Tehran University Medical Journal

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Background: Preterm labor is defined as delivery before 37 weeks of gestation. Recurrence of preterm labor in future pregnancies is 6-8%. History of preterm labor is a strong risk factor for future preterm labor. Preterm labor is the leading cause of neonatal mortality in developed countries, but permanent morbidity in these premature neonates has many side effects for the newborn as well as their family members and society. For this reason we conducted a survey to identify risk factors for recurrent preterm delivery among primiparous women with previous preterm delivery.
Methods: This prospective case–control study included patients from three university hospitals, namely Imam Khomeini, Shariati and Mirza Koochakkhan Hospitals, all in Tehran, Iran. Subjects, including 539 primiparous women who delivered preterm (22–36 weeks), were divided into two groups: 47 had a second preterm delivery (study group) and 492 had first preterm delivery (control group). Exclusion criteria were induced preterm delivery due to medical indications in mother and primigravid. Data collection and analysis was performed using SPSS 10 and t-test and χ2 test were used to analyze the significance of the results.
Results: From a total of 6,537 deliveries, we found 539 cases of preterm delivery, among which 47 cases were identified as recurrent preterm delivery. The control group was composed of 492 deliveries. The recurrence of preterm delivery was 8.7%. Uterine anomaly, cardiovascular, renal and thyroid disease in mother and blood group A had a significant correlation with recurrent preterm delivery.
Conclusion: Expectant mothers with uterine anomalies, cardiovascular, renal or thyroid diseases or group A blood type should receive extra care, observation and instructions in order to limit the risk of preterm delivery and its subsequent effects.

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Background: ABO incompatibility hemolytic disease of the newborn is a common cause of clinical jaundice and causes two-thirds of the hemolytic disease in newborns. This study was undertaken to determine the frequency of ABO incompatibility hemolytic disease and its complications in newborns undergoing exchange transfusion.

Methods: This prospective and descriptive study was performed in jaundiced newborn infants during a three-year period. Inclusion criteria were: maternal blood type O, newborn blood type A or B, rising indirect hyperbilirubinemia in the first two days of life, positive immunohematologic test for newborns and exchange transfusion. Exclusion criteria were: incomplete information, other accompanying diseases that induce hyperbilirubinemia. All newborn infants received phototherapy before and after exchange transfusion. We did not use intravenous immunoglobulin, hemoxygenase inhibitor drugs and blood products before exchange transfusion.

Results: Double-volume exchange transfusion via umbilical cord catheter was performed in 96 patients, 19 (20%) of whom suffered from ABO incompatibility. Of these 19 newborns, two-thirds (13) were preterm infants. The minimum level of serum bilirubin was 10 mg/dl and the maximum serum bilirubin level was 35 mg/dl. In six patients (32%) serum bilirubin levels were >25mg/dl. The most common blood group was type A for newborns. Immunohematologic tests were positive in 84% of the mothers. ABO incompatibility hemolytic disease was the fourth and second most common reasons for blood exchange transfusion in preterm and term infants, respectively. Laboratory complications were more common than clinical complications. The etiology of 48% of the alloimmunization and 42% of the hemolytic disease in these newborns was ABO incompatibility.

Conclusions: Mothers with blood group O and newborns with blood group A or B with positive immunohematologic tests in first hours of life are at high risk for hemolytic disease. Therefore, in this high-risk group, further therapy including prophylactic phototherapy, intravenous immunoglobulin and intramuscular protoporphyrins are necessary to prevent severe jaundice and decrease the need for exchange transfusion.

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Background: Jaundice is the most common cause of neonatal admission within the first month after birth. Therefore, by identifying the causes of jaundice based on the infant’s age at disease onset and age at hospital admission and providing the required training, jaundice can be managed and its associated complications can be prevented. This study was performed to evaluate the causes of neonatal jaundice, based on the infant’s age at disease onset and age at hospital admission.

Methods: In this cross-sectional study, out of 3,130 infants with jaundice, referring to Ghaem Hospital, Mashhad, Iran, from 2003 to 2015, 2,658 newborns were selected. Causes of jaundice are determined based on hematocrit, direct and indirect bilirubin, Coombs test, reticulocyte count, blood group and Rh of mother and neonate, thyroid tests, glucose-6-phosphate dehydrogenase (G6PD) enzyme testing, urinalysis, urine culture, and If necessary, Na, blood urea nitrogen, creatinine and other tests depending on the doctor's supervision. After confirming jaundice in infants, based on the physician’s diagnosis and laboratory results, a researcher-made questionnaire including the infant’s characteristics, was completed.

Results: Based on our study, 27.9% of infants had identified as causes of jaundice. Known causes of jaundice were blood group incompatibility (40%), infection (19%), G6PD enzyme deficiency (12%), endocrine disorders (8%), neonatal hypernatremic dehydration (7%), polycythemia (6%), congenital heart disease (CHD) (4%), occult bleeding (3%) and Crigler-Najjar syndrome (2%). The most common time of hospital admission of jaundice was 4-6 days after birth due to blood incompatibilities, occult bleeding, endocrine disorders, hypernatremic dehydration, CHD, polycythemia and G6PD enzyme deficiency. Moreover, the most common time of admission due to infection was after the first week of birth.

Conclusion: The most common age of onset of jaundice was first three days of birth for blood incompatibility, although they were admitted two days later. Therefore, neonatal admission at appropriate time at onset of jaundice and receiving prompt treatments can reduce the probable complications (e.g., kernicterus).