Retinopathy of prematurity: risk factors in a prospective population-based study

Outcomes of near confluent laser versus combined less dense laser and bevacizumab treatment of prethreshold ROP Type 1 Zone 2: a randomized controlled trial

BACKGROUND

To evaluate the results of near confluent laser therapy versus combined less dense laser and intra vitreal bevacizumab in treatment of infants with type 1 retinopathy of prematurity (ROP) in zone II.

METHODS

This is a prospective double-blinded randomized clinical trial study. Infants with Type 1 ROP in Zone 2 were randomized into case and control groups. Conventional laser therapy was executed for control group and combination of IVB and laser treatment was employed for the case group.

RESULTS

Eighty-six eyes from 43 infants were analyzed in this trial. The first group included 42 eyes from 21 infants receiving a combination of laser ablation and IVB. The second group contained 44 eyes from 22 infants who received only conventional laser therapy. The combined IVB and laser ablation group demonstrated the neovascularization regression (20 out of 21 infants) one week after the procedure. In the conventional laser therapy group, this regression was found in (12 out of 22 infants) within one week after laser therapy (P = 0.001). Plus disease regression was observed in 20 (20/21) of combined treatment group and 7 infants (7/22) of conventional laser treatment group after one week.

CONCLUSION

Combined less dense laser and bevacizumab treatment resulted in more rapid regression in comparison with the conventional laser treatment.

TRIAL REGISTRATION

IRCT20201120049450N1, 27/12/2021.

International Variation in the Management of Patent Ductus Arteriosus and Its Association with Infant Outcomes: A Survey and Linked Cohort Study

OBJECTIVE

To assess whether treating patients with a presymptomatic patent ductus arteriosus (PDA), based on early routine echocardiography, performed regardless of clinical signs, improved outcomes.

STUDY DESIGN

This multicenter, survey-linked retrospective cohort study used an institutional-level questionnaire and individual patient-level data and included infants of <29 weeks of gestation born in 2014-2016 and admitted to tertiary neonatal intensive care units (NICUs) of 9 population-based national or regional neonatal networks. Infants in NICUs receiving treatment of presymptomatic PDA identified by routine echocardiography and those not were compared for the primary composite outcome (early death [≤7 days after birth] or severe intraventricular hemorrhage) and secondary outcomes (any in-hospital mortality and major morbidities).

RESULTS

The unit survey (response rates of 86%) revealed a wide variation among networks in the treatment of presymptomatic PDA (7%-86%). Among 246 NICUs with 17 936 infants (mean gestational age of 26 weeks), 126 NICUs (51%) with 7785 infants treated presymptomatic PDA. The primary outcome of early death or severe intraventricular hemorrhage was not significantly different between the NICUs treating presymptomatic PDA and those who did not (17% vs 21%; aOR 1.00, 95% CI 0.85-1.18). The NICUs treating presymptomatic PDA had greater odds of retinopathy of prematurity treatment (13% vs 7%; aOR 1.47, 95% CI 1.01-2.12); however, it was not significant in a sensitivity analysis excluding Japanese data.

CONCLUSIONS

Treating presymptomatic PDA detected by routine echocardiography was commonplace but associated with no significant benefits. Well-designed trials are needed to assess the efficacy and safety of early targeted PDA treatment.

Retinopathy of prematurity: a review of risk factors and their clinical significance

Retinopathy of prematurity (ROP) is a retinal vasoproliferative disease that affects premature infants. Despite improvements in neonatal care and management guidelines, ROP remains a leading cause of childhood blindness worldwide. Current screening guidelines are primarily based on two risk factors: birth weight and gestational age; however, many investigators have suggested other risk factors, including maternal factors, prenatal and perinatal factors, demographics, medical interventions, comorbidities of prematurity, nutrition, and genetic factors. We review the existing literature addressing various possible ROP risk factors. Although there have been contradictory reports, and the risk may vary between different populations, understanding ROP risk factors is essential to develop predictive models, to gain insights into pathophysiology of retinal vascular diseases and diseases of prematurity, and to determine future directions in management of and research in ROP.

Retinopathy of prematurity in Indonesia: Incidence and risk factors

BACKGROUND

Retinopathy of prematurity (ROP) is a vaso-proliferative disease of the eye, which mainly affects preterm newborn infants with an incompletely vascularized retina. The incidence of ROP has increased in industrialized countries due to the increased survival of extremely low birth weight (ELBW) infants. ROP is also increasing in developing countries like Indonesia, where it is most likely due to the improved survival of ELBW infants.

OBJECTIVE

To ascertain the incidence of ROP and possible risk factors associated with the development of ROP in preterm infants in Indonesia.

METHODS

We reviewed the literature on the incidence and potential risk factors for the development of ROP in Indonesia, obtained data from three referral eye clinics and added data from our institution.

RESULTS

The reported incidence of all stages of ROP in infants with a gestational age of <32 weeks ranged from 18-30%. One study showed that ROP also occurred at older gestational ages. Blindness due to ROP was seen in infants up to 35 weeks and with a birth weight of 2000 g.

CONCLUSION

Retinopathy of prematurity is an important cause of ocular morbidity and blindness in Indonesia. The overall incidence of ROP in infants born below 32 weeks in Indonesia is higher than in developed countries, and it is seen in infants with older gestational ages. This might be due to a less strict monitoring during the use of oxygen in Indonesia compared to industrialized countries.

Prevalence of retinopathy of prematurity in Iran: a systematic review and Meta-analysis

AIM

To estimate overall prevalence of retinopathy of prematurity (ROP) in Iran using a systematic review and Meta-analysis.

METHODS

A systematic review and Meta-analysis was performed of all published studies pertaining to prevalence of ROP using international and national electronic databases (ISI Web of Sciences, PubMed, Scopus, Google Scholar, SID, MagIran, and IranMedex) from their inception until May 2016 with standard keywords. Begg and Egger tests were used to examine the publication bias and Cochran test and I² statistics were used to evaluate the statistical heterogeneity. Pooled estimate of the prevalence of ROP were calculated using random effects Meta-analysis.

RESULTS

The publication bias assumption was rejected by Egger tests with P-value equal to 0.024. The results of Cochran test and I² statistics revealed substantial heterogeneity (Q=1099.02, df=25, I²=97.7%, P=0.001). The overall prevalence of ROP using the random effect model in Iran was 26.1% (95% CI: 20.3%-31.8%).

CONCLUSION

The prevalence of ROP is relatively high in Iran. Low birth weight and gestational age are significant risk factors for the disease. Improved care, including oxygen delivery and monitoring, for preterm babies in all facility settings would reduce the number of babies affected with ROP.

