Effects of suboptimal intra-uterine growth on preterm infants between 30 and 32 weeks' gestation.

OBJECTIVE: To investigate the affects of suboptimal intra-uterine growth on the outcome of low-birth-weight (LBW) infants. DESIGN: Prospective observational study. SETTING: Neonatal unit of a tertiary care hospital. PATIENTS: A total of 104 LBW infants with a gestation of 30-32 weeks were selected from a larger cohort that had previously been studied to ascertain the prevalence of respiratory distress syndrome (RDS) and periventricular-intraventricular haemorrhage (PV-IVH). OUTCOME MEASURES: Multivariate analysis was used to examine the association between RDS, PV-IVH and death, and the adequacy of intra-uterine growth. RESULTS: Infants with a higher birth weight ratio or birth weight > or = 25th percentile had an increased risk of developing RDS, particularly where ventilatory support was required. However, PV-IVH was associated with immediate perinatal events and not with intra-uterine growth. Mortality was not affected by intra-uterine growth, since those < 25th percentile. In spite of being at lower risk for RDS, showed a trend towards more infection-related deaths. CONCLUSIONS: The 'intra-uterine stress' experienced by infants with suboptimal intra-uterine growth appears to protect partially against RDS, but confers no overall advantage in terms of survival.

Prevalence of hyaline membrane disease in black and white low-birth-weight infants.

Previous studies in South Africa and elsewhere have suggested that there are ethnic differences in the prevalence of hyaline membrane disease (HMD). This study compared the prevalence of HMD between black and white infants with birth weights of 1,000-1,749 g. A cohort of black and one of white low-birth-weight infants were enrolled at Baragwanath and Johannesburg Hospitals respectively. Black infants were found to have a higher rate of intra-uterine growth retardation. When compared according to either birth weight or gestational age categories, black infants had a significantly lower prevalence of HMD. For example, between 29 and 34 weeks' gestation 36.2% of black and 62.5% of white infants developed HMD (P < 0.001). The reasons for these differences are not clear, however, and require further study.

Periventricular-intraventricular haemorrhage in low-birth-weight infants at Baragwanath Hospital.

The prevalence of periventricular-intraventricular haemorrhage (PV-IVH) among very-low-birth-weight infants at Baragwanath Hospital has not been well documented. In this prospective study, a total of 282 live-born infants with birth weights of 1,000-1,749 g were studied over a 4 1/2-month period. Every infant had at least one cranial ultrasound examination at 7-10 days of age, while one-third of non-ventilated and all ventilated infants had ultrasound examinations on days 3, 7 and 14. Where possible, all infants had a follow-up ultrasound scan at 40 weeks' post-conceptional age. The overall prevalence of PV-IVH was 53% for infants weighing less than 1,500 g at birth and 52% for infants born at less than 35 weeks' gestation, but only 12% had either grade III or grade IV haemorrhages. The prevalence and severity of PV-IVH increased with both decreasing birth weight and decreasing gestational age and was also predicted by the need for active resuscitation at birth, mechanical ventilation and the development of pneumothorax. A total of 93% of infants without PV-IVH survived, but survival decreased with increasing grade of PV-IVH. Germinal matrix cysts were noted on follow-up in 55% of surviving infants with grade I PV-IVH. Very-low-birth-weight infants at Baragwanath Hospital therefore seem to have a higher prevalence of PV-IVH when compared with reported figures, but this is due mainly to an increase in smaller haemorrhages.