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- Endler, Margit
(författare)
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Characterizing retained placenta : epidemiology and pathophysiology of a critical obstetric disorder
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Retained placenta is associated with severe postpartum hemorrhage but its etiology and pathophysiology are largely unknown. Certain studies have suggested that retained placenta is associated to defective placentation disorders- pregnancy disorders with an initial defective placentation resulting in increased oxidative stress. The aim of this thesis was to investigate risk factors for and consequences of retained placenta, determine whether retained placenta and defective placentation disorders are epidemiologically associated and to assess if this association is supported at the molecular and histological level. Methods and Main Results: Study I was a case-control study comparing pregnancy and deliveryrelated variables in women with retained placenta and controls (n=408 in each group) after singleton vaginal birth. The study found that retained placenta was associated with severe postpartum hemorrhage and that a history of abortion or recurrent miscarriage, pre-eclampsia, preterm delivery and prolonged oxytocin use in the current pregnancy were independent risk factors for retained placenta. Study II was a population based cohort study investigating the association between retained placenta and defective placentation disorders (pre-eclampsia, preterm birth, small-for-gestational-age birth and stillbirth) in primiparous women giving vaginal birth at 32-41 gestational weeks between 1997 and 2009 in Sweden (n=386 607). The study found that retained placenta was associated to pre-eclampsia, spontaneous preterm birth, small-for-gestational-age birth and stillbirth. The risk was further increased for women with these disorders among preterm deliveries. Study III was a cross-sectional pilot study investigating the antioxidative enzyme Glutathione Peroxidase 1 (GPX1) and the transcription factor Nuclear Factor Kappa-light-chain-enhancer of activated β-cells (NFκB), as markers of antioxidative defence capacity and inflammation, in 29 retained and 31 non-retained placentas. The study found that retained placentas showed a tendency of lower median concentrations GPX1 and were significantly more likely to have a low level of GPX1 protein concentration. There were no differences in expression ofNFκB. Study IV was a case-control study comparing histological signs of maternal underperfusion and inflammation in retained (n=49) and non-retained (n=47) placentas. The study found that retained placentas had a significantly smaller surface area, were more oblong in shape and showed overall more signs of maternal placental underperfusion compared to non-retained placentas. Conclusions: Retained placenta is epidemiologically associated to defective placentation disorders, a finding which is supported in part by signs of decreased antioxidative capacity in the placenta and increased histological signs of maternal placental underperfusion. Prolonged oxytocin use may exacerbate the risk of retained placenta. Risk awareness of retained placenta should guide preparedness during the third stage of labor given the high risk of severe postpartum hemorrhage that the disorder entails.
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| 2. |
- Endler, Margit, et al.
(författare)
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Oxidative stress and inflammation in retained placenta : a pilot study of protein and gene expression of GPX1 and NF kappa B
- 2016
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Ingår i: BMC Pregnancy and Childbirth. - : Springer Science and Business Media LLC. - 1471-2393 .- 1471-2393. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Background: Retained placenta is associated with severe postpartum hemorrhage. Its etiology is unknown and its biochemistry has not been studied. We aimed to assess whether levels of the antioxidative enzyme Glutathione Peroxidase 1 (GPX1) and the transcription factor Nuclear Factor kappa beta (NF kappa beta), as markers of oxidative stress and inflammation, were affected in retained placentas compared to spontaneously released placentas from otherwise normal full term pregnancies. Methods: In a pilot study we assessed concentrations of GPX1 by ELISA and gene (mRNA) expression of GPX1, NF kappa beta and its inhibitor I kappa beta alpha, by quantitative real-time-PCR in periumbilical and peripheral samples from retained (n = 29) and non-retained (n = 31) placental tissue. Results: Median periumbilical GPX1 concentrations were 13.32 ng/ml in retained placentas and 17.96 ng/ml in nonretained placentas (p = 0.22), peripheral concentrations were 13.27 ng/ml and 19.09 ng/ml (p = 0.08). Retained placental tissue was more likely to have a low GPX1 protein concentration (OR 3.82, p = 0.02 for periumbilical and OR 3.95, p = 0. 02 for peripheral samples). Median periumbilical GPX1 gene expressions were 1.13 for retained placentas and 0.88 for non-retained placentas (p = 0.08), peripheral expression was 1.32 and 1.18 (p = 0.46). Gene expressions of NF kappa beta and I kappa beta alpha were not significantly different between retained and non-retained placental tissue. Conclusions: Women with retained placenta were more likely to have a low level of GPX1 protein concentration in placental tissue compared to women without retained placenta and retained placental tissue showed a tendency of lower median concentrations of GPX1 protein expression. This may indicate decreased antioxidative capacity as a component in this disorder but requires a larger sample to corroborate results.
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| 3. |
- Granfors, Michaela, et al.
(författare)
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Placental location and pregnancy outcomes in nulliparous women : A population-based cohort study
- 2019
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : WILEY. - 0001-6349 .- 1600-0412. ; 98:8, s. 988-996
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The impact of placenta previa on pregnancy, delivery and infant outcomes has been extensively studied. However, less is known about the possible association of placental location other than previa with pregnancy outcomes. The aim of this study was to investigate if placental location other than previa is associated with adverse pregnancy, delivery and infant outcomes.Material and methods: This is a population-based cohort study, with data from the regional population-based Stockholm-Gotland Obstetric Cohort, Sweden, from 2008 to 2014. The study population included 74 087 nulliparous women with singleton pregnancies resulting in live-born infants, with information about placental location from the second-trimester ultrasound screening. The association between placental location (fundal, lateral, anterior or posterior) and pregnancy outcomes was estimated using logistic regression analysis. Odds ratios (OR) with 95% confidence intervals (95% CI) were calculated, and adjustments were made for maternal age, height, country of birth, smoking in early pregnancy, sex of the infant and in vitro fertilization. Main outcome measures were pregnancy, delivery and infant outcomes.Results: Compared with posterior placental location, fundal and lateral placental locations were associated with a number of adverse pregnancy outcomes, the most important being: very preterm birth (<32 weeks of gestation) (adjusted OR [aOR] 1.78, 95% CI 1.18-2.63 and aOR 2.12, 95% CI 1.39-2.25, respectively), moderate preterm birth (32-36 weeks of gestation) (aOR 1.23, 95% CI 1.001-1.51 and aOR 1.62, 95% CI 1.32-2.00, respectively), small-for-gestational-age birth (aOR 1.67, 95% CI 1.34-2.07 and aOR 1.77, 95% CI 1.39-2.25, respectively) and manual removal of the placenta in vaginal births (aOR 3.27, 95% CI 2.68-3.99 and aOR 3.27, 95% CI 2.60-4.10, respectively). Additionally, lateral placental location was associated with preeclampsia (aOR 1.30, 95% CI 1.03-1.65) and severe postpartum hemorrhage (aOR 1.42, 95% CI 1.27-1.82).Conclusions: Compared with posterior placental location, fundal and lateral placental locations are associated with a number of adverse pregnancy, delivery and infant outcomes.
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