New-onset maternal gestational hypertension and risk of retinopathy of prematurity

Pathophysiology of Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a complex disease involving development of the neural retina, ocular circulations, and other organ systems of the premature infant. The external stresses of the ex utero environment also influence the pathophysiology of ROP through interactions among retinal neural, vascular, and glial cells. There is variability among individual infants and presentations of the disease throughout the world, making ROP challenging to study. The methods used include representative animal models, cell culture, and clinical studies. This article describes the impact of maternal-fetal interactions; stresses that the preterm infant experiences; and biologic pathways of interest, including growth factor effects and cell-cell interactions, on the complex pathophysiology of ROP phenotypes in developed and emerging countries.

Systemic Cytokines in Retinopathy of Prematurity

Retinopathy of prematurity (ROP), a vasoproliferative vitreoretinal disorder, is the leading cause of childhood blindness worldwide. Although angiogenic pathways have been the main focus, cytokine-mediated inflammation is also involved in ROP etiology. Herein, we illustrate the characteristics and actions of all cytokines involved in ROP pathogenesis. The two-phase (vaso-obliteration followed by vasoproliferation) theory outlines the evaluation of cytokines in a time-dependent manner. Levels of cytokines may even differ between the blood and the vitreous. Data from animal models of oxygen-induced retinopathy are also valuable. Although conventional cryotherapy and laser photocoagulation are well established and anti-vascular endothelial growth factor agents are available, less destructive novel therapeutics that can precisely target the signaling pathways are required. Linking the cytokines involved in ROP to other maternal and neonatal diseases and conditions provides insights into the management of ROP. Suppressing disordered retinal angiogenesis via the modulation of hypoxia-inducible factor, supplementation of insulin-like growth factor (IGF)-1/IGF-binding protein 3 complex, erythropoietin, and its derivatives, polyunsaturated fatty acids, and inhibition of secretogranin III have attracted the attention of researchers. Recently, gut microbiota modulation, non-coding RNAs, and gene therapies have shown promise in regulating ROP. These emerging therapeutics can be used to treat preterm infants with ROP.

Neonatal outcomes of twins <29 weeks gestation of mothers with hypertensive disorders of pregnancy

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are associated with dysfunctional placentation and are a major cause of maternal and neonatal morbidity and mortality. Twin pregnancies have a larger placental mass and are a risk factor for HDP. The effect of HDP on neonatal outcomes in twin pregnancies is unknown.

METHODS

Retrospective cohort study using the Canadian Neonatal Network database from 2010-2018 of twin infants <29 weeks gestation born to mothers with HDP and normotensive pregnancies. Using multivariable models, we determined adjusted odds ratios (AORs) and 95% confidence intervals (CI) for mortality, bronchopulmonary dysplasia, severe neurologic injury, severe retinopathy of prematurity (ROP), necrotizing enterocolitis, and nosocomial infection in twin infants of mothers with HDP compared to twin infants of normotensive mothers.

RESULTS

Of the 2414 eligible twin infants <29 weeks gestational age, 164 (6.8%) were born to mothers with HDP and had higher odds of severe ROP (AOR 2.48, 95% CI 1.34-4.59). Preterm twin infants born to mothers with HDP also had higher odds of mortality (AOR 2.02, 95% CI 1.23-3.32). There was no difference in other outcomes.

CONCLUSION

Preterm twin infants <29 weeks gestation of HDP mothers have higher odds of severe ROP and mortality.

IMPACT

Hypertensive disorders of pregnancy, associated with placental dysfunction, are a major cause of maternal and neonatal morbidity and mortality. Twin pregnancy, associated with a larger placental mass, is a risk factor for hypertensive disorders of pregnancy. The effect of hypertensive disorders of pregnancy on outcomes of preterm twins is unknown. Preterm twins of mothers with hypertensive disorders of pregnancy are at higher risk of severe retinopathy of prematurity and mortality. Our data can be used to counsel parents and identify infants at higher risk of severe retinopathy of prematurity and mortality.

Development and Validation of a Deep Learning Model to Predict the Occurrence and Severity of Retinopathy of Prematurity

Importance

Retinopathy of prematurity (ROP) is the leading cause of childhood blindness worldwide. Prediction of ROP before onset holds great promise for reducing the risk of blindness.