Pharmacologic interventions for the prevention and treatment of retinopathy of prematurity

Retinopathy of prematurity (ROP), a significant morbidity in prematurely born infants, is the most common cause of visual impairment and blindness in children and persists till adulthood. Strict control of oxygen therapy and prevention of intermittent hypoxia are the keys in the prevention of ROP, but pharmacologic interventions have decreased risk of ROP. Various drug classes such as methylxanthines (caffeine), VEGF inhibitors, antioxidants, and others have decreased ROP occurrence. The timing of pharmacologic intervention remains unsettled, but early prevention rather than controlling disease progression may be preferred. These drugs act through different mechanisms, and synergistic approaches should be considered to maximize efficacy and safety.

Neonatal Risk Factors for Treatment-Demanding Retinopathy of Prematurity: A Danish National Study

PURPOSE

One goal of the study was to identify "new" statistically independent risk factors for treatment-demanding retinopathy of prematurity (ROP). Another goal was to evaluate whether any new risk factors could explain the increase in the incidence of treatment-demanding ROP over time in Denmark.

DESIGN

A retrospective, register-based cohort study.

PARTICIPANTS

The study included premature infants (n = 6490) born in Denmark from 1997 to 2008.

METHODS

The study sample and the 31 candidate risk factors were identified in 3 national registers. Data were linked through a unique civil registration number. Each of the 31 candidate risk factors were evaluated in univariate analyses, while adjusted for known risk factors (i.e., gestational age [GA] at delivery, small for gestational age [SGA], multiple births, and male sex). Significant outcomes were analyzed thereafter in a backward selection multiple logistic regression model.

MAIN OUTCOME MEASURES

Treatment-demanding ROP and its associations to candidate risk factors.

RESULTS

Mechanical ventilation (odds ratio [OR], 2.84; 95% confidence interval [CI], 1.99-4.08; P < 0.01) and blood transfusion (OR, 1.97; 95% CI, 1.20-3.14; P = 0.01) were the only new statistically independent risk factors, in addition to GA at delivery, SGA, multiple births, and male sex. Modification in these prognostic factors for ROP did not cause an increase in treatment-demanding ROP.

CONCLUSIONS

In a large study population, blood transfusion and mechanical ventilation were the only new statistically independent risk factors to predict the development of treatment-demanding ROP. Modification in the neonatal treatment with mechanical ventilation or blood transfusion did not cause the observed increase in the incidence of preterm infants with treatment-demanding ROP during a recent birth period (2003-2008).

The New Zealand 1986 very low birth weight cohort as young adults: mapping the road ahead

Background

Very low birth weight (less than 1500 g) is associated with increased morbidity and costs of health care in childhood. Emerging evidence suggests these infants face a range of health and social problems as young adults. We studied all New Zealand very low birth weight infants born in 1986 (when 58 % were exposed to antenatal corticosteroids) in infancy, with later follow-up at 7 to 8 years and 23 to 24 years. We now aim to assess the cohort at 26–28 years compared with controls.

Methods/design

The case sample will comprise a minimum of 250 members of the 1986 New Zealand national very low birth weight cohort (77 % of survivors). Outcomes will be compared with a control group of 100 young adults born at term in 1986. Following written informed consent, participants will travel to Christchurch for 2 days of assessments undertaken by experienced staff. Medical assessments include growth measures, vision, respiratory function, blood pressure and echocardiogram, renal function, dental examination and blood tests. Cognitive and neuropsychological functioning will be assessed with standard tests, and mental health and social functioning by participant interview. A telephone interview will be conducted with a parent or significant other person nominated by the respondent to gain a further perspective on the young person’s health and functioning. All those born at less than 28 weeks’ gestation, plus a random subset of the cohort to a total of 150 cases and 50 controls, will be offered cranial magnetic-resonance imaging. Statistical analysis will examine comparison with controls and long-term trajectories for the very low birth weight cohort.

Discussion

The research will provide crucial New Zealand data on the young adult outcomes for very low birth weight infants and address gaps in the international literature, particularly regarding cardiovascular, respiratory, visual and neurocognitive outcomes. These data will inform future neonatal care, provide evidence-based guidelines for care of preterm graduates transitioning to adult care, and help shape health education and social policies for this high risk group.

Trial registration

Australian New Zealand Clinical Trials Registry ACTRN12612000995875. Registered 1 October 2012

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0413-9) contains supplementary material, which is available to authorized users.

Retinopathy of prematurity: Risk factors and variability in Canadian neonatal intensive care units

OBJECTIVE

To identify predictors of severe retinopathy of prematurity (ROP) in a large population-based cohort and to examine risk-adjusted variations across units.

STUDY DESIGN

Retrospective analysis of Canadian Neonatal Network data on neonates with birth weight <1500 g who were screened for ROP between 2003 and 2010. Characteristics of infants with and without ROP were compared and a risk-adjusted model for severe ROP was developed. Rates of severe ROP were compared between sites.

RESULTS

1163 of 9187 (12.7%) infants developed severe ROP. Lower gestational age, male sex, small for gestational age, patent ductus arteriosus, late onset sepsis, more than two blood transfusions, inotrope use, and outborn status were associated with an increased risk of severe ROP. Severe ROP rates varied significantly between units.

CONCLUSION

Younger, smaller and sicker male infants had higher adjusted risks of severe ROP and rates varied significantly among sites.

The Specificity of the WINROP Algorithm Can Be Significantly Increased by Reassessment of the WINROP Alarm

BACKGROUND

Retinopathy of prematurity (ROP) is a sight-threatening disease affecting extremely preterm infants. The introduction of new ROP screening surveillance systems, with higher sensitivity and specificity than established ROP screening guidelines, has the potential to reduce the number of stressful eye examinations in these infants.

OBJECTIVES

To improve the specificity of the WINROP (Weight, Insulin-like growth factor-I, Neonatal, ROP) surveillance system, identifying extremely preterm infants requiring treatment for ROP.

METHODS

Two cohorts that had previously been subjected to WINROP analyses were included and reevaluated in this study. The weight at WINROP alarm for extremely preterm infants, born at gestational age <27 weeks, was reevaluated and by establishing 'safe' WINROP alarm weight limits, an intersample reassessment of WINROP alarm was performed. The two cohorts were as follows: (1) the Extremely Preterm Infants in Sweden Study (EXPRESS) cohort, infants born in Sweden during 2004-2007 (n = 407), and (2) extremely preterm infants in a North American cohort, born during 2006-2009 (n = 566).

RESULTS

In the EXPRESS cohort, 12.5% (40/319) of the infants who previously received a WINROP alarm were now reassessed as having no alarm; the specificity of WINROP in EXPRESS increased from 23.9% (86/360) to 35.0% (126/360). In the North American cohort, 15.4% (81/526) were reassessed as having no alarm; the specificity increased from 8.5% (38/447) to 26.6% (119/447). The sensitivity persisted as 97.5% in EXPRESS (45/47) and 98.3% (117/119) in the North American cohort.

CONCLUSIONS

The specificity of the WINROP surveillance system for extremely preterm infants can be significantly improved by reassessment using the weight at WINROP alarm.

