The role of the maternal and fetal inflammatory response in retinopathy of prematurity

Progress in the study of association between hematological indicators and retinopathy of prematurity (Review)

Retinopathy of prematurity (ROP) is a retinopathy caused by abnormal proliferation of blood vessels in premature infants. It can lead to retinal detachment and, in severe cases, blindness, rendering ROP a critical condition. Advances in neonatal medicine have improved survival rates of low birth weight and low gestational age infants. However, this progress has also led to a rise in incidence of ROP. Currently, premature birth, low birth weight and high postpartum oxygen levels are independent risk factors for ROP. Other factors include mode of delivery, multiple births, anemia, blood transfusion, maternal pregnancy factors, neonatal bronchopulmonary dysplasia, use of surfactants, arterial ductus arteriosus and necrotizing enterocolitis. Laboratory indicators in premature infants such as platelet count, levels of blood glucose, inflammatory cells, lipid and hemoglobin and blood transfusion may also be associated with ROP. However, the etiology and pathogenesis of ROP are not fully understood. A number of factors may influence the onset and progression of ROP, including decreased platelet counts, decreased hemoglobin levels, increased white blood cell counts, increased blood glucose levels, and disorders of lipid metabolism. The present study reviewed the effects of platelet count, hemoglobin, blood glucose, inflammatory cells and factors, blood lipids, and plasma metabolic pathways on ROP.

The histologic fetal inflammatory response and neonatal outcomes: systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate the prognostic role of concomitant histological fetal inflammatory response with chorioamnionitis on neonatal outcomes through a systematic review and meta-analysis of existing literature.

DATA SOURCES

The primary search was conducted on October 17, 2021, and it was updated on May 26, 2023, across 4 separate databases (MEDLINE, the Cochrane Central Register of Controlled Trials, Embase, and Scopus) without using any filters.

STUDY ELIGIBILITY CRITERIA

Observational studies reporting obstetrical and neonatal outcomes of infant-mother dyads with histological chorioamnionitis and histological fetal inflammatory response vs infant-mother dyads with histological chorioamnionitis alone were eligible. Studies that enrolled only preterm neonates, studies on neonates born before 37 weeks of gestation, or studies on neonates with very low birthweight (birthweight <1500 g) were included. The protocol was registered with the International Prospective Register of Systematic Reviews (registration number: CRD42021283448).

METHODS

The records were selected by title, abstract, and full text, and disagreements were resolved by consensus. Random-effect model-based pooled odds ratios with corresponding 95% confidence intervals were calculated for dichotomous outcomes.

RESULTS

Overall, 50 studies were identified. A quantitative analysis of 14 outcomes was performed. Subgroup analysis using the mean gestational age of the studies was performed, and a cutoff of 28 weeks of gestation was implemented. Among neonates with lower gestational ages, early-onset sepsis (pooled odds ratio, 2.23; 95% confidence interval, 1.76-2.84) and bronchopulmonary dysplasia (pooled odds ratio, 1.30; 95% confidence interval, 1.02-1.66) were associated with histological fetal inflammatory response. Our analysis showed that preterm neonates with a concomitant histological fetal inflammatory response are more likely to develop intraventricular hemorrhage (pooled odds ratio, 1.54; 95% confidence interval, 1.18-2.02) and retinopathy of prematurity (pooled odds ratio, 1.37; 95% confidence interval, 1.03-1.82). The odds of clinical chorioamnionitis were almost 3-fold higher among infant-mother dyads with histological fetal inflammatory response than among infant-mother dyads with histological chorioamnionitis alone (pooled odds ratio, 2.99; 95% confidence interval, 1.96-4.55).

CONCLUSION

This study investigated multiple neonatal outcomes and found association in the case of 4 major morbidities: early-onset sepsis, bronchopulmonary dysplasia, intraventricular hemorrhage, and retinopathy of prematurity.

Histological Chorioamnionitis and Funisitis as New Risk Factors for Retinopathy of Prematurity: A Meta-analysis

OBJECTIVE

 The role of placental inflammation in neonatal morbidities is underestimated due to lack of placental examination. This meta-analysis aims to assess the association between histological chorioamnionitis (HCA) with and without funisitis (FUN) and risk of retinopathy of prematurity (ROP).