Objective

To develop and validate a deep learning (DL) system to predict the occurrence and severity of ROP before 45 weeks' postmenstrual age.

Design, Setting, and Participants

This retrospective prognostic study included 7033 retinal photographs of 725 infants in the training set and 763 retinal photographs of 90 infants in the external validation set, along with 46 characteristics for each infant. All images of both eyes from the same infant taken at the first screening were labeled according to the final diagnosis made between the first screening and 45 weeks' postmenstrual age. The DL system was developed using retinal photographs from the first ROP screening and clinical characteristics before or at the first screening in infants born between June 3, 2017, and August 28, 2019.

Exposures

Two models were specifically designed for predictions of the occurrence (occurrence network [OC-Net]) and severity (severity network [SE-Net]) of ROP. Five-fold cross-validation was applied for internal validation.

Main Outcomes and Measures

Area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity to evaluate the performance in ROP prediction.

Results

This study included 815 infants (450 [55.2%] boys) with mean birth weight of 1.91 kg (95% CI, 1.87-1.95 kg) and mean gestational age of 33.1 weeks (95% CI, 32.9-33.3 weeks). In internal validation, mean AUC, accuracy, sensitivity, and specificity were 0.90 (95% CI, 0.88-0.92), 52.8% (95% CI, 49.2%-56.4%), 100% (95% CI, 97.4%-100%), and 37.8% (95% CI, 33.7%-42.1%), respectively, for OC-Net to predict ROP occurrence and 0.87 (95% CI, 0.82-0.91), 68.0% (95% CI, 61.2%-74.8%), 100% (95% CI, 93.2%-100%), and 46.6% (95% CI, 37.3%-56.0%), respectively, for SE-Net to predict severe ROP. In external validation, the AUC, accuracy, sensitivity, and specificity were 0.94, 33.3%, 100%, and 7.5%, respectively, for OC-Net, and 0.88, 56.0%, 100%, and 35.3%, respectively, for SE-Net.

Conclusions and Relevance

In this study, the DL system achieved promising accuracy in ROP prediction. This DL system is potentially useful in identifying infants with high risk of developing ROP.

Endothelial dysfunction in preterm infants: The hidden legacy of uteroplacental pathologies

Millions of infants are born prematurely every year worldwide. Prematurity, particularly at lower gestational ages, is associated with high mortality and morbidity and is a significant global health burden. Pregnancy complications and preterm birth syndrome strongly impact neonatal clinical phenotypes and outcomes. The vascular endothelium is a pivotal regulator of fetal growth and development. In recent years, the key role of uteroplacental pathologies impairing endothelial homeostasis is emerging. Conditions leading to very and extremely preterm birth can be classified into two main pathophysiological patterns or endotypes: infection/inflammation and dysfunctional placentation. The first is frequently related to chorioamnionitis, whereas the second is commonly associated with hypertensive disorders of pregnancy and fetal growth restriction. The nature, timing, and extent of prenatal noxa may alter fetal and neonatal endothelial phenotype and functions. Changes in the luminal surface, oxidative stress, growth factors imbalance, and dysregulation of permeability and vascular tone are the leading causes of endothelial dysfunction in preterm infants. However, the available evidence regarding endothelial physiology and damage is limited in neonates compared to adults. Herein, we discuss the current knowledge on endothelial dysfunction in the infectious/inflammatory and dysfunctional placentation endotypes of prematurity, summarizing their molecular features, available biomarkers, and clinical impact. Furthermore, knowledge gaps, shadows, and future research perspectives are highlighted.

Pregnancy-induced hypertension and retinopathy of prematurity: a meta-analysis

PURPOSE

Retinopathy of prematurity (ROP), one of the leading causes of childhood blindness, is a complex condition in which various antenatal and neonatal factors participate at different stages of the disease. This meta-analysis was conducted to investigate whether pregnancy-induced hypertension (PIH) was associated with ROP by summarizing all available evidence.

METHODS

PubMed, EMBASE, Web of Science, EBSCO and SCOPUS databases were searched for all relevant studies published from inception to April 2020. Studies investigating the association between PIH and ROP were included.

