Study characteristics and outcomes for studies characterising neonates by gestational age and birth weight
Categorisation method | Type of study (comparator groups) | Study | Country of study | Total number of babies | Population (gestation (weeks +days)/birth weight (g)) | Outcomes reported by included studies | ||||||||
Mortality timeframe | Survival timeframe | Morbidity | ||||||||||||
Undefined | Perinatal | Neonatal | Discharge | Infant | 2 years | Discharge | 2 years | |||||||
Gestational age | Inutero versus exutero transfer to NICU | Lamont et al28 | UK | 206 | 28+0–29+6 | ![]() | Non-significant difference in incidence of IVH. | |||||||
30+0–31+6 | NS | Significant reduction in incidence of IVH. | ||||||||||||
Truffert et al31 | France | 157 | 27+0–30+6 | NS | Non-significant difference in incidence of survival (up to 2 years of age) without disability.* | |||||||||
Hauspy et al32 | Belgium | 315 | 28+0–29+6 | NS | Non-significant difference in incidence of RDS. | |||||||||
30+0–31+6 | NS | |||||||||||||
Lee et al33 | Canada | 2148 | 27+0–29+6 | NS | Non-significant difference in incidence of IVH, NEC and ROP. Significant reduction in incidence of RDS and CLD. | |||||||||
30+0–31+6 | NS | Non-significant difference in incidence of IVH, NEC, ROP and CLD. Significant reduction in incidence of RDS. | ||||||||||||
Boland et al13 | Australia | 250 | 28+0–31+6 | ![]() | No other outcomes measured. | |||||||||
Level of unit of birth (NICU vs non-NICU) | Holmgren and Högberg 34 | Sweden | 394 | 28+0–31+6 | NS | NS | NS | Non-significant difference in incidence of asphyxia† | ||||||
Johansson et al29 | Sweden | 1636 | 28+0–31+6 | NS | No other outcomes measured. | |||||||||
Level of unit of care (NICU vs non-NICU) | Field et al30 | UK | 171 | 29+0–30+6 | NS | No other outcomes measured. | ||||||||
Jonas and Lumley35 | Australia | 3331 | 28+0–31+6 | ![]() | No other outcomes measured. | |||||||||
Birth weight | Inutero versus exutero transfer to NICU | Miller et al38 | USA | 94 | 1000–1500 | ![]() | No other outcomes measured. | |||||||
Watkinson and McIntosh44 | UK | 154 | 1001–1500 | ![]() | No other outcomes measured. | |||||||||
Powell and Pharoah42 | UK | 390 | 1000–1500 | ![]() | No other outcomes measured. | |||||||||
Obladen et al40 | Germany | 220 | 1000–1249 | NS | Non-significant difference in incidence of IVH. | |||||||||
1250–1499 | NS | No other outcomes measured. | ||||||||||||
Mohamed and Aly39 | USA | 36 493 | 1000–1500 | Significant reduction in incidence of IVH. | ||||||||||
Level of unit of birth (NICU vs non-NICU) | Gortmaker et al36 | USA | 4874 | 1000–1500 | ![]() | ![]() | No other outcomes measured. | |||||||
Powell et al41 | USA | 947 | 1000–1500 | NS | No other outcomes measured. | |||||||||
Yeast et al1 | USA | 2852 | 1000–1500 | ![]() | No other outcomes measured. | |||||||||
Sanderson et al43 | USA | 1345 | 1000–1249 | ![]() | No other outcomes measured. | |||||||||
1250–1499 | NS | No other outcomes measured. | ||||||||||||
Gould et al37 | USA | undefined (<4405) | 1000–1500 | NS | No other outcomes measured. | |||||||||
Warner et al18 | USA | 474 | 1000–1500 | NS | Non-significant difference in incidence of NEC (Bell stage II or III) or death. Significant reduction in incidence of BPD or death, IVH (grade III or IV) or death, ROP or death. |
↑denotes direction of significant difference found between comparator groups (first comparator vs second comparator), and NS denotes lack of significant difference between comparator groups). For example, Jonas 1997 showed a significantly lower (arrow in downward direction) neonatal mortality for those babies born between 28+0 and 31+6 in a NICU (first comparator) versus a non-NICU (second comparator).
*Disability is a composite outcome measure consisting of cerebral palsy, deafness, Brunet-Lézine developmental score <80.63
†Asphyxia refers to Apgar score <5 at 10 min of age.
BPD, bronchopulmonary dysplasia; CLD, chronic lung disease; IVH, intraventricular haemorrhage; NEC, necrotising enterocolitis; NICU, neonatal intensive care unit; RDS, respiratory distress syndrome; ROP, retinopathy of prematurity.