Incidence and risk factors of retinopathy of prematurity in mashhad, northeast iran

BACKGROUND

Retinopathy of prematurity (ROP) is a vascular retinal disease that can cause low vision or blindness and affects premature newborns of very low birth weight.

OBJECTIVES

The purpose of this study was to determine the incidence and risk factors for ROP among very premature infants in Mashhad located northeast of Iran.

MATERIAL AND METHODS

In this cross-sectional study performed between 2006 and 2010, predisposing factors and severity of ROP were evaluated in very premature infants (<32 gestational weeks). Consecutive infants were enrolled at birth and screened for ROP at 4 to 6 weeks of age by indirect ophthalmoscopy. Severe ROP was defined as stage 4 or 5. Chi-square, Student's t-, and Fisher's test were used for statistical analysis.

RESULTS

The incidence of ROP was 26.2%. Significant differences between the ROP and control groups were observed, these include; gestational age, sex, birth weight, Apgar score, durationof parenteral nutrition, oxygen therapy, phototherapy, maximum PaO2 and minimum SpO2 (P < 0.05). Severe ROP was seen in 31.4% (11/32) of ROP cases (5.4% of newborns).

CONCLUSION

The incidence of ROP is relatively high in this region. Risk factors for ROP among very premature infants include hypoxia, severe hyperoxia, relatively low blood SPO2, gestational age, birth weight, and Apgar score.

Capacity building of nurses providing neonatal care in Rio de Janeiro, Brazil: methods for the POINTS of care project to enhance nursing education and reduce adverse neonatal outcomes

Background

Increased survival of preterm infants in developing countries has often been accompanied by increased morbidity. A previous study found rates of severe retinopathy of prematurity varied widely between different neonatal units in Rio de Janeiro. Nurses have a key role in the care of high-risk infants but often do not have access to ongoing education programmes. We set out to design a quality improvement project that would provide nurses with the training and tools to decrease neonatal mortality and morbidity. The purpose of this report is to describe the methods and make the teaching package (POINTS of care--six modules addressing Pain control; optimal Oxygenation; Infection control; Nutrition interventions; Temperature control; Supportive care) available to others.

Methods/Design

Six neonatal units, caring for 40% of preterm infants in Rio de Janeiro were invited to participate. In Phase 1 of the study multidisciplinary workshops were held in each neonatal unit to identify the neonatal morbidities of interest and to plan for data collection. In Phase 2 the teaching package was developed and tested. Phase 3 consisted of 12 months data collection utilizing a simple tick-sheet for recording. In Phase 4 (the Intervention) all nurses were asked to complete all six modules of the POINTS of care package, which was supplemented by practical demonstrations. Phase 5 consisted of a further 12 months data collection. In Phase 1 it was agreed to include inborn infants with birthweight ≤ 1500 g or gestational age of ≤ 34 weeks. The primary outcome was death before discharge and secondary outcomes included retinopathy of prematurity and bronchopulmonary dysplasia. Assuming 400-450 infants in both pre- and post-intervention periods the study had 80% power at p = < 0.05 to detect an increase in survival from 68% to 80%; a reduction in need for supplementary oxygen at 36 weeks post menstrual age from 11% to 5.5% and a reduction in retinopathy of prematurity requiring treatment from 7% to 2.5%.

Discussion

The results of the POINTS of Care intervention will be presented in a separate publication.

Trial registration

Current Controlled Trials: ISRCTN83110114

Adopting Western Retinopathy of Prematurity Screening Programs in Eastern Countries, are we Screening Properly?

PURPOSE

To describe retinopathy of prematurity (ROP) among Jordanian preterm infants and evaluate the efficacy of applying current Western screening guidelines for Jordanian preterms.

MATERIALS AND METHODS

In this retrospective, descriptive hospital-based study, we collected data on preterm infants who were referred by their neonatologist for ROP screening at King Abdullah University Hospital between July 2006 and June 2007. Guidelines suggested by the American Academy of Pediatrics were followed. Additionally, older preterms considered at risk for ROP by the neonatal intensive care unit were screened. Any neonate with stage 1 ROP or higher in either eye was considered a positive case of ROP.

RESULTS

Ninety-one preterms were included in the study. The median birth weight was 1390 gm (range,730-1980 gms) and the gestational age ranged from 26 to 35 weeks with 64.8% of preterms ≤ 32 weeks. ROP occurred in 28.6% of all patients, in 20% of infants with birth weight greater than 1500 gms and in 9.4% of preterms with gestational age ≥ 32 weeks. Six patients (6.6%) required laser treatment, two with low birth weight greater than 1250 gm and one was 33 weeks of age. Consanguinity was identified in 19.2% of infants with ROP while consanguinity in infants who did not develop ROP was 1.9%. This difference was statistically significant (P<0.05).

CONCLUSION

ROP occurs in premature infants in Jordan with gestational age above 32 weeks and birth weight above 1250 gm. Future guidelines for screening should incorporate the current study outcomes. A prospective, population-based is required to set national guidelines for ROP screening in the Jordanian population and similarly for different populations worldwide. Consanguinity may play a role in ROP development and further genetic studies may aid in elucidating the pathogenesis of ROP.

Neonatal outcomes of very preterm infants admitted to a tertiary center in Lithuania between the years 2003 and 2005

The objectives of the study are to investigate gestational age-specific mortality and neonatal outcomes in preterm infants admitted to a tertiary center in Lithuania, and to make comparison with tertiary centers in western countries. Three hundred thirty-eight newborns born at ≤ 32 weeks of gestation and with birth weight ≤ 1,500 g between 1 January 2003 and 31 December 2005, admitted to the neonatal intensive care unit at Kaunas Medical University Hospital, were prospectively investigated. Mortality and associations between maternal, perinatal, and neonatal variables and short-term outcomes were examined for two gestational age (GA) groups (group I, extremely preterm, 22-27 weeks GA; group II, very preterm, 28-32 weeks GA). Mortality in group I was 53.5% and 2.9% in group II. GA <28 weeks, Apgar score <5 at 5 min, and birth weight <1,000 g posed the highest risk for death. Overall, 78.2% of the surviving infants were discharged from hospital without adverse short-term outcomes. The incidence of bronchopulmonary dysplasia (BPD) was 6.3%, of retinopathy of prematurity (ROP) requiring treatment 4.2%, of intraventricular hemorrhage (IVH) III-IV 10.9%, and for cystic periventricular leukomalacia (cPVL) 8.0%. In conclusion, a decade after introduction of perinatal programs, mortality in the very preterm group is similar to those reported from cohorts in western countries. In the extremely preterm group, however, mortality is still higher. Neonatal outcomes such as ROP are now similar, and BPD is lower to those in other cohorts, whereas the incidence of brain lesions is still higher. We speculate that differences in outcomes between studies may be explained by differences in resources, definitions, and treatment routines.

Retinopathy of prematurity and maternal age

PURPOSE

To determine the risk factors, especially maternal risk factors, associated with the development of retinopathy of prematurity (ROP) in premature babies.

