[Risk factors analysis and prognosis of renal pelvis dilatation in high-risk infants in monocenter].

Objective: To explore the prognosis and risk factors of pyelectasis in high-risk infants. Methods: This was a retrospective study. Totally 960 high-risk infants, who accepted type B ultrasonic examination for fetus at 28th week of gestation and for newborns in 48 hours after birth, were included in the study in departments of obstetrics and eonatology, Shunyi Maternal and Children's Hospital of Beijing Children's Hospital during May 2012 to April 2013. The degree of pyelectasis was classified using Grignon grade and the paients were followed up for 3 years. The factors of epidemiology, high risk pregnant women, fetus and high-risk newborns that relate to pyelectasis were summarized. High-risk factors were analyzed by using logistic multivariate regression analysis. Results: Of 960 high-risk infants, 103 had abnormal urinary ultrasound results, 87 (9.1% of high-risk infants) were diagnosed with pyelectasis, 16 (1.7% of high-risk infants) were diagnosed with congenital anomalies of the kidney and urinary tract. According to the degree of pyelectasis, 68 infants were Grignon grade Ⅰ, male:female ratio=5.8∶1, left side:right side ratio=1.91∶1; 19 infants were Grignon grade Ⅱ, male:female ratio=5.33∶1, left side:right side ratio=2.12∶1. Postnatal follow-up results showed that pyelectasis disappeared in 48 cases (55% of pyelectasis cae), 40 infants were Grignon grade Ⅰ (59% of all Grignon grade Ⅰ patients), 8 infants were Grignon grade Ⅱ (42% of all Grignon grade Ⅱ patients); The result of risk factors analysis showed that the risk of pyelectasis in males was 4.368 times that of females (95% CI: 2.33-8.189, P< 0.05); the risk of pyelectasis in low birth weight infants was 22.434 times that of non low birth weight infants (95% CI : 5.883-85.547, P< 0.05). Conclusion: The incidence of pyelectasis in high-risk infants was 9.1%. The mitigation rate of pyelectasis in Grignon grade Ⅰ to Ⅱ in fetal or newborn period is high. Patients in Grignon grade Ⅲ and above in fetal or new born period had high risk of congenital anomalies of the kidney and urinary tract. The risk of pyelectasis of male was higher than that of female; the risk of pyelectasis of low birth weight infant was higher than appropriate for gestational age infants.