Inhibitory effects of maternal smoking on the development of severe retinopathy of prematurity

Systemic Factors Associated with a Thinner Choroid in Preterm Infants

Purpose

To identify systemic health factors associated with a thinner choroid, which has been hypothesized as a cause of poor visual outcomes in low–birth weight infants.

Design

The prospective, observational Study of Eye Imaging in Preterm Infants (BabySTEPS) enrolled infants recommended for retinopathy of prematurity screening based on the American Association of Pediatrics guidelines.

Participants

Infants who underwent imaging with investigational handheld OCT at 36 ± 1 weeks’ postmenstrual age (PMA) as part of BabySTEPS.

Methods

Average choroidal thickness was measured across the central subfoveal 1 mm. We concurrently collected maternal and infant clinical health data. Univariate and multivariate linear regression analyses were performed to evaluate factors associated with choroidal thickness. The left and right eyes showed similar thicknesses, so their average was used for analysis.

Main Outcomes Measures

Association between infant health factors and subfoveal choroidal thickness.

Results

Subfoveal choroidal thickness was measurable in 82 of 85 infants and 94% of eyes. Mean choroidal thickness was 231 ± 78 μm. In the univariate analysis, a thinner choroid was associated with decreased growth velocity (P < 0.001), lower birth weight (P < 0.001), smaller head circumference (P < 0.001), younger gestational age (P = 0.01), the presence of patent ductus arteriosus (P = 0.05), sepsis or necrotizing enterocolitis (P = 0.03), bronchopulmonary dysplasia (P = 0.03), pulmonary interstitial emphysema (P = 0.002), more days on oxygen support (P < 0.001), and being on oxygen support at 36 weeks (P < 0.001) and at the time of imaging (P < 0.001). In the multivariate analysis, growth velocity (P = 0.002) and oxygen support at the time of OCT imaging (P = 0.004) remained associated with a thinner choroid.

Conclusions

A thinner choroid is associated independently with growth velocity and receiving oxygen support at 36 ± 1 weeks PMA. This suggests that choroidal development in preterm infants may be related to growth rate in the first weeks of life and the prolonged use of supplemental oxygen. Longitudinal studies are needed to assess differences in choroidal thickness before 36 weeks PMA and to assess their impact on visual outcomes.

How to prevent ROP in preterm infants in Indonesia?

BACKGROUND AND AIMS

Retinopathy of prematurity (ROP) is a severe disease in preterm infants. It is seen more frequently in Low-Middle Income Countries (LMIC) like Indonesia compared to High-Income Countries (HIC). Risk factors for ROP development are -extreme- preterm birth, use of oxygen, neonatal infections, respiratory problems, inadequate nutrition, and blood and exchange transfusions. In this paper, we give an overview of steps that can be taken in LMIC to prevent ROP and provide guidelines for screening and treating ROP.

METHODS

Based on the literature search and data obtained by us in Indonesia's studies, we propose guidelines for the prevention, screening, and treatment of ROP in preterm infants in LMIC.

RESULTS

Prevention of ROP starts before birth with preventing preterm labor, transferring a mother who might deliver <32 weeks to a perinatal center and giving corticosteroids to mothers that might deliver <34 weeks. Newborn resuscitation must be done using room air or, in the case of very preterm infants (<29-32 weeks) by using 30% oxygen. Respiratory problems must be prevented by starting continuous positive airway pressure (CPAP) in all preterm infants <32 weeks and in case of respiratory problems in more mature infants. If needed, the surfactant should be given in a minimally invasive manner, as ROP's lower incidence was found using this technique. The use of oxygen must be strictly regulated with a saturation monitor of 91-95%. Infections must be prevented as much as possible. Both oral and parenteral nutrition should be started in all preterm infants on day one of life with preferably mothers' milk. Blood transfusions can be prevented by reducing the amount of blood needed for laboratory analysis.

