newborns with BAV were matched 1:2 to newborns with a tricuspid aortic valve (non-BAV group) on sex, singleton/twin pregnancy, gestational age, weight, and age at time of examination.

EXPOSURES

Transthoracic echocardiography within 60 days after birth.

MAIN OUTCOMES AND MEASURES

Primary outcome was BAV prevalence and types, ie, number of raphes and spatial orientation of raphes or cusps (no raphes), according to the classification system of Sievers and Schmidtke (classified as type 0, 1, or 2, with numbers indicating the number of raphes). Secondary outcome was valve function and BAV-associated aortopathy, defined as aortic diameter z score of 3 or greater or coarctation.

RESULTS

In total, 25 556 newborns (51.7% male; mean age, 12 [SD, 8] days) underwent echocardiography. BAV was diagnosed in 196 newborns (prevalence, 0.77% [95% CI, 0.67%-0.88%]), with male-female ratio 2.1:1. BAV was classified as type 0 in 17 newborns (8.7% [95% CI, 5.5%-13.5%]), type 1 in 178 (90.8% [95% CI, 86.0%-94.1%]) (147 [75.0% {95% CI, 68.5%-80.5%}] right-left coronary raphe, 27 [13.8% {95% CI, 9.6%-19.3%}] right coronary-noncoronary raphe, 4 [2.0% {95% CI, 0.8%-5.1%}] left coronary-noncoronary raphe), and type 2 in 1 (0.5% [95% CI, 0.1%-2.8%]). Aortic regurgitation was more prevalent in newborns with BAV (n = 29 [14.7%]) than in those without BAV (1.3%) (absolute % difference, 13.4% [95% CI, 7.8%-18.9%]; P < .001). Newborns with BAV had higher flow velocities across the valve (0.67 [95% CI, 0.65-0.69] m/s vs 0.61 [95% CI, 0.60-0.62] m/s; mean difference, 0.06 m/s [95% CI, 0-0.1]) and larger aortic root and tubular ascending aortic diameters than those without BAV (10.7 [95% CI, 10.7-10.9] mm vs 10.3 [95% CI, 10.2-10.4] mm; mean difference, 0.43 mm [95% CI, 0.2-0.6 mm] and 9.8 [95% CI, 9.6-10.0] mm vs 9.4 [95% CI, 9.3-9.5] mm; mean difference, 0.46 mm [95% CI, 0.30-0.70], respectively) (P < .001 for all). Aortopathy was seen in 65 newborns (33.2%) with BAV (62 with aortic z score ≥3; 3 with coarctation).

CONCLUSIONS AND RELEVANCE

Among newborns in Copenhagen, the prevalence of BAV was 0.77%. Aortopathy was common in newborns with BAV, suggesting that it also represents a fetal malformation.

Why we succeed and fail in detecting fetal growth restriction: A population-based study

INTRODUCTION

The objective of this study was to explore the association between detection of fetal growth restriction and maternal-, healthcare provider- and organizational factors.

MATERIAL AND METHODS

A historical, observational, multicentre study. All women who gave birth to a child with a birthweight <2.3rd centile from 1 September 2012 to 31 August 2015 in Zealand, Denmark, were included. The population was identified through the Danish Fetal Medicine Database. Medical charts were reviewed to obtain data regarding maternal characteristics and information on the healthcare professionals. Date of authorization for the midwives and obstetricians involved was extracted from the Danish Health Authorization Registry. Multivariable Cox regression models were used to identify predictors of antenatal detection of fetal growth restriction, and analyses were adjusted for hospital, body mass index, parity, the presence of at least one risk factor and experience of the first midwife, number of midwife visits, number of visits to a doctor, the experience of the consultant midwife or the educational level of the doctor, the number of scans and gaps in continuity of midwife-care. Antenatal detection was defined as an ultrasound estimated fetal weight <2.3rd centile (corresponding to -2 standard deviations) prior to delivery.

RESULTS

Among 78 544 pregnancies, 3069 (3.9%) had a fetal growth restriction. Detection occurred in 31% of fetal growth-restricted pregnancies. Clinical experience (defined as years since graduation) of the first consultation midwife was positively associated with detection, with a hazard ratio [HR] of 1.15, 95% confidence interval [CI] 1.03-1.28), for every 10 years of additional experience. The hazard of detection increased with the number of midwife consultations (HR 1.15, 95% CI 1.05-1.26) and with multiparity (HR 1.28, 95% CI 1.03-1.58). After adjusting for all covariates, an unexplained difference between hospitals (P = .01) remained.

CONCLUSIONS

The low-risk nullipara may constitute an overlooked group of women at increased risk of antenatal non-detection of fetal growth restriction. Being screened by experienced midwives during early pregnancy and having access to multiple midwife consultations may improve future diagnosis.

