Potential Role of Bilirubin in Preventing Retinopathy of Prematurity.

BACKGROUND: One of the most common problems in preterm neonates is retinopathy of prematurity (ROP). It has been shown antioxidants may be effective in preventing the development and progression of ROP. Considering the antioxidant properties of bilirubin, we decided to investigate the bilirubin level in neonates with ROP and compare it with healthy neonates. METHODS: This case-control study was performed on VLBW neonates admitted to the NICU of Ghaem Hospital in Mashhad between 2014 and 2020 for a Jaundice evaluation. Complete neonate's characteristics, maternal history and laboratory results were collected in a questionnaire. Then the neonates were examined for ROP by a fellowship of the retina of an ophthalmologist at 32 weeks or four weeks after birth. The highest bilirubin levels during their hospitalization were also recorded. RESULTS: Of 427 neonates examined, 121 (37.7%) had a normal eye examination, and 266 (62.3%) had ROP. The mean weight, gestational age and bilirubin were 1455.8 ± 431.4 grams, 31.6 ± 2.3 weeks and 8.8 ± 2.4 mg/dl, respectively. There was a significant difference between controls and neonates with ROP with regard to birth weight, duration of intermittent positive pressure ventilation (IPPV), duration of oxygen therapy, first and fifth minute Apgar scores, the maximum level of bilirubin and gestational age (P < 0.05). It was observed that the maximum level of bilirubin was lower in neonates with higher stages of ROP. CONCLUSION: According to the results of this study, higher levels of bilirubin in neonates may be a protective factor against ROP. Moreover, increased levels of bilirubin are associated with reduced severity of ROP. Therefore, prophylaxis phototherapy in premature infants may need to be reconsidered.

Comparison of Vitamin D Levels in Premature Infants with and without Retinopathy of Prematurity.

BACKGROUND: Retinopathy of prematurity (RoP) is a cause of newborn blindness. Several predisposing factors have been reported to contribute to the disease process. The current study aimed to compare serum vitamin D levels in infants with and without RoP. METHODS: This case-control study was conducted on 154 very low birth weight (VLBW) infants admitted to Ghaem hospital, Mashhad, Iran, during 2016-2019. Retinal examination for RoP was done at the 32nd week of pregnancy and vitamin D level was determined using the infants' first-day serum samples. A researcher-made questionnaire including maternal, infant, laboratory, and retinal examination information was used as the data collection tool. RESULTS: Out of 154 infants in the study, 56 (36.4%) were normal while 98 (63.6%) had RoP. Based on the severity of retinopathy, 43 infants (43.9%) were at stage I, 48 (49%) at stage II, and 7 (7.1%) at stage III. Significant differences in neonatal (P<0.001) and maternal (P=0.015) vitamin D levels, first and fifth minute Apgar scores (P=0.034 and P=0.001, respectively), and weight (P=0.014) were found between the infants with and without RoP. CONCLUSION: The incidence of RoP was higher in infants with lower gestational age, lower birth weight, low first and fifth minutes Apgar scores, and male sex. Low serum levels of vitamin D in premature infants and their mothers were associated with incidence of RoP. The higher the stage of RoP, the greater was the severity of vitamin D deficiency. Thus, controlling the maternal vitamin D level during pregnancy, consumption of vitamin D supplements, and investigation of serum vitamin D levels in premature infants are recommended. Early correction of vitamin D deficiency may lead to reduction of RoP.

Comparison of hyperbilirubinemia incidence between the newborns of zinc-taking and non-zinc-taking mothers during the third trimester of pregnancy.

BACKGROUND: Identification and control of the risk factors for hyperbilirubinemia can reduce the incidence and complications of this condition. Serum zinc level in newborns is reported to be one of the factors affecting the severity and incidence of neonatal hyperbilirubinemia. Therefore, the present study was conducted to compare hyperbilirubinemia incidence in neonates of zinc-taking and non-zinc-taking mothers. METHODS: In this observational study, we compared the incidence of hyperbilirubinemia during the first week of birth between newborns whose mothers had received zinc supplement during the third trimester of pregnancy (case group) with those whose mothers had not taken zinc supplement (control group). The checklist of newborns' conditions in both case and control groups was completed based on the obtained data regarding the infants, mothers, and laboratory findings. Data was analyzed using chi-squared test and t-test. RESULTS: The mean serum levels of zinc were 79.76±15 mg/dl and 70.93±15.67mg/dl in mothers who had received zinc during the third trimester and those who had not taken zinc supplement, respectively. The mean serum level of zinc in newborns who underwent phototherapy was 41.68±9.21 mg/dl, while it was 68.53±20.85 mg/dl in neonates who did not receive phototherapy. In addition, 36% of the neonates whose mothers had not received zinc required phototherapy, while only 11% of newborns whose mothers had taken zinc supplement received phototherapy. CONCLUSION: Zinc consumption during the third trimester of pregnancy increased the serum zinc level in both newborns and mothers and reduced the incidence and severity of idiopathic hyperbilirubinemia requiring treatment.

Comparison of birth weights of neonates of mothers receiving vs. not receiving zinc supplement at pregnancy.

BACKGROUND: Zinc is an essential element for normal embryogenesis and embryonic and neonatal development. Therefore, we compared the birth weights of neonates born to mothers who consumed zinc supplement during pregnancy with that of neonates born to mothers who did not. METHODS: In a cross-sectional study, we divided 200 pregnant mothers into two groups: case group (mothers receiving zinc supplement during pregnancy) and control group (mothers not receiving zinc supplement during pregnancy) Then, the neonate's cord zinc level and mother's serum level were measured and neonate's growth charts (weight, height and head circumference)were completed. RESULTS: In this study, both groups of mothers were observed to have zinc deficiency; 35% of the mothers who consumed zinc supplements and 81% of the mothers who did not consume zinc supplements (P < 0.001). Based on the results, maternal serum of zinc (P < 0.001), neonatal birth weight (P = 0.008), maternal age (P < 0.001) and parity (P < 0.01) in zinc-supplemented group were higher. Neonatal birth weight was associated moderately with mother's zinc serum levels and poorly with neonatal serum zinc levels. CONCLUSION: Zinc consumption during pregnancy increases serum zinc level of mother and neonatal weight. Neonatal weight has a higher correlation to maternal serum zinc level.