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Coming dissertations at MedFak

  • Ophthalmological follow-up in young adults born premature and screened for retinopathy of prematurity Author: Dýrleif Pétursdóttir Link: Publication date: 2021-05-21 11:38

    Prematurely born children have a higher risk of ophthalmological and neurodevelopmental disorders than those born at term. There is a paucity of long-term prospective follow-up studies on the visual function of prematurely born adults. The current study reported the outcome of young adult individuals born after the introduction of treatment for retinopathy of prematurity (ROP).

    The aim of the study was to assess visual function, visual-motor integration, refraction and its development, as well as strabismus, stereoacuity, accommodation and convergence in prematurely born young adults.

    The participants were prematurely born, between 1 November 1988 and 31 October 1990, having a birth weight of ≤1,500 g, in Stockholm County, Sweden. These individuals were initially part of a prospective population-based study on the incidence of ROP in the neonatal period, followed until 3.5 years of age, and examined again at 10 years of age, together with a control group of term born individuals. At 25–29 years of age, 59 of the preterms and 44 controls underwent an extensive ophthalmological examination and a developmental test of visual-motor integration.

    The preterms had lower visual acuity than the controls at distance and near. Mean deviation of the visual field was reduced in preterms, as was contrast sensitivity. A crowding ratio of ≥1.5 was more prevalent in preterms. In a test of visual-motor integration, the preterms had inferior results compared to controls, in which a neurological complication at 2.5 years of age was the strongest risk factor. The preterms had greater values of myopia and hyperopia, as well as anisometropia and astigmatism, where the highest risk was found in preterms who had been treated for ROP. The spherical equivalent decreased around 1 D in both groups from 10 years to 25–29 years of age. Strabismus was found in 7/59 (12%) preterms and 1/44 (2%) controls. More preterms had subnormal stereoacuity, where the strongest risk factor was a neurological complication at 2.5 years of age. Preterms had worse amplitude of accommodation. No differences were found regarding convergence.

    Prematurely born individuals had reduced visual function, worse visual-motor integration, higher prevalence of refractive errors and strabismus, and worse stereoacuity than term born controls in young adulthood. These lifelong effects could be correlated to previous cryotherapy for ROP or neurological complications, but not always, suggesting a role of prematurity per se.

  • Capturing and addressing preschool children’s emotional and behavioural problems : Using parents’, teachers’ and children’s perspectives Author: Anton Dahlberg Link: Publication date: 2021-05-20 13:18

    Emotional and behavioural problems (EBP) are among the most common mental health problems in preschool children. EBP are also associated with poor parent mental health. Untreated, EBP can persist or worsen over time. In order to capture and address preschool children’s EBP, we need scientifically valid instruments that can access the perspectives of informants from different contexts of the child. We also need cut-off values for questionnaires assessing EBP that are representative of the population. Parenting support is a recommended intervention for addressing EBP in preschool children. Most parenting support programmes have a solid evidence-base and show positive effects on child EBP and parent wellbeing. However, we need a better understanding of the children’s emotional and relational experiences, especially in relation to their parents. Further, although the implementation of evidence-based interventions is a complex matter with substantial impact on intervention success, few studies assess the implementation process of parenting programmes. 

    The studies constituting this thesis focused on preschool children. The Strengths and Difficulties Questionnaire (SDQ) was assessed for capturing EBP. Study I assessed the construct validity of the SDQ and its five subscales, when rated by fathers and preschool teachers. Confirmatory factor analysis was applied to evaluate construct validity. Results indicated that the SDQ can be used as an instrument to measure EBP in preschool children, rated by parents and preschool teachers. In study II, we established Swedish norms for the SDQ for preschool children. Results suggested lower SDQ cut-offs for Swedish preschool children compared with other countries, and higher cut-offs for boys compared with girls. In study III, preschool children whose parents participated in a parenting programme were interviewed regarding their emotional and relational experiences at home. Data were analysed using qualitative content analysis. The children provided accounts of negative and positive interactions with their parents, elaborately describing a coercive cycle with escalating conflicts and lack of problem resolution. In study IV, the implementation of the parenting programme Triple P in a preschool setting was assessed using the RE-AIM framework. Results indicated a successful implementation that relied on customisation of the programme; assessment of the process from parent, staff, and organisation levels; interdisciplinary collaboration; and continuous work on securing maintenance over time. 

    This thesis provides pieces to a complex puzzle of understanding and addressing child mental health problems, particularly EBP. Assessing EBP from different perspectives and promoting children’s voices are essential, as well as actively working with the implementation of evidence-based programmes.

  • Impact of pregnancies on ovarian cancer : Risk, prognosis and tumor biology Author: Camilla Sköld Link: Publication date: 2021-05-12 10:18

    Ovarian cancer is the most lethal gynecological malignancy. The etiology is complex and not fully understood, partly since ovarian cancer is not one distinct disease, but rather several histologically and clinically different subtypes. The two main groups are epithelial (90%) and non-epithelial (10%) cancers, further divided into five epithelial and two main non-epithelial subtypes. Women who have given birth have a lower risk of developing epithelial ovarian cancer, and the risk is further reduced with each additional childbirth. However, the association between several pregnancy-related factors, such as pregnancy length, maternal age at birth, offspring size, and subsequent risk of ovarian cancer has been unclear. In addition, the impact of pregnancy-related risk factors on non-epithelial ovarian cancer is unknown. Further, the underlying mechanism behind the protection of childbirth has not been revealed and the prognostic impact of pregnancies is not established.

    In my first two studies, I evaluated associations between pregnancy-related factors and risk of epithelial ovarian cancer and its different subtypes [Study I] and non-epithelial ovarian cancer [Study II]. These case-control studies were based on linked data from the population-based medical birth registers and cancer registers in Denmark, Finland, Norway and Sweden. In Study I, preterm birth was associated with an increased risk of epithelial ovarian cancer among parous women, whereas increased number of births and pregnancies at older age were associated with decreased risk. In Study II, increasing age at last birth was associated with lower risk of sex cord-stroma cell tumors (SCSTs), as was shorter time since last birth.

    In Study III, the prognostic impact of parity on both epithelial and non-epithelial ovarian cancer by subtype was investigated by linkage of data from the Swedish medical birth register, the cancer register and the cause of death register. Parity was associated with reduced cancer-specific mortality in ovarian germ cell tumors. We found no prognostic impact of parity in patients with SCSTs or epithelial ovarian cancer.

    In Study IV, we investigated whether hormones and proteins involved in pregnancy and tumor development differed according to the woman’s parity status in patients with high-grade serous ovarian cancer. Parous women more often had progesterone receptor (PR) positive tumors, in comparison with nulliparous women, and increased number of children was associated with PR positive tumors.

    In summary, a woman’s reproductive history will not only impact on the risk of developing ovarian cancer, but also have a long-lasting influence on the tumor biology.