Threshold stage of retinopathy of prematurity: maternal and neonatal risk factors

Modifiable Risk Factors and Preventative Strategies for Severe Retinopathy of Prematurity

Severe ROP is characterized by the development of retinal fibrovascular proliferation that may progress to retinal detachment. The purpose of this report is to review five of the most common and well-studied perinatal and neonatal modifiable risk factors for the development of severe ROP. Hyperoxemia, hypoxia, and associated prolonged respiratory support are linked to the development of severe ROP. While there is a well-established association between clinical maternal chorioamnionitis and severe ROP, there is greater variability between histologic chorioamnionitis and severe ROP. Neonatal sepsis, including both bacterial and fungal subtypes, are independent predictors of severe ROP in preterm infants. Although there is limited evidence related to platelet transfusions, the risk of severe ROP increases with the number and volume of red blood cell transfusions. Poor postnatal weight gain within the first six weeks of life is also strongly tied to the development of severe ROP. We also discuss preventative strategies that may reduce the risk of severe ROP. Limited evidence-based studies exist regarding the protective effects of caffeine, human milk, and vitamins A and E.

Retinopathy of prematurity and placental histopathology findings: A retrospective cohort study

Aim

Retinopathy of prematurity (ROP) is a biphasic vaso-proliferative disease that has the potential to cause blindness. In addition to prematurity and hyperoxia, perinatal infection and inflammation have been reported to play a critical role in the pathogenesis of ROP. The aim of this study was to assess the association between placental inflammation and the severity of ROP.

Methods

A retrospective study of infants (<30 weeks of gestational age) born at the King Edward Memorial Hospital, a tertiary perinatal center in Western Australia.

Results

A total of 878 infants were included in this study (ROP stage 0-2 = 829; 3 or more = 49). The presence of maternal chorioamnionitis appeared to show signs of an association with reduced odds of severe ROP: mild chorioamnionitis OR=0.43 (95% CI: 0.17, 1.05) and severe chorioamnionitis OR=0.68 (95% CI: 0.29, 1.60). A strong association was observed for oxygen supplementation at 36 weeks (OR: 5.16; p < 0.001), exposure to postnatal steroids (OR: 6.65; p < 0.001), and receipt of platelet transfusion (OR: 8.21; p < 0.001).

Conclusion

Maternal chorioamnionitis or fetal chorioamnionitis was associated with reduced odds of severe ROP. A strong association was found in infants who needed oxygen supplementation at 36 weeks and those who required steroids or platelets in the postnatal period.

The prenatal phase of retinopathy of prematurity

AIM

To explore the current literature on prenatal inflammation-associated risk factors for retinopathy of prematurity (ROP).

METHODS

Subjective summary of selected experimental and epidemiological publications that support the authors' central hypothesis that the aetiology of ROP begins before birth.

RESULTS

Based on current evidence we suggest that, contrary to current aetiological models, the process of ROP development begins with a prephase in utero. This beginning is likely initiated by inflammatory responses that are associated with intrauterine infection.

CONCLUSION

We propose a novel aetio-pathogenetic model of ROP and suggest that the effects of postnatal exposure to inflammatory stressors (resulting from infection or hyperoxia or both) as well as those of other pre- and postnatal contributors to the complex pathogenesis of ROP might be modified by the prenatal phase of the disease.

Retinopathy prematurity: a systematic review and meta-analysis study based on neonatal and maternal risk factors

BACKGROUND

Retinopathy of prematurity is the abnormal development of retinal arteries in preterm neonates less than 32 weeks and weighing 1500 g, and less, which can lead to visual impairment during life and blindness. This study aims to investigate the relationship between some clinical characteristics of neonates and mothers with Retinopathy of prematurity in the world via a systematic review and meta-analysis.

MATERIALS AND METHODS

The present study is a systematic review and meta-analysis on the relationship between maternal and neonatal clinical variables with Retinopathy of prematurity in the world from the beginning of 2000 to the end of 2020. Accordingly, all English articles published on the topic were searched in scientific databases of Web of Science, PubMed, Google Scholar, Science Direct, and Scopus. The articles were searched independently by two researchers. Statistical analysis of data was performed using fixed and random effects model statistical tests in the meta-analysis, Cochran, meta-regression, I² index, Funnel plot, and Begg's by STATA software program, version 14.