Neonatal complications and neurophysiological development in twins - a long-term follow-up study

Objectives: To investigate the association between neonatal complications and neurophysiological development in twins at 18 and 48-60 months of age.Methods: This was a secondary analysis of 841 Danish mono- and dichorionic diamniotic twins from a randomized controlled trial (PREDICT study), which included an assessment of the twin's neurophysiological development using the Ages and Stages Questionnaire (ASQ) that had been filled out by the parents at 18 and 48 or 60 months. The correlation within twin pairs was accounted for by the method of generalized estimating equation. Models were adjusted for maternal educational score and gestational age at delivery.Results: ASQ data were available for 823 children at 18 months and 425 children at 48 or 60 months. Low maternal educational score and preterm delivery <34 weeks were associated with a lower ASQ score at 48-60 months (-15.4 points (95%CI -26.4; -4.5) and -13.2 points (95%CI -23.8; -2.5), respectively). Neonatal sepsis and a compound of intraventricular hemorrhage, retinopathy of prematurity and necrotizing enterocolitis (IVH/ROP/NEC) were associated with lower ASQ score at 18 months (-15.3 points (95%CI -28.1; -2.5) and -30.8 points (95%CI -59.5; -2.1), respectively). Children with IVH/ROP/NEC had a lower ASQ score at 48-60 months (-34.2 points (95%CI -67.9; -0.6)). The associations were not specific to only one ASQ domain.Conclusion: Several neonatal complications are associated with poorer neurophysiological development in twins during childhood, even after adjustment for gestational age at delivery.

Outcomes of monoamniotic twin pregnancies managed primarily in outpatient care-a Danish multicenter study

INTRODUCTION

Monoamniotic twin pregnancies are high-risk pregnancies, and management by inpatient or frequent outpatient care is recommended. We report the outcomes of a national cohort of monoamniotic twin pregnancies managed primarily as outpatients.

MATERIAL AND METHODS

We prospectively analyzed the recorded data from the Danish Fetal Medicine Database, local databases, and medical records of all monoamniotic twin pregnancies diagnosed at the first trimester scan or later, and managed at the six major fetal medicine centers in Denmark over a 10-year period.

RESULTS

Sixty-one monoamniotic twin pregnancies were included. Thirteen pregnancies were terminated early. Of the remaining 48 pregnancies with a normal first trimester scan, there were 36 fetal losses (25 spontaneous miscarriages <22⁺⁰  weeks, 3 late terminations and 8 intrauterine deaths >22 weeks) and 60 liveborn children (62.5%), all of whom were delivered by cesarean delivery at a median gestational age of 33⁺⁰  weeks. Three children had minor malformations and there was 1 pregnancy with twin-to-twin transfusion syndrome. After 26⁺⁰  weeks, 78.8% were managed as outpatients. Intrauterine death occurred in 3.8% of outpatients and in 28.6% of inpatients (admitted due to complications). At weeks 32, 33 and 34, the prospective risk of intrauterine death was 6.9%, 4.2% and 5.9%, respectively.

CONCLUSION

In this nationwide, unselected population, only 62.5% of fetuses with a normal first trimester scan were born alive. In contrast, the mortality was 3.8% after 26 weeks among the 78.8% of the cohort that was managed as outpatients. More knowledge is still needed to predict which pregnancies are at the highest risk of intrauterine death.

[Heterotopic pregnancy following in vitro fertilization with excision of ruptured cornual pregnancy and eventually caesarean section close to term]

We describe a rare case of heterotopic pregnancy following in vitro fertilization with transferring of two embryos in a 39-year-old woman with previous bilateral salpingectomy. An ultrasound examination was performed on the day before admission showing a vital intrauterine pregnancy and no ectopic pregnancy. The woman was admitted with a ruptured cornual pregnancy at ten weeks of gestation. Laparotomy was performed on vital indication with excision of the ruptured haemorrhagic cornual pregnancy. The intrauterine pregnancy continued uneventfully with obstetric and fetal medicine specialist monitoring. A healthy boy was delivered by elective caesarean section.

Long-term effects of prenatal progesterone exposure: neurophysiological development and hospital admissions in twins up to 8 years of age

OBJECTIVES

To perform a neurophysiological follow-up at 48 or 60 months of age in children exposed prenatally to progesterone compared with a placebo and evaluate their medical histories up to 8 years of age.