RESULTS

A total of 29 studies were finally included for the meta-analysis after study selection. The results showed there are both no significant association between PIH and the occurrence of ROP in case-control studies (OR 0.91, 95%CI 0.59 to 1.40, I²  = 81%, p = 0.67) and cohort studies (OR 1.32, 95%CI 0.89 to 1.98, I²  = 93%, p = 0.17). The conclusion was same between pre-eclampsia and ROP (OR 0.82, 95%CI: 0.50 to 1.35, I²  = 83%, p = 0.43 in case-control studies and OR 1.70, 95%CI: 0.82 to 3.50, I²  = 95%, p = 0.15 in cohort studies).

CONCLUSION

In summary, this meta-analysis did not reveal a consistent result, the conclusion remains inconclusive, and further studies will be needed to come to a conclusion for the effect of maternal PIH on ROP and foster a better understanding of the prevention of ROP.

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.

Neonatal respiratory outcomes in pregnancy induced hypertension: introducing a novel index

Objective: To evaluate short-term respiratory outcomes, mortality and bronchopulmonary dysplasia (BPD) in preterm infants born to mothers with and without pregnancy induced hypertension (PIH).Methods: Exposed infants <33 weeks' gestation were matched to controls in a 1:2 ratio, based on gestation, sex and antenatal steroid exposure in this retrospective cohort study. Primary outcomes were a novel cumulative respiratory index (cRI) (product of mean airway pressure-hours and FiO₂-hours while on invasive ventilation during first 72 hours), mortality and BPD.Results: Seventy-nine exposed infants were matched with 158 controls. cRI was higher in exposed infants (median 1854; IQR 186-13,901) versus controls (median 1359; IQR 210-11,302) but not statistically significant (p = .63). On conditional regression analysis, PIH did not predict cRI (adjusted β = 0.96; 95% CI = 0.79-1.17; p = .712). No association between PIH and mortality (unadjusted odds ratio [OR] = 3.14; 95% CI = 0.76-13.0; p=.11) was identified. PIH was significantly associated with BPD on univariate analysis (OR = 2.29; 95% CI = 1.02-5.17; p=.046), but not after adjustment (aOR = 1.26; 95% CI = 0.38-4.19; p=.7).Conclusions: PIH was not associated with cRI, mortality or BPD in this study. Further validation of cRI and exploration of its relationship with PIH as well as neonatal outcomes is warranted.

Pregnancy-induced hypertension and neonatal outcomes: a systematic review and meta-analysis

OBJECTIVE

Pregnancy-induced hypertension (PIH) is associated with preterm delivery but its independent impact on neonatal outcomes remains unclear. We sought to systematically review and meta-analyze clinical outcomes of preterm infants <37 weeks' gestation born to mothers with and without PIH.

STUDY DESIGN

Medline, Embase, PsychINFO and CINAHL were searched from January 2000 to October 2016. Studies with low-moderate risk of bias reporting neonatal outcomes based on PIH as primary exposure variable were included. Data were extracted independently by two co-authors.

RESULTS

PIH was associated with lower mortality (3 studies; adjusted odds ratio (aOR) 0.65; 95% confidence interval (CI) 0.54 to 0.79), lower severe retinopathy of prematurity (ROP) (2 studies; aOR 0.83; 0.72 to 0.96) and lower severe brain injury (2 studies; unadjusted OR (uOR) 0.57; 0.49 to 0.66). No association between PIH and short-term respiratory outcomes, bronchopulmonary dysplasia (BPD) or necrotizing enterocolitis (NEC) was identified. In subgroup analysis among infants <29 weeks' gestation, BPD odds were higher (3 studies; aOR 1.15; 1.06 to 1.26), whereas mortality lower (2 studies; aOR 0.73; 0.69 to 0.77). In subgroup analysis limited to severe PIH, odds of mortality (3 studies; uOR 2.36; 1.07 to 5.22) and invasive ventilation (3 studies; uOR 3.26; 1.11 to 9.61) were higher. In subgroup analysis limited to preeclampsia, odds of BPD (3 studies; uOR 1.21; 95% CI:1.03 to 1.43) and NEC were higher (3 studies; uOR 2.79; 95% CI:1.57 to 4.96).

CONCLUSION

PIH was associated with reduced odds of mortality and ROP (all infants), but higher odds for BPD (<29 weeks' gestation). The paradoxical reduction in mortality may be due to survival bias and deserves further exploration in future studies.

