The relationship between severe hypertensive diseases of pregnancy and moderate-severe bronchopulmonary dysplasia.

OBJECTIVE: Determine the association between severe hypertensive disease of pregnancy (HDP) with moderate-severe bronchopulmonary dysplasia (BPD) in preterm infants (< 31 weeks' gestation). STUDY DESIGN: Preterm birth cohort study of 693 mother-infant dyads. Severe HDP was defined as severe preeclampsia, HELLP syndrome or eclampsia. The outcome was moderate-severe BPD classified at 36 weeks corrected gestational age, per the NICHD Consensus statement. RESULTS: 225 (32%) mothers developed severe HDP and 234 (34%) infants had moderate-severe BPD. There was an interaction between severe HDP and gestational age (p = 0.03). Infants born at < 25 weeks gestation to mothers with HDP had increased odds for moderate-severe BPD compared to infants of normotensive mothers delivering at the same gestational age. Infants born > 28 weeks to mothers with severe HDP had decreased odds for the outcome, though not statistically significant. CONCLUSIONS: Severe HDP has a differential effect on the development of moderate-severe BPD based on gestational age.

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

PROBLEM: There is a paucity of research on the contribution of placental inflammation to severe retinopathy of prematurity (ROP). METHOD OF STUDY: A retrospective cohort study (n = 1217) was conducted of infants screened for ROP (2006-2016). The outcomes of the study were severe ROP (type 1 or type 2 ROP) and low grade ROP. We categorized the placental pathology as the presence of (i) maternal plus fetal inflammatory response, (ii) maternal inflammatory response only, (iii) fetal inflammatory response only and, (iv) no evidence of a maternal or fetal inflammatory response. The data were analyzed using univariate and multivariate logistic regression analyses (P < .05). RESULTS: In this cohort, the number of infants with the maternal plus fetal inflammatory response, the maternal inflammatory response only, the fetal inflammatory response only, and no maternal or fetal inflammatory response was 305 (25%), 82 (7%), 8 (1%), and 822 (67%), respectively. Adjusted for covariates, the maternal plus fetal inflammatory response was a significant risk factor for severe ROP (AOR = 2.6, 95% CI 1.1-5.9, P = .03). None of the categories of placental inflammation were significantly associated with low grade ROP. CONCLUSION: Placental pathology distinguished by the maternal plus fetal inflammatory response was a significant risk factor for severe ROP. Our study supports a link between intrauterine inflammatory events and the subsequent development of severe ROP.

Human trophoblast-derived hydrogen sulfide stimulates placental artery endothelial cell angiogenesis.

Endogenous hydrogen sulfide (H2S), mainly synthesized by cystathionine ß-synthase (CBS) and cystathionine γ-lyase (CTH), has been implicated in regulating placental angiogenesis; however, the underlying mechanisms are unknown. This study was to test a hypothesis that trophoblasts synthesize H2S to promote placental angiogenesis. Human choriocarcinoma-derived BeWo cells expressed both CBS and CTH proteins, while the first trimester villous trophoblast-originated HTR-8/SVneo cells expressed CTH protein only. The H2S producing ability of BeWo cells was significantly inhibited by either inhibitors of CBS (carboxymethyl hydroxylamine hemihydrochloride, CHH) or CTH (ß-cyano-L-alanine, BCA) and that in HTR-8/SVneo cells was inhibited by CHH only. H2S donors stimulated cell proliferation, migration, and tube formation in ovine placental artery endothelial cells (oFPAECs) as effectively as vascular endothelial growth factor. Co-culture with BeWo and HTR-8/SVneo cells stimulated oFPAEC migration, which was inhibited by CHH or BCA in BeWo but CHH only in HTR-8/SVneo cells. Primary human villous trophoblasts (HVT) were more potent than trophoblast cell lines in stimulating oFPAEC migration that was inhibited by CHH and CHH/BCA combination in accordance with its H2S synthesizing activity linked to CBS and CTH expression patterns. H2S donors activated endothelial nitric oxide synthase (NOS3), v-AKT murine thymoma viral oncogene homolog 1 (AKT1), and extracellular signal-activated kinase 1/2 (mitogen-activated protein kinase 3/1, MAPK3/1) in oFPAECs. H2S donor-induced NOS3 activation was blocked by AKT1 but not MAPK3/1 inhibition. In keeping with our previous studies showing a crucial role of AKT1, MAPK3/1, and NOS3/NO in placental angiogenesis, these data show that trophoblast-derived endogenous H2S stimulates placental angiogenesis, involving activation of AKT1, NOS3/NO, and MAPK3/1.

