Type 1 diabetes during pregnancy, birth, and breastfeeding

<p dir="ltr">Background</p><p dir="ltr">Managing Type 1 diabetes (T1D) during pregnancy remains a clinical challenge due to the increased risks of complications for both mother and child, making the well-documented benefits of breastfeeding especially important in this context. To reduce the risk of complications, evidence-based care is essential throughout the perinatal period. In Sweden, perinatal care for pregnant women with T1D is managed by decentralised, hospital-specific guidelines without evaluation of the perinatal outcomes over the past two decades. Breastfeeding also plays a vital role in perinatal care; therefore, antenatal colostrum expression is recommended for women with T1D to support the early provision of exclusive colostrum. However, the composition of antenatal colostrum in women with T1D has not been previously explored.</p><p dir="ltr">Aim <br><br>This thesis aims to improve care for pregnant women with T1D and their newborns by studying care provision in terms of guidelines, colostrum composition, and maternal and neonatal outcomes.</p><p dir="ltr">Method</p><p dir="ltr">Study 1 was a descriptive study aimed at comparing all the Swedish guidelines for the management of T1D during pregnancy and birth in terms of the degree of consensus among them. The second aim was to measure adherence to three of these guidelines in use at four hospitals and to describe the pregnancy and labour outcomes in relation to the level of adherence.</p><p dir="ltr">Study 2 was a prospective cohort study that aimed to investigate and compare the macronutrient content in colostrum collected from women with and without T1D during gestational weeks 36 to 40 and postpartum days one to five. The study also aimed to compare the colostrum contents between women with and without T1D. A secondary aim was to compare the colostrum content from postpartum day one with colostrum from all the other timepoints and with formula.</p><p dir="ltr">Study 3 was a retrospective cohort study using the Swedish Medical Birth Register to explore the odds of adverse neonatal outcomes in newborns of mothers with T1D compared to those of mothers without T1D during the years 2010-2022.</p><p dir="ltr">Study 4 was a retrospective cohort study that utilized the Swedish Medical Birth Register to explore the odds of adverse maternal outcomes in women with T1D compared to women without T1D during the years 2010-2022.</p><p dir="ltr">Results</p><p dir="ltr">No complete consensus was identified across the 30 hospital guidelines. Adherence to the guidelines with a rate of 270% was found to be low. A high adherence to the birth guidelines was significantly more common when the birth was induced. When pregnancy or birth guidelines were followed with low adherence non-instrumental vaginal births occurred more often.</p><p dir="ltr">The colostrum content, specifically in terms of fat, carbohydrates, protein, and kilocalories, varied between the time points. Colostrum differed in protein in antenatal colostrum between women with and without T1D. Colostrum from postpartum day one was more similar to antenatal colostrum than colostrum from days two to five, and compared with formula.</p><p dir="ltr">Neonates born to mothers with T1D had significantly increased odds of adverse neonatal outcomes, such as stillbirth, congenital malformations, premature birth, being born large for gestational age, and neonatal death.</p><p dir="ltr">Women with T1D were generally taller and more often classified as overweight or obese, with higher rates of chronic kidney disease, chronic hypertension, smoking, and having been born in a Nordic country compared to women without T1D. T1D was significantly associated with increased odds of adverse maternal outcomes such as caesarean section, shoulder dystocia, postpartum haemorrhage, and endometritis.</p><p dir="ltr">Conclusion</p><p dir="ltr">Developing an evidence-based national guideline for preconception and perinatal care with high adherence, incorporating a recommendation to supplement fed newborns with antenatal colostrum, could help improve health outcomes for pregnant women with T1D and their newborns.</p><h3>List of scientific papers</h3><p dir="ltr">I. <b>Goldberg A,</b> Ursing C, Ekéus C, Wiberg-Itzel E. Swedish guidelines for type 1 diabetes and pregnancy outcomes: A nationwide descriptive study of consensus and adherence. Prim Care Diabetes. 2021;15(6):1040-51.<br><a href="https://doi.org/10.1016/j.pcd.2021.08.003" rel="noreferrer" target="_blank">https://doi.org/10.1016/j.pcd.2021.08.003</a><br><br></p><p dir="ltr">II. <b>Goldberg A,</b> Pettersson H, Ekéus C, Ursing C, Wiberg-Itzel E, Tingström J. Comparison Between Antenatal and Postnatal Colostrum From Women With and Without Type 1 Diabetes. J Hum Lact. 2025;41(2):254-62.<br><a href="https://doi.org/10.1177/08903344251318285" rel="noreferrer" target="_blank">https://doi.org/10.1177/08903344251318285</a><br><br></p><p dir="ltr">III. <b>Goldberg A,</b> Wiberg-Itzel E, Tingström J, Ekeus C. Neonatal Outcomes Among Neonates of Women With and Without Type 1 Diabetes in Sweden From 2010 to 2022. Acta Paediatr. 2025.<br><a href="https://doi.org/10.1111/apa.70230" rel="noreferrer" target="_blank">https://doi.org/10.1111/apa.70230</a><br><br></p><p dir="ltr">IV. <b>Goldberg A,</b> Wiberg-Itzel E, Tingström J, Ekeus C. Maternal outcomes among women with and without Type 1 Diabetes in Sweden. [Submitted]</p>