Pre-eclampsia and the risk of retinopathy of prematurity in preterm infants with birth weight <1500 g and/or <31 weeks' gestation

Objective

To evaluate the relationship between pre-eclampsia and development of retinopathy of prematurity (ROP) in infants with birth weight of <1500 g and/or gestation <31 weeks.

Methods

A retrospective cohort study comprising infants born to mothers with pre-eclampsia between January 2007 and June 2010 at a single tertiary care centre. Their ROP outcome was compared with infants born to the next two normotensive mothers with a ±1 week gestational age difference. Pearson χ² test was used for categorical variables and Mann-Whitney U test was used for continuous variables. Multivariable regression was used to estimate the OR of ROP with prenatal pre-eclampsia exposure and adjust for confounders.

Results

Of the 97 infants in the pre-eclampsia group, 27 (27%) developed ROP and of the 185 infants in the normotensive group, 50 (27%) developed ROP. On multivariable regression modelling, pre-eclampsia was not a risk factor for the development of ROP (OR 1.4, 95% CI 0.46 to 4.1). Gestational age, intrauterine growth restriction and blood transfusion were significant risk factors for the development of ROP.

Conclusions

In our cohort, pre-eclampsia was not a significant risk factor for the development of ROP. Intrauterine growth restricted infants of pre-eclamptic and normotensive mothers were at higher risk of ROP.

Association of maternal hypertensive disorders with retinopathy of prematurity: A systematic review and meta-analysis

BACKGROUD

The role of maternal hypertensive disorders in pregnancy (HDP) in the development of retinopathy of prematurity (ROP) is unclear.

METHODS

Studies were retrieved through literature searches in PubMed, EMBASE, Web of Science and the Cochrane Library up to May 5, 2016 without language restrictions. Cohort or case-control studies that reported the association of maternal hypertensive disorders and retinopathy of prematurity were eligible. Either a fixed- or a random-effects model was used to calculate the overall combined risk estimates.

RESULTS

Thirteen cohort studies involving a total of 45082 individuals were included in the review. The pooled odds ratios of maternal hypertensive disorders in pregnancy for any stage and severe stages of ROP was 1.12 (95%CI: 0.90-1.40) and 0.80 (95%CI: 0.47-1.35), respectively. Sensitivity analyses confirmed that no single study qualitatively influenced the pooled OR. However, substantial heterogeneity and publication bias were observed in the meta-analysis.

CONCLUSIONS

Additional larger, prospective and well-adjusted studies are needed to determine the association between HDP and ROP, especially regarding the effects of different types of maternal hypertensive disorders in pregnancy on retinopathy of prematurity.

Association of Gestational Hypertensive Disorders with Retinopathy of prematurity: A Systematic Review and Meta-analysis

The role of gestational hypertensive disorders, which includes both pre-eclampsia and gestational hypertension, in the development of retinopathy of prematurity (ROP) has been controversial. Therefore, this systematic review and meta-analysis is to evaluate the association between gestational hypertensive disoders and ROP. Eligible studies published up to June 5, 2016 were identified from MEDLINE and EMBASE that evaluated the association between the two conditions. Totally 1142 published records were retrieved for screening, 925 of them eligible for detailed evaluation. Finally 19 studies involving 45281 infants with 5388 cases of ROP met our criteria for meta-analysis. Gestational hypertensive disorders were not associated with ROP (unadjusted OR: 0.89; P = 0.38; adjusted OR: 1.35; P = 0.18). Subgroup analyses also revealed no significant association between ROP with pre-eclampsia (unadjusted OR: 0.85; P = 0.29; adjusted OR:1.29; P = 0.28) or with gestational hypertension (unadjusted OR: 1.10; P = 0.39; adjusted OR: 1.25; P = 0.60) separately. Sensitivity analysis indicated our results were robust. We concluded no significant association between gestational hypertensive disorders and ROP. More large scale well-conducted prospective cohorts on the topic are needed.

Natural history of retinopathy of prematurity: two-year outcomes of a prospective study

PURPOSE

To investigate the 2-year outcomes of the natural history of retinopathy of prematurity (ROP) in Taiwan.

METHODS

A prospective study was conducted at two tertiary medical centers. Premature infants were screened and examined for ROP. The postmenstrual ages of developing each stage of ROP and the associated risk factors were recorded.