METHODS

A matched case-control study involving premature patients was undertaken retrospectively. The case group consisted of premature babies with the subsequent development of ROP. The control group consisted of gestational age-matched and sex-matched premature babies that did not develop ROP during the follow-up period. Risk factors involving patient demographics and maternal characteristics were compared between the case and control groups.

RESULTS

A total of 144 patients were included in this study (72 patients in the case group and 72 patients in the control group). Among the 66 possible risk factors compared, only birth weight and maternal age were found to be significant risk factors. Birth weight was significantly lower in the case group (1,248.7 +/- 257.8 g vs. 1,335.5 +/- 297.2 g, P = 0.01), and maternal age was significantly older in the case group compared with that in the control group (31.2 +/- 5.1 years vs. 28.2 +/- 5.3 years, P < 0.001). The odds ratio of having babies with ROP was 2.9 when the maternal age was >30 years.

CONCLUSION

Older maternal age is a newly identified risk factor for the development of ROP in premature babies.

Retinopathy of prematurity in very low birth weight infants and the potential protective role of indomethacin

BACKGROUND AND OBJECTIVE

To describe clinical features of very low birth weight (VLBW) infants and examine the effect of indomethacin on the incidence of retinopathy of prematurity (ROP).

PATIENTS AND METHODS

Medical records of all VLBW infants over a 4-year period were reviewed. Data regarding systemic and ophthalmic examinations were analyzed.

RESULTS

Forty-seven infants with ROP were evaluated. Most infants had bilateral stage 1 or 2 disease extending 5 clock hours. Infants with ROP had younger mean gestational age, had lower gestational weight, and demonstrated higher incidence of diseases of prematurity. These infants were exposed to increased doses of surfactant and higher oxygen concentration for a prolonged duration given their immature pulmonary status. Independent predictors of ROP susceptibility also included length of hospitalization and Apgar score at 5 minutes. Patent ductus arteriosus was more common among infants with ROP. Approximately half of the infants who received one or two doses of indomethacin had ROP, but the ROP rate was decreased in infants who received three doses.

CONCLUSION

Premature infants with younger gestational age, lower gestational weight, and severe morbidities were found to have an increased prevalence of ROP. Indomethacin treatment for patent ductus arteriosus may have a protective role in the development of severe ROP.

Retinopathy of prematurity in Bangladeshi neonates

BACKGROUND

Retinopathy of prematurity (ROP) is a potentially blinding eye disorder that primarily affects premature infants. Increased survival of extremely low birth weight infants following advances in antenatal and neonatal care has resulted in a population of infants at high risk of developing ROP. Long term morbidity of ROP has a spectrum ranging from myopia to blindness. Screening programs and early intervention can provide enormous economic and social benefits.

MATERIALS AND METHODS

Preterm infants of gestational age <33 weeks admitted to the Special Care Nursery of Dhaka Shishu Hospital for a trial of topical emollient therapy during December 1998-July 2003 were followed-up after hospital discharge, including detailed ophthalmologic examination. Detailed history regarding risks during pregnancy, delivery and hospital stay was documented. ROP cases were managed according to the stage of the disease at diagnosis.

RESULTS

Five out of the 114 (4.4%) children seen in follow-up were diagnosed with ROP. Low gestational age, low birth weight, administration of oxygen, apneic spells, sepsis and blood transfusions were common factors among cases who developed ROP.

CONCLUSION

As survival of preterm infants in low resource settings increases, ROP will become increasingly important as a potential cause of blindness, emphasizing the critical need for ophthalmologic examination in premature infants, with immediate initiation of treatment when ROP is diagnosed.

Human recombinant erythropoietin and the incidence of retinopathy of prematurity: a multiple regression model

BACKGROUND

Recombinant human erythropoietin (rhEPO) is used for the treatment of anemia of prematurity. However, it has also been found to have properties similar to vascular endothelial growth factor (VEGF), the major angiogenic factor implicated in the pathogenesis of retinopathy of prematurity (ROP). We sought to determine whether rhEPO is an independent risk factor for the development of ROP.

METHODS

Data were analyzed from 264 infants admitted to the Loma Linda University Children's Hospital neonatal intensive care unit in 1994 and 2002. The data included demographic characteristics, incidence of major morbidities, rhEPO treatment, number of red blood cell transfusions received, and incidence and severity of ROP. A multiple logistic regression model was used to determine the relation of the studied risk factors to the incidence (any stage) and severity (threshold ROP requiring cryotherapy or laser photocoagulation) of ROP.

RESULTS

The risk of developing ROP increased among infants who received >20 doses of rhEPO was higher compared with those who received < or =20 doses (OR, 3.53; 95% CI, 1.59, 7.85). These infants were also more likely to require laser photocoagulation (OR, 4.31; 95% CI, 1.99, 9.33). The age at which rhEPO was started was also a significant risk factor, with those starting rhEPO after 20 days of age having almost fourfold the risk of ROP compared with those starting it on or before 20 days of age (OR, 3.57; 95% CI, 1.59, 8.03).

CONCLUSIONS

rhEPO was found to be a significant independent risk factor for the development of ROP.

Risk factors for acute retinopathy of prematurity

We prospectively studied the risk factors and the incidence of retinopathy of prematurity (ROP) in 195 consecutive preterm infants. Birth weight and duration of mechanical ventilation were the only factors that were significantly associated with the incidence of ROP. While indomethacin increases the risk of developing ROP, maternal antenatal steroids have a protective effect against the development of severe stages of ROP. The presence of intraventricular hemorrhage increases the risk of severe ROP.

Indomethacin prophylaxis or expectant treatment of patent ductus arteriosus in extremely low birth weight infants?

BACKGROUND

Indomethacin prophylaxis or expectant treatment are common strategies for the prevention or management of symptomatic patent ductus arteriosus (sPDA).

OBJECTIVE

To compare the clinical responses of extremely low birth weight (ELBW) infants to indomethacin prophylaxis with that of other infants who were managed expectantly by being treated with indomethacin or surgically only after an sPDA was detected.

METHODS

Retrospective cohort investigation of 167 ELBW infants who received indomethacin prophylaxis (study) and 167 ELBW infants (control) treated expectantly who were matched by year of birth (1999 to 2006), birth weight, gestational age (GA) and gender.

RESULTS

Mothers of the two groups of infants were comparable demographically and on the history of preterm labor, pre-eclampsia, antepartum steroids and cesarean delivery. Study and control infants were similar in birth weight, GA, low 5 min Apgar scores, surfactant administration, the need for arterial blood pressure control, bronchopulmonary dysplasia and neonatal mortality. Necrotizing enterocolitis, spontaneous intestinal perforations, intraventricular hemorrhage grade III to IV, periventricular leukomalacia and stage 3 to 5 retinopathy of prematurity occurred also with similar frequency in both groups of infants. In the indomethacin prophylaxis group, 29% of the infants developed sPDA, and of them 38% responded to indomethacin treatment. In the expectantly treated group, 37% developed sPDA, and of them 59% responded to indomethacin treatment. Overall, surgical ligation rate for sPDA was similar between both groups of patients.

