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Item Case-Control Study of Congenital Anomalies: Study Methods and Nonresponse Bias Assessment.(Wiley Periodicals LLC, 2025-02-20) Eng A; Mannetje AT; Ellison-Loschmann L; Borman B; Cheng S; Lawlor DA; Douwes J; Pearce NBACKGROUND: To describe the methods of a congenital anomalies case-control study conducted in New Zealand, discuss the encountered methodological difficulties, and evaluate the potential for nonresponse bias. METHODS: The potential cases (n = 2710) were New Zealand live births in 2007-2009 randomly selected from the New Zealand Congenital Anomalies Registry. The potential controls (n = 2989) included live births identified from the Maternity and Newborn Information System, frequency matched to cases by the child's year of birth and sex. Mothers were invited to complete an interview covering demographic, lifestyle, and environmental factors. Response probabilities for case and control mothers were evaluated in relation to maternal age, deprivation, occupation, and ethnicity, available from the Electoral Roll, and inverse probability weights (IPWs) for participation were calculated. Odds ratios (ORs) for key demographic and selected risk factors were estimated through unconditional logistic regression, with and without IPW. RESULTS: A total of 652 (24%) of case mothers and 505 (17%) of control mothers completed the interview. Younger and more deprived mothers were underrepresented among the participants, particularly for controls, resulting in inflated ORs of associations with congenital anomalies for younger age, Māori ethnicity, deprivation, and risk factors under study, such as blue-collar occupations and smoking, indicative of nonresponse bias. Nonresponse bias was minimized through IPW, resulting in ORs and exposure prevalence estimates similar to those based on the prerecruitment sample. CONCLUSIONS: Attaining high participation rates was difficult in this study that was conducted in new mothers, particularly for the controls. The resulting nonresponse bias was minimized through IPW.Item Resisting stigma: the role of online communities in young mothers' successful breastfeeding.(BioMed Central Ltd, 2024-03-06) Severinsen C; Neely E; Hutson RBACKGROUND: Breastfeeding initiation and continuation rates are shaped by complex and interrelated determinants across individual, interpersonal, community, organisational, and policy spheres. Young mothers, however, face a double burden of stigma, being perceived as immature and incompetent in their mothering and breastfeeding abilities. In this study, we aimed to understand the experiences of young mothers who exclusively breastfed for six months and beyond and explore their experiences of stigma and active resistance through social media. METHODS: In 2020, in-depth telephone interviews about breastfeeding experiences were conducted with 44 young mothers under age 25 in Aotearoa New Zealand who breastfed for six months or longer. Participants were recruited via social media. Interviews were audio-recorded, transcribed and analysed thematically. RESULTS: Analysis yielded four themes on young mothers' negotiation of breastfeeding and support. The first three themes revealed young mothers' encounters with socio-cultural contexts. They faced negative judgments about maturity and competence, adverse guidance to supplement or cease breastfeeding, and an undermining of their breastfeeding efforts. The fourth theme showed how young mothers sought alternative support in online environments to avoid negative interactions. Online spaces provided anonymity, convenience, experiential knowledge and social connections with shared values. This facilitated identity strengthening, empowerment and stigma resistance. CONCLUSION: Our research highlights the importance of online communities as a tool for young mothers to navigate and resist the societal stigmas surrounding breastfeeding. Online spaces can provide a unique structure that can help counteract the adverse effects of social and historical determinants on breastfeeding rates by fostering a sense of inclusion and support. These findings have implications for the development of breastfeeding promotion strategies for young mothers and highlight the potential of peer support in counteracting the negative impacts of stigma. The research also sheds light on the experiences of young mothers within the health professional relationship and the effects of stigma and cultural health capital on their engagement and withdrawal from services. Further research should examine how sociocultural barriers to breastfeeding stigmatise and marginalise young mothers and continue to reflect on their socio-political and economic positioning and how it can exacerbate inequities.Item Do Micronutrient and Omega-3 Fatty Acid Supplements Affect Human Maternal Immunity during Pregnancy? A Scoping Review(MDPI (Basel, Switzerland), 2022-01-15) Rees G; Brough L; Orsatti GM; Lodge A; Walker S; Pérez-Cano FJMaternal dietary micronutrients and omega-3 fatty acids support