Different policies on prenatal ultrasound screening programmes and induced abortions explain regional variations in infant mortality with congenital malformations

Screening of congenital heart disease in the second trimester of pregnancy: current knowledge and new perspectives to the clinical practice

OBJECTIVE

Congenital heart diseases are common in foetuses, with an incidence greater than six times that of chromosomal abnormalities; however, experts in cardiac anatomy have evaluated only the foetuses of pregnant women with increased risk for congenital heart disease. Over the years, it has become clear that congenital heart disease occur in foetuses of low-risk women. In the mid-1980s, a proposal to expand the assessment of cardiac anatomy was presented to obstetricians in order to improve prenatal screening. With the aim to systematise and improve the diagnosis of congenital heart disease in foetuses, the International Society of Ultrasound in Obstetrics and Gynecology established an ultrasound heart examination guideline. In this review, we have described the important features of this guideline and discussed the applications of this tool in clinical practice.

METHODS

We performed a literature search of the National Library of Medicine for publications released between 2000 and 2012; we used search terms pertinent to congenital heart disease, such as foetal echocardiography, foetal heart and cardiac screening examination.

RESULTS

The guidelines serve as a standard and help to systematise the screening for congenital heart diseases, but we think that some topics may be added to design the most appropriate screening method. However, we cannot expand the topics to be evaluated in this examination without good training of sonographers who undergo this screening.

CONCLUSION

Although the screening standardisation is a good tool to be used in day-to-day practice, the increment of aortic and ductal archs and colour Doppler to heart screening could be useful to detect further cardiac defects.

Impact of fetal echocardiography

Prenatal diagnosis of congenital heart disease is now well established for a wide range of cardiac anomalies. Diagnosis of congenital heart disease during fetal life not only identifies the cardiac lesion but may also lead to detection of associated abnormalities. This information allows a detailed discussion of the prognosis with parents. For continuing pregnancies, appropriate preparation can be made to optimize the postnatal outcome. Reduced morbidity and mortality, following antenatal diagnosis, has been reported for coarctation of the aorta, hypoplastic left heart syndrome, and transposition of the great arteries. With regard to screening policy, most affected fetuses are in the “low risk” population, emphasizing the importance of appropriate training for those who undertake such obstetric anomaly scans. As a minimum, the four chamber view of the fetal heart should be incorporated into midtrimester anomaly scans, and where feasible, views of the outflow tracts should also be included, to increase the diagnostic yield. Newer screening techniques, such as measurement of nuchal translucency, may contribute to identification of fetuses at high risk for congenital heart disease and prompt referral for detailed cardiac assessment.

[Neonatal and perinatal mortality in hospitals of the Basque Country-Navarre Neonatal Study Group (GEN-VN) during the period 2000-2006]

BACKGROUND

In 2000, the Basque-Navarre Neonatal Study Group (GEN-VN) was created with a clear objective of studying the perinatal and neonatal health outcomes in newborns.

OBJECTIVE

The aim of this investigation is to present the trends of neonatal and perinatal mortality and their causes in the hospitals of the Basque-Navarre Neonatal Study Group from 2000 to 2006.

PATIENTS AND METHOD

A descriptive study was carried out on the 157,623 births in the participating hospitals of the Basque-Navarre Neonatal Study Group, from 2000 to 2006. During this period, of the total births, 156.904 were born alive, there were 719 foetal deaths and 363 newborns died within the first 28 days of life. Perinatal and neonatal mortality was analysed, raw and stratified by gestational age and birth weight.

RESULTS

The Basque -Navarre Neonatal Study Group collects from 80.5% to 96.8% of all the births reported by the authorities. There is a decreasing trend in foetal and perinatal mortality rates from 2000 to 2006. However, neonatal mortality rates shows a stable trend when compared with the descense in the last years of the 20th century. The most frequent causes of death are respiratory, infections and the congenital anomalies.