CONCLUSION

In our experience, indomethacin prophylaxis does not show any advantages over expectant early treatment on the management of sPDA in ELBW infants. Although no deleterious effects were observed, prophylaxis exposed a significant number of infants who may have never developed sPDA, to potential indomethacin-related complications.

Risk factors for acute retinopathy of prematurity

We prospectively studied the risk factors and the incidence of retinopathy of prematurity (ROP) in 195 consecutive preterm infants. Birth weight and duration of mechanical ventilation were the only factors significantly associated with the incidence of ROP. While indomethacin increases the risk of developing ROP, maternal antenatal steroids have a protective effect against the development of severe stages of ROP. The presence of intraventricular hemorrhage increases the risk of severe ROP.

Variation in rates of severe retinopathy of prematurity among neonatal intensive care units in the Australian and New Zealand Neonatal Network

AIM

To analyse variations in rates of severe retinopathy of prematurity (ROP) among neonatal intensive care units (NICUs) in the Australian and New Zealand Neonatal Network (ANZNN), adjusting for sampling variability and for case mix.

METHODS

25 NICUs were included in the study of 2105 infants born at less than 29 weeks in 1998 and 1999, who survived to 36 weeks post-menstrual age and were examined for ROP. The observed NICU rates of severe ROP were adjusted for case mix using logistic regression on gestation, weight for gestational age and sex, and for sampling variability using shrinkage estimates. The corrected rate in the best 20% of NICUs was identified and NICU variations in rates were compared with those in 2000-1.

RESULTS

The overall (unadjusted) rate of severe ROP in the NICUs was 9.6% (interquartile range 5.4-12.8%). After adjusting for both case mix and sampling variability there remained significant variation among the NICUs. 20% of NICUs had a rate of severe ROP </=5.9%. Variation in rates among NICUs showed a similar pattern in both time periods. If the overall network rate was reduced to 5.9%, the 20th centile of the adjusted rates, there would be 79 fewer cases in a 2 year period, in contrast with 26 fewer if rates in the two units with excess rates improved to the average.

CONCLUSIONS

Considerable variation in rates of severe ROP among NICUs remained after adjustment for case mix and sampling variability. These data will facilitate investigation of potentially better practices associated with a reduced risk of severe ROP.

Trends in the incidence of severe retinopathy of prematurity in a geographically defined population over a 10-year period

OBJECTIVE

To examine trends in the incidence of severe (> or =grade 3) retinopathy of prematurity (ROP) in infants with birth weight of < or =1250 g in a geographically defined population over a 10-year period.

METHODS

An observational study was conducted of all infants who had a birth weight < or =1250 g and were born to mothers who were resident in the county of Leicestershire, United Kingdom, during the period January 1, 1990, to December 30, 1999. Cases were identified by the Trent Neonatal Survey. The incidence of severe ROP (> or =grade 3) was compared in 2 successive 5-year periods: 1990-1994 and 1995-1999.

RESULTS

Comparing the first 5-year period (1990-1994) with the second (1995-1999), the total number of live births fell (60 789 vs 56 564). However, there was a significant increase in the number of births with birth weight < or =1250 g (including live and dead; 615 vs 734; live births only: 455 vs 556). Survival to 42 weeks of infants who were born at < or =1250 g was significantly better in the latter time period (203 vs 302; odds ratio [OR] for death: 0.54; 95% confidence interval [CI]: 0.39-0.75). The number of cases of severe ROP was 4 times higher during the second time period compared with the first (9 vs 36). A significantly increased risk for the development of severe ROP was seen during the second time period (OR: 2.92; 95% CI: 1.37-6.20). Even after allowing for the change in gestation induced by the improved survival during the second time period, the increased risk remained (OR: 2.81; 95% CI: 1.27-6.21).

CONCLUSIONS

There is strong evidence that the incidence of severe ROP among infants with birth weight < or =1250 g increased in the latter half of the last decade. The increased risk seems to be independent of the increase in survival.

Screening for retinopathy of prematurity: results of a retrospective 3-year study of 502 infants

PURPOSE

To describe the surveillance, results of screening, and treatment of retinopathy of prematurity (ROP) in a university hospital setting in southeast France.

PATIENTS AND METHODS

Five hundred two premature infants were included in the screening protocol between January 1997 and December 1999. Criteria for inclusion in the study were a gestational age of 32 weeks or younger, a birth weight of less than 1,501 g, or both. The first fundus examination was performed between 4 and 6 weeks of life. Thereafter, fundus examination was performed in the absence of ROP every 2 weeks until complete retinal vasculature developed, gestational age of 50 weeks, or death. Examination was weekly in cases of retinopathy, biweekly if progression was ascertained, and less frequent only if regression was evident. Hospital records were reviewed to assess the presence or absence and eventual degree of ROP.

RESULTS

Stage 1 was observed in 32 infants, and stage 2 in 11 infants; all of these cases regressed. Three cases of bilateral stage 3 (two threshold and one prethreshold) disease underwent diode laser peripheral retinal ablation and regressed. One infant with bilateral stage 3 disease who underwent peripheral cryoablative surgery progressed to stage 4A in one eye and 4B in the other eye and then underwent scleral buckling surgery in the second eye.

CONCLUSIONS

Despite survival increasing with improved neonatal intensive care, the incidence of ROP does not appear to be increasing. In our center, the incidence appears to be lower than previously reported.

Retinopathy of prematurity: causation

The incidence of ROP is birth weight dependent and restricting therapeutic oxygen levels has dramatically reduced the incidence of ROP in infants of birth weight >1000 g. However, the incidence of ROP has remained high in very low birth weight (VLBW) infants and this appears to be related to these babies being more ill. Several risk factors have been identified in this group, however oxygen variability, rather than high levels, has been correlated with severity of disease in recent clinical and animal studies. Difficulties in defining 'normal' oxygen in this group has meant the optimal range of oxygen therapy has not yet been defined. Clinical studies are now underway using even lower oxygen therapy ranges. The impact this may have on ROP, neurological and respiratory outcomes will require further study.

Breast milk feeding and cognitive ability at 7-8 years

OBJECTIVE

To examine the association between duration of breast milk feeding and cognitive ability at 7-8 years in a birth cohort of very low birthweight infants.

DESIGN

280 survivors from a national birth cohort of 413 New Zealand very low birthweight infants born in 1986 were assessed at age 7-8 years on measures of verbal and performance intelligence quotient (IQ) using the WISC-R. At the same time mothers were questioned as to whether they had elected to provide expressed breast milk at birth and the total duration of breast milk feeding.

