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Objective: To assess whether parents who were born small for gestational age (below the 10th birthweight centile, SGA) have increased risk of severe or mild placental abruption. To assess whether a history of SGA in other family members modifies this intergenerational effect.Design: Prospective population-based observational study.Setting: The Medical Birth Registry of Norway.Population: From 1967 to 2013, 785 333 mother-offspring pairs, 643 066 father-offspring pairs, 272 941 maternal tetrads (i.e. her offspring, sibling, and niece/nephew), and 265 505 paternal tetrads were identified.Methods: Cohort study based on linked data from the Medical Birth Registry of Norway.Main Outcome Measures: Relative risk (RR) of severe placental abruption (preterm birth, birthweight below the 10th centile, or perinatal death) and mild placental abruption (other cases) in families with SGA.Results: Mothers who were born SGA had increased risk of severe placental abruption (RR 1.5; 95% confidence interval, 95% CI 1.3-1.8), but not mild abruption. The paternal effects were weaker. The combined effect of SGA in the mother and her sibling on severe abruption was twofold (RR 2.4; 95% CI 1.7-3.3) compared with birthweight centiles ≥10 for both. Similarly, the effect of adding an SGA niece/nephew was twofold (RR 2.3; 95% CI 1.3-3.9), whereas the combined effect of SGA in the mother, her sibling and her niece/nephew was fourfold (RR 3.6; 95% CI 1.9-6.8).Conclusions: Women who were born SGA have an increased risk of severe placental abruption. The corresponding paternal effect was modest. A history of SGA in other family members increases the generational effect.Tweetable Abstract: Women born small for gestational age have excess risk of placental abruption. [ABSTRACT FROM AUTHOR]

Introduction: Previous studies have established a history of shoulder dystocia as an important risk factor for shoulder dystocia, but studies on shoulder dystocia by severity are scarce. It is unknown if shoulder dystocia tends to be passed on between generations. We aimed to assess the recurrence risk of shoulder dystocia by severity in the same woman and between generations on both the maternal and paternal side. We also assessed the likelihood of a second delivery and planned cesarean section after shoulder dystocia., Material and Methods: This was a population-based cohort study, using data from the Medical Birth Registry of Norway. To study recurrence in the same mother, we identified 1 091 067 pairs of first and second, second and third, and third and fourth births in the same mother. To study intergenerational recurrence, we identified an individual both as a newborn and as a mother or father in 824 323 mother-offspring pairs and 614 663 father-offspring pairs. We used Bayesian log-binomial multilevel regression to calculate relative risks (RR) with 95% credible intervals., Results: In subsequent deliveries in the same woman the unadjusted RR of recurrence was 7.05 (95% credible interval 6.39-7.79) and 2.99 (2.71-3.31) after adjusting for possible confounders, including current birthweight. The RRs were higher with severe shoulder dystocia as exposure or outcome. With severe shoulder dystocia as both exposure and outcome, unadjusted and adjusted RR was 20.42 (14.25-29.26) and 6.29 (4.41-8.99), respectively. Women with severe and mild shoulder dystocia and those without had subsequent delivery rates of 71.1, 68.9 and 69.0%, respectively. However, the rates of planned cesarean section in subsequent deliveries for those without shoulder dystocia, mild and severe were 1.3, 5.2 and 16.0%, respectively. On the maternal side the unadjusted inter-generational RR of recurrence was 2.82 (2.25-3.54) and 1.41 (1.05-1.90) on the paternal side. Corresponding adjusted RRs were 1.90 (1.51-2.40) and 1.19 (0.88-1.61), respectively., Conclusions: We found a strong recurrence risk of shoulder dystocia, especially severe, in subsequent deliveries in the same woman. The inter-generational recurrence risk was higher on the maternal than paternal side. Women with a history of shoulder dystocia had more often planned cesarean section., (© 2024 The Authors. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).)