RESULTS

A total of 698 infants were included. The incidences of ROP and treatment-requiring ROP in all patients with ROP were 29.7% and 37.2%. When only including patients with birth weight of 1,250 g or less, the incidences were 62.2% and 39.1%, respectively. In patients with ROP with birth weight over 1,250 g, 25% of them developed treatment-requiring ROP. The median postmenstrual ages for the development of Stage 1, Stage 2, and Type 1 ROP were 33.0, 34.0, and 34.7 weeks, respectively. Gestational age at birth and birth weight were the most important factors associated with treatment-requiring ROP (hazard ratios of 0.3 and 0.6).

CONCLUSION

Our hospital-based study reveals an earlier postmenstrual age of developing ROP in this Asian population than in the Early Treatment for ROP study. Infants with birth weight over 1,250 g could still develop treatment-requiring ROP. Suboptimal oxygen control, different genetic dispositions among different races, inconsistencies in ROP diagnosis, and earlier screening might account for such a phenomenon.

Incidence and risk factors of retinopathy of prematurity in two neonatal intensive care units in North and South China

BACKGROUND

To investigate the incidence and risk factors of retinopathy of prematurity (ROP) in two Neonatal Intensive Care Units in North and South of China, respectively.

METHODS

We studied data concerning 472 infants with gestational age (GA) ≤ 34 weeks or birth weight (BW) ≤ 2000 g who were admitted to the Zhujiang Hospital of Southern Medical University and the Fourth Hospital of Shijiazhuang between January 1, 2011 and December 31, 2011. Clinical information about perinatal neonates was collected and was confirmed by reviewing medical charts. The incidence and severity of ROP were assessed in the screened population. Main outcome measures are the incidence and severity of ROP. The relationship of clinical risk factors and the development of ROP were analyzed.

RESULTS

The overall incidence of ROP was 12.7%, and the overall incidence of type 1 ROP was 2.3%; 9.4% of infants in Zhujiang Hospital had ROP compared to 15.0% infants in the Fourth Hospital of Shijiazhuang developed ROP, and the difference is statistically significant. ROP was significantly associated with GA (odds ratio [OR]: 0.77 [0.62-0.95], P = 0.015), BW (OR: 0.998 [0.996-0.999], P = 0.008), maternal supplemental oxygen administration before and during delivery (OR: 4.27 [1.21-15.10], P = 0.024) and preeclampsia (OR: 6.07 [1.73-21.36] P = 0.005). The risk factors for ROP are different in two hospitals. In Zhujiang Hospital, BW is the independent risk factors for ROP while GA, BW and preeclampsia in the Fourth Hospital in Shijiazhuang Conclusions: Retinopathy of prematurity incidence is different based on area. Incidence of ROP is still high in China. More efforts need to prevent ROP.

Association between ADH1C and ALDH2 polymorphisms and alcoholism in a Turkish sample

BACKGROUND

Polymorphisms in the genes encoding alcohol metabolizing enzymes are associated with alcohol dependence.

AIM

To evaluate the association between the alcohol dehydrogenase 1C (ADH1C) Ile350Val and aldehyde dehydrogenase 2 (ALDH2) Glu504Lys polymorphisms and alcohol dependence in a Turkish sample.

METHODS

235 individuals (115 alcohol-dependent patients and 120 controls) were genotyped for ADH1C and ALDH2 with PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism). Association between the polymorphisms and family history, daily and maximum amount of alcohol consumed was investigated. The associations between alcohol dependence, severity of consumption and family history and the polymorphisms were analyzed by chi-square or Fisher's exact test where necessary. Relationship between genotypes and dependence related features was evaluated using analysis of variance (ANOVA).

RESULTS

The -350Val allele for ADH1C (ADH1C*2) was increased in alcohol-dependent patients (P = 0.05). In individuals with a positive family history, the genotype distribution differed significantly (P = 0.031) and more patients carried the Val allele compared with controls (P = 0.025). Genotyping of 162 participants did not reveal the -504Lys allele in ALDH2.

CONCLUSIONS

These findings suggest that ADH1C*2 is associated with alcohol dependence in the Turkish population displaying a dominant inheritance model. ADH1C*2 allele may contribute to the variance in heritability of alcohol dependence. The ALDH2 -504Lys/Lys or Glu/Lys genotypes were not present in alcohol-dependent patients, similar to that seen in European populations and in contrast to the findings in the Asian populations.

