Feeding mode of Australian infants in the first 12 months of life: An assessment against national breastfeeding indicators

Background: In 2011, Australia published a set of 6 population-level indicators assessing breastfeeding, formula use, and the introduction of soft/semisolid/solid foods. Objectives: This study aimed to report the feeding practices of Australian infants against these indicators and determine the predictors of early breastfeeding cessation and introduction of solids. Methods: Mother–infant dyads (N = 1470) were recruited postnatally in 2 Australian capital cities and regional areas of 1 state between February 2008 and March 2009. Demographic and feeding intention data were collected by self-completed questionnaire at infant birth, with feeding practices (current feeding mode, age of breastfeeding cessation, age of formula and/or solids introduction) reported when the infant was between 4 and 7 months of age, and around 13 months of age. Multiple logistic regression was used to determine the predictors of breastfeeding cessation and solids introduction. Results: Although initiation of breastfeeding was almost universal (93.3%), less than half of the infants were breastfed to 6 months (41.7%) and 33.3% were receiving solids by 4 months. Women who were socially disadvantaged, younger, less educated, unpartnered, primiparous, and/or overweight were most likely to have ceased breastfeeding before 6 months of age, and younger and/or less educated women were most likely to have introduced solid food by 4 months of age. Not producing adequate milk was the most common reason provided for cessation of breastfeeding. Conclusion: The feeding behaviors of Australian infants in the first 12 months fall well short of recommendations. Women need anticipatory guidance as to the indicators of breastfeeding success and the tendency of women to doubt the adequacy of their breast milk supply warrants further investigation.

Child temperament and parental personality: continuity and transactional change

Studying the continuity and underlying mechanisms of temperament change from early childhood through adulthood is clinically and theoretically relevant. Knowledge of the continuity and change of temperament from infancy onwards, especially as perceived by both parents is, however, still scanty. Only in recent years have researchers become aware that personality, long considered as stable in adulthood, may also change. Further, studies that focus on the transactional change of child temperament and parental personality also seem to be lacking, as are studies focusing on transactions between child temperament and more transient parental characteristics, like parental stress. Therefore, this longitudinal study examined the degree of continuity of temperament over five years from the infant s age of six months to the child s age of five and a half years, as perceived by both biological parents, and also investigated the bidirectional effects between child temperament and parents personality traits and overall stress experienced during that time. First, moderate to high levels of continuity of temperament from infancy to middle childhood were shown, depicting the developmental links between affectively positive and well-adjusted temperament characteristics, and between characteristics of early and later negative affectivity. The continuity of temperament was quantitatively and qualitatively similar in both parents ratings. The findings also demonstrate that infant and childhood temperament characteristics cluster to form stable temperament types that resemble personality types shown in child and adult personality studies. Second, the parental personality traits of extraversion and neuroticism were shown to be highly stable over five years, but evidence of change in relation to parents views of their child s temperament was also shown: an infant s higher positive affectivity predicted an increase in parental extraversion, while the infant s higher activity level predicted a decrease in parental neuroticism over five years. Furthermore, initially higher parental extraversion predicted higher ratings of the child s effortful control, while initially higher parental neuroticism predicted the child s higher negative affectivity. In terms of changes in parental stress, the infant s higher activity level predicted a decrease in maternal overall stress, while initially higher maternal stress predicted a higher level of child negative affectivity in middle childhood. Together, the results demonstrate that the mother- and father-rated temperament of the child shows continuity during the early years of life, but also support the view that the development of these characteristics is sensitive to important contextual factors such as parental personality and overall stress. While parental personality and experienced stress were shown to have an effect on the child s developing temperament, the reverse was also true: the parents own personality traits and perceived stress seemed to be highly stable, but also susceptible to their experiences of their child s temperament.