DISCUSSION

Preterm babies should be born in facilities able to care for them optimally. The use of oxygen must be strictly regulated. ROP screening is mandatory in infants born <34 weeks, and infants who received supplemental oxygen for a prolonged period. In case of progression of ROP, immediate mandatory treatment is required.

CONCLUSION

Concerted action is needed to reduce the incidence of ROP in LMIC. "STOP - R1O2P3" is an acronym that can help implement standard practices in all neonatal intensive care units in LMIC to prevent development and progression.

Maternal smoking as an independent risk factor for the development of severe retinopathy of prematurity in very preterm infants

BACKGROUND/OBJECTIVES

Retinopathy of prematurity (ROP) is a severe neonatal complication potentially leading to visual impairment and blindness. Known risk factors include preterm birth, low birth weight and respiratory support. Limited and contradictory data exist on the risk of maternal smoking during pregnancy on the development of ROP. This study aims to investigate smoking as an independent risk factor for the development of severe ROP (≥stage 3).

SUBJECTS/METHODS

This is a single centre retrospective case-control study of prospectively collected clinical data of infants born before 32 weeks of gestation between 2001 and 2012 at a tertiary care university hospital. The association between maternal smoking during pregnancy and the development of severe ROP was analyzed by multivariate logistic regression.

RESULTS

In total, n = 751 infants born < 32 weeks of gestation were included in this study. In total, 52.9% (n = 397) were diagnosed with ROP and 10.8% (n = 81) developed ROP ≥ stage 3. In total, 8.4% (n = 63) mothers presented with a history of smoking during pregnancy, which was associated to a higher rate of ROP (OR 2.59, 95% CI 1.10-6.12). Low gestational age, low birth weight and prolonged respiratory support were confirmed as independent risk factors for the development of severe ROP.

CONCLUSIONS

To date, this is the largest study evaluating the effect of maternal smoking on the development of ROP. Maternal smoking during pregnancy is identified as an independent risk factor for the development of severe ROP in preterm infants born < 32 weeks of gestation.

Current evidence and outcomes for retinopathy of prematurity prevention: insight into novel maternal and placental contributions

Retinopathy of prematurity (ROP) is a blinding morbidity of preterm infants, which represents a significant clinical problem, accounting for up to 40% of all childhood blindness. ROP displays a range of severity, though even mild disease may result in life-long visual impairment. This is complicated by the fact that our current treatments have significant ocular and potentially systemic effects. Therefore, disease prevention is desperately needed to mitigate the life-long deleterious effects of ROP for preterm infants. Although ROP demonstrates a delayed onset of retinal disease following preterm birth, representing a potential window for prevention, we have been unable to sufficiently alter the natural disease course and meaningfully prevent ROP. Prevention therapeutics requires knowledge of early ROP molecular changes and risk, occurring prior to clinical retinal disease. While we still have an incomplete understanding of these disease mechanisms, emerging data integrating contributions of maternal/placental pathobiology with ROP are poised to inform novel approaches to prevention. Herein, we review the molecular basis for current prevention strategies and the clinical outcomes of these interventions. We also discuss how insights into early ROP pathophysiology may be gained by a better understanding of maternal and placental factors playing a role in preterm birth.

Extreme prematurity, treated retinopathy, bronchopulmonary dysplasia and cerebral palsy are significant risk factors for ophthalmological abnormalities at 6.5 years of age

AIM

This study evaluated the contributions of various prenatal and postnatal predictive factors to a documented high prevalence of ophthalmological abnormalities in children aged 6.5 years who were born extremely preterm.

METHODS

We carried out a prospective population-based study of all children born in Sweden at a gestational age of 22 + 0 to 26 + 6 weeks based on the Extremely Preterm Infants in Sweden Study. The main outcome measures were a combined score of visual impairment, refractive errors and strabismus at 6.5 years of age. Models of univariate and multivariable regression were used to analyse potential prenatal and postnatal predictive factors at different clinically relevant time-points from one minute after birth to 30 months.