STUDY DESIGN

 Forty-five studies reporting (unadjusted) data on HCA without FUN and HCA with FUN in neonates with ROP were included. Primary outcomes were any stage ROP and severe ROP. Potential confounders explored were gestational age (GA) at birth, birthweight, maternal steroid use, necrotizing enterocolitis, sepsis (suspected/proven) and mechanical ventilation duration.

RESULTS

 Neonates with HCA had increased risk for any stage ROP (odds ratio [OR] 1.8; 95% confidence interval [CI] 1.3-2.4) and severe ROP (OR 1.5; 95% CI 1.2-1.8) compared with neonates without HCA. The rates of any stage ROP (OR 1.8; 95% CI 1.4-2.2) and severe ROP (OR 1.4; 95% CI 1.1-1.6) were higher in neonates with FUN compared with neonates without FUN. Multivariate meta-regression analysis suggests that lower GA increases the effect size between FUN and severe ROP.

CONCLUSION

 This meta-analysis confirms that presence of HCA and FUN are risk factors for any stage ROP and severe ROP. Structured histological placental examination of HCA and FUN may be a tool to further refine the ROP risk profile.

KEY POINTS

· This systematic review confirms that HCA is a risk factor for ROP.. · This meta-analysis reveals that FUN results in an even higher risk for developing ROP.. · Placental examination of HCA/FUN may be a tool to further refine the ROP risk profile..

Cord blood transforming growth factor-β-induced as predictive biomarker of retinopathy of prematurity in preterm infants

PURPOSE

To determine whether 14 inflammation-, angiogenesis-, and adhesion-related proteins in cord blood (CB), alone or in combination with conventional perinatal factors, could predict retinopathy of prematurity (ROP) in preterm infants.

METHODS

Data from 111 preterm infants (born at ≤ 32.0 weeks) were retrospectively reviewed. The levels of endoglin, E-selectin, HSP70, IGFBP-3/4, LBP, lipocaline-2, M-CSFR, MIP-1α, pentraxin 3, P-selectin, TGFBI, TGF-β1, and TNFR2 were assessed in stored CB samples collected at birth using ELISA kits. The primary endpoints included severe ROP (≥ stage 3) and type 1 ROP requiring treatment.

RESULTS

ROP was diagnosed in 29 infants (26.1%), among whom 14 (12.6%) had severe ROP and seven (6.3%) had type 1 ROP. Multivariate logistic regression showed that decreased CB TGFBI levels were significantly associated with severe ROP and type 1 ROP after adjusting for gestational age at birth. Stepwise regression analysis allowed to design prediction models with good accuracy, which comprised low CB TGFBI levels and low birth weight (BW) as predictors for severe ROP (area under the curve [AUC] = 0.888), and low CB endoglin levels and low BW as predictors for type 1 ROP (AUC = 0.950). None of the other CB proteins evaluated were found to be associated with severe ROP or type 1 ROP.

CONCLUSIONS

Low CB TGFBI levels are associated with severe ROP and type 1 ROP, independently of gestational age. Moreover, combined predictive models based on CB TGFBI and endoglin levels, along with BW data, may act as good indicators at birth for the neonatal risk of ROP progression.

A novel marker for predicting type 1 retinopathy of prematurity: C-reactive protein/albumin ratio

PURPOSE

We aimed to investigate whether the C-reactive protein (CRP) to albumin ratio (CAR) an inflammatory predictor can be used as a marker for the development of ROP.

METHODS

Gestational age, birth weight, gender, neonatal, and maternal risk factors were recorded. The patients were divided into two groups: those who did not develop ROP (ROP -) and those who developed ROP (ROP +). The ROP + group was further separated into two groups: those who required treatment (ROP + T) and those who were not treated (ROP + NT). The following parameters were noted in the first postnatal week and at the end of the first postnatal month: CRP, albumin, CAR, white blood cell (WBC), neutrophil, lymphocyte, neutrophil-to-lymphocyte ratio (NLR), distribution red cell width (RDW), platelet (Plt), and RDW/platelet ratio.