A case of true hermaphroditism reveals an unusual mechanism of twinning

Traditionally twins are classified as dizygous or fraternal and monozygous or identical (Hall Twinning, 362, 2003 and 735-743). We report a rare case of 46,XX/46,XY twins: Twin A presented with ambiguous genitalia and Twin B was a phenotypically normal male. These twins demonstrate a third, previously unreported mechanism for twinning. The twins underwent initial investigation with 17-hydroxyprogesterone and testosterone levels, pelvic ultrasound and diagnostic laparoscopy. Cytogenetic analysis was performed on peripheral blood cells and skin fibroblasts. Histological examination and Fluorescence in situ hybridization studies on touch imprints were performed on gonadal biopsies. DNA analysis using more than 6,000 DNA markers was performed on skin fibroblast samples from the twins and on peripheral blood samples from both parents. Twin A was determined to be a true hermaphrodite and Twin B an apparently normal male. Both twins had a 46,XX/46,XY chromosome complement in peripheral lymphocytes, skin fibroblasts, and gonadal biopsies. The proportion of XX to XY cells varied between the twins and the tissues evaluated. Most significantly the twins shared 100% of maternal alleles and approximately 50% of paternal alleles in DNA analysis of skin fibroblasts. The twins are chimeric and share a single genetic contribution from their mother but have two genetic contributions from their father thus supporting the existence of a third, previously unreported type of twinning.

Bacillus cereus spores and cereulide in food-borne illness

B. cereus is a gram-positive bacterium that possesses two different forms of life:the large, rod-shaped cells (ca. 0.002 mm by 0.004 mm) that are able to propagate and the small (0.001 mm), oval shaped spores. The spores can survive in almost any environment for up to centuries without nourishment or water. They are insensitive towards most agents that normally kill bacteria: heating up to several hours at 90 ºC, radiation, disinfectants and extreme alkaline (≥ pH 13) and acid (≤ pH 1) environment. The spores are highly hydrophobic and therefore make them tend to stick to all kinds of surfaces, steel, plastics and live cells. In favorable conditions the spores of B. cereus may germinate into vegetative cells capable of producing food poisoning toxins. The toxins can be heat-labile protein formed after ingestion of the contaminated food, inside the gastrointestinal tract (diarrhoeal toxins), or heat stable peptides formed in the food (emesis causing toxin, cereulide). Cereulide cannot be inactivated in foods by cooking or any other procedure applicable on food. Cereulide in consumed food causes serious illness in human, even fatalities. In this thesis, B. cereus strains originating from different kinds of foods and environments and 8 different countries were inspected for their capability of forming cereulide. Of the 1041 isolates from soil, animal feed, water, air, used bedding, grass, dung and equipment only 1.2 % were capable of producing cereulide, whereas of the 144 isolates originating from foods 24 % were cereulide producers. Cereulide was detected by two methods: by its toxicity towards mammalian cells (sperm assay) and by its peculiar chemical structure using liquid-chromatograph-mass spectrometry equipment. B. cereus is known as one of the most frequent bacteria occurring in food. Most foods contain more than one kind of B. cereus. When randomly selected 100 isolates of B. cereus from commercial infant foods (dry formulas) were tested, 11% of these produced cereulide. Considering a frequent content of 103 to 104 cfu (colony forming units) of B. cereus per gram of infant food formula (dry), it appears likely that most servings (200 ml, 30 g of the powder reconstituted with water) may contain cereulide producers. When a reconstituted infant formula was inoculated with >105 cfu of cereulide producing B. cereus per ml and left at room temperature, cereulide accumulated to food poisoning levels (> 0.1 mg of cereulide per serving) within 24 hours. Paradoxically, the amount of cereulide (per g of food) increased 10 to 50 fold when the food was diluted 4 - 15 fold with water. The amount of the produced cereulide strongly depended on the composition of the formula: most toxin was formed in formulas with cereals mixed with milk, and least toxin in formulas based on milk only. In spite of the aggressive cleaning practices executed by the modern dairy industry, certain genotypes of B. cereus appear to colonise the silos tanks. In this thesis four strategies to explain their survival of their spores in dairy silos were identified. First, high survival (log 15 min kill ≤ 1.5) in the hot alkaline (pH >13) wash liquid, used at the dairies for cleaning-in-place. Second, efficient adherence of the spores to stainless steel from cold water. Third, a cereulide producing group with spores characterized by slow germination in rich medium and well preserved viability when exposed to heating at 90 ºC. Fourth, spores capable of germinating at 8 ºC and possessing the psychrotolerance gene, cspA. There were indications that spores highly resistant to hot 1% sodium hydroxide may be effectively inactivated by hot 0.9% nitric acid. Eight out of the 14 dairy silo tank isolates possessing hot alkali resistant spores were capable of germinating and forming biofilm in whole milk, not previously reported for B. cereus. In this thesis it was shown that cereulide producing B. cereus was capable of inhibiting the growth of cereulide non-producing B. cereus occurring in the same food. This phenomenon, called antagonism, has long been known to exist between B. cereus and other microbial species, e.g. various species of Bacillus, gram-negative bacteria and plant pathogenic fungi. In this thesis intra-species antagonism of B. cereus was shown for the first time. This brother-killing did not depend on the cereulide molecule, also some of the cereulide non-producers were potent antagonists. Interestingly, the antagonistic clades were most frequently found in isolates from food implicated with human illness. The antagonistic property was therefore proposed in this thesis as a novel virulence factor that increases the human morbidity of the species B. cereus, in particular of the cereulide producers.