CONCLUSIONS

Collecting regional data improves the quality of neonatal and perinatal mortality studies. Very low birth weight and very low gestational age newborns require special quality of care due their high mortality (54.8% of neonatal mortality in 2006), therefore further studies are required on the impact of these newborns on neonatal mortality in our hospitals.

Mortality patterns among very preterm babies: a comparative analysis of two European regions in France and England

OBJECTIVE

To explore the differences in outcome of very preterm pregnancies between two geographically defined populations in Europe with similar socioeconomic characteristics and healthcare provision but different organisational arrangements for perinatal care.

DESIGN

Prospective cohort study.

SETTING

Nord Pas-de-Calais (NPC), France, and Trent, UK.

PARTICIPANTS

All pregnancy outcomes 22(+0) to 32(+6) weeks' gestational age for resident mothers.

OUTCOME MEASURES

Mortality patterns (antepartum death, intrapartum death, labour ward death and neonatal unit death) among very preterm babies were analysed by region. Multinomial logistic regression was used to model regional differences for a variety of pregnancy outcomes and to adjust for regional differences in the organisation of perinatal care.

RESULTS

Delivery of very preterm infants was significantly higher in Trent compared with NPC (1.9% v 1.5% of all births, respectively (p<0.001)). Stillbirth rate was significantly higher in NPC than in Trent (23.0%, 95% CI 20.0% to 26.5% v 14.4%, 95% CI 12.3% to 16.6%, respectively (p<0.001)) and survival to discharge was higher in Trent than in NPC (74.6%, 95% CI 71.9% to 77.1% v 66.7%, 95% CI 63.3% to 69.9%, respectively (p<0.001)). Probability of intrapartum and labour ward death in NPC was more than five times higher than Trent (relative risk 5.3, 95% CI 2.2 to 13.1 (p<0.001)).

CONCLUSION

The high rate of very preterm deliveries and the larger proportion of these infants recorded as live born in Trent appear to be the cause of the excess neonatal mortality seen in the routine statistics. Information about very preterm babies (not usually included in routine statistics) is vital to avoid inappropriate interpretation of international perinatal and infant data. This study highlights the importance of including deaths before transfer to neonatal care and emphasises the need to include the outcome of all pregnancies in a population in any comparative analysis.

The impact of multiple pregnancies and malformations on perinatal mortality

AIM

To evaluate the impact of the rate of multiple pregnancies and congenital malformations on perinatal mortality.

METHODS

The study is based on data from the perinatal audit in Vejle County Denmark. Fetal deaths with gestational age > or = 22 weeks and deaths in livebirths within the first 28 days after birth were included in the calculated perinatal mortality. Total number of births was 30,181 and 252 pregnancies and 268 fetuses/infants were evaluated. The study period was 1995-2000. There was no routine ultrasound screening for congenital malformations in the county, though midtrimester ultrasound was used to assess gestational age.

RESULTS

Perinatal mortality was 8.9 per 1000 births with no significant change over time. Rate of multiple pregnancies was 1.94% ranging from 1.81% during the first 3 years to 2.06% for the last 3 years (not significant). Fetuses and infants from multiple pregnancies contributed 18% of all deaths. Perinatal mortality for single births was 7.6 per 1000 births and for multiple births 42.2/1000 (P<0.0001). The distribution of gestational age for single and multiple births was highly significant (P<0.0001) with 67% of multiple pregnancies with GA < 28 weeks compared to 26% of single pregnancies. Nineteen percent of all deaths were caused by congenital malformations and the majority of these were potentially detectable by ultrasound investigation.

CONCLUSIONS

The increasing rate of multiple pregnancies makes it difficult to see improvements in perinatal mortality. Calculated from the perinatal mortality in single and multiple pregnancies in Vejle County assisted conceptions contribute with an an excess of 45 perinatal deaths per year in Denmark. The difference between countries in rate of multiple pregnancies and in prenatal ultrasound screening recommendations for malformations makes it difficult to compare perinatal mortality.