Sepsis is responsible for 50% of intrahospital maternal deaths worldwide. Incidence is increasing in both low and middle-, and high-income countries. There is little data on incidence and clinical outcomes of obstetric infections including maternal sepsis in the Nordic countries. The aims of this study are to give estimates of the occurrence of obstetric infections and maternal sepsis in a Norwegian hospital cohort, assess the quality of management of maternal sepsis cases, and evaluate the usefulness of diagnostic codes to identify maternal sepsis retrospectively. We conducted a retrospective cohort study of pregnant, labouring, post-abortion, and postpartum women. We assessed the accuracy of the diagnostic code most frequently applied for maternal sepsis, O85. We found 7.8% (95% confidence interval 7.1-8.5) infection amongst pregnant, labouring, and postpartum women. The incidence of maternal sepsis was 0.3% (95% confidence interval 0.2-0.5), and the majority of sepsis cases were recorded in the postpartum period. Two thirds of women were given broad-spectrum antibiotics at the time sepsis was diagnosed, but only 15.4% of women with puerperal sepsis were given antimicrobials in accordance with national guidelines. When used retrospectively, obstetric infection codes are insufficient in identifying both maternal and puerperal sepsis, with only 20.3% positive predictive value for both conditions. In conclusion, obstetric infections contribute significantly to maternal morbidity in Norway's second largest maternity hospital. This study provides incidences of maternal infections for hospitalised patients in temporal relation to pregnancy, labour, abortion and the postpartum period, knowledge which is valuable for planning of health care services and allocation of resources. In addition, the study highlights areas where improvement is needed in clinical handling of maternal sepsis. There is need for studies on the management quality and use of correct diagnostic codes in this patient category., (© 2024. The Author(s).)

Purpose: This study examines individual aggregation of postpartum hemorrhage (PPH), paternal contribution and how offspring birthweight and sex influence recurrence of PPH. Further, we wanted to estimate the proportion of PPH cases attributable to a history of PPH or current birthweight., Methods: We studied all singleton births in Norway from 1967 to 2017 using data from Norwegian medical and administrational registries. Subsequent births in the parents were linked. Multilevel logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CI) for PPH defined as blood loss > 500 ml, blood loss > 1500 ml, or the need for blood transfusion in parous women. Main exposures were previous PPH, high birthweight, and fetal sex. We calculated adjusted population attributable fractions for previous PPH and current high birthweight., Results: Mothers with a history of PPH had three- and sixfold higher risks of PPH in their second and third deliveries, respectively (adjusted OR 2.9; 95% CI 2.9-3.0 and 6.0; 5.5-6.6). Severe PPH (> 1500 ml) had the highest risk of recurrence. The paternal contribution to recurrence of PPH in deliveries with two different mothers was weak, but significant. If the neonate was male, the risk of PPH was reduced. A history of PPH or birthweight ≥ 4000 g each accounted for 15% of the total number of PPH cases., Conclusion: A history of PPH and current birthweight exerted strong effects at both the individual and population levels. Recurrence risk was highest for severe PPH. Occurrence and recurrence were lower in male fetuses, and the paternal influence was weak., (© 2022. The Author(s).)

Objective: To explore risk profiles of the different types of postpartum hemorrhage (PPH >500ml or severe PPH >1500ml) and their recurrence risks in a subsequent delivery., Methods: With data from The Medical Birth Registry of Norway and Statistics Norway we performed a population-based cohort study including all singleton deliveries in Norway from 1967-2017. Multilevel logistic regression was used to calculate odds ratio (OR), with 95% confidence interval (CI), with different PPH types (PPH >500ml or PPH >1500ml (severe PPH) combined with retained placenta, uterine atony, obstetric trauma, dystocia, or undefined cause) as outcomes., Result: We identified 277 746 PPH cases of a total of 3 003 025 births (9.3%) from 1967 to 2017. Retained placenta (and/or membranes) was most often registered as severe PPH (29.3%). Maternal, fetal, and obstetric characteristics showed different associations with the PPH types. Male sex of the neonate was associated with reduced risk of PPH. This effect was strongest on PPH due to retained placenta (adjusted OR, (aOR): 0.80, 95% CI 0.78-0.82), atony (aOR 0.92, 95% CI: 0.90-0.93) and PPH with undefined cause (aOR 0.96, 95% CI: 0.95-0.97). Previous cesarean section showed a strong association with PPH due to dystocia (aOR of 13.2, 95% CI: 12.5-13.9). Recurrence risks were highest for the same type: PPH associated with dystocia (aOR: 6.8, 95% CI: 6.3-7.4), retained placenta and/or membranes (aOR: 5.9, 95% CI: 5.5-6.4), atony (aOR: 4.0, 95% CI: 3.8-4.2), obstetric trauma (aOR: 3.9, 95% CI: 3.5-4.3) and PPH of undefined cause (aOR: 2.2, 95% CI: 2.1-2.3)., Conclusion: Maternal, fetal and obstetric characteristics had differential effects on types of PPH. Recurrence differed considerably between PPH types. Retained placenta was most frequently registered with severe PPH, and showed strongest effect of sex; delivery of a boy was associated with lower risk of PPH. Previous cesarean increased the risk of PPH due to dystocia., Competing Interests: The authors have declared that no competing interests exist.

