Table 6.

Effectiveness on infant outcomes

Infant outcomes	Review	Intervention	Effectiveness of the intervention on the outcome			Additional information on impact
			Positive impact	No impact	Inconclusive
Infant’s quality of relationship with mother	Evans et al. 2014 [26]	KC, TH, SM NSTEP-P	√	–	–	Effect sizes ranged from small, 0.35 to large, − 1.60. Large effect size observed with KC (1.60) and TH (− 0.87)
Behaviour improvement	Herd et al. 2014 [32]	IHDP, M-MITP, VIBeS Plus	√	–	–	Small, but significant, effect on behaviour outcomes. IHDP improved behaviour up to 3 years of age, the VIBeS Plus program up to 4 years and the M- MITP up to 5 years
		APIP	–	√	–	No improvement in child behaviour
	Zhang et al., 2014 [24]	MITP, COPE	√	–	–	Symbolic behaviour (understanding spoken language /object use in play)
Temperament	Benzies et al. 2013 [30]	M-MITP	√	–	–	Positive effect at 3 and 6 months. Effect size not reported
	Zhang et al., 2014 [24]	MITP, COPE	√	–	–	Statistical significance not reported
Nutrition and growth	Goyal et al., 2013 [33]	IHDP, others not specified	–	–	√	Mixed findings with one study demonstrating a significant intervention effect on weight and length during infancy (at 4 and 12 months)
	Boundy et al., 2016 [21]	KC	–	√	–	No improvements in weight gain or body length growth
Breast feeding	Boundy et al., 2016 [21]	KC	√	–	–	Improvements in exclusive breast feeding
	Zhang et al., 2014 [24]	MITP, COPE	√	–	–	Improvements in general breast feeding
Height and head circumference	McGregor et al., 2012 [35]	KC	√	–	–	Improvements in height & head circumference reported by one study
Head circumference	Boundy et al., 2016 [21]	KC	√	–	–	Improvements in head circumference
Decrease in infant heart rate and pain	Boundy et al., 2016 [21]	KC	–	√	–	Ineffective with respect to heart rate, respiration, and pain experience
	McGregor et al., 2012 [35]	KC	√	–	–	Infant’s heart rates and pain scores significantly decreased during intervention (p = .007 and p = .005, respectively) and post-intervention (p = .03 and p = .04, respectively), although there was no significant differences in infants’ stress levels
Reduction in morbidity and health service utilisation	Goyal et al., 2013 [33]	IHDP	–	–	√	Mixed findings. Small, statistically significant increase in maternally reported minor illnesses at 3 years of age, but only for infants weighing, 1500 g, and no effect on serious health conditions. No significant effects on rates of hospitalization or acute care visits
	Boundy et al., 2016 [21]	KC	√	–	–	RR = 0.53 (Neonatal sepsis), RR = 0.22 (Hypothermia), RR = 0.12 (Hypoglycemia)
	Lawn et al., 2010 [31]	KC	√	–	–	RR = 0.34 (RCT evidence)
Reduction in hospital readmission	Boundy et al., 2016 [21]	KC	√	–	–	Reduced hospital readmission by 58%
Lower mortality	Boundy et al., 2016 [21]	KC	√	–	–	Significant protective effect on mortality. Mortality 36% lower among low birth weight new borns.
	Lawn et al., 2010 [31]	KC	√	–	–	Large effect size, RR = 0.49 (RCT evidence) and RR = 0.68 (non-RCT evidence)
Early mental development/neurodevelopment	Vanderveen et al., 2009 [23]	APIP, KC, COPE, IHDP, NIDCAP, others not specified	√	–	–	Large effect size at 6 months Weighted Mean Difference (WMD) = 3.55, p = 0.05), 12 months (WMD = 5.57, p = 0.0009), 24 months (WMD = 7.59, p = 0.0003) and 36 months (WMD = 9.66, p < 0.0001)
	Zhang et al., 2014 [24]	MITP, COPE	√	–	–	Statistical significance not reported
Long term mental development (at 5 years)	Vanderveen et al., 20,092 [23]	APIP, IHDP, others not specified	–	√	–	WMD = −1.36, (P = 0.24)
Early cognitive development (infancy & preschool age)	Spittle et al., 2015 [34]	Early interventions including MITP, IHDP, M-MITP, IBAIP, CBIP, HBIP, SPEEDI, others not specified	√	–	–	Infancy -developmental quotient (DQ): standardised mean difference (SMD) 0.32 [0.16, 0.47]; P < 0.001; 16 studies; 2372 participants. Preschool age -intelligence quotient (IQ); SMD 0.43 [0.32–0.54]; P < 0.001; eight studies; 1436 participants.
	Benzies et al. 2013 [30]	M-MITP, NBAS	√	–	–	Effective at 4 months (NBAS) and 3 and 6 months (M-MITP)
Long term cognitive development	Spittle et al., 2015 [34]	MITP, IHDP, APIP	–	√	–	School age – IQ: SMD 0.18 [− 0.08, 0.43]; P = 0.17; five studies; 1372 participants
Early motor development	Spittle et al., 2015 [34]	Early interventions including MITP, IHDP, M-MITP, IBAIP, CBIP, HBIP, SPEEDI, others not specified	√	–	–	Small significant effect in motor development in infancy. Motor scale DQ: SMD 0.10 [0.10, 0.19]
Long term motor development			–	√	–	SMD −0.18, 95% CI -0.47 to 0.11; P = 0.22. Only five included studies reported outcomes at preschool age (n = 3) or at school age (n = 2).
Early psychomotor development	Vanderveen et al., 2009 [23]	IHDP, NIDCAP, others not specified	√	–	–	6 months WMD = 3.47 (_3.92, 10.86) P = 0.36, 12 months WMD = 5.10 (1.44, 8.75) P = 0.006, 24 months WMD = 2.47 (_2.01, 6.94) P = 0.28)
General child development	Benzies et al. 2013 [30]	VIBeS Plus	√	–	–	Short term 0–24 months
	Goyal et al., 2013 [33]	Home visiting interventions	√	–	–	Overall effect at infancy, z = 6.98 (p < 0.001)
	Zhang et al., 2014 [24]	M-MITP, COPE, MITP	√	–	–	Overall development up to 12 months

Interventions: APIP Avon Premature Infant Project, CBIP Clinic-Based Intervention programme, COPE Creating Opportunities for Parent Empowerment, HBIP Home Based intervention programme, IBAIP Infant Behavioural Assessment and Intervention Program, IHDP Infant Health and Development Program, KC Kangaroo Care, M-MITP Modified Mother Infant transaction programme, MITP Mother–Infant Transaction Program, NBAS Neonatal Behavioral Assessment Scale, NIDCAP Newborn Individualised Developmental & Assessment Programme, NSTEP-P Nursing Systems Towards Effective Parenting-Preterm, SM State Modulation, SPEEDI Supporting Play Exploration and Early Development Intervention, TH Traditional Holding, VIBeS Plus Victorian Infant Brain Studies