Eur J Pediatr https://doi.org/10.1007/s00431-017-3031-8
ORIGINAL ARTICLE
Screening investigations in small-for-gestational-age near-term and term infants Mohan B. Krishnamurthy 1 & Abigail Popiel 2 & Atul Malhotra 1,3,4
Received: 28 August 2017 / Revised: 3 October 2017 / Accepted: 4 October 2017 # Springer-Verlag GmbH Germany 2017
Abstract The aims of this study are to examine how frequently near-term and term small-for-gestational-age (SGA) infants were investigated in our clinical practice, whether being born less than the third centile for weight increased the yield of positive investigations, and whether there were additional characteristics in infants with positive investigations. This retrospective cohort study was compiled using a database of a large maternity network, using the search near term and term gestational age (greater than or equal to 35 weeks) over a span of 4 years. SGA babies were further filtered into less than the tenth centile and third centile. Out of a population of 30,461 infants in the study period, 3437 (11.3%) SGA infants were identified. Four hundred fifteen SGA infants (12.1%) underwent screening investigations, of which 49 infants (11.8%) yielded a positive investigation. 27.2% of karyotypes, 12.8% of cranial ultrasounds and 0.4% of urine CMV tests showed positive results in < 10th centile group. Being born less than the third centile for weight did not increase the yield
of positive investigations. Most infants with positive investigations had an additional maternal or neonatal characteristic or risk factor present. Conclusion: SGA babies without additional maternal or neonatal characteristics have a poor yield on neonatal screening investigations. Additional characteristics may be considered while deciding whether a SGA infant needs screening investigation. What is Known: • Small-for-gestational-age (SGA) infants have an increased risk of shortand long-term complications. • Whilst the causes for SGA are multifactorial, there has been a tendency to undertake screening investigations like Toxoplasma, Others, Rubella, Cytomegalovirus, Herpes group of viruses (TORCH) screening and cranial ultrasounds in the neonatal period. What is New: • Comprehensive study investigating the rates of screening in near-term and term SGA population. • The yield of screening tests for near-term and term SGA infants without additional antenatal and postnatal characteristics is low.
Communicated by Patrick Van Reempts * Atul Malhotra [email protected] Mohan B. Krishnamurthy [email protected] Abigail Popiel [email protected] 1
Monash Newborn, Monash Children’s Hospital, Melbourne, Australia
2
Monash University, Melbourne, Australia
3
Department of Paediatrics, Monash University, Melbourne, Australia
4
Monash Newborn, Monash Children’s Hospital, 246 Clayton Road, Clayton, VIC 3168, Australia
Keywords IUGR . Cranial ultrasound . Karyotype . Cytomegalovirus Abbreviations AGA Appropriate for gestational age BMI Body mass index BOS Birthing outcome summary CMV Cytomegalovirus CTG Cardiotocography HIE Hypoxic ischaemic encephalopathy HSV Herpes simplex virus IUGR Intrauterine growth restriction IVH Intraventricular haemorrhage
Eur J Pediatr
NICU PCR SCN SGA TORCH USG
Neonatal intensive care unit Polymerase chain reaction Special care nursery Small for gestational age Toxoplasma, others, rubella, cytomegalovirus, herpes virus Ultrasonograph
Introduction The term small-for-gestational-age (SGA) is applied to any neonate with birth weight below the tenth centile for their corresponding gestational age [2]. SGA babies comprise both term and preterm babies [1]. There is considerable variation in the prevalence of infants born SGA ranging between 4 and 15% across Europe [11], around 5% in Australasia [4], 5–41% (term SGA) and 1–3% (preterm SGA) in developing countries [3, 14]. The terms IUGR and SGA are often used interchangeably incorrectly; an SGA baby may not necessarily be growth restricted in utero, while an intrauterine growth restriction (IUGR) baby may be of normal weight for their gestational age. However, both IUGR and SGA babies have higher morbidity and mortality compared to that of appropriate-forgestational-age (AGA) babies, with neonatal, childhood, and long-term complications [6]. The likelihood of stillbirth (8.8 vs. 2.5 per 1000 births) and neonatal mortality (14.0 vs. 5.5 per 1000 births) in SGA infants has been noted to be threefold higher compared with AGA infants. During childhood, babies born SGA are more likely to have developmental delay with motor and minor neurological dysfunction, behavioural disorders and learning difficulties [9, 13, 15]. There are many factors that may contribute to IUGR or a baby being born SGA which include maternal, foetal and placental factors. Current antenatal investigations to screen for SGA babies are focused around foetal surveillance including ultrasound biometry [10], with additional investigations sometimes indicated, such as Doppler ultrasound of the uterine artery, maternal TORCH serology and amniocentesis [16]. Postnatally, screening investigations including cranial ultrasound, TORCH serology, urine cytomegalovirus (CMV) polymerase chain reaction (PCR) and karyotype are frequently performed in SGA babies to elucidate a cause for SGA at birth.
