AbstractsMedical & Health Science

In Sweden, preterm infants are preferably fed human milk. Very preterm infants (< 32 weeks), who are unable to breastfeed, are fed with expressed maternal milk via a nasogastric tube. Mothers of these infants often experience difficulties in establishing and maintaining lactation. The majority of women excrete cytomegalovirus (CMV) in their breast milk. CMV transmitted through maternal milk can cause symptomatic infection in preterm infants presenting as a sepsis like syndrome, pneumonitis, hepatopathy or enterocolitis. Routine freezing of maternal milk decreases the CMV load in breast milk and is used in some neonatal centers to reduce CMV transmission to preterm infants. The aims of the studies in this thesis were to document existing routines pertaining to breast milk use for preterm infants in Sweden, to investigate predictors of maternal milk feedings in extremely preterm infants (EPIs, < 28 weeks), to evaluate the rate and clinical expression of postnatal CMV infection in EPIs, to evaluate the effect of routine freezing of maternal milk on CMV transmission rate, CMV associated disease and neonatal morbidity and mortality in EPIs and to evaluate the prevalence of CMV infection in intestinal specimens from infants with necrotizing enterocolitis (NEC), spontaneous intestinal perforation (SIP) and related surgical conditions. In a national cross sectional study in 2006 in Sweden, we found that 27 of 36 (75%) neonatal units had their own milk bank. Milk donors were screened for human immunodeficiency virus, human T-lymphotropic virus, and hepatitis B and C viruses by 27 (100%), 14 (52%), and 22 (81%) of the milk banks, respectively. Bacterial culture was performed on donor milk in 24 (89%) milk banks. Donor milk was pasteurized in 22 (81%) milk banks. In 11 of the 36 (31%) neonatal units maternal milk was frozen to reduce the risk ofCMV transmission. Nutritional analysis of donor and/or maternal milk was performed in 25 (69%) units. In a prospective cohort study at the neonatal units in Stockholm, including 97 mothers and their singleton EPIs, predictors of maternal milk feedings in EPIs during the first 6 weeks of life and at discharge were evaluated. Favorable predictors of maternal milk feedings the first 6 weeks of life were high maternal milk feedings (>90%) at second week of life, maternal university education and Nordic origin of the mother. The proportion of maternal milk feedings the first 6 weeks of life and maternal age were positively associated to the provision of maternal milk feedings at discharge while maternal overweight was an unfavorable predictor. High maternal milk feedings (>90%) at second week of life, assisted reproduction technology and maternal employment were predictive factors for exclusive maternal milk feedings at discharge. Ten EPIs and their 6 mothers were included in a pilot study at the neonatal unit, Astrid Lindgrens Children´s hospital to evaluate the rate and clinical expression of breast milk induced CMV infection. Five (83%) mothers were CMV-seropositive; of these,…