The relationship of the subtypes of preterm birth with retinopathy of prematurity.

BACKGROUND: Retinopathy of prematurity is an adverse outcome of preterm birth and is a leading cause of childhood blindness. The relationship between the subtypes of preterm birth with retinopathy of prematurity is understudied. OBJECTIVE: To investigate whether there is a difference in the incidence of type 1 or type 2 retinopathy of prematurity in infants with preterm birth resulting from spontaneous preterm labor, a medical indication of preterm birth, or preterm premature rupture of the membranes. STUDY DESIGN: A retrospective cohort study was conducted of 827 infants screened for retinopathy of prematurity who were delivered at a single tertiary care center in Colorado. All infants fulfilled the American Academy of Pediatrics 2013 screening criteria for retinopathy of prematurity defined as "infants with a birth weight of ≤1500 g or gestational age of 30 weeks or less (as defined by the attending neonatologist) and selected infants with a birth weight between 1500 and 2000 g or gestational age of >30 weeks with an unstable clinical course, including those requiring cardiorespiratory support and who are believed by their attending pediatrician or neonatologist to be at high risk for retinopathy of prematurity." Two independent reviewers masked to retinopathy of prematurity outcomes determined whether preterm birth resulted from spontaneous preterm labor, medical indication of preterm birth, or preterm premature rupture of the membranes. Discrepancies were resolved by a third reviewer. Data were analyzed with univariate and multivariable logistic regression. RESULTS: In our cohort, the frequency of preterm birth resulting from spontaneous preterm labor, medical indication of preterm birth, or preterm premature rupture of the membranes was 34%, 40%, and 26%, respectively. The mean gestational age (weeks, days) ± SD (range) in the cohort and across the preterm birth subtypes was as follows: entire cohort, 28 weeks, 6 days ± 2 weeks, 3 days (23 weeks, 3 days - 36 weeks, 4 days); spontaneous preterm labor, 28 weeks 1 day ± 2 weeks, 3 days (23 weeks, 3 days - 33 weeks, 4 days); medical indication of preterm birth, 29 weeks, 1 day ± 2 weeks, 2 days (24-36 weeks, 4 days); preterm premature rupture of the membranes, 28 weeks, 4 days ± 2 weeks, 1 day (24-33 weeks, 1 day). Among infants with type 1, type 2, or no retinopathy of prematurity, the incidence of type 1 or type 2 retinopathy of prematurity in births from spontaneous preterm labor, medical indication of preterm birth, and preterm premature rupture of the membranes was 37 of 218 (17%), 27 of 272 (10%), and 10 of 164 (6%), respectively. Adjusted for gestational age, birth weight, and multiparity and compared with the preterm premature rupture of the membranes group, the odds ratios of spontaneous preterm labor and medical indication of preterm birth for type 1 or type 2 retinopathy of prematurity were 6.1 (95% confidence interval, 1.8 to 20, P = .003) and 5.5 (95% confidence interval, 1.4 to 21, P = .01), respectively. Among neonates born after preterm premature rupture of the membranes, the probability of developing type 1 or type 2 retinopathy of prematurity was greatest in infants with rupture of membrane duration of up to 24 hours. After 24 hours, the probability of developing type 1 or type 2 retinopathy of prematurity declined. The odds of developing type 1 or type 2 retinopathy of prematurity was 9.0 (95% confidence interval 2.3 to 34, P = .002) in infants who had preterm premature rupture of the membranes ≤ 24 hours compared with infants who had preterm premature rupture of the membranes > 24 hours. CONCLUSION: Type 1 or type 2 retinopathy of prematurity are adverse ocular outcomes linked with not only lower gestational age and birth weight at delivery but also with events in the intrauterine environment that trigger a preterm birth. The reduced incidence of type 1 or type 2 retinopathy of prematurity in the preterm premature rupture of the membranes group compared with other causes of preterm birth may be related to the perinatal therapies associated with preterm premature rupture of the membranes (such as corticosteroids, antibiotics, maternal-fetal surveillance), which may have an inhibitory effect on the development of retinopathy of prematurity. We suggest that the physiologic events that predispose infants to type 1 or type 2 retinopathy of prematurity begin before delivery.