Äidinmaito - terveysjuomaa ja normaalibakteereita

The chemical composition of breast milk has been studied in detail in the past decades. Hundreds of new antibacterial and antiviral components have been found. Several molecules have been found to promote the proper function of neonatal intestine. However, microbiological studies of breast milk have been, until recently, focused mainly on detecting harmful and pathogenic bacteria and viruses. Natural microbial diversity of human milk has not been widely studied before the work reported in this thesis. This is mainly because breast milk has traditionally been thought to be sterile - even if a certain amount of commensal bacteria have usually been detected in milk samples. The first part of this licentiate thesis contains a short literature review about the anatomy and physiology of breast feeding, human milk chemical and microbiological composition, mastitis, intestinal flora and bacteriocins. The second part reports on the experiments of the licentiate work, concentrating on the microbial diversity in the milk of healthy breast-feeding mothers, and the ability of these bacteria to produce antibacterial substances against pathogenic bacteria. The results indicate that human milk is a source of commensal bacteria for infant intestine. 509 random isolates from 40 breast milk samples were isolated and identified by 16S rRNA sequencing. Median bacterial count was about 600 colony forming units per milliliter. Over half of the isolates were staphylococci, and almost one third streptococci. The most common species were skin bacteria Staphylococcus epidermidis and oral bacteria Streptococcus salivarius and Streptococcus mitis. Lactic acid bacteria, identified as members of Lactobacillus-, Lactococcus- and Leuconostoc -genera, were found in five milk samples. Enterococci were found in three samples. A novel finding in this study is the capability of these commensal bacteria to inhibit the growth of pathogens. In 90 precent of the milk samples commensal bacteria inhibiting the growth of Staphylococcus aureus were found. In 40 precent of samples the colonies could block the growth completely. One fifth of the isolated Staph. epidermidis strains, half of Str. salivarius strains, and all lactic acid bacteria and enterococci could inhibit or block the growth of Staph. aureus. In further study also Listeria innocua- and Micrococcus luteus active isolates were found in 33 and 11 precent of milk samples (out of 140). Furthermore, two Lactococcus lactis isolates from the breast milk were shown to produce bacteriocin nisin, which is an antimicrobial molecule used as a food preservative. The importance of these human milk commensal bacteria in the development of newborn intestinal flora and immune system, as well as in preventing maternal breast infections, should be further explored.

Monitoring exposure to polycyclic aromatic hydrocarbons in an Australian population using pooled urine samples

Integrated exposure to polycyclic aromatic hydrocarbons (PAHs) can be assessed through monitoring of urinary mono-hydroxylated PAHs (OH-PAHs). The aim of this study was to provide the first assessment of exposure to PAHs in a large sample of the population in Queensland, Australia including exposure to infant (0-4. years). De-identified urine specimens, obtained from a pathology laboratory, were stratified by age and sex, and pooled (n. =. 24 pools of 100) and OH-PAHs were measured by gas chromatography-isotope dilution-tandem mass spectrometry. Geometric mean (GM) concentrations ranged from 30. ng/L (4-hydroxyphenanthrene) to 9221. ng/L (1-naphthol). GM of 1-hydroxypyrene, the most commonly used PAH exposure biomarker, was 142. ng/L. The concentrations of OH-PAHs found in this study are consistent with those in developed countries and lower than those in developing countries. We observed no association between sex and OH-PAH concentrations. However, we observed lower urinary concentrations of all OH-PAHs in samples from infants (0-4. years), children (5-14. years) and the elderly (>. 60. year old) compared with samples from other age groups (15-29, 30-44 and 45-59. years) which may be attributed to age-dependent behaviour-specific exposure sources.

Differences in parent regulation beliefs and maternal postnatal depressive symptoms in early weeks

Postnatal depression is consistently associated with couple relationship qualities. Substantial infant care requirements in early weeks may highlight differences in parenting beliefs between mother and father. We calculated difference scores in parenting beliefs (disparity) in a community sample of 209 parent dyads. Contrary to previous research regarding ‘disagreement’ which could be interpreted as discord, independently measured disparity was not associated with maternal depressive symptoms. Coparenting interventions should promote respectful negotiation rather than resolution of differences.