development of the fetal and neonatal immune system. Whether supplementation is similarly beneficial for the mother during gestation has received limited attention. A scoping review of human trials was conducted looking for evidence of biochemical, genomic, and clinical effects of supplementation on the maternal immune system. The authors explored the literature on PubMed, Cochrane Library, and Web of Science databases from 2010 to the present day using PRISMA-ScR methodology. Full-length human trials in English were searched for using general terms and vitamin A, B12, C, D, and E; choline; iodine; iron; selenium; zinc; and docosahexaenoic/eicosapentaenoic acid. Of 1391 unique articles, 36 were eligible for inclusion. Diverse biochemical and epigenomic effects of supplementation were identified that may influence innate and adaptive immunity. Possible clinical benefits were encountered in malaria, HIV infections, anemia, Type 1 diabetes mellitus, and preventing preterm delivery. Only limited publications were identified that directly explored maternal immunity in pregnancy and the effects of micronutrients. None provided a holistic perspective. It is concluded that supplementation may influence biochemical aspects of the maternal immune response and some clinical outcomes, but the evidence from this review is not sufficient to justify changes to current guidelines.Item Double-blind RCT of fish oil supplementation in pregnancy and lactation to improve the metabolic health in children of mothers with overweight or obesity during pregnancy: study protocol(BMJ Publishing Group Ltd, 2020-12-15) Satokar VV; Cutfield WS; Derraik JGB; Harwood M; Okasene-Gafa K; Beck K; Cameron-Smith D; O'Sullivan JM; Sundborn G; Pundir S; Mason RP; Albert BBIntroduction Maternal obesity during pregnancy is associated with adverse changes in body composition and metabolism in the offspring. We hypothesise that supplementation during pregnancy of overweight and obese women may help prevent the development of greater adiposity and metabolic dysfunction in children. Previous clinical trials investigating fish oil supplementation in pregnancy on metabolic outcomes and body composition of the children have not focused on the pregnancies of overweight or obese women. Methods and analysis A double-blind randomised controlled trial of fish oil (providing 3 g/day of n-3 polyunsaturated fatty acids) versus an equal volume of olive oil (control) taken daily from recruitment until birth, and in breastfeeding mothers, further continued for 3 months post partum. Eligible women will have a singleton pregnancy at 12–20 weeks’ gestation and be aged 18–40 years with body mass index ≥25 kg/m2 at baseline. We aim to recruit a minimum of 128 participants to be randomised 1:1. Clinical assessments will be performed at baseline and 30 weeks of pregnancy, including anthropometric measurements, fasting metabolic markers, measures of anxiety, physical activity, quality of life and dietary intake. Subsequent assessments will be performed when the infant is 2 weeks, 3 months and 12 months of age for anthropometry, body composition (dual-energy X-ray absorptiometry (DXA)) and blood sampling. The primary outcome of the study is a between-group difference in infant percentage body fatness, assessed by DXA, at 2 weeks of age. Secondary outcomes will include differences in anthropometric measures at each time point, percentage body fat at 3 and 12 months and homeostatic model assessment of insulin resistance at 3 months. Statistical analysis will be carried out on the principle of intention to treat. Ethics and dissemination This trial was approved by the Northern A Health and Disabilities Ethics Committee, New Zealand Ministry of Health (17/NTA/154). Results will be published in a peer-reviewed journal. Trial registration number ACTRN12617001078347p; Pre-results.Item Maternal thyroid function, postnatal depression, the intake and status of iodine, selenium, and iron in postpartum women and their infants : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Manawatū, New Zealand(Massey University, 2021) Jin, YingBackground: Thyroid dysfunction is a common health issue in women, with a higher prevalence found in postpartum women. Postnatal depression (PND) is a maternal health issue which can exacerbate negative health effects on their newborns. Iodine, selenium, and iron are three essential nutrients for the synthesis of thyroid hormones. Historically, dietary insufficiency of iodine and selenium exist in New Zealand. To improve iodine status, the New Zealand government introduced mandatory fortification of bread with iodised salt (2009), and recommended iodine supplementation (150 µg/day) for all pregnant and breastfeeding women (2010). Mostly, the iron status of postpartum women in New Zealand is rarely medically examined, unless high levels of blood loss during childbirth are recorded. Objectives: The overall aim of this PhD thesis was to investigate maternal thyroid function, postnatal depression, and the intake and status of iodine, selenium and