RESULTS

We evaluated 131 premature infants who met the inclusion criteria. There was no difference between the main groups in hemogram parameters and CAR at the postnatal first week. WBC count (p = 0.011), neutrophil count (p = 0.002), and NLR were high (p = 0.004) in the ROP + group at the end of the postnatal 1st month. The CAR level at the end of the first month was higher in the ROP + group (p = 0.027). CAR was similar between the ROP + T and ROP + NT groups (p = 0.112) in the postnatal first week but higher in the treatment-required group at the end of the first month (p < 0.01).

CONCLUSION

High CAR and high NLR at the end of the postnatal first month can be used to predict the development of severe ROP.

Association of inflammatory and angiogenic biomarkers in maternal plasma with retinopathy of prematurity in preterm infants

OBJECTIVE

To investigate whether various novel inflammatory and angiogenic biomarkers in maternal plasma, alone or in combination with baseline antenatal factors, could predict retinopathy of prematurity (ROP) in preterm infants.

METHODS

A retrospective cohort study was conducted on 140 premature singleton neonates born to women with preterm birth (≤32 weeks) and screened for ROP. Maternal blood obtained at the time of admission was assayed for CRP, endoglin, endostatin, IGFBP-2, IGFBP-3, IL-6, LBP, MMP-8, PlGF, S100A8/A9, TGFBI, and VEGFR-1. The primary outcome measures included severe ROP (stage 3 or higher) and type 1 ROP requiring treatment.

RESULTS

ROP was present in 25.7% (36/140) of the study population, including 20 (14.3%) cases of severe ROP and 14 (10%) with type 1 ROP. Multiple logistic regression analyses revealed significant associations between high concentrations of maternal plasma LBP and severe ROP, and between elevated plasma IL-6 and LBP levels and type 1 ROP (all P < 0.05), while adjusting for confounders (i.e., gestational age [GA] at sampling). Prenatal prediction models for severe ROP and type 1 ROP were developed by combining plasma IL-6 or LBP levels with GA at sampling, which showed good discriminatory power (area under the curve = 0.747 and 0.854, respectively).

CONCLUSIONS

IL-6 and LBP in maternal plasma were found to be independently associated with severe ROP and type 1 ROP. Prediction models based on these biomarkers along with GA at sampling may serve as good prenatal indicators for the neonatal risk of ROP progression in women at risk of preterm birth.

Identification of clinical factors associated with timing and duration of spontaneous regression of retinopathy of prematurity not requiring treatment

OBJECTIVE

Identify clinical factors that delay or prolong spontaneous regression of retinopathy of prematurity (ROP).

STUDY DESIGN

Secondary analysis of three prospective studies with 76 infants with ROP not requiring treatment, born ≤30 weeks postmenstrual age (PMA) and ≤1500 grams. Outcomes were PMA at greatest severity of ROP (PMA MSROP), at which regression began, at time of complete vascularization (PMA CV), and regression duration. Pearson's correlation coefficients, t-tests, or analyses of variance were calculated.

RESULTS

Increased positive bacterial cultures, hyperglycemia, transfusion volume of platelets and red blood cells and severity of ROP were associated with later PMA MSROP. Positive bacterial cultures, maternal chorioamnionitis, and less iron deficiency were associated with later PMA CV and prolonged regression duration. Slower length gain was associated with later PMA CV. P < 0.05 for all.

CONCLUSIONS

Preterm infants with inflammatory exposures or linear growth impairment may require longer surveillance for ROP resolution and complete vascularization.

Relationship of maternal inflammatory response and fetal inflammatory response to duration and intensity of intra-amniotic infection and inflammation

INTRODUCTION

We aimed to use two indices, amniotic fluid interleukin-6 (IL-6) concentration at diagnosis and diagnosis-to-delivery interval, to clarify the frequencies of maternal inflammatory response (MIR) and fetal inflammatory response (FIR) in the placenta of patients with intra-amniotic infection and intra-amniotic inflammation (IAI).

METHODS

This is a single-center retrospective cohort study. From August 2014 to April 2020, participants were diagnosed with IAI with or without microbial invasion of the amniotic cavity (MIAC) using amniocentesis. IAI was defined as concentrations of amniotic IL-6 ≥ 2.6 ng/mL. MIAC was defined as a positive amniotic fluid culture. IAI with MIAC was defined as an intra-amniotic infection. We calculated the cut-off values for IL-6 concentration in the amniotic fluid at diagnosis and the diagnosis-to-delivery interval for MIR-positive cases among those with intra-amniotic infection.