RESULT

A total of 191 studies with a sample size of 140,921 persons were including in the meta-analysis. Accordingly, Preterm delivery ≤28 weeks (OR:6.3, 95% CI:4.9-8.1), Birth Weight ≤1000 g (OR:5.8, 95% CI:4.8-6.8), Birth Weight ≤1500 g (OR:4.8, 95% CI:3.8-6.1), PROM (OR:1.2, 95% CI:1.0-1.4), induced fertility (OR:1.9, 95% CI:1.1-3.0) and Chorioamnionitis (OR:1.5, 95% CI:1.0-2.2) There was a statistically significant association with retinopathy.

CONCLUSION

Based on the results of the present meta-analysis, the risk of retinopathy of prematurity in neonates born at 28 weeks and less, LBW (weight 1500 g and less), neonatal hypotension, chorioamnionitis, and induced fertility increases.

Retinopathy of prematurity in infants without fetal growth restriction is decreased with the progression of acute histologic chorioamnionitis: New observation as a protective factor against retinopathy of prematurity

INTRODUCTION

IGF-1 deficiency in prenatal period is known to be a definite pathophysiology of retinopathy of prematurity(ROP), which is more frequent in infants with fetal growth restriction(FGR). Of note, recent reports demonstrated intra-amniotic inflammation(IAI) closely linked to acute histologic chorioamnionitis(acute-HCA) is associated with a decrease in intact-form of IGFBP-1, ultimately rising the probability of an increase in IGF-1. Therefore, we hypothesized ROP in preterm-infants without FGR would be decreased with the progression of acute-HCA.

METHODS

The frequency of ROP was examined in 85 singleton preterm-infants(24.5weeks ≤ gestational-age[GA] at delivery<30weeks) due to either preterm-labor and intact-membranes(PTL) or preterm premature rupture of membranes(preterm-PROM) without FGR(birth-weight<5th percentile for GA). Patients were divided according to the progression of inflammation in extra-placental membranes(EPM) and the progression of inflammation in chorionic-vessel(CV) and umbilical-cord(UC).

RESULTS

1) ROP was present in 40%(34/85) of study-population; 2) Of note, there was a significant stepwise-decrease in ROP with the progression of inflammation in EPM(inflammation-free EPM vs. inflammation restricted to CD vs. amnionitis; 55.6%[15/27]vs.39.5%[17/43]vs.13.3%[2/15]) and the progression of inflammation in CV and UC(inflammation-free CV and UC vs. inflammation restricted to CV and umbilical vessels vs. inflammation in Wharton's jelly[WJ]; 49.2%[29/59]vs.25.0%[3/12]vs.14.3%[2/14])(each-for P < 0.05, Chi-square test and each-for P < 0.01, linear-by-linear association); 3) Multiple logistic-regression analysis demonstrated amnionitis(Odds-Ratio 0.120, 95%Confidence-Interval 0.022-0.654, P = 0.014) and inflammation in WJ(Odds-Ratio 0.124, 95%Confidence-Interval 0.022-0.694, P = 0.018) were independent protective-factors against ROP.

DISCUSSION

ROP in preterm-infants due to PTL or preterm-PROM without FGR is decreased with the progression of acute-HCA. This finding may be an evidence to suggest the progression of acute-HCA is closely associated with reducing the pathophysiology of ROP.

Maternal and birth cohort studies in the Gulf Cooperation Council countries: a systematic review and meta-analysis

BACKGROUND

We systematically reviewed and chronicled exposures and outcomes measured in the maternal and birth cohort studies in the Gulf Cooperation Council (GCC) countries and quantitatively summarized the weighted effect estimates between maternal obesity and (1) cesarean section (CS) and (2) fetal macrosomia.