RESULTS

Some 73% of mothers provided expressed breast milk and 37% breast fed for four months or longer. Increasing duration of breast milk feeding was associated with increases in both verbal IQ (p < 0.001) and performance IQ (p < 0.05): children breast fed for eight months or longer had mean (SD) verbal IQ scores that were 10.2 (0.56) points higher and performance IQ scores that were 6.2 (0.35) points higher than children who did not receive breast milk. These differences were substantially reduced after control for selection factors associated with receipt of breast milk. Nevertheless, even after control for confounding, there remained a significant (p < 0.05) association between duration of breast milk feeding and verbal IQ: children breast fed for eight months or longer had adjusted mean (SD) verbal IQ scores that were 6 (0.36) points higher than the scores of those who did not receive breast milk.

CONCLUSIONS

These findings add to a growing body of evidence to suggest that breast milk feeding may have small long term benefits for child cognitive development.

Poor postnatal weight gain: a risk factor for severe retinopathy of prematurity

PURPOSE

This study aimed to investigate the relationship between rate of postnatal weight gain and severity of retinopathy of prematurity (ROP).

METHODS

All infants (n = 111) screened for ROP at a single tertiary intensive care nursery over a 2-year period with an estimated gestational age of 30 weeks or less and follow-up to at least 42 weeks' postconception were included. The authors performed a retrospective review of records and statistical analysis of risk factors for ROP using multivariate analysis.

RESULTS

Infants with severe (stage 3 or greater) ROP gained an average 10.9 g/kg per day in the first 6 weeks of life, compared to a mean of 9.6 g/kg per day for those with mild or no ROP (P =.04). By multiple regression, which included birth weight, gestational age, and 9 other reported risk factors, there was an association between rate of postnatal weight gain and severity of ROP (P =.02). By stepwise regression, 4 variables were associated with ROP severity: estimated gestational age at birth (P =.002), rate of postnatal weight gain (P = .0002), volume of transfused erythrocytes (P =.0001), and culture-proven sepsis (P = .02).

CONCLUSION

Poor postnatal weight gain is a risk factor for the development of severe (stage 3 or greater) ROP. Ophthalmologists should take note of those infants who gain less than 50% of their birth weight in the first 6 weeks of life.

Severity of neonatal retinopathy of prematurity is predictive of neurodevelopmental functional outcome at age 5.5 years. Behalf of the Cryotherapy for Retinopathy of Prematurity Cooperative Group

OBJECTIVE

The purpose of this study was to assess the relation between neonatal retinopathy of prematurity (ROP) in very low birth weight infants and neurodevelopmental function at age 5.5 years.

METHODS

Longitudinal follow-up of children occurred in 2 cohorts of the Multicenter Cryotherapy for Retinopathy of Prematurity Study. The extended natural history cohort followed 1199 survivors of <1251 g birth weight from 5 centers. The threshold randomized cohort (ThRz) followed 255 infants <1251 g from 23 centers who developed threshold ROP and who consented to cryotherapy to not more than 1 eye. At 5.5 years both cohorts had ophthalmic and acuity testing and neurodevelopmental functional status determined with the Functional Independence Measure for Children (WeeFIM).

RESULTS

Evaluations were completed on 88.7% of the extended natural history cohort; 87% had globally normal functional skills (WeeFIM: >95). As ROP severity increased, rates of severe disability increased from 3.7% among those with no ROP, to 19.7% of those with threshold ROP. Multiple logistic regression analysis demonstrated that better functional status was associated with favorable visual acuity, favorable 2-year neurological score, absence of threshold ROP, having private health insurance, and black race. Evaluations were completed on 87.4% of the ThRz children. In each functional domain, the 134 children with favorable acuity in their better eye had fewer disabilities than did the 82 children with unfavorable acuity: self-care disability 25.4% versus 76.8%, continency disability 4.5% versus 50.0%, motor disability 5.2% versus 42.7%, and communicative-social cognitive disability 22.4% versus 65.9%, respectively.

CONCLUSION

Severity of neonatal ROP seems to be a marker for functional disability at age 5. 5 years among very low birth weight survivors. High rates of functional limitations in multiple domains occur in children who had threshold ROP, particularly if they have unfavorable visual acuity.

Very low birthweight and asthma by age seven years in a national cohort

Several studies have suggested that very low birthweight (VLBW < 1500 g) is associated with increased rates of respiratory problems in childhood and that the presence of chronic lung disease further increases the risk. We aimed to assess rates of asthma at 7-8 years of age in a national cohort of VLBW infants born in 1986 and for whom perinatal data were available. Two hundred ninety-nine former VLBW children (96% of surviving children living in New Zealand) were assessed at a home visit. Parents were asked a comprehensive questionnaire, including three questions aimed at assessing morbidity from asthma: 1) was the child diagnosed as having asthma before age 7 years; 2) was the child still experiencing asthma at the age of 7 years; and 3) was the child prescribed daily medication for asthma at the age of 7 years. Overall, 50% of the cohort had been diagnosed with asthma before age 7, compared with 27% of a sample of New Zealand children assessed contemporaneously in an international study; 32% had asthma at age 7, and 11% were taking daily medication. All three categories of asthma were associated with a family history of asthma, but there was no association with any perinatal factors. A diagnosis of asthma before age 7 was more likely when the mother smoked in pregnancy (P < 0.005) and currently smoked (P < 0.01), and trended so when parents lacked high school qualifications and in Maori or Pacific Island families (P < 0.10). In contrast, daily medication was more frequent when parents had educational qualifications and in non-Maori or Pacific Island families (P < 0.05). On multiple logistic regression, a family history of asthma was a significant predictor for any and current asthma (P < 0.001) and daily medication (P < 0.05); maternal smoking in pregnancy was a significant predictor for any asthma (P < 0.05); and non-Maori or Pacific Island ethnicity was a significant predictor for asthma treatment (P < 0.05). We conclude that rates of childhood asthma are high in this VLBW cohort, but the high prevalence appears to be unrelated to perinatal factors, including respiratory morbidity. There are suggestions that social factors contribute to both asthma risk and treatment.

Severe retinopathy of prematurity and its association with different rates of survival in infants of less than 1251 g birth weight

BACKGROUND

There is controversy over whether improved survival of preterm infants has resulted in a higher incidence of severe (grade 3 or greater) retinopathy of prematurity (ROP).

AIM

To compare survival rates and rates of > or = stage 3 ROP-that is, with a high risk of sequelae-in preterm infants in five English cities where, anecdotally, the incidence of ROP is reported to show considerable variation.

METHODS

All infants of birth weight < 1500 g and or gestational age < 32 weeks, born in 1994 in one of the cities or transferred in within 48 hours, were studied. The populations were adjusted for case mix variation using CRIB (clinical risk index for babies, a disease severity scoring system). The incidence of severe ROP, the actual death rate, and that adjusted for disease severity were determined.