RESULTS

The amniotic fluid IL-6 concentration at diagnosis and diagnosis-to-delivery interval were 15.8 ng/mL and 12 h, respectively. Among cases with intra-amniotic infection, MIR was 98% (52/53) positive, i.e., when either of the two cut-off values was exceeded. There were no significant differences between the frequencies of MIR and FIR. In cases with IAI but no MIAC, the frequencies of MIR and FIR were significantly lower than those with intra-amniotic infection, except when neither of the two cut-off values was exceeded.

DISCUSSION

We clarified the MIR- and FIR-positive cases in intra-amniotic infection and cases with IAI but no MIAC according to condition, including the diagnosis-to-delivery interval.

Association of Funisitis with Short-Term Outcomes of Prematurity: A Frequentist and Bayesian Meta-Analysis

The fetal systemic inflammatory response associated with intra-amniotic inflammation may play a key role in the pathogenesis of complications of preterm birth. Funisitis is the histologic equivalent of the fetal inflammatory response, whereas chorioamnionitis represents a maternal inflammatory response. We conducted a frequentist and Bayesian model average (BMA) meta-analysis of studies investigating the effects of funisitis on short-term outcomes of prematurity. Thirty-three studies (12,237 infants with gestational age ≤ 34 weeks) were included. Frequentist meta-analysis showed that funisitis was associated with an increased risk of any bronchopulmonary dysplasia (BPD), moderate/severe BPD, retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), any sepsis, early-onset sepsis (EOS), and mortality. However, Bayesian meta-analysis showed that the evidence in favor of the alternative hypothesis (i.e., funisitis is associated with an increased risk of developing the outcome) was strong for any IVH, moderate for severe IVH and EOS, and weak for the other outcomes. When the control group was restricted to infants having chorioamnionitis without funisitis, the only outcome associated with funisitis was any IVH. In conclusion, our data suggest that the presence of funisitis does not add an additional risk to preterm birth when compared to chorioamnionitis in the absence of fetal inflammatory response.

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.

Early and late onset sepsis and retinopathy of prematurity in a cohort of preterm infants

This study investigates the impact of antenatal and postnatal infection or inflammation on the onset and progression of Retinopathy of Prematurity (ROP). We retrospectively collected clinical and demographic data of preterm infants with birth weight ≤ 1500 g or gestational age < 30 weeks admitted to the neonatal intensive care unit of Verona from 2015 to 2019. Uni- and multivariable analysis was performed to evaluate the potential effect of selected variables on the occurrence of any stage ROP and its progression to severe ROP, defined as ROP requiring treatment. Two hundred and eighty neonates were enrolled and 60 of them developed ROP (21.4%). Oxygen need for 28 days and late-onset sepsis (LOS) increased the risk of any grade ROP after adjusting for birth weight and gestational age (OR 6.35, 95% CI 2.14–18.85 and OR 2.49, 95% CI 1.04–5.94, respectively). Days of mechanical ventilation and of non-invasive ventilation increased the risk of progression to severe ROP after adjusting for birth weight and gestational age (OR 1.08, CI 1.02–1.14 and OR 1.06, CI 1.01–1.11, respectively). Exposure to infection with production of inflammatory mediators may contribute to increase the risk of ROP occurrence in very preterm neonates.

Retinopathy of prematurity in Saudi Arabia: Exploring maternal risk factors

PURPOSE:

Retinopathy of prematurity (ROP) is a preventable blinding disorder affecting preterm infants. To date, maternal risk factors have not been studied in Saudi Arabia. This study aims to identify possible maternal risk factors for any stage and type 1 ROP.

MATERIALS AND METHODS:

A total of 295 preterm infants screened for ROP between November 2013 and December 2018 at a Saudi Arabian tertiary-care hospital were included. We included infants with a gestational age ≤ 32 weeks and/or birth weight (BW) ≤1500 g. We analyzed 28 maternal and neonatal risk factors.