METHODS

We searched MEDLINE-PubMed, Embase, Cochrane Library, Scopus, and Web of Science electronic databases up to 30 June 2019. We considered all maternal and birth cohort studies conducted in the six GCC countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and United Arab Emirates (UAE)). We categorized cohort studies on the basis of the exposure(s) (anthropometric, environmental, medical, maternal/reproductive, perinatal, or socioeconomic) and outcome(s) (maternal or birth) being measured. Adjusted weighted effect estimates, in the form of relative risks, between maternal obesity and CS and fetal macrosomia were generated using a random-effects model.

RESULTS

Of 3502 citations, 81 published cohort studies were included. One cohort study was in Bahrain, eight in Kuwait, seven in Qatar, six in Oman, 52 in Saudi Arabia, and seven in the UAE. Majority of the exposures studied were maternal/reproductive (65.2%) or medical (39.5%). Birth and maternal outcomes were reported in 82.7% and in 74.1% of the cohort studies, respectively. In Saudi Arabia, babies born to obese women were at a higher risk of macrosomia (adjusted relative risk (aRR), 1.15; 95% confidence interval (CI), 1.10-1.20; I2 = 50%) or cesarean section (aRR, 1.21; 95% CI, 1.15-1.26; I2 = 62.0%). Several cohort studies were only descriptive without reporting the magnitude of the effect estimate between the assessed exposures and outcomes.

CONCLUSIONS

Cohort studies in the GCC have predominantly focused on reproductive and medical exposures. Obese pregnant women are at an increased risk of undergoing CS delivery or macrosomic births. Longer-term studies that explore a wider range of environmental and biological exposures and outcomes relevant to the GCC region are needed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017068910.

Cumulative evidence for association of sepsis and retinopathy of prematurity

BACKGROUND

Retinopathy of prematurity (ROP) is a retinal vasoproliferative disease affected by multiple factors such as infection and preterm birth. The role of sepsis in the development of ROP remains controversial. This systematic review and meta-analysis aimed to identify the impact of sepsis on ROP.

METHODS

The PubMed, Embase, and Cochrane Library databases were searched using terms related to sepsis and ROP. Cohort or case-control studies that reported the association of sepsis and ROP were eligible. The odds ratios (ORs) together with the 95% confidence interval (CI) were extracted from the studies or computed by authors if not provided.

RESULTS

Thirty-four studies were ultimately included in this meta-analysis. The pooled results showed that sepsis increased the risk for the development of any stage ROP (OR = 2.16; 95% CI: 1.65-2.82). Both early onset (OR = 2.50; 95% CI: 1.97-3.18) and late-onset (OR = 1.37; 95% CI: 1.22-1.55) sepsis were associated with severe ROP. Furthermore, both bacterial sepsis (OR = 1.74; 95% CI: 1.21-2.50) and fungal sepsis (OR = 2.96; 95% CI: 2.05-4.28) were also found to be associated with severe ROP.

CONCLUSION

Sepsis increased the risk of any stage ROP, especially for the severe ROP. Further high-quality clinical studies are needed to eliminate heterogeneity and publication bias to validate these findings.

Association between sepsis and retinopathy of prematurity: a systematic review and meta-analysis

OBJECTIVE

To explore the association between sepsis and retinopathy of prematurity (ROP) in premature infants.

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

We performed a systematic search of PubMed, the Cochrane Library and Embase from 1 January, 2000, to 1 January, 2018, with no language restrictions and reported the relationship between sepsis and ROP.

ELIGIBILITY CRITERIA

Original observational studies, including cohort studies and case-control studies.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently completed the study selection and data extraction. The OR and corresponding 95% CI were used to measure the risk of sepsis in patients with ROP. The heterogeneity between studies was evaluated using Cochran's Q test and the I2 statistic. The Newcastle-Ottawa Scale was adopted to evaluate the quality of each of the included studies, and the Grading of Recommendations Assessment, Development and Evaluation approach was used to assess the quality of the evidence.

RESULTS

Sixteen studies with a total sample size of 12 466 premature infants and 2494 cases of ROP were included in this meta-analysis. Adjusted analysis showed that sepsis was closely related to any stage of ROP (OR = 1.57, 95% CI 1.31 to 1.89) and severe stage of ROP (OR = 2.33, 95% CI 1.21 to 4.51) in premature infants, with 56.3% and 81.8% heterogeneity, respectively. Subgroup analyses showed that heterogeneity was obvious in prospective cohort studies (I2 = 62.1%, p<0.001). In a sensitivity analysis, we found that removing any single study did not significantly change the overall effect value. The quality of the evidence was rated as low for both any stage of ROP and severe stage of ROP.

