Original article
Congenital hydrocephalus – prevalence, prenatal diagnosis and outcome of pregnancy in four European regions

https://doi.org/10.1016/j.ejpn.2009.03.005Get rights and content

Abstract

Objective

To describe prevalence, prenatal diagnosis and outcome for fetuses and infants with congenital hydrocephalus.

Methods

Data were taken from four European registries of congenital malformations (EUROCAT). The registries included are based on multiple sources of information and include information about livebirths, fetal deaths with GA  20 weeks and terminations of pregnancy for fetal anomaly (TOPFA). All cases from the four registries diagnosed with congenital hydrocephalus and born in the period 1996–2003 were included in the study. Cases with hydrocephalus associated with neural tube defects were not included in the study.

Results

Eighty-seven cases with congenital hydrocephalus were identified during the study period giving an overall prevalence of 4.65 per 10,000 births. There were 41 livebirths (47%), four fetal deaths (5%) and 42 TOPFA (48%). Nine percent of all cases were from a multiple pregnancy. Additional non-cerebral major malformations were diagnosed in 38 cases (44%) and karyotype anomalies in eight cases (9%). Median GA at TOPFA was 21 weeks. Among livebirths 61% were diagnosed prenatally at a median GA of 31 weeks (range 17–40 weeks) and median GA at birth was 37 weeks. Fourteen liveborn infants (34%) died within the first year of life with the majority of deaths during the first week after birth.

Conclusion

Congenital hydrocephalus is a severe congenital malformation often associated with other congenital anomalies. CH is often diagnosed prenatally, although sometimes late in pregnancy. A high proportion of affected pregnancies result in termination for severe fetal anomaly and there is a high mortality in livebirths.

Introduction

Congenital hydrocephalus is characterized by an abnormal accumulation of cerebrospinal fluid (CSF) in the brain.1 In the fetus and the infant the main clinical sign is enlargement of the head although in some cases with cerebral ventriculomegaly the head circumference is within normal limits. The CSF may be under pressure causing compression and damage to the brain. The reason for the accumulation of the CSF is an imbalance between production and absorption of the CSF. The most common causes of congenital hydrocephalus are obstruction of the cerebral aqueduct flow, Arnold Chiari malformation or Dandy–Walker malformation.2

In fetuses and infants the diagnosis of hydrocephalus is usually made following ultrasound scans. With the increasing number and quality of prenatal ultrasound investigations more cases are now diagnosed antenatally. The first prenatal signs of hydrocephalus may be visible on ultrasound around 18–20 weeks of gestation, the “banana sign” though in some cases the hydrocephalus is only visible later in gestation. Parents face difficult decisions on whether to continue or terminate the pregnancy when the diagnosis is made late in the second trimester and information on prognosis related to scan findings is lacking. For optimal counselling data on pregnancy outcome and childhood outcome in liveborn infants with congenital hydrocephalus are needed.

As congenital hydrocephalus is rare and because hydrocephalus also may be acquired after perinatal events (tumours, cerebral bleeding, CNS infections) publications give outcome data on these groups of infants together,3 or include infants with spina bifida4 or cover a long time period in order to have a reasonable number of cases.5 Further published series only give data on liveborn infants referred for surgery.4, 5, 6

The aim of this study is to give the prevalence of congenital hydrocephalus in four European regions using population-based data from European Surveillance of Congenital Anomalies (EUROCAT) and describe prenatal diagnosis, outcome of pregnancy and mortality for the liveborn infants.

Section snippets

Materials and methods

EUROCAT registries are population-based and the geographically defined populations and methods of case ascertainment of EUROCAT are described elsewhere (http://www.eurocat.ulster.ac.uk/memberreg). The registries are based on multiple sources of information such as hospital records, birth and death certificates and post mortem examinations, and include information about livebirths (LB), fetal deaths (FD) with gestational age (GA)  20 weeks and terminations of pregnancy (TOPFA) after prenatal

Results

Fig. 1 shows the total number of cases pre- and postnatally diagnosed with outcome of pregnancy and survival.

Discussion

Our study found a prevalence of CH at 4.65 per 10,000 births. Prevalence of CH (as defined in this study) has previously been reported to be 3.7 per 10,000 births in a Northern Region in the UK 1985–19969 and 8.1 per 10,000 births in Strasbourg, France 1979– 1987.10 In the French study a large proportion of cases (29%) were diagnosed in infancy (after 1 week). As the definition of CH is broad without strict criteria for the size of the ventricles, prevalence may differ between studies. In our

Acknowledgements

The National Perinatal Epidemiology Unit Oxford is funded by the Department of Health in England. The views expressed in this paper are those of the authors and do not necessarily reflect the views of the Department of Health.

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