iron in mothers and infants during their first postpartum year. Method: This observational longitudinal cohort study was conducted in Palmerston North, New Zealand, from June 2016 to December 2017. Mother-infant pairs attended study visits at three, six and twelve months postpartum (3MPP, 6MPP, and 12MPP). Online questionnaires investigated maternal iodine knowledge, supplement use, mode of infant feeding, and sociodemographic characteristics. Weighed four-day dietary diary, with urine/blood/breastmilk samples, were taken to measure maternal iodine, selenium, and iron intake/status. Infant iodine and selenium concentrations were determined in spot urine samples. The Edinburgh Postnatal Depression Scale was used to screen for PND. At 6MPP, serum thyroid hormones [free triiodothyronine, free thyroxine, thyroid stimulating hormone (TSH), thyroglobulin (Tg) and anti-Tg and thyroid peroxidase antibodies] and thyroid volume were measured. Results: At 3MPP, 87 breastfeeding mother-infant pairs were recruited, followed up at 6MPP (n = 78) and 12MPP (n = 71). At 6MPP, 18% of women had thyroid dysfunction. Median total thyroid volume was 6.1 mL. Median (p25, p75) Tg was 11.4 (8.6, 18.6) µg/L, above 10 µg/L. Median maternal plasma selenium was 105.8 (95.6, 115.3) µg/L; 23% (17/74) being below 95 µg/L; with 4% of women experiencing iron deficiency without anaemia. Women with marginally lower plasma selenium were 1.14% times more likely to have abnormal TSH concentrations. Over the first postpartum year, maternal median urinary iodine concentration (MUIC) was 82 (46, 157) µg/L, 85 (43, 134) µg/L, and 95 (51, 169) µg/L, all below 100 µg/L; median BMIC was 69 (52, 119) µg/L, 59 (39, 108) µg/L, and 35 (26, 54) µg/L, all below the recommended 75 µg/L. Median maternal iodine intake was 151 (99, 285) µg/day, with 58% below the Estimated Average Requirement (EAR). At 3MPP, 46% of women took iodine-containing supplements, this reduced to 11% at 6MPP, and 6% at 12MPP. Women who used iodine-containing supplements had significantly higher MUIC (111 vs 68 µg/L) and BMIC (84 vs 62 µg/L) than non-users (P < 0.001). Infants fed by women using iodine-containing supplements had a higher MUIC (150 vs 86 µg/L, P = 0.036) than those of non-users. Infant MUIC at 3MPP [115 (69, 182) µg/L] and 6MPP [120 (60, 196) µg/L] were below 125 µg/L (suggested cut-point for iodine adequacy in infants). Median maternal selenium intake was 62 (51, 85) µg/day and 56% had intakes below the EAR. Median infant selenium intakes at 3MPP and 6MPP were 9 and 8 µg/day. Median maternal urinary selenium concentrations were 22, 22, and 26 µg/L across three time points, respectively. The highest prevalence of minor depression was observed in women with mean plasma selenium at 106 µg/L. Conclusions: A high prevalence of thyroid dysfunction was observed in a cohort of postpartum women who were iodine deficient, with suboptimal selenium intake, but having mostly adequate iron status. Women with low plasma selenium were likely to experience thyroid dysfunction. Iodine deficiency of lactating women remains, particularly for those who did not use iodine-containing supplements. The low use of iodine-containing supplements is concerning during later breastfeeding. Maternal selenium intake/status was suboptimal. Relation between selenium status and risk of PND was inconclusive. Iodine/selenium intake and status of infants were suboptimal.Item Dietary choices of New Zealand women during pregnancy and lactation : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics at Massey University, Albany, New Zealand(Massey University, 2020) Brown, Kimberley JaneBackground: A woman and her offspring’s health is affected by the maternal diet during pregnancy and lactation. Because of the importance of the diet, there is a large emphasis on women making optimal dietary choices, as recommended by specific guidelines, in pregnancy and lactation. Dietary recommendations are different from other life stages because of altered nutrient requirements and a heightened need for food safety practices. Currently, there is limited evidence available about dietary choices, food safety practices, and sources of nutrition information of New Zealand women during pregnancy and lactation. This information is important to inform strategies to improve the support that women receive during pregnancy and lactation as it identifies what recommendations are currently being effectively communicated. Aim: To investigate New Zealand women’s dietary choices, food safety practices, and sources of nutrition information during pregnancy and lactation. Methods: Women from New Zealand were invited to participate in this observational study between January and June 2019. Participants were required to be pregnant or within six months postpartum. Women completed a demographic, pregnancy food frequency, and food choice questionnaire during or retrospectively to their pregnancy. Postpartum women also completed a lactation food frequency and food choice questionnaire. Results: Women (n=458) consumed a range of