RESULTS

The rate of severe ROP per 1000 births was higher in city 1 than in all the other cities. This increase in comparison with city 2 and city 4 was significant (city 1, 167 (95% confidence interval (CI) 96 to 260); city 2, 24 (6 to 59); city 4, 16 (1 to 84)). A significant difference was not seen between city 1 and cities 3 (23 (1 to 120)) and 5 (74 (21 to 79)). The relative risk of developing severe ROP in city 1 compared with all the other cities was 5.5 (2.5 to 11.9). The actual death rate per 1000 births in city 1 was significantly lower than that predicted by modelling death against CRIB score (city 1: actual 270; predicted 385 (95% CI 339 to 431)). In contrast, the other cities had actual death rates as predicted, or worse than predicted, by CRIB.

INTERPRETATION

A significantly higher incidence of severe ROP was identified in one of the five cities studied. Variation in survival rates among high risk infants may explain this observation.

A comparison of dense versus less dense diode laser photocoagulation patterns for threshold retinopathy of prematurity

OBJECTIVE

To determine if the density of diode laser photocoagulation for the treatment of zone 1 or zone 2 threshold retinopathy of prematurity (ROP) affects the rate of progression of the disease.

DESIGN

Retrospective, nonrandomized, comparative trial (n = 12) and prospective, randomized, clinical trial (n = 46).

PARTICIPANTS

Two surgeons treated a total of 107 eyes from 58 patients with zone 1 or zone 2 threshold ROP within 72 hours of diagnosis. The two consecutive groups of patients were treated with two different diode laser photocoagulation patterns between May 1995 and October 1997 and were observed for at least 3 months.

INTERVENTION

All patients underwent diode laser photocoagulation of the peripheral avascular retina extending from the ridge of extraretinal proliferation to the ora serrata. One cohort received a near confluent laser pattern, whereas the second cohort received a pattern of laser spots placed 1 to 1.5 burn widths apart.

MAIN OUTCOME MEASURES

Anatomic outcome, rate of progression to stage 4 or 5 retinopathy of prematurity, postoperative complications, and timing and frequency of retreatment.

RESULTS

For analysis, the retrospective and randomized outcome data were grouped. The rate of progression in the near confluent laser treatment group was 3.6% overall, 0% of zone 1 eyes, and 3.8% of zone 2 eyes. The rate of progression in the less dense treatment group was 29% overall, 44% of zone 1 eyes, and 21 % of zone 2 eyes. Mean time to retreatment was 16 days in cohort 1 and 24 days in cohort 2.

CONCLUSIONS

A dense pattern of diode laser treatment for threshold ROP and prompt retreatment for residual plus disease significantly reduce the rate of progression in eyes with zone 2 disease (P = 0.02) and may be beneficial in eyes with zone 1 disease.

Randomized double-blind controlled trial comparing the effects of ibuprofen with indomethacin on cerebral hemodynamics in preterm infants with patent ductus arteriosus

A prospective randomized controlled trial was performed to compare the effects of ibuprofen with indomethacin on cerebral hemodynamics measured using near infrared spectroscopy in preterm infants during treatment for patent ductus arteriosus. Infants were randomly assigned to three intravenous doses of either indomethacin (0.20-0.25 mg/kg, 12 hourly) or ibuprofen (5-10 mg/kg, 24 hourly) and also received a dose of saline. The primary end points of the study were the effects of the first dose on cerebral blood flow (CBF) and cerebral blood volume. Fifteen infants received indomethacin and 18 received ibuprofen. The group mean (SD) values for CBF (mL x 100 g(-1) x min(-1)) before and after the first dose of indomethacin were 13.6 (4.1) and 8.3 (3.1), respectively, the change being significant (p<0.001). In contrast, no significant changes in CBF were observed with the first dose of ibuprofen, the respective before and after values being 13.3 (3.2) and 14.9 (4.7) mL x 100 g(-1) x min(-1). The median (interquartile range) value for change in cerebral blood volume (mL/100 g) after the first dose in the indomethacin group was -0.4 (-0.3 to -0.6) and in the ibuprofen group was 0.0 (0.1 to -0.1), the difference between the two groups being significant (p<0.001). Cerebral oxygen delivery changed significantly after the first dose in the indomethacin group but not in the ibuprofen group. Significant reductions in CBF, cerebral blood volume, and cerebral oxygen delivery also occurred after the 24-h dose of indomethacin, but there were no significant changes after the 48-h dose of saline in the indomethacin group or after the 24- and 48-h doses of ibuprofen. The patent ductus arteriosus closure rates after indomethacin and ibuprofen were 93 and 78%, respectively. We conclude that ibuprofen, unlike indomethacin, has no adverse effects on cerebral hemodynamics and appears to mediate patent ductus arteriosus closure.

Prospective study of New Zealand infants with birth weight less than 1500 g and screened for retinopathy of prematurity: visual outcome at age 7-8 years

AIM

To determine the visual outcome at 7-8 years in very low birth weight (VLBW: birth weight < 1500 g) infants screened for retinopathy of prematurity (ROP).

METHODS

In 1986 all 413 VLBW infants admitted to neonatal units in New Zealand were enrolled in a prospective study of acute ROP. Surviving infants were traced and assessed at a home visit. Visual assessment comprised examination for abnormal and range of eye movements, visual fields, distance and near visual acuity, stereopsis, and photorefraction.

RESULTS

Of 338 infants surviving to discharge, 313 (93%) had been examined for acute ROP. ROP was present in 66 (21%: ROP+), absent in 247 (ROP-), with 25 not examined (NA). 298 children (96% survivors resident in New Zealand: 91% all survivors) were assessed. Any visual problem occurred in 79% ROP+ and 60% ROP-/NA (p < 0.01). Distance visual acuity less than 4/10 in the worse eye occurred in 29% ROP+ and 15% ROP-/NA (p < 0.05); and in the better eye in 19% ROP+ and 5% ROP-/NA (p < 0.001). Any myopia in the worse eye occurred in 36% ROP+ and 18% ROP-/NA (p < 0.01); and in the better eye in 25% ROP+ and 11% ROP-/NA (p < 0.01). Strabismus, including treated, occurred in 33% ROP+ and 19% ROP-/NA (p < 0.05). Overall, 11% had astigmatism and 18% hypermetropia with no difference between the groups.

CONCLUSION

In a population based study it was confirmed that VLBW is associated with an increased risk of visual problems at school age. A history of ROP is associated with an additional risk of poor outcome, including a near doubling of poor distance acuity, myopia, and strabismus.

Prospective study of New Zealand very low birthweight infants: outcome at 7-8 years

OBJECTIVE

To determine the survival and sensorineural outcome at 7-8 years in very low birthweight (VLBW) infants born in New Zealand in 1986.

METHODOLOGY

In 1986 all VLBW New Zealand infants admitted to neonatal units were enrolled in a prospective study of acute retinopathy of prematurity. Surviving infants were traced and were assessed at a home visit. Parents were asked a comprehensive questionnaire, and children underwent a visual assessment including photorefraction and were tested with the Revised Wechsler Intelligence Scale for Children (WISC-R).