RESULTS

We focused on 399 known extremely preterm survivors and compared them to 300 full-term controls. Significant antecedents for ophthalmological abnormalities included prematurity per se, retinopathy of prematurity that required treatment, severe bronchopulmonary dysplasia and cerebral palsy. Severe intraventricular haemorrhage was no longer a significant risk factor when we adjusted it for the 30-month cognitive and neuromotor development outcomes.

CONCLUSION

This time-course risk analysis model showed a changing panorama of significant risk factors for ophthalmological abnormalities in children aged 6.5 years who were born extremely preterm.

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.

Evaluation of Oxygen Supplementation Status as a Risk Factor Associated with the Development of Severe Retinopathy of Prematurity

Purpose: The effects of oxygen supplementation status and other clinical risk factors on the development of severe retinopathy of prematurity (ROP) were evaluated. Methods: Clinical records of 143 newborn infants with a gestational age of 32 weeks or less were reviewed. Severe ROP was diagnosed when photocoagulation due to progression to stage 3 was identified or when ‘plus disease' developed. The factors were evaluated with univariate and multivariate logistic regression analyses between the groups with severe (n = 24) and non-severe (n = 119) ROP. Results: Gestational age, birth weight, duration of oxygen supplementation, duration of directional positive air pressure and maximum fraction of inspiratory oxygen (FiO2) were significantly associated with severe ROP in the univariate analyses. In the multivariate analysis, a longer duration of oxygen supplementation and a higher maximum FiO2 were revealed as significant risk factors associated with severe ROP. Conclusions: Duration of oxygen supplementation and maximum FiO2 required were important factors associated with severe ROP.

Smoking during pregnancy and vision difficulties in children: a systematic review

Cigarette smoking during pregnancy is a major public health concern. Intra-uterine exposure to maternal cigarette smoking is associated with increased risks of growth and neurodevelopmental problems during childhood and later life. Few studies have focussed on visual difficulties in children in the context of maternal smoking during pregnancy. A systematic search of online databases was carried out between February and May 2013 to examine the trend in visual outcomes in children exposed to maternal cigarette smoking during intra-uterine life. Twenty-four non-randomized studies were identified. Each study was rated for quality using the Newcastle-Ottawa Scale. Most studies (n = 18) reported fetal exposure to active or passive maternal cigarette smoking to be associated with an increased risk of adverse visual outcomes in children. In particular, there were higher rates of strabismus, refractive errors and retinopathy among children of women who smoked during pregnancy. These findings suggest that fetal exposure to cigarette smoke is a significant risk factor for visual problems during later life and that certain visual faculties, such as the intraocular muscles and retinal neurons, are more affected than others. The findings provide evidence in support of public health policies aimed at reducing fetal exposure to smoking by advising both women and their partners to quit smoking during pregnancy.

Incidence of retinopathy of prematurity and risk factors among premature infants at a neonatal intensive care unit in Canada

PURPOSE

To study the incidence of retinopathy of prematurity (ROP) in a neonatal intensive care unit and obtain information on risk factors associated with ROP.

METHODS

Four hundred twenty-three infants were screened for ROP between July 2006 and July 2010. Demographic information, clinical data, and risk factors were reviewed.

RESULTS

The incidence was 40.4% (171 infants) for ROP, 9.2% (39 infants) for severe ROP, and 5.67% (24 infants) for laser treatment. Mean gestational age and birth weight were significantly lower among infants with ROP versus those without ROP (26 ± 0.13 vs 28.55 ± 0.12 weeks, P < .0001 and 840.5 ±17.49 vs 1,190.24 ± 20.20 g, P < .0001, respectively). Birth weight (P < .001), gestational age (P < .001), mechanical ventilation therapy (P = .039), and necrotizing enterocolitis (P = .019) were independent risk factors for ROP.

CONCLUSION

Gestational age and birth weight were the most significant risk factors for developing ROP. The study population had an elevated percentage of infants with birth weight less than 1,000 g (extremely low birth weight), yet there was no corresponding increase in severe ROP incidence and treatment when compared to other studies.