METHODS

In this study, Danish participants of the PREDICT study, including 989 surviving children from 498 twin pregnancies, were followed-up. PREDICT was a placebo-controlled randomized clinical trial examining the effect of progesterone for prevention of preterm delivery in unselected twin pregnancies. Medical histories of the children were reviewed and neurophysiological development was evaluated by the parent-completed Ages and Stages Questionnaire (ASQ) at either 48 or 60 months after the estimated date of delivery. We used the method of generalized estimating equation to account for the correlation within twins.

RESULTS

A total of 492 children had been exposed prenatally to progesterone and 497 to placebo. There was no difference in the number of admissions to or length of stay in hospital between the treatment groups, and we found no overall difference in the rates of diagnoses made. However, the odds ratios (ORs) for a diagnosis concerning the heart was 1.66 (95% CI, 0.81-3.37), favoring placebo, among all children, 2.38 (95% CI, 1.07-5.30) in dichorionic twins and 8.19 (95% CI, 1.02-65.6) in all children when excluding diagnoses made at outpatient clinic visits. ASQ scores were available for 437 children (progesterone, n = 225; placebo, n = 212). Mean ASQ score was slightly higher in the progesterone group compared with the placebo group (P = 0.03). In dichorionic twins, the risk of having a low ASQ score (< 10(th) centile) was decreased in the progesterone group (OR, 0.34 (95% CI, 0.14-0.86)).

CONCLUSION

Second- and third-trimester exposure of the fetus to progesterone does not seem to have long-term harmful effects during childhood, but future studies should focus on cardiac disease in the child. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Prenatal detection of congenital heart disease in a low risk population undergoing first and second trimester screening

OBJECTIVES

The prenatal detection rate of congenital heart disease (CHD) is low compared with other fetal malformations. Our aim was to evaluate the prenatal detection of CHD in Eastern Denmark.

METHODS

Fetuses and infants diagnosed with CHD in the period 01.01.2008-31.12.2010 were assessed regarding prenatal detection rate and accuracy, as well as correlation with nuchal translucency (NT) thickness.

RESULTS

Out of 86 121 infants, 831 were born with CHD (0.96%). The prenatal detection rate of 'all CHD' was 21.3%, of 'Major CHD' 47.4%. Full agreement between prenatal and postnatal/autopsy findings was found in 96% of prenatally detected diagnoses. An NT thickness >95(th) percentile was found in 15.0% fetuses with 'Major CHD'. Of 'Major CHDs' detected prenatally, 77% were picked up at the time of the malformation scan at weeks 18-21.

CONCLUSIONS

Nearly half of 'Major CHDs' were detected prenatally. The prenatal cardiac diagnoses showed a high degree of accuracy. Increased NT thickness as a screening tool for CHD performed moderately but is an important high risk group for specialist examination. A minority of the prenatally detected CHDs was identified because of extra scans performed in high risk pregnancies. © 2014 John Wiley & Sons, Ltd.

Use of 'non-medical' ultrasound imaging before mid-pregnancy in Copenhagen

We have investigated prospectively how many pregnant women purchase ultrasound imaging before week 20, why they purchase scans, and which professional skills and certifications women expect the person performing the scan to have. In addition, we wanted to investigate whether the women were aware of any professional authorization procedures. Women attending the second trimester malformation scan of the Danish Prenatal Screening Program (n = 645) filled in a questionnaire about their use of non-medical ultrasound scans. Of these women, 154 (24%) had bought ultrasound scans: 50% wanted to have the fetal health and development checked and 49% wanted to find out the gender of the fetus. In addition, 68% felt that they received an evaluation of the fetal health state and 58% believed that there was legislation demanding a professional authorization needed to perform ultrasound imaging. This study shows that there is a significant demand among pregnant women for commercial ultrasound imaging of their fetus for various reasons. Knowledge of certifications and requirements for legal authorization is, however, sparse.

[A rare form of twin-twin transfusion syndrome]

Twin anaemia-polycythaemia sequence (TAPS) is a rare form of feto-fetal transfusion between monochorionic twins. It occurs spontaneously or after laser surgery for twin-twin transfusion syndrome. TAPS is characterized by a large inter-twin haemoglobin difference and can be detected both ante- and postnatally. This is a case report of TAPS, detected antenatally by a routine scanning of monochorionic twins in gestational week 29.

Increased nuchal translucency, normal karyotype and infant development

OBJECTIVE

To investigate whether chromosomally normal fetuses with a nuchal translucency (NT) ≥ 99th percentile(3.5 mm) in the first trimester have an increased risk of delayed development at 2 years of age.

METHODS

The study included children of women from 10 Danish hospitals who had fetal NT either ≥ 99th percentile (Group 1) or <95th percentile (Group 2) in the first trimester. The groups were matched by gender,gestational age at birth and maternal age. There were twice as many children in Group 2 as in Group 1. Follow-up was conducted at 2 years of age, infant development being assessed by the 'Ages and Stages Questionnaire'. The cutoff value for delayed development was defined as the 5th percentile from the first 100 questionnaires from Group 2.