RESULTS

Four hundred and thirteen VLBW infants were admitted to neonatal units in 1986, 338 (81.8%) surviving to discharge, 12 children died after discharge, 17 were traced to overseas, seven declined to participate and four were untraced, leaving 298 (96% survivors resident in New Zealand) who were assessed at a mean age of 7.6 (+/- 0.4 years, 15 children (5.0%) had severe disability, 14 (4.7%) moderate disability, and 46 (15.4%) mild disability. Blindness (vision worse than 6/60) occurred in eight children (2.7%), deafness requiring aids in four (1.3%), any form of cerebral palsy in 17 (5.7%), and an JQ score on the WISC-R > 1 SD below the mean in 62 (20.8%). There was no significant difference in outcome for children with birthweight < 1000 g and 1000-1499 g.

CONCLUSIONS

Long-term (7-8 year) survival and disability rates in this national cohort of VLBW infants is comparable with that reported from other populations. Although a majority of children have no disability a sizeable proportion do perform poorly on the WISC-R. This may relate in part to problems such as a short attention span and poor visual-motor integration.

Risk factors associated with retinopathy of prematurity (ROP) in northern Jutland, Denmark 1990-1993

This population-based, historical, follow-up study analysed possible risk factors for retinopathy of prematurity (ROP) and resulting visual impairment in newborns over a period of 3 1/2 years in the County of Northern Jutland, Denmark. The study subjects were 141 infants with birth weight < or = 1500 grams and gestational age < 35 completed weeks who survived to a first eye examination at 5 weeks. The incidence of ROP (all stages) was 18%, and the frequency of severe visual impairment from ROP was 14/100,000 live births. A logistic regression analysis identified low gestational age, multiple births, continuous oxygen treatment, and male sex as risk factors for ROP. The main factor in the prevention of ROP is to prevent preterm births.

Duration of oxygen therapy and exchange transfusion as risk factors associated with retinopathy of prematurity in very low birthweight infants

One hundred and thirteen consecutive infants with a very low birthweight of less than 1500 g were followed prospectively for 6 months to determine the incidence of retinopathy of prematurity (ROP) and associated risk factors. Of this group, 36 (31.9%) infants developed ROP (13 infants had stage 1 ROP, nine had stage 2, six had stage 3, six had stage 4, and two had cicatricial stage ROP). Stepwise logistic regression analysis of various potential risk factors (birthweight, gestation, duration of oxygen therapy, duration of ventilation, highest documented PaO2 and exchange transfusion) showed that only two risk factors were significantly associated with the development of ROP. These risk factors were: the duration of oxygen therapy (p = 0.0005) and exchange transfusion during the neonatal period (odds ratio 5.754, 95% confidence interval 1.002 to 32.997, p = 0.049). The equation of the regression model is: log (odds of developing ROP) = -0.8395 + 0.1447 (OXY)- 0.8750 (ET), where OXY is the duration of oxygen therapy in days, ET = -1 when there was a history of exchange transfusion, and ET = 1 when there was no history of exchange transfusion.

Outcome of neonates transported between Level III centres depends upon centre of care

This study aimed to clarify whether the adverse outcomes seen in babies transported between New Zealand Level III intensive care nurseries were due to the transport itself or to possible differences in care in different centres. The outcomes of 34 infants inborn at National Women's Hospital, Auckland but transported to other centres were compared with those of 68 matched controls inborn at the receiving centres and with 68 controls inborn and cared for at National Women's Hospital. Transport was associated with a transient (non-significant) deterioration in respiratory status but no increase in chronic lung disease. However, infants cared for elsewhere, whether transported or control, had more periventricular hemorrhage than Auckland babies (23% and 29% vs 15%, P = 0.03) and worse neurodevelopmental outcome (70% and 66% vs 88% of those whose outcomes were known were normal at follow up, P = 0.002). We conclude that differences in care between centres may be more important than the transport itself in determining the long-term outcome of transported neonates.

Retinopathy of prematurity

Retinopathy of prematurity (ROP) remains a nonpreventable disorder associated with extreme prematurity. Recent advances in establishing the International Classification of ROP have facilitated both clinical care and research, highlighted by the demonstration of the effectiveness of cryoablative therapy for vision-threatening ROP. For those individuals who have ROP, early and life-long ophthalmic follow-up is critical. This is true for those with any residual retinal scars that we now know can lead to later vision loss as well as those who require services for the visually impaired.

Adverse effects of neonatal transport between level III centres

The effect of neonatal transport between level III intensive care nurseries was studied by comparing the outcome of 40 infants inborn at a regional level III centre but transported to other level III nurseries for intensive care, with 80 matched inborn controls. Transport appeared to affect respiratory status adversely but transiently. However, transported infants grew less well than control infants (32% were below 3rd centile for weight at 36 weeks vs 15% of controls), were more likely to suffer periventricular haemorrhage (40 vs 21% of controls) and had a worse neurodevelopmental outcome (70% normal at follow up vs 83% of controls). It can be concluded that for infants inborn at the National Women's Hospital, Auckland, transport to another level III centre for intensive care is associated with an increased risk of adverse outcome.

Retinopathy of prematurity

ROP is a common disorder among extremely low-birth-weight premature infant survivors and may cause total vision loss in as many as 2% to 4% of those weighing less than 2 lb (1 kg) at birth. Regular examinations begun in the intensive care unit permit early detection and treatment of progressive ROP, reducing visual impairment. Ongoing research into antioxidants, angiogenesis, light exposure, and newer surgical techniques may offer new approaches for preventing and treating established ROP. Infants who have had ROP that regressed should continue regular ophthalmologic follow-up to detect and treat myopia, strabismus, and if they have cicatricial sequelae, late retinal detachments as teens or adults. Infants who develop retinal detachments should be referred for early intervention and special education programs and remain in regular ophthalmologic follow-up for the detection and treatment of further ophthalmic complications.

Chronic lung disease in very low birthweight infants: a prospective population-based study

A prospective population-based study of chronic lung disease among all very low birthweight infants (birthweight 500-1499 g) born in New Zealand in 1986 is reported. Of 413 of these infants admitted to neonatal units, 355 (86%) survived to 28 days. An additional 50 infants were recorded as liveborn but died in the labour ward or other place of birth. Both observed survival and survival adjusted for birthweight, gestation and gender were significantly (P less than 0.05) better in larger centres. Oxygen requirement was assessed at 28 days of age, 36 weeks equivalent gestation and 84 days of age, when 38.6, 23.1 and 13.8% of infants, respectively, were being treated with oxygen. To examine the joint effects of predictor variables on oxygen requirement at each age, the data were analysed using multiple logistic regression methods. At 28 days, lower birthweight, shorter gestation, respiratory distress syndrome (all P less than 0.0001), and gender and hospital principally caring for the infant (both P less than 0.05) were significantly associated with treatment with oxygen. In comparison with other studies, New Zealand appears to have a relatively high rate of chronic lung disease. We speculate that a contributing factor may be the small size of some regional neonatal units.