RESULTS:

The incidence of ROP at any stage and Type 1 were 31.9% and 7%, respectively. In the univariate analysis, the only maternal factor associated with any stage of ROP was spontaneous vaginal delivery (P = 0.049), but no maternal factor was an independent risk factor for type 1 ROP. Multivariate logistic regression analysis identified lower BW, lower gestational age and longer neonatal intensive care unit stay as independent risk factors for the development of ROP at any stage (P < 0.05). For Type 1 ROP, lower BW, and intraventricular hemorrhage were significant independent risk factors (P < 0.05).

CONCLUSION:

The only maternal risk factor related to ROP was spontaneous vaginal delivery, which increased the risk of any stage of ROP. The single most predictive risk factor for any stage of ROP and Type 1 ROP was low BW. These findings emphasize the role of the obstetrician in promoting health care and modifying maternal risk factors to prevent preterm births related to a low BW.

Correlation between systemic immune-inflammation index and routine hemogram-related inflammatory markers in the prognosis of retinopathy of prematurity

Purpose:

To evaluate the prognostic potential of systemic inflammatory index in the course of retinopathy of prematurity (ROP).

Methods:

This is a retrospective case-control study. 303 infants with a gestational age of ≤35 weeks were screened with and without ROP at birth and 1 month after the birth of complete blood counts (CBC) were included in this study. Serum neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte (PLR), and systemic immune-inflammation index (SII) was calculated at birth and one month after. LMR was calculated by dividing the absolute lymphocyte count by the absolute monocyte count. NLR and PLR were determined by dividing the absolute neutrophil count or the absolute platelet count by the absolute lymphocyte count, respectively. The SII was calculated by the formula = neutrophilxplatelet/lymphocyte. All statistical analyses were performed using SPSS 22 (SPSS for Windows, version 22.0; SPSS, Inc. Chicago, IL, USA).

Results:

A total of 303 infants were included 145 with ROP and 158 without ROP. The NLR, LMR, PLR and SII values were 0.56 ± 1.17/0.51 ± 1.04 (P = 0.997), 13.7 ± 18/9.49 ± 13.1 (P = 0.014), 31.69 ± 68/24.1 ± 37.7 (P = 0.268), 131.42 ± 326/124.66 ± 267 (P = 0.935) in with ROP and without ROP infant at birth respectively. The NLR, LMR, PLR, and SII values were 0.68 ± 1.27/0.34 ± 0.99 (P = 0.001), 2.58 ± 6.01/2.46 ± 14.5 (P = 0.706), 47.5 ± 78.33/33.55 ± 42.4 (P = 0.035), and 253 ± 681/114 ± 345 (P = 0.001), respectively in with ROP and without ROP infant at 1 month after birth.

Conclusion:

The NLR, PLR, and SII seem an independent predictor of the development of ROP.

Maternal-Fetal Inflammation in the Placenta and the Developmental Origins of Health and Disease

Events in fetal life impact long-term health outcomes. The placenta is the first organ to form and is the site of juxtaposition between the maternal and fetal circulations. Most diseases of pregnancy are caused by, impact, or are reflected in the placenta. The purpose of this review is to describe the main inflammatory processes in the placenta, discuss their immunology, and relate their short- and long-term disease associations. Acute placental inflammation (API), including maternal and fetal inflammatory responses corresponds to the clinical diagnosis of chorioamnionitis and is associated with respiratory and neurodevelopmental diseases. The chronic placental inflammatory pathologies (CPI), include chronic villitis of unknown etiology, chronic deciduitis, chronic chorionitis, eosinophilic T-cell vasculitis, and chronic histiocytic intervillositis. These diseases are less-well studied, but have complex immunology and show mechanistic impacts on the fetal immune system. Overall, much work remains to be done in describing the long-term impacts of placental inflammation on offspring health.

Efficacy of Aflibercept Treatment and Its Effect on the Retinal Perfusion in the Oxygen-Induced Retinopathy Mouse Model of Retinopathy of Prematurity

INTRODUCTION

Bevacizumab and ranibizumab, which are anti-vascular endothelial growth factor (VEGF) medications, are used frequently in the treatment for retinopathy of prematurity (ROP) in infants. Aflibercept, or VEGF Trap, has been used anecdotally, but translation and clinical studies are lacking.