Aims The aims of this study were to determine the yield of postnatal screening investigations, specifically cranial ultrasound, karyotype and TORCH screening, including urine CMV PCR, in near-term and term SGA babies, with an additional aim of
determining whether babies born under the third centile for birth weight had a higher yield of positive investigations.
Methods This retrospective cohort study was performed at a large hospital network (Monash Health) in Melbourne, Australia. A birthing outcome summary (BOS) database was used for data collection, investigating term and near-term babies (35 weeks and above) born over a 4-year period from January 2012 to December 2015 inclusive. Babies were filtered to include only those with birth weight under the tenth centile according to their gestational age, with an additional note made if they were also less than the third centile for their gestational age. All near-term and term SGA babies (35 weeks and above) born in the study period were included in the study. Only babies with inadequate information were excluded. Cut-off weights for less than the tenth centile according to gestational age were determined according to charts devised by Dobbins et al. [5]. Electronic database searches (scanned medical records, BOS) were conducted for antenatal, perinatal and postnatal data. Pathology and radiology databases were used to assess the screening tests performed in SGA babies, with the most common investigations documented being cranial ultrasound, karyotype, TORCH serology, and urine CMV PCR. The number of screening tests requested and the number of positive results were recorded. Maternal and neonatal characteristics of all near-term and term SGA infants investigated were studied. Long-term outcomes of a specific group of babies (with cranial ultrasound and chromosomal abnormalities) were ascertained by reviewing the electronic inpatient and outpatient records. Descriptive statistics and analysis was conducted. Data was presented as median (range) or number (percentage). Maternal and neonatal dichotomous characteristics were compared between groups using chi-square tests to assess crude differences. Statistical significance was set at < 0.05.
Results Our study was conducted in a large hospital network caring for a diverse group of population with the maternal country of birth being Australia and New Zealand in 35.8% (N = 1227), Asia (including South and Southeast Asia) in 48.6% (N = 1667), Middle East in 5.2% (N = 180), Africa in 4.7% (N = 160), Europe in 3.1% (N = 107) and others in 2.6% (N = 90). Of a total sample size of 30,461 babies in the study period, 3437 infants were identified as SGA. Three thousand four hundred thirty-one included babies with adequate information were less than the tenth centile, equating to approximately 11.3% of the total population, with 1004 of
Eur J Pediatr
having a positive finding on cranial ultrasound, 22 having a positive karyotype result, and one baby having a positive urine CMV PCR. Three infants had both cranial ultrasound (USG) and karyotype test positive.
30461 Total term live births between 2012-2015
Types of positive results
3437 (11.3%) Infants with birth th
weight
ORIGINAL ARTICLE
Screening investigations in small-for-gestational-age near-term and term infants Mohan B. Krishnamurthy 1 & Abigail Popiel 2 & Atul Malhotra 1,3,4
Received: 28 August 2017 / Revised: 3 October 2017 / Accepted: 4 October 2017 # Springer-Verlag GmbH Germany 2017
Abstract The aims of this study are to examine how frequently near-term and term small-for-gestational-age (SGA) infants were investigated in our clinical practice, whether being born less than the third centile for weight increased the yield of positive investigations, and whether there were additional characteristics in infants with positive investigations. This retrospective cohort study was compiled using a database of a large maternity network, using the search near term and term gestational age (greater than or equal to 35 weeks) over a span of 4 years. SGA babies were further filtered into less than the tenth centile and third centile. Out of a population of 30,461 infants in the study period, 3437 (11.3%) SGA infants were identified. Four hundred fifteen SGA infants (12.1%) underwent screening investigations, of which 49 infants (11.8%) yielded a positive investigation. 27.2% of karyotypes, 12.8% of cranial ultrasounds and 0.4% of urine CMV tests showed positive results in < 10th centile group. Being born less than the third centile for weight did not increase the yield
of positive investigations. Most infants with positive investigations had an additional maternal or neonatal characteristic or risk factor present. Conclusion: SGA babies without additional maternal or neonatal characteristics have a poor yield on neonatal screening investigations. Additional characteristics may be considered while deciding whether a SGA infant needs screening investigation. What is Known: • Small-for-gestational-age (SGA) infants have an increased risk of shortand long-term complications. • Whilst the causes for SGA are multifactorial, there has been a tendency to undertake screening investigations like Toxoplasma, Others, Rubella, Cytomegalovirus, Herpes group of viruses (TORCH) screening and cranial ultrasounds in the neonatal period. What is New: • Comprehensive study investigating the rates of screening in near-term and term SGA population. • The yield of screening tests for near-term and term SGA infants without additional antenatal and postnatal characteristics is low.