Introduction: Studies on the family aggregation of postpartum hemorrhage (PPH) are scarce and with inconsistent results, and to what extent current birthweight influences recurrence between relatives remains to be studied. Further, family aggregation of PPH has been studied from an individual, but not from a public heath perspective. We aimed to investigate family aggregation of PPH in Norway, how birthweight influences these effects, and to estimate the proportion of PPH cases attributable to a family history of PPH and current birthweight., Material and Methods: Using data from the Medical Birth Registry of Norway, Statistics Norway, and Central Population Registry of Norway we identified individuals as newborns, parents, grandparents, and full and half-siblings, and studied 1 002 687 mother-offspring, 841 164 father-offspring, and 761 011 both-parents-offspring pairs. We used multilevel logistic regression to calculate odds ratios (OR) with 95% CI., Results: If the birth of the mother but not of the father involved PPH, then the OR of PPH (>500 mL) in the next generation was 1.44 (95% CI 1.39-1.49). If the birth of the father but not of the mother involved PPH, then OR was 1.12 (95% CI 1.08-1.16). These effects were stronger in severe PPH. Recurrence between siblings was highest between full sisters (OR 1.47, 95% CI 1.41-1.52), followed by maternal half-sisters, paternal half-sisters, and partners of full brothers. A family history of PPH or birthweight of 4000 g or more accounted for ≤5% and 15% of the total number of PPH cases, respectively., Conclusions: A history of PPH in relatives influenced the recurrence risk of PPH in a dose-response pattern consistent with the anticipated proportion of shared genes. The recurrence was highest through the maternal line., (© 2021 The Authors. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).)

Introduction: Cesarean section is the single most important risk factor for postpartum infection. Where the rest of the world shows increasing trends, the cesarean section rates are low in Norway and risk factors for infection after cesarean section may differ in high and low cesarean section settings. The goal of this study was to examine independent risk factors for surgical site infection after cesarean delivery in a setting of low cesarean section rates., Material and Methods: We conducted a hospital-based case-control study at Haukeland University Hospital. We included women who presented to our hospital with surgical site infection after cesarean section during the years 2014-2016 (n = 75). Controls were selected at a ratio of 2:1 (n = 148). Cases and controls were compared with respect to maternal and pregnancy characteristics using uni- and multivariable logistic regression models. Main outcome measures were anticipated risk factors for surgical site infection., Results: The occurrence of surgical site infection was 0.4% and 5.4% after elective and emergency cesarean section, respectively. Compared to women without surgical site infection, women with surgical site infection were almost thrice more obese before pregnancy (OR 2.8, 95% CI 1.2-7.0), four times more likely to have preexisting psychiatric conditions (OR 4.4, 95% CI 1.1-17.6), and five times more likely to receive blood transfusion (OR 5.1, 95% CI 1.4-18.8). Signs of infection during labor was a marginally significant risk factor for surgical site infection (OR 2.0, 95% CI 1.0-5.4)., Conclusions: Emergency cesarean section was a significant risk factor for surgical site infection. Pregestational obesity, preexisting psychiatric conditions, and blood transfusion during or following delivery, were independent risk factors for surgical site infection. Signs of infection during labor was a marginally significant risk factor. Women with either of these risk factors should be carefully monitored and evaluated for signs of infection in the postpartum period., (© 2021 The Authors. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).)