RESULTS

In a 1-year period 202 of 33 266 fetuses (0.6%)had NT ≥ 3.5 mm. Of these, 99 (49.0%) were liveborn with normal karyotype and normal ultrasound findings during pregnancy. The response rate to the ASQ was 83.3% in Group 1 and 71.4% in Group 2. A low ASQ score was found in 1.3% (1/80) and 4.4% (6/137)in Groups 1 and 2, respectively (P = 0.265), but no difference was found in the mean ASQ score between the two groups (P = 0.160).

CONCLUSION

Fetuses with NT ≥ 99th percentile, normal karyotype and normal ultrasound findings during pregnancy had no increased risk of developmental delay at 2 years of age compared with fetuses with normal NT(<95th percentile).

Influence of chorionicity on perinatal outcome in a large cohort of Danish twin pregnancies

OBJECTIVE

To assess outcome in twin pregnancies according to chorionicity.

METHODS

A cohort was retrieved from local ultrasound databases at 14 obstetric departments in Denmark, comprising all twin pregnancies with two live fetuses scanned between weeks 11 and 14 in the period 1 January 2004 to 31 December 2006. Outcome data were retrieved from the National Board of Health.

RESULTS

Among 2038 twin pregnancies, 1757 (86.2%) were dichorionic (DC) and 281 (13.8%) were monochorionic diamniotic (MC). In MC pregnancies, the rate of spontaneous fetal loss in both second and third trimesters was more than threefold higher than the comparable rate in DC pregnancies: 6.0% vs. 1.9% for at least one fetus in the second trimester (P < 0.001) and 2.1% vs. 0.7% in the third trimester (P = 0.03). In 98.4% of DC pregnancies and in 91.1% of MC pregnancies, at least one infant was liveborn. Amongst pregnancies with two live fetuses at 24 weeks, the proportion with two live infants at 28 days after delivery was 97.5% and 95.1%, respectively.

CONCLUSIONS

The increased incidence of fetal loss in MC pregnancies compared with DC pregnancies predominantly occurs before 24 weeks' gestation. After this stage, although the risk of intrauterine fetal death is still higher in MC than in DC pregnancies, if both fetuses are alive at 24 weeks, the chance of a woman having two live infants 1 month after delivery is similar in MC and DC pregnancies.

[Down's syndrome risk assessment in Denmark--secondary publication]

In 2004 The Danish National Board of Health introduced a new guideline regarding prenatal screening. All pregnant women are now offered a Down's syndrome risk assessment. The new guideline has had an impact on the number of invasive early prenatal procedures. The number of procedures fell by 50% from 2000 to 2006. 90% of the foetuses with Down's syndrome are detected prenatally. Denmark is one of the first countries in the world in which risk assessment for Down's syndrome has been successfully implemented at a national level.

[Prenatal diagnosis of chromosome aberrations after implementation of screening for Down's syndrome]

INTRODUCTION

First trimester screening for Down's syndrome was evaluated by the National Board of Health in 2004, and recommended to all pregnant women in the form of an informed choice. We have reviewed prenatal and postnatal chromosome aberrations in 3 counties in Denmark during the years of implementation in 2004, 2005 and 2006.

MATERIALS AND METHODS

Risk evaluation based on combined screening (fetal nuchal translucency measurement and serum screening of the pregnant woman) was introduced in the counties of Copenhagen, Roskilde and Storstrom, covering approximately 1.1 million inhabitants. We registered the number of chorionic villus biopsies (CVS) and amniocenteses (AC), as well as the number of cases with trisomy, triploidy and sex chromosome aberrations found prenatally. We also registered the number of children born with Down's syndrome during the period.

RESULTS

The number of CVS/AC decreased from 1382 to 790, or 40%. There was an increase in the number of foetuses diagnosed with trisomy 21: in 2004 trisomy 21 was diagnosed in 12 foetuses, in 2006 the number was 30. The number of children born with Down's syndrome was 10 and 5 in 2004 and 2006, respectively. National figures from the Danish central cytogenetic registry confirm a decrease in children born with Down's syndrome.

CONCLUSION

The implementation of combined screening in 3 counties resulted in a reduction in invasive procedures (chorionic villus samples and amniocenteses) by 40%, which is in accordance with the aims of the National Board of Health. As expected, a significant increase in the number of prenatally diagnosed foetuses with trisomy 21 was observed. The number of children born with Down's syndrome decreased, but the numbers are small. The investigation does not review aspects of organisation or counselling and psychosocial issues.