OBJECTIVE

This study investigates the efficacy of aflibercept at reducing areas of non-perfused retina and studies its effect on normal angiogenesis in the oxygen-induced retinopathy mouse model of ROP.

METHODS

C57BL/6 J mice were assigned to room air control (n = 21 eyes) or hyperoxia with 75% oxygen (n = 84 eyes). The hyperoxic mice were assigned to 1 of 3 groups: 0 ng (n = 14 eyes), 100 ng (n = 35 eyes), or 1,000 ng (n = 35 eyes) of intravitreal aflibercept administered on postnatal day 14. Eyes were enucleated at PN17 and PN25 postinjection. Retinas were stained with anti-collagen IV antibody and photographed with microscopy. Areas of perfused and non-perfused retina were quantified using ImageJ software. Statistical comparisons were made using ANOVA with Tukey post hoc comparisons.

RESULTS

At PN17, there was no significant difference in the area of non-perfused retina between the hyperoxic control and the 100 and 1,000 ng aflibercept groups. At PN25, the 100 ng (p < 0.05) and 1,000 ng (p = 0.008) treatment groups displayed less non-perfusion compared to hyperoxic controls. At the 1,000 ng dose, there was increased non-perfusion compared to the 100 ng dose (p = 0.02). There was reduced non-perfusion by PN25 compared to PN17 for the 100 ng group (p < 0.05), with no difference in the 1,000 ng group.

CONCLUSIONS

The study shows that the area of non-perfused retina decreases effectively with aflibercept at PN25 with 100 ng dosage. With the 1,000 ng dosage, there is an inhibition of the physiologic angiogenesis with a higher area of non-perfused retina.

Relationship between severe bronchopulmonary dysplasia and severe retinopathy of prematurity in premature newborns

BACKGROUND

Bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP) are two adverse sequelae of preterm birth associated with abnormal vascular development. The purpose of this study was to characterize the relationship between these two outcomes at a single institution.

METHODS

The medical records of infants screened for ROP at the University of Colorado Hospital between January 2012 and December 2017 were reviewed retrospectively. ROP was classified according to Early Treatment Retinopathy of Prematurity (ET-ROP) criteria; BPD, according to the 2010 Criteria from the National Institute for Child Health and Human Development. We examined the relationship between moderate-severe BPD and the development of severe ROP (type 1 or 2) using univariate analysis and multivariable logistic regression with the odds ratio as a measure of association. Covariates included gestational age and birth weight at delivery.

RESULTS

A total of 625 cases were reviewed. Of these, 64 infants (10%) developed severe ROP and 176 (28%) infants developed moderate-severe BPD. We found a significant relationship between these two outcomes following adjustments for gestational age, birth weight, and multiparity (OR = 3.2; 95% CI, 1.6-6.5 [P < 0.01]).

CONCLUSIONS

In our cohort of preterm infants, we found a significant relationship between moderate-severe BPD with severe ROP. We hypothesize that these two neonatal outcomes have links with a common pathogenesis.

Prenatal and postnatal inflammation-related risk factors for retinopathy of prematurity

OBJECTIVE

To evaluate the relationship between prenatal and postnatal inflammation-related risk factors and severe retinopathy of prematurity (ROP).

STUDY DESIGN

The study included infants born <30 weeks in California from 2007 to 2011. Multivariable log-binomial regression was used to assess the association between prenatal and postnatal inflammation-related exposures and severe ROP, defined as stage 3-5 or surgery for ROP.

RESULTS

Of 14,816 infants, 10.8% developed severe ROP. Though prenatal inflammation-related risk factors were initially associated with severe ROP, after accounting for the effect of these risk factors on gestational age at birth through mediation analysis, the association was non-significant (P = 0.6). Postnatal factors associated with severe ROP included prolonged oxygen exposure, sepsis, intraventricular hemorrhage, and necrotizing enterocolitis.

CONCLUSION

Postnatal inflammation-related factors were associated with severe ROP more strongly than prenatal factors. The association between prenatal inflammation-related factors and ROP was explained by earlier gestational age in infants exposed to prenatal inflammation.