Introduction: In pregnancies after a previous cesarean section (CS), a planned repeat CS delivery has been associated with excess risk of adverse outcome. However, also the alternative, a trial of labor after CS (TOLAC), has been associated with excess risks. A TOLAC failure, involving a non-planned CS, carries the highest risk of adverse outcome and a vaginal delivery the lowest. Thus, the decision regarding delivery mode is pivotal in clinical handling of these pregnancies. However, even with a high TOLAC rate, as seen in Norway, repeat CSs are regularly performed for no apparent medical reason. The objective of the present study was to assess to which extent demographic, socioeconomic, and health system factors are determinants of TOLAC and TOLAC failure in low risk pregnancies, and whether any effects observed changed with time., Materials and Methods: The study group comprised 24 645 second deliveries (1989-2014) after a first delivery CS. Thus, none of the women had prior vaginal deliveries or more than one CS. Included pregnancies were low risk, cephalic, single, and had gestational age ≥ 37 weeks. Data were obtained from the Medical Birth Registry of Norway (MBRN). The exposure variables were (second delivery) maternal age, length of maternal education, maternal country of origin, size of the delivery unit, health region (South-East, West, Mid, North), and maternal county of residence. The outcomes were TOLAC and TOLAC failure, as rates (%), relative risk (RR) and relative risk adjusted (ARR). Changes in determinant effects over time were assessed by comparing rates in two periods, 1989-2002 vs 2003-2014, and including these periods in an interaction model., Results: The TOLAC rate was 74.9%, with a TOLAC failure rate of 16.2%, resulting in a vaginal birth rate of 62.8%. Low TOLAC rates were observed at high maternal age and in women from East Asia or Latin America. High TOLAC failure rates were observed at high maternal age, in women with less than 11 years of education, and in women of non-western origin. The effects of health system factors, i.e. delivery unit size and administrative region were considerable, on both TOLAC and TOLAC failure. The effects of several determinants changed significantly (P < 0.05) from 1989-2002 to 2003-2014: The association between non-TOLAC and maternal age > 39 years became weaker, the association between short education and TOLAC failure became stronger, and the association between TOLAC failure and small size of delivery unit became stronger., Conclusion: Low maternal age, high education, and western country of origin were associated with high TOLAC rates, and low TOLAC failure rates. Maternity unit characteristics (size and region) contributed with effects on the same level as individual determinants studied. Temporal changes were observed in determinant effects., Competing Interests: The authors have declared that no competing interests exist.

Severe obstetric complications are not extensively studied and individual cases are used too little and inappropriately in quality improvement activities, due to limited numbers and prioritization of quantitative research. Nordic and European experts performed a qualitative pilot study using anonymized cases of peripartum hysterectomy. It was feasible to anonymize narratives and we learned lessons in the form of themes for improved clinical care and future research. Therefore, we plan a Nordic anonymized review of the care of women who have undergone peripartum hysterectomy based on narratives. The qualitative outcomes of clinically relevant themes for quality improvement and research will add value to the quantitative analyses from the Nordic medical birth registries. In the longer term, we believe that qualitative audits should be an essential part of the process of continuing improvement in maternity care., (© 2019 Nordic Federation of Societies of Obstetrics and Gynecology.)

Introduction: In most pregnancies after a cesarean section, a trial of labor is an option. The objective of the study was to explore trial of labor and its failure in pregnancies with medical risk conditions, in a population with a high trial of labor rate., Material and Methods: In a cohort study (n = 57 109), using data from the Medical Birth Registry of Norway 1989-2014, women with a second delivery after a first pregnancy cesarean section were included. Preterm, multiple, and non-cephalic deliveries were excluded. The outcomes were trial of labor and failed trial of labor, assessed as rates and relative risk, using deliveries without risk conditions as reference. Temporal trends were assessed by 3-year periods. The exposures were selected medical risk conditions, ie previous offspring death, labor dystocia, diabetes, heart conditions, chronic hypertension, chronic kidney disease, rheumatoid arthritis, thyroid disease, asthma, prepregnancy psychiatric conditions, epilepsy, obesity, gestational diabetes, eclampsia and preeclampsia, gestational hypertension, major malformations, second-pregnancy psychiatric conditions, assisted reproduction, macrosomia, and small-for-gestational-age neonates. Induced onset of labor was compared with spontaneous onset of labor for each condition studied., Results: In risk pregnancies (n = 31 994) the trial of labor rate was 64.9% and failure rate was 27.6%, compared with 74.6% and 16.4% in pregnancies without any of the risk conditions studied (n = 25 115). The lowest trial of labor rates were observed in diabetes type 1 (49.5%), diabetes type 2 (46.7%), maternal heart conditions (54.5%), and pregnancy-related psychiatric conditions (19.7%). The highest failure rates were observed in diabetes type 1 (43.1%), diabetes type 2 (40.3%), maternal obesity (36.9%), gestational diabetes (36.0%), and offspring macrosomia (43.0%). Induced labor was associated with failed trial of labor (P < .05), whereas after spontaneous labor, failure rates were less than 40% in all conditions studied., Conclusions: In conditions with high rates of failed trial of labor, eg diabetes, macrosomia, and obesity, a planned cesarean section might be a better option than a trial of labor, particularly if induction of delivery might be needed., (© 2019 Nordic Federation of Societies of Obstetrics and Gynecology.)