Sleep and self-regulation from birth to 7 years: A retrospective study of children with and without ADHD at 8-9 years

Objective To examine mean level differences, and longitudinal and reciprocal relations among behavioral sleep problems, emotional dysregulation, and attentional regulation across early childhood for children with and without ADHD at 8-9 years. Method This study used data from Growing Up in Australia: The Longitudinal Study of Australian Children (LSAC) – Infant Cohort (n = 4109 analyzed). Children with and without ADHD were identified at age 8-9 years via parent-report of ADHD diagnosis and the 5-item Inattention-Hyperactivity subscale from the Strengths and Difficulties Questionnaire. Maternal report of child sleep problems and self-regulation was collected at 0-1, 2-3, 4-5 and 6-7 years of age. ANOVA was used to compare mean level differences in sleep problems, emotional and attentional regulation by ADHD group. Longitudinal structural equation modeling examined the relations among sleep and self-regulation across time in children with and without ADHD. Results Children with ADHD had persistently elevated levels of sleep problems (from infancy) and emotional and attentional dysregulation compared to controls (from 2-3 years of age). Sleep problems, emotional dysregulation, and attentional regulation were stable over time for both groups. Sleep problems were associated with greater emotional dysregulation two years later from 2-3 years of age for both groups, which in turn was associated with poorer attentional regulation. There was no direct relationship between sleep problems and later attentional regulation. Conclusion Sleep problems in children with and without ADHD are associated with emotional dysregulation, which in turn contributes to poorer attentional functioning. This study highlights the importance of assessing and managing sleep problems in young children.

Early childhood profiles of sleep problems and self-regulation predict later school adjustment

Background Children’s sleep problems and self-regulation problems have been independently associated with poorer adjustment to school, but there has been limited exploration of longitudinal early childhood profiles that include both indicators. Aims This study explores the normative developmental pathway for sleep problems and self-regulation across early childhood, and investigates whether departure from the normative pathway is associated with later social-emotional adjustment to school. Sample This study involved 2880 children participating in the Growing Up in Australia: The Longitudinal Study of Australian Children (LSAC) – Infant Cohort from Wave 1 (0-1 years) to Wave 4 (6-7 years). Method Mothers reported on children’s sleep problems, emotional, and attentional self-regulation at three time points from birth to 5 years. Teachers reported on children’s social-emotional adjustment to school at 6-7 years. Latent profile analysis was used to establish person-centred longitudinal profiles. Results Three profiles were found. The normative profile (69%) had consistently average or higher emotional and attentional regulation scores and sleep problems that steadily reduced from birth to 5. The remaining 31% of children were members of two non-normative self-regulation profiles, both characterised by escalating sleep problems across early childhood and below mean self-regulation. Non-normative group membership was associated with higher teacher-reported hyperactivity and emotional problems, and poorer classroom self-regulation and prosocial skills. Conclusion Early childhood profiles of self-regulation that include sleep problems offer a way to identify children at risk of poor school adjustment. Children with escalating early childhood sleep problems should be considered an important target group for school transition interventions.

A Patchwork of memories 1911-1997

Memoir describes her life in Germany, her decision to leave Germany after the death of her parents, and to work in the United States in 1934. Detailed description of every day life in Germany (after World War I) and in the United States, and later of various travels all over the world. Also mentions her German-Jewish ancestors on her maternal side (great-great-grandparents: Moritz and Fanny Hertz, great-grandmother: Helene Hertz nee Orthenberger), who had a textile business.