CONCLUSIONS

Sepsis increases the risk of ROP in preterm infants. However, considering that all included studies are observational and causality can rarely be established, additional evidence is needed to substantiate this finding and provide advice for practice.

Chorioamnionitis as a risk factor for retinopathy of prematurity: An updated systematic review and meta-analysis

The role of chorioamnionitis (CA) in the development of retinopathy of prematurity (ROP) is difficult to establish, because CA-exposed and CA-unexposed infants frequently present different baseline characteristics. We performed an updated systematic review and meta-analysis of studies reporting on the association between CA and ROP. We searched PubMed and EMBASE for relevant articles. Studies were included if they examined preterm or very low birth weight (VLBW, <1500g) infants and reported primary data that could be used to measure the association between exposure to CA and the presence of ROP. Of 748 potentially relevant studies, 50 studies met the inclusion criteria (38,986 infants, 9,258 CA cases). Meta-analysis showed a significant positive association between CA and any stage ROP (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.11 to 1.74). CA was also associated with severe (stage ≥3) ROP (OR 1.63, 95% CI 1.41 to 1.89). Exposure to funisitis was associated with a higher risk of ROP than exposure to CA in the absence of funisitis. Additional meta-analyses showed that infants exposed to CA had lower gestational age (GA) and lower birth weight (BW). Meta-regression showed that lower GA and BW in the CA-exposed group was significantly associated with a higher risk of ROP. Meta-analyses of studies with data adjusted for confounders could not find a significant association between CA and ROP. In conclusion, our study confirms that CA is a risk factor for developing ROP. However, part of the effects of CA on the pathogenesis of ROP may be mediated by the role of CA as an etiological factor for very preterm birth.

Increased postnatal concentrations of pro-inflammatory cytokines are associated with reduced IGF-I levels and retinopathy of prematurity

OBJECTIVE

Retinopathy of prematurity (ROP) is a multifactorial disease linked to low insulin-like growth factor (IGF)-I levels and perhaps to postnatal inflammation. Here, we investigated the longitudinal postnatal serum concentrations of pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α in relation to IGF-I levels and ROP.

DESIGN

The study cohort included 52 infants born before 31 gestational weeks. The infants were screened for ROP and classified as non-ROP (n=33), non-proliferative ROP (stages 1 and 2; n=10), or proliferative ROP (stage 3, all treated for ROP; n=9). Blood samples were collected at birth, 24h after birth, and then weekly until at least 36weeks postmenstrual age (PMA) (i.e., up to 13weeks after birth). Circulating levels of IL-6 and TNF-α were evaluated in relation to circulating IGF-I levels and ROP.

RESULTS

IL-6 levels negatively correlated with IGF-I levels between 5 and 8weeks after birth, (p<0.01 to p<0.05). At birth, the IL-6 and TNF-α levels were similar independent of later ROP. Twenty-four hours after birth, both IL-6 and TNF-α levels had increased in infants later treated for ROP (p<0.05). Postnatal, infants treated for ROP had higher IL-6 levels than infants without ROP.

CONCLUSIONS

The pro-inflammatory response is associated with low IGF-I levels and the development of ROP.

Type I retinopathy of prematurity in infants with birth weight less than 1251 g: incidence and risk factors for its development in a nursery in Kuwait

Purpose:

To report the rate of acute retinopathy of prematurity (ROP) and Type I ROP among infants with birth weight (BW) <1251 g and identify the risk factors for the development of Type I ROP.

Materials and Methods:

A retrospective review of ROP records of infants with BW <1251 g was performed to identify infants with acute ROP and Type I ROP. Infants with Type I ROP were compared with those without Type I ROP to assess the risk factors for the development of Type I ROP. P < 0.05 was statistically significant. Multivariate analysis was performed and odds ratio (OR) and 95% confidence intervals (CI) were calculated.