Communicated by Patrick Van Reempts * Atul Malhotra [email protected] Mohan B. Krishnamurthy [email protected] Abigail Popiel [email protected] 1
Monash Newborn, Monash Children’s Hospital, Melbourne, Australia
2
Monash University, Melbourne, Australia
3
Department of Paediatrics, Monash University, Melbourne, Australia
4
Monash Newborn, Monash Children’s Hospital, 246 Clayton Road, Clayton, VIC 3168, Australia
Keywords IUGR . Cranial ultrasound . Karyotype . Cytomegalovirus Abbreviations AGA Appropriate for gestational age BMI Body mass index BOS Birthing outcome summary CMV Cytomegalovirus CTG Cardiotocography HIE Hypoxic ischaemic encephalopathy HSV Herpes simplex virus IUGR Intrauterine growth restriction IVH Intraventricular haemorrhage
Eur J Pediatr
NICU PCR SCN SGA TORCH USG
Neonatal intensive care unit Polymerase chain reaction Special care nursery Small for gestational age Toxoplasma, others, rubella, cytomegalovirus, herpes virus Ultrasonograph
Introduction The term small-for-gestational-age (SGA) is applied to any neonate with birth weight below the tenth centile for their corresponding gestational age [2]. SGA babies comprise both term and preterm babies [1]. There is considerable variation in the prevalence of infants born SGA ranging between 4 and 15% across Europe [11], around 5% in Australasia [4], 5–41% (term SGA) and 1–3% (preterm SGA) in developing countries [3, 14]. The terms IUGR and SGA are often used interchangeably incorrectly; an SGA baby may not necessarily be growth restricted in utero, while an intrauterine growth restriction (IUGR) baby may be of normal weight for their gestational age. However, both IUGR and SGA babies have higher morbidity and mortality compared to that of appropriate-forgestational-age (AGA) babies, with neonatal, childhood, and long-term complications [6]. The likelihood of stillbirth (8.8 vs. 2.5 per 1000 births) and neonatal mortality (14.0 vs. 5.5 per 1000 births) in SGA infants has been noted to be threefold higher compared with AGA infants. During childhood, babies born SGA are more likely to have developmental delay with motor and minor neurological dysfunction, behavioural disorders and learning difficulties [9, 13, 15]. There are many factors that may contribute to IUGR or a baby being born SGA which include maternal, foetal and placental factors. Current antenatal investigations to screen for SGA babies are focused around foetal surveillance including ultrasound biometry [10], with additional investigations sometimes indicated, such as Doppler ultrasound of the uterine artery, maternal TORCH serology and amniocentesis [16]. Postnatally, screening investigations including cranial ultrasound, TORCH serology, urine cytomegalovirus (CMV) polymerase chain reaction (PCR) and karyotype are frequently performed in SGA babies to elucidate a cause for SGA at birth.
Aims The aims of this study were to determine the yield of postnatal screening investigations, specifically cranial ultrasound, karyotype and TORCH screening, including urine CMV PCR, in near-term and term SGA babies, with an additional aim of
determining whether babies born under the third centile for birth weight had a higher yield of positive investigations.
Methods This retrospective cohort study was performed at a large hospital network (Monash Health) in Melbourne, Australia. A birthing outcome summary (BOS) database was used for data collection, investigating term and near-term babies (35 weeks and above) born over a 4-year period from January 2012 to December 2015 inclusive. Babies were filtered to include only those with birth weight under the tenth centile according to their gestational age, with an additional note made if they were also less than the third centile for their gestational age. All near-term and term SGA babies (35 weeks and above) born in the study period were included in the study. Only babies with inadequate information were excluded. Cut-off weights for less than the tenth centile according to gestational age were determined according to charts devised by Dobbins et al. [5]. Electronic database searches (scanned medical records, BOS) were conducted for antenatal, perinatal and postnatal data. Pathology and radiology databases were used to assess the screening tests performed in SGA babies, with the most common investigations documented being cranial ultrasound, karyotype, TORCH serology, and urine CMV PCR. The number of screening tests requested and the number of positive results were recorded. Maternal and neonatal characteristics of all near-term and term SGA infants investigated were studied. Long-term outcomes of a specific group of babies (with cranial ultrasound and chromosomal abnormalities) were ascertained by reviewing the electronic inpatient and outpatient records. Descriptive statistics and analysis was conducted. Data was presented as median (range) or number (percentage). Maternal and neonatal dichotomous characteristics were compared between groups using chi-square tests to assess crude differences. Statistical significance was set at < 0.05.
Results Our study was conducted in a large hospital network caring for a diverse group of population with the maternal country of birth being Australia and New Zealand in 35.8% (N = 1227), Asia (including South and Southeast Asia) in 48.6% (N = 1667), Middle East in 5.2% (N = 180), Africa in 4.7% (N = 160), Europe in 3.1% (N = 107) and others in 2.6% (N = 90). Of a total sample size of 30,461 babies in the study period, 3437 infants were identified as SGA. Three thousand four hundred thirty-one included babies with adequate information were less than the tenth centile, equating to approximately 11.3% of the total population, with 1004 of
Eur J Pediatr
having a positive finding on cranial ultrasound, 22 having a positive karyotype result, and one baby having a positive urine CMV PCR. Three infants had both cranial ultrasound (USG) and karyotype test positive.
30461 Total term live births between 2012-2015
Types of positive results
3437 (11.3%) Infants with birth th
weight