Aggressive posterior retinopathy of prematurity in two of the triplets: a case report

Aggressive posterior retinopathy of prematurity is identified as a rare, rapidly progressing and severe form of retinopathy of prematurity (ROP). Here, we report the diagnosis and treatment of aggressive posterior retinopathy of prematurity (APROP) in two of the triplets born at low birth weight and small gestational age. A case concerning two triplets who were born at 31 weeks' gestational age with low birth weight and reached bilateral threshold APROP was reported. The ROP of triplets A and B had the characteristic features of aggressive diseases, which were posterior location, prominence of plus disease and rapid progression. Low birth weight and small gestational age, multiple pregnancies, pregnancy-induced hypertension and older age of the mother might account for the presentations of APROP. These cases demonstrate the importance of early screening and diagnosis in APROP infants. Prompt and adequate laser photocoagulation with a large number of high-intensity closely performed spots and early retreatment could be effective and safe for preventing the progression of APROP with plus disease in zone 1 or 2 in premature triplets.

Erythropoietin and retinopathy of prematurity: a meta-analysis

We performed a meta-analysis to study the association between erythropoietin (EPO) and the development of retinopathy of prematurity (ROP) in preterm newborn infants. Studies were identified through PubMed (1966-) and ISI databases (1965-) literature searches. Results and effect sizes are expressed as odds ratio (OR) with 95 % confidence intervals (CI). Fourteen studies identified to the meta-analysis, including 3,484 preterm newborn infants. A total of 563 of 1,221 babies treated with EPO had ROP (46.1 %) vs. 420 of 1,134 babies without EPO (37.0 %). No significant difference was found in the ROP risk between the two groups, with the OR 1.592 (95 % CI 0.901-2.812). A total of 192 of 1,298 babies treated with EPO had severe ROP (stage 3-4) (14.8 %) vs. 166 of 1,199 babies without EPO (13.8 %). The OR was 1.203 (95 % CI 0.763-1.896). No significant publication bias was found. Sensitivity analyses showed the results were robust.

CONCLUSION

Our meta-analysis indicates that EPO treatment is not associated with the development of ROP in preterm infants. But this conclusion should be confirmed by further high-quality researches.

Association of maternal hypertension and chorioamnionitis with preterm outcomes

OBJECTIVES

We compared the relative effect of hypertensive disorders of pregnancy and chorioamnionitis on adverse neonatal outcomes in very preterm neonates, and studied whether gestational age (GA) modulates these effects.

METHODS

A cohort of neonates 23 to 30 weeks' GA, born in 2008 to 2011 in 82 hospitals adhering to the Italian Neonatal Network, was analyzed. Infants born from mothers who had hypertensive disorders (N = 2096) were compared with those born after chorioamnionitis (N = 1510). Statistical analysis employed logistic models, adjusting for GA, hospital, and potential confounders.

RESULTS

Overall mortality was higher after hypertension than after chorioamnionitis (odds ratio [OR], 1.39; 95% confidence interval [CI], 1.08-1.80), but this relationship changed across GA weeks; the OR for hypertension was highest at low GA, whereas from 28 weeks' GA onward, mortality was higher for chorioamnionitis. For other outcomes, the relative risks were constant across GA; infants born after hypertension had an increased risk for bronchopulmonary dysplasia (OR, 2.20; 95% CI, 1.68-2.88) and severe retinopathy of prematurity (OR, 1.48; 95% CI, 1.02-2.15), whereas there was a lower risk for early-onset sepsis (OR, 0.25; 95% CI, 0.19-0.34), severe intraventricular hemorrhage (OR, 0.65; 95% CI, 0.48-0.88), periventricular leukomalacia (OR, 0.70; 95% CI, 0.48-1.01), and surgical necrotizing enterocolitis or gastrointestinal perforation (OR, 0.47; 95% CI, 0.31-0.72).

CONCLUSIONS

Mortality and other adverse outcomes in very preterm infants depend on antecedents of preterm birth. Hypertension and chorioamnionitis are associated with different patterns of outcomes; for mortality, the effect changes across GA weeks.

