Prematurity not associated with early mortality in infants on ART

Prematurity is a known risk for infant mortality. Other risks include maternal immunosuppression, delayed initiation of ART and low baseline CD4 percentage.

Investigators from the Perinatal HIV Research Unit (PHRU) in Soweto, South Africa showed findings at the 2011 paediatric workshop from a cohort study designed to investigate prematurity among children born in 2009 and initiated on ART before one year of age. The study was a database and record review.

The background characteristics of the infants at time ART initiation are shown in Table 1.

Table 1: Background characteristics of term vs preterm infants at ART initiation
	Preterm (n=31)	Term (n=114)	p-value
Median age weeks (IQR)	8.5 (7.4 – 13.1)	9.9 (7.9-15.1)	0.19
Median CD4% (IQR)	26.6 (19.7-32.7)	31.5 (22.4-39.5)	0.025
Median CD4 cells/mm3 (IQR)	1820 (1194-2409)	1768 (1217-2497)	0.87
Viral load log copies/mL (IQR)	5.9 (5.69-5.88)	5.9 (5.75-5.88)	0.89
Exclusive formula feeding (%)	24 (80%)	88 (79%)	0.93

Table 1: Background characteristics of term vs preterm infants at ART initiation

Preterm (n=31)

Term (n=114)

p-value

Median age weeks (IQR)

8.5

(7.4 – 13.1)

9.9

(7.9-15.1)

0.19

Median CD4% (IQR)

26.6

(19.7-32.7)

31.5

(22.4-39.5)

0.025

Median CD4 cells/mm3 (IQR)

1820

(1194-2409)

1768

(1217-2497)

0.87

Viral load log copies/mL (IQR)

5.9

(5.69-5.88)

5.9

(5.75-5.88)

0.89

Exclusive formula feeding (%)

24 (80%)

88 (79%)

0.93

The investigators reported no difference in mortality between preterm and term infants, respectively, 3% vs 4% (OR 1.9; 95%CI 0.5-6.7). Lost to follow up was 8% overall.

Univariate analysis revealed non-significant p-values for all variables ie preterm vs term, baseline CD4%, baseline viral load, breast vs formula feeding and maternal PMTCT. The investigators noted the small sample size and that the mortality rate was low in this study.

They concluded that although HIV-infected preterm infants have significantly lower CD4% than term infants, with early ART initiation they are not at increased risk of mortality.

Lazarus E et al. Prematurity is not a risk factor for early mortality in HIV-infected infants on antiretroviral therapy. 3rd International workshop on HIV paediatrics. 15-16 July 2011. Rome, Italy. Poster abstract P_18.