Results:

Among the 207 infants with BW <1251 g, acute ROP occurred in 154 infants (74.4%) and Type I ROP in 95 eyes of 50 infants (24.4%). The numbers of infants with BW <750 g and BW <1000 g were 19.3% and 58.4%, respectively, and the incidences of Type I ROP were 50% and 36.4%, respectively, among them. Forty-four (46.3%) eyes were treated at stage 2+ ROP in zone I or II. All the eyes treated for Type I ROP showed complete regression. Gestational age at birth (OR 0.657, 95% CI: 0.521-0.827; P < 0.0001) and number of ventilated days (OR 1.017, 95% CI: 1.005-1.029; P = 0.006) were identified as independent risk factors for the development of Type I ROP.

Conclusions:

The rate of Type I ROP in this study is higher than that in previous studies due to the higher number of infants with BW <1000 g in our cohort and the treatment of more eyes with stage 2+ ROP. However, all the treated eyes had a favorable outcome. Gestational age at birth and number of ventilated days were independent risk factors for the development of Type I ROP.

Results of screening for retinopathy of prematurity in a large nursery in Kuwait: Incidence and risk factors

AIMS

The aim of the study was to report the incidence of retinopathy of prematurity (ROP) and severe ROP and identify the risk factors for their development in a large nursery in Kuwait.

MATERIALS AND METHODS

This was a retrospective, interventional, non-comparative, hospital-based study. Retrospective review of ROP records of premature babies having either birth weight of less than 1501 g or gestational age at birth of 34 weeks or less and born between January 2001 and August 2003.

STATISTICAL ANALYSIS

By univariate and multivariate logistic regression analysis.

RESULTS

Out of the 599 babies studied, 38.9% developed ROP and 7.8% needed treatment for severe ROP. Multivariate analysis showed low birth weight (OR 13.753, 95% CI 3.66-51.54; ( P < 0.001), gestational age (OR 13.75, 95% CI 3.66-51.54; P < 0.001), surfactant (OR 1.72, 95% CI 1.04-2.83; P = 0.032) and stay in the intensive care unit for longer than 15 days (OR 2.25, 95% CI 1.05-4.85; P = 0.033) to be significant for the development of any ROP. Low birth weight (OR 22.86, 95% CI 3.86-134.82; P = 0.001), bacterial sepsis (OR 3.27, 95% CI 1.51-7.05; P = 0.002) and need for surfactant (OR 4.41, 95% CI 0.94 -20.56; P = 0.059) were found to be the risk factors for severe ROP needing laser treatment.

CONCLUSION

The incidence of both any ROP and ROP needing treatment are comparable to other studies. Low birth weight is the most important risk factor for both any ROP and severe ROP.

Outcome of early-onset sepsis in a national cohort of very low birth weight infants

BACKGROUND

Early-onset sepsis (EOS) is associated with significant morbidity and mortality among infants with a very low birth weight (VLBW); however, there is a sparse amount of complete data on large cohorts.

OBJECTIVE

To evaluate the mortality and major morbidities among VLBW infants with EOS.

METHODS

This was a population-based observational study. Data were prospectively collected by the Israel Neonatal Network on all VLBW infants born in Israel from 1995 through 2005. Univariate and multivariable analyses were performed to assess the independent association of EOS on morbidity and mortality of VLBW infants.

RESULTS

The study cohort included 15 839 infants, of whom 383 (2.4%) developed EOS. EOS was associated with significantly increased odds for mortality (odds ratio [OR]: 2.57 [95% confidence interval (CI): 1.97-3.35]), severe intraventricular hemorrhage (OR: 2.24 [95% CI: 1.67-3.00]), severe retinopathy of prematurity (OR: 2.04 [95% CI: 1.32-3.16]), and bronchopulmonary dysplasia (OR: 1.74 [95% CI: 1.24-2.43]). EOS was associated with an increased risk of death and/or severe neurologic morbidity (OR: 2.92 [95% CI: 2.27-3.80]).

CONCLUSIONS

Although only 2.4% of VLBW infants had an episode of EOS, these infants were at an approximately threefold excess risk of death or major neurologic morbidities.