Contemporary uses of erythropoietin in pregnancy: a literature review

OBJECTIVE

The objectives of this study were to survey the current research and provide an update on the uses and benefits of erythropoietin (EPO) in pregnancy and the postpartum period.

DATA SOURCES

A review of MEDLINE (1947 to present) was performed. Search terms included "erythropoietin," "pregnan*," with subheadings of "administration & dosage," "pharmacokinetics," "therapeutic use," "fetus," "fertility."

METHOD OF STUDY SELECTION

We reviewed relevant articles published from 2002 to 2012. Case reports, observational studies, case-control studies, randomized controlled trials, retrospective analyses, animal studies, and review articles were included. Articles were selected if they discussed a use of EPO in pregnancy or the immediate postpartum period, as well as use of EPO in the neonate.

TABULATION, INTEGRATION, AND RESULTS

Authors independently reviewed and extracted data. Of the 65 articles reviewed, 45 were included. Erythropoietin was used in the treatment of maternal anemia. Because of the molecule's large size, recombinant EPO does not appear to cross the placenta. No fetal morbidity or mortality was noted. Therefore, this is a safe therapy that can be used in pregnancy. Use of EPO may be especially important for women who decline blood products. Neonatal uses of EPO show benefit in the treatment of anemia due to blood type incompatibility.

CONCLUSIONS

Erythropoietin is gaining popularity as a therapeutic option during pregnancy and the postpartum period. Further investigation is needed to establish a standard dosage and dosing interval. New studies reviewing its use in the neonate for perinatal-hypoxic injury and anemia due to blood type incompatibility provide exciting opportunities for further therapeutic use.

TARGET AUDIENCE

Obstetricians and gynecologists, family physicians.

LEARNING OBJECTIVES

After completing this CME activity, physicians should be better able to treat anemia in pregnancy, including causes and interventions; assess renal disease in pregnancy, targets of hemoglobin, precautions, and treatment considerations; and evaluate erythropoietin use in neonates and fetuses, including benefits, complications, and areas for upcoming research/uses.

Preeclampsia and retinopathy of prematurity in preterm births

OBJECTIVE

The relationship between gestational hypertension, preeclampsia, and the risk of retinopathy of prematurity (ROP) remains unclear. Thus, we used a large cohort database to study the influence of maternal gestational hypertension and preeclampsia on the occurrence of ROP in preterm infants.

METHODS

We used data from a previous retrospective cohort study that includes 25,473 eligible preterm neonates. We examined the association between gestational hypertension, preeclampsia, and ROP while controlling for potential confounders by multiple logistic regression analysis.

RESULTS

Of the 8758 early preterm infants (gestational age <34 weeks), 1024 (11.69%) had ROP, while of the 16,715 late preterm infants, only 29 (0.17%) had ROP. After adjusting for confounders, preeclampsia was associated with a significantly reduced risk of ROP (adjusted odds ratio [aOR], 0.65; 95% confidence interval [CI], 0.49-0.86 for early preterm birth; aOR, 0.10; 95% CI, 0.01-0.93 for late preterm birth; aOR, 0.66; 95% CI, 0.50-0.87 for all preterm births). Gestational hypertension was not significantly associated with ROP at early or late preterm births.

CONCLUSIONS

Preeclampsia, but not gestational hypertension, was associated with a reduced risk of ROP in preterm births.

Association between assisted reproductive technology and advanced retinopathy of prematurity

Purpose

To investigate the associations between assisted reproductive technology (ART) and severe retinopathy of prematurity (ROP) requiring treatment.

Methods

Retrospective analyses of inborn preterm infants screened for severe ROP at the Weill Cornell Medical Center Neonatal Intensive Care Unit at the New York-Presbyterian Hospital by single factor logistic regression and multifactor models.

Results

Of 399 ethnically diverse infants, 253 were conceived naturally and 146 by ART. Eight (3.16%) patients conceived naturally, and 11 (7.53%) with ART required laser treatment. In multifactor analyses, significant risks for severe ROP requiring treatment included both gestational age (odds ratio [OR] 0.34; 95% confidence interval [CI] 0.23–0.52; P < 0.001) and ART ([OR] 4.70; [CI], 1.52–4.57; P = 0.007).

Conclusions

ART is associated with severe ROP requiring treatment in this cohort. This is the first report that demonstrates a statistically significant association between ART and severe ROP requiring treatment in infants in the US.