foods from the four food groups (fruit and vegetables, breads and cereals, milk and milk products, and meat/meat alternatives/eggs). A large percentage reported adding or increasing, limiting, and avoiding foods. Cow’s milk, the most frequently daily consumed dairy product, was more commonly reported in pregnancy (93%) than lactation (64%). A range of fruit, vegetables, protein, and grain foods were consumed daily in pregnancy and lactation. The majority of women followed food safety recommendations in particular avoidance of alcohol (92%), raw milk products (86%), and raw/smoked/precooked fish/seafood (84%). Dietary information was acquired from a range of sources. The greatest dietary influences included midwives, New Zealand pregnancy and breastfeeding guidelines, and family/friends. Women also frequently reported receiving dietary advice from their lead maternal carer, handouts, the internet, and alternative health practitioners. During lactation, women received information from more potentially unreliable sources including family/ friends, the internet, and alternative health practitioners. Infant symptoms also frequently affected women’s food choices in lactation. Conclusion: Women implement significant dietary changes during pregnancy and lactation. Women are likely to add, remove, and limit food during pregnancy following the New Zealand pregnancy guidelines; advice from health professionals, the internet, magazines/books/newspapers; or because of food safety concerns. Lactating women are likely to make dietary changes because of infant symptoms or advice received from midwives, alternative health practitioners, family/ friends, and the internet.Item "I could cope so much better if I could just get a good night's sleep" : maternal sleep and mental health from early pregnancy to three years post birth : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Public Health at Massey University, Wellington, New Zealand(Massey University, 2020) Ladyman, Clare IonaHealthy sleep is vital to health and wellbeing at all life stages. But for many women, achieving restorative and satisfying sleep consistently throughout pregnancy is challenging. Because vulnerability to experiencing depressive symptoms increases with poor sleep and poor sleep influences the development and trajectory of depressive symptoms, sleep is an important and modifiable factor in the prevention and treatment of depression. Pregnancy is also considered a key teachable life stage as mothers wish to be healthy in order to protect their unborn baby. Yet research investigating non-pharmacological sleep education interventions for preventing perinatal depression is scarce. This thesis comprises three studies that investigate the relationship between maternal sleep health and depression. It presents findings from a scoped review examining sleep health throughout pregnancy; a longitudinal analysis of depression trajectories from late pregnancy to three years post-birth and the association of different sleep dimensions to trajectory group membership; and, the development, implementation and efficacy of a sleep education pilot intervention designed to promote sleep health and reduce the likelihood of depressive symptoms throughout pregnancy. Findings from the scoped review showed that while sleep in pregnancy is highly variable from one woman to the next, significant changes to sleep throughout pregnancy were not indicated for women who were considered physically and mentally healthy. However, the results of the longitudinal analysis revealed that for a sub-group of women, poor sleep was significantly associated with clinically elevated and persistent depressive symptoms throughout the perinatal period and into their child’s preschool years, with the probability of experiencing depressive symptoms especially pronounced for Māori women. The Sleep HAPi pilot study found recruiting and retaining previously depressed women into a longitudinal perinatal sleep education study achievable and the study design highly acceptable to participants. Similar to the results of the scoped review, self-reported sleep duration, quality, timing, continuity and daytime sleepiness remained stable throughout pregnancy, and at intervention end none of the women in this study were experiencing clinically elevated depressive symptoms. Sleep HAPi women were compared to a control group from a previous study with no sleep education component; Sleep HAPi mothers had significantly better sleep initiation and experienced fewer depressive symptoms at intervention completion, though results require confirmation in a larger randomised control group study. Collectively, the findings from these studies highlight the strong relationship between sleep and maternal mental health. Sleep education interventions, such as Sleep HAPi, show promise for minimising depressive symptoms, and optimising sleep for pregnant women. These findings have important health care practice and policy implications and the potential to improve outcomes for mothers, children, families and society.