Tila tilassa : Liturgian ja tilan dialogi alttarin äärellä

This study examines the organisation and transformation of altar space in the modern Evangelical Lutheran Church of Finland in liturgical and architectural perspective. The research data consists of 65 altar spaces in The Finnish Evangelical Lutheran church buildings. All of these were characterised in Church Government records as churches , built 1962 1999 and had been consecrated. The main data was collected by means of observation, photographing, and drawing sketches of altar spaces. The focus of this study concerns the organisation of modern Finnish Evangelical Lutheran altar spaces and, in particular, their changes also in relation to the liturgical movement. The challenge of this approach was especially in discovering the spatial identity of an altar space in terms of unequivocal boundaries. The analysis was realised in three stages. Interiors, the organisation of altar space, as well as architectonic qualities of altar spaces in terms of floor elevations, shapes of ceilings, lighting, and openings in the altar space were analysed. Moreover, attention was focused on furnishing and fixed versus movable pieces of furniture (such as the altar, altar rail, the pulpit, the baptismal font, and lectern). Finally, the potential qualitative and quantitative changes in altar space were examined. All in all, the majority of churches in the data featured elongated church halls with an altar at the end of the nave. To look at the data in chronological perspective, increasingly wide church halls had been built since the 1980s (yet there was only one central hall in which the altar was placed at the middle point of the church). Every third church altar was movable. As for the focal point of this study and the altar in particular, it was my aim to pay attention to the versus populum altar and its development in relation to the (Lutheran) liturgy. Hence, it was meaningful to determine, in terms of interior design, whether liturgists were able to celebrate facing the people attending the service. In the 1960s and 70s, a versus orientem altar featured in more than half of all new Finnish Lutheran churches, yet in 2000 two out of three churches featured a versus populum altar. For architectural and esthetic reasons (and not primarily due to liturgical ideas), also altars standing freely off the walls had been constructed. In terms of the liturgy, versus populum altars had been realised in expectation of increased communication between liturgist and worshippers. However, the analysis indicated that the altar could also become a divider of space. This aspect is a novel finding in relation to earlier and concurrent discussions concerning the liturgical movement. This study concluded, all in all, that altars had been increasingly constructed closer and closer to the worshiping parish and, accordingly, used increasingly often in the versus populum manner. Lecterns were often movable until the millennium this was the case in most altar spaces. Baptismal fonts did not have a permanent place in this data, and the data even included altar spaces with no baptismal fonts in the choir, nor the church hall. The position and status of fonts was generally weakened even if baptism in the Lutheran Church was regarded as one of the two sacraments together with the eucharist. The study concluded that even if baptism is regarded as a sacrament in the church, the position and status of baptismal fonts had weakened overall in newer church architecture. In other words, the tendency of the liturgical movement to emphasise the service and its celebration had obviously had its effect on the placement of baptismal fonts in the church hall. This research indicated that the pieces of furniture that mostly involved (many kinds of) visual and spatial changes included the altar and the lectern. In certain instances, fixed furnishings had been substituted by movable pieces or, moreover, new pieces of furniture and paraphernalia such as music instruments, pieces of art, tables, chairs and plants were brought in. In the Evangelical Lutheran Church of Finland, liturgical changes were principally inspired by the Catholic Church, in which liturgical changes are essentially based on Canon Law. Unlike Finnish Lutheranism, Catholicism provides detailed rules and principles even regarding the design of an altar space. According to this study, in the Finnish Lutheran Church, the primarily functional nature of given guidelines and instructions characterises several practical solutions in furnishing.