Introduction: Trial of labor (TOLAC) is an option in most preganancies after a cesarean section The objective of the study was to compare perinatal outcome in TOLAC and non-TOLAC deliveries in a population with high TOLAC rates., Material and Methods: This was a cohort study based on population data from the Medical Birth Registry of Norway. We included term, cephalic, single, second deliveries, 1989-2009, after a first cesarean section (n = 43 422). TOLAC, TOLAC failure, non-TOLAC deliveries, and after high-risk and low-risk pregnancies (no risk/any risk), were compared with respect to offspring mortality, 5-minute Apgar score Apgar < 7 and < 4, transfer to a neonatal intensive care unit, and neonatal respiratory distress syndrome., Results: Statistically significant differences were observed (P <0.05). In the low-risk group the offspring mortality was 2.3/1000 in TOLAC compared with 0.9/1000 in non-TOLAC. In the high-risk group, the offspring mortality was 3.7/1000 in TOLAC compared with 0.9/1000 in non-TOLAC, and the 5-minute Apgar score < 4 was 3.1/1000 in TOLAC compared with 0.9/1000 in non-TOLAC. In both risk groups, TOLAC delivery had a higher rate of 5-minute Apgar score < 7. In the low-risk group, non-TOLAC deliveries had a higher rate of neonatal respiratory distress syndrome than TOLAC deliveries., Conclusions: We observed higher risk of offspring mortality and lower 5-minute Apgar score in TOLAC than in non-TOLAC. Possible causes and preventive measures should be explored., (© 2018 Nordic Federation of Societies of Obstetrics and Gynecology.)

Introduction: Obstetric anal sphincter injurie (OASI) in vaginal births are a serious complication, and are associated with maternal morbidity. Focus on modifiable factors in midwives clinical skills and competences contributing to prevent the occurrence of OASI are essential. The objective of this study was to investigate the association between OASI and factors related to midwife-led birth such as manual support of perineum, active delivery of baby's shoulders, maternal birth position, and pushing and breathing techniques in second stage of labour., Methods: A prospective cross sectional study including primiparous (n = 129) and multiparous (n = 628) women in midwife-led non-instrumental deliveries with OASI (n = 96) or intact perineum (n = 661). Data were collected in a university hospital in Norway with two different birth settings: an alongside midwife-led unit with approximately 1500 births per year and an obstetrical unit with approximately 3500 births per year. In midwife-led births, there were a total of 2.6% OASI and 18.9% intact perineum., Results: The sample consisted of 757 women, 12.7% suffered OASI and 87.3% of participating women had an intact perineum. This selected sample compares the most serious outcome (OASI), and the optimal outcome (intact perineum).In primiparous women, 61 women suffered OASI and 68 women had intact perineum, while for multipara women, 35 women suffered OASI and 593 women had intact perineum. There was an increased risk of OASI if women actively pushed when the head was crowning compared to breathing the head out (adjusted OR: 3.10; 95% CI: 1.75 to 5.47). The maternal birth position associated with the lowest risk of OASI was kneeling position (adjusted OR: 0.15; 95% CI: 0.03 to 0.70), supine maternal birth position (adjusted OR: 2.52; 95% CI: 1.04 to 4.90) and oxytocin augmentation more than 30 min in second stage (OR: 1.93; 95% CI: 1.68 to 15.63) were associated with an increased risk of OASI, when adjusting for maternal, foetal, and obstetric factors., Conclusion: Our study suggests that actively pushing when the baby's head is crowning, a supine maternal birth position and oxytocin augmentation more than 30 min in second stage, were associated with increased risk of OASI when compared to intact perineum. A kneeling maternal birth position was associated with a decreased risk of OASI., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objective: To assess whether parents who were born small for gestational age (below the 10th birthweight centile, SGA) have increased risk of severe or mild placental abruption. To assess whether a history of SGA in other family members modifies this intergenerational effect., Design: Prospective population-based observational study., Setting: The Medical Birth Registry of Norway., Population: From 1967 to 2013, 785 333 mother-offspring pairs, 643 066 father-offspring pairs, 272 941 maternal tetrads (i.e. her offspring, sibling, and niece/nephew), and 265 505 paternal tetrads were identified., Methods: Cohort study based on linked data from the Medical Birth Registry of Norway., Main Outcome Measures: Relative risk (RR) of severe placental abruption (preterm birth, birthweight below the 10th centile, or perinatal death) and mild placental abruption (other cases) in families with SGA., Results: Mothers who were born SGA had increased risk of severe placental abruption (RR 1.5; 95% confidence interval, 95% CI 1.3-1.8), but not mild abruption. The paternal effects were weaker. The combined effect of SGA in the mother and her sibling on severe abruption was twofold (RR 2.4; 95% CI 1.7-3.3) compared with birthweight centