NCARDRS Congenital Anomaly Official Statistics Report, 2020

Amniocentesis
 

Antenatal procedure involving the removal of a sample of amniotic fluid for the purposes of chromosomal or genetic testing.

The period from conception to birth.

Antenatal diagnosis
 

A diagnosis in a pregnancy at any gestation prior to delivery.

Babies is used throughout, from the early stages of pregnancy through to the neonatal period and refers to all pregnancy outcomes; live births, stillbirths, late miscarriages between 20-23 complete weeks and terminations at any gestation.

Birth prevalence of congenital anomalies

The total number of babies diagnosed with a congenital anomaly (live births, stillbirths, late miscarriages, and terminations of pregnancy for fetal anomaly) compared to the total number of births (live births and stillbirths).

Births/total births
 

Live births and stillbirths as recorded by the Office for National Statistics

Case ascertainment

Proportion of notifications of congenital anomalies reported to NCARDRS out of all cases of congenital anomaly in the population.

Chorionic villus sampling (CVS)
 

Antenatal procedure involving the removal of a sample of placental tissue for the purposes of chromosomal or genetic testing.

Confidence interval (see Technical details document for more information)
 

Expresses the uncertainty of a statistic as a range in which the true value would be expected to be found on repeated sampling. Estimates with non-overlapping confidence intervals are considered statistically significantly different.

Congenital anomaly
 

Condition present at delivery, probably originating before birth, and includes structural, chromosomal, genetic, and biochemical anomalies.

Estimated date of delivery (EDD)
 

The estimated delivery date of a pregnancy, calculated as 40 weeks gestation.

EUROCAT
 

European Surveillance of Congenital Anomalies – European network of population-based registries for the epidemiological surveillance of congenital anomalies.

NHS Fetal Anomaly Screening Programme (FASP)

National Health Service (NHS) screening programme for specified structural and chromosomal anomalies during pregnancy using laboratory and/or ultrasound tests.

FASP conditions

The auditable conditions screened under the Fetal Anomaly Screening Programme (FASP).

Anencephaly (Q00*)

Spina bifida (Q05*)

Transposition of great arteries (Q20.3)

Atrioventricular septal defect (Q21.2*)

Tetralogy of Fallot (Q21.3, Q21.82)

Hypoplastic left heart (Q23.4)

Cleft lip +/- palate (Q36*, Q37*)

Bilateral renal agenesis (Q60.1)

Lethal skeletal dysplasia (Q77.0*, Q77.1, Q77.2, Q77.8*, Q78.0*)

Congenital diaphragmatic hernia (Q79.0*)

Exomphalos (Q79.2)

Gastroschisis (Q79.3)

Trisomy 21 (Q90*)

Trisomy 18 (Q91*)

 Trisomy 13 (Q91*)

Fetal medicine 

Sub-speciality of antenatal care focused on high-risk pregnancies including those affected by a congenital anomaly.

Feticide

A procedure to stop the fetal heart and cause the demise of the fetus in the uterus as defined by the Royal College of Obstetricians and Gynaecologists.

Full karyotype

Visual inspection of all chromosomes down the microscope, enabling assessment of chromosome number and integrity.

Genetic anomalies

Includes genetic syndromes, hereditary skin disorders, skeletal dysplasias and chromosomal anomalies as defined by EUROCAT.

Hospital Episode Statistics (HES)
 

Database of all admissions, Accident and Emergency attendances, procedures, and outpatient appointments at NHS hospitals in England.

Infant deaths

Deaths from birth to under 1 year of age as recorded by Child and infant mortality data from the ONS

Infant mortality

The number of infant deaths per 10,000 live births.

Invasive testing
 

Antenatal tests including amniocentesis and chorionic villus sampling used to diagnose chromosomal and genetic anomalies. In these tests, a needle is inserted directly into the uterus to take a sample.

Late miscarriage
 

Late fetal deaths from 20 to 23 completed weeks of gestation.

Live birth

A baby showing signs of life at birth as recorded by the Office for National Statistics

Live birth prevalence

The total number of babies diagnosed with a congenital anomaly that are live born compared to the total number of live births.

Major congenital anomaly subgroup (see Technical Guidance document for more information on these subgroups)

The high-level body system and anomaly type groupings of congenital anomalies as defined by the NCARDRS modified version of EUROCAT’s subgroups.

Mother

The term mother is used throughout to refers to anyone who has become pregnant, regardless of the outcome of pregnancy.

Non-genetic anomalies
 

Includes anomalies with no known genetic cause. Not all babies undergo genetic testing, so it is likely that some of these anomalies are of genetic origin.

Non-invasive prenatal testing (NIPT)

Screening test for specific chromosomal disorders by testing fragments of fetal DNA found in the maternal blood stream.

Office for National Statistics (ONS)

Body responsible for collection and production of statistics related to the economy, population, and society of the UK.

Outcome of pregnancy
 

Outcome of the end of the pregnancy, as distinct to the civil registerable nature of the birth. Stillbirths or live births that have been preceded by a termination procedure are categorised in this report as a termination

Palliative care
 

Medical care for a condition focusing on relief of symptoms rather than treating the underlying condition.

Partial trisomy
 

Extra genetic material is present, but only from part of the chromosome, not the entire chromosome. For the first time, to ensure consistency throughout the report and internationally, partial trisomies are also included in the trisomy groups for prevalence reporting.

Perinatal deaths
 

Stillbirths and deaths under 7 days of age as recorded by the Office for National Statistics.

Perinatal mortality

The number of perinatal deaths per 10,000 total births.

Post-neonatal period

From 28 days of life to 1 year of age.

Rapid aneuploidy testing
 

A genetic test with a short turnaround time; it counts the copy number of specific regions on chromosomes 13, 18, 21, X and Y.

Rare diseases

Non-cancerous, usually non-infectious diseases that affect <1:2000 in the population at risk with an Orphanet Rare Disease classification.

Severe congenital heart disease (CHD)

This includes the following congenital heart anomalies:

Common arterial truncus

Transposition of great vessels

Single ventricle

Atrioventricular septal defect

Tetralogy of Fallot

Tricuspid atresia and stenosis

Ebstein’s anomaly

Pulmonary valve atresia

Aortic valve atresia/stenosis

Hypoplastic left heart

Hypoplastic right heart

Coarctation of aorta

Total anomalous pulmonary venous return

Stillbirths

A baby born after 24 or more completed weeks of gestation and which did not, at any time, breathe or show signs of life as recorded by the Office for National Statistics.

Teratogen

Substance or other factor that can cause congenital anomaly by affecting fetal development.

Termination of pregnancy

Term used to describe the deliberate ending of a pregnancy with the intention that the fetus will not survive.

This includes terminations of pregnancy for fetal anomaly (TOPFA) as well as terminations of pregnancy for other medical reasons where a fetal anomaly was present.

Where a pregnancy ends in a termination, the baby may be born dead, or if parents have not opted for prior feticide, the baby may be born alive but die shortly after. Depending on the gestation at which a termination takes place (before or after 24 weeks), it may [(GM1] instead be registered as a stillbirth.

Tertiary service

A hospital which provides specialist care following referral from a local provider, this may include antenatal or postnatal specialities.

Trisomy

Trisomy is a condition that results in an extra copy of a chromosome in all or some of an individual’s cells. Down’s syndrome (Trisomy 21), Edwards syndrome (Trisomy 18) and Patau syndrome (Trisomy 13) are the most common forms of trisomy associated with pregnancies that can progress to full term.

Total births

Total number of live births and stillbirths.