Vedestä vai Hengestä? : Uuras Saarnivaaran kasteteologia

Of water or the Spirit? Uuras Saarnivaara s theology of baptism The aim of the study was to investigate PhD and ThD Uuras Saarnivaara s views on baptism as well as their possible changes and the reasons for them. Dr Saarnivaara said himself that he searched for the truth about the relationship between baptism and faith for decades, and had faltered in his views. The method of this research is systematic analysis. A close study of the source material shows that Dr Saarnivaara s views on baptism have most likely changed several times. Therefore, special attention was paid to the time periods defined by when his literary works were published. This resulted in revealing the different perspectives he had on baptism. The fact that Dr Saarnivaara worked on two continents Europe and North America added a challenge to the research process. At the beginning of the research, I described Dr Saarnivaara s phases of life and mapped out his vast literary production as well as presented his theological basis. Saarnivaara s theological view on the means of grace and their interrelation in the church was influenced by the Laestadian movement, which caused him to adopt the view that the Holy Spirit does not dwell in the means of grace, but in the believers. Thus the real presence of Christ in the means of grace is denied. God s word is divided into Biblical revelation and proclamation by believers through the means of grace. Also, the sacraments are overshadowed by the preached word. Because grace is received through the word of the gospel preached publicly or privately by a believer, the preacher s status gains importance at the expense of the actual means of grace. Saarnivaara was intrigued by the content of baptism from the time he was a student until the end of his life. As a young theologian, he would adopt the opinions of his teachers as well as the view of the Evangelical Lutheran Church of Finland, which at the time was dominated by the pietistic movement and the teachings of J. T. Beck. After Saarnivaara had converted to the Laestadian movement, moved to the United States and started his Luther research, he adopted a view on baptism which was to a great extent in accordance with Luther and the Lutheran Symbolical Books. Saarnivaara considered his former views on baptism unbiblical and publicly apologised for them. In the 1950s, after starting his ministry within the Finnish neopietistic movements, Saarnivaara adopted a Laestadian-neopietistic doctrine of baptism. During his Beckian-pietistic era, Saarnivaara based his baptism theology on the event of the disciples of Jesus being baptised by John the Baptist, the revival of Samaria in the Book of Acts and the conversion of Cornelius and his family, all cases where the receiving of the Holy Spirit and the baptism were two separate events in time. In order to defend the theological unity of the Bible, Saarnivaara had to interpret Jesus teachings on baptism in the Gospels and the teachings of the Apostles in the New Testament letters from a viewpoint based on the three events mentioned above. During his Beckian-pietistic era, the abovementioned basic hermeneutic choice caused Saarnivaara to separate baptism by water and baptism by the Holy Spirit in his salvation theology. Simultaneously, the faith of a small child is denied, and rebirth is divided into two parts, the objective and the subjective, the latter being moved from the moment of baptism to a possible spiritual break-through at an age when the person possesses a more mature understanding. During his Laestadian-Lutheran era, Saarnivaara s theology of baptism was biblically consistent and the same for all people regardless of the person s age. Small children receive faith in baptism through the presence of Christ. The task of other people s faith is limited to the act of bringing the child to the baptism so that the child may receive his/her own faith from Christ and be born again as a child of God. The doctrine of baptism during Saarnivaara s Laestadian-neopietistic era represents in many aspects the emphases he presented during his first era, although they were now partly more radical. Baptism offers grace; it is not a means of grace. Justification, rebirth and salvation would take place later on when a person had reached an age with a more mature understanding through the word of God. A small child cannot be born again in baptism because being born again requires personal faith, which is received through hearing and understanding the law and the gospel. Saarnivaara s views on baptism during his first and third era are, unlike during his second era, quite controversial. The question of the salvation of a small child goes unanswered, or it is even denied. The central question during both eras is the demand of conversion and personal faith at a mature age. The background for this demand is in Saarnivaara s anthropology, which accentuates man s relationship to God as an intellectual and mental matter requiring understanding, and which needs no material instruments. The two first theological eras regarding Saarnivaara s doctrine of baptism lasted around ten years. The third era lasted over 40 years until his death.

Heparin versus 0.9% sodium chloride intermittent flushing for the prevention of occlusion in long term central venous catheters in infants and children: A systematic review

Background Around the world, guidelines and clinical practice for the prevention of complications associated with central venous catheters (CVC) vary greatly. To prevent occlusion, most institutions recommend the use of heparin when the CVC is not in use. However, there is debate regarding the need for heparin and evidence to suggest normal saline may be as effective. The use of heparin is not without risk, may be unnecessary and is also associated with increased costs. Objectives To assess the clinical effects (benefits and harms) of heparin versus normal saline to prevent occlusion in long-term central venous catheters in infants, children and adolescents. Design A Cochrane systematic review of randomised controlled trials was undertaken. - Data sources: The Cochrane Vascular Group Specialised Register (including MEDLINE, CINAHL, EMBASE and AMED) and the Cochrane Register of Studies were searched. Hand searching of relevant journals and reference lists of retrieved articles was also undertaken. - Review Methods: Data were extracted and appraisal undertaken. We included studies that compared the efficacy of normal saline with heparin to prevent occlusion. We excluded temporary CVCs and peripherally inserted central catheters. Rate ratios per 1000 catheter days were calculated for two outcomes, occlusion of the CVC, and CVC-associated blood stream infection. Results Three trials with a total of 245 participants were included in this review. The three trials directly compared the use of normal saline and heparin. However, between studies, all used different protocols with various concentrations of heparin and frequency of flushes. The quality of the evidence ranged from low to very low. The estimated rate ratio for CVC occlusion per 1000 catheter days between the normal saline and heparin group was 0.75 (95% CI 0.10 to 5.51, two studies, 229 participants, very low quality evidence). The estimated rate ratio for CVC-associated blood stream infection was 1.48 (95% CI 0.24 to 9.37, two studies, 231 participants; low quality evidence). Conclusions It remains unclear whether heparin is necessary for CVC maintenance. More well-designed studies are required to understand this relatively simple, but clinically important question. Ultimately, if this evidence were available, the development of evidenced-based clinical practice guidelines and consistency of practice would be facilitated.