Seguimiento de recién nacidos de peso menor o igual a 1.500 g y edad gestacional menor o igual a 32 semanas durante los 2 primeros años de edad corregida: comparación de 2 periodos de tiempo

Evaluation of very low birth weight (≤ 1,500 g) as a risk indicator for sensorineural hearing loss

INTRODUCTION AND OBJECTIVE

Hearing plays an essential role in the acquisition, development and maintenance of the properties of the speech and language. Birth weight is an indicator of biological maturation of the newborn. Premature newborns with very low birth weight (VLBW<1,500 g) constitute a group with the highest risk of sensorineural hearing loss. Our objective was to ascertain the degree of hearing loss, sensorineural hearing loss and presence of the association to other risk factors for hearing loss in VLBW infants included in the Universal Hearing Loss Screening Programme at the University Mother-Child Hospital of Gran Canaria (Spain) in the 2007-2010 period.

MATERIAL AND METHODS

This was a retrospective study of 364 infants with VLBW, measured by transient evoked otoacoustic emissions and auditory brainstem response.

RESULTS

There were 112 newborn (30.8%) referred for auditory brainstem response. A diagnosis of hearing loss was given to 22 newborns (2.2%), 14 had conductive hearing loss and 8, sensorineural hearing loss (SNHL), of which 2 had bilateral profound hearing loss. The VLBW newborn presented the association to another risk factor in more than a quarter of the sample studied. All those diagnosed with SNHL were premature.

CONCLUSIONS

The percentage of VLBW newborns diagnosed with hearing loss is higher than expected in the general population. All those diagnosed with SNHL were premature and presented one or 2 hearing risk factors associated with VLBW.

Population-based estimates of in-unit survival for very preterm infants

BACKGROUND

Estimates of the probability of survival of very preterm infants admitted to NICU care are vital for counseling parents, informing care, and planning services. In 1999, easy-to-use charts of survival according to gestation, birth weight, and gender were published in the United Kingdom. These charts are widely used in clinical care and for benchmarking survival, and they form the core of the Clinical Risk Index for Babies II score. Since their publication, the survival of preterm infants has improved, and the charts therefore need updating.

METHODS

A logistic model was fitted with gestational age, birth weight, and gender. Nonlinear functions were estimated by using fractional polynomials. Bootstrap methods were used to assess the internal validity of the final model. The final model was assessed both overall and for subgroups of infants by using Farrington's statistic, the c-statistic, Cox regression coefficients, and the Brier score.

RESULTS

A total of 2995 white singleton infants born at 23(+0) to 32(+6) weeks' gestation in 2008 through 2010 were identified; 2751 (91.9%) infants survived to discharge. A prediction model was estimated and good model fit confirmed (area under receiver-operating characteristics curve = 0.86). Survival ranged from 27.7% (23 weeks) to 99.1% (32 weeks) for boys and from 34.5% (23 weeks) to 99.3% (32 weeks) for girls. Updated charts were produced showing estimated survival according to gestation, birth weight and gender, together with contour plots displaying points of equal survival.

CONCLUSIONS

These survival charts have been updated and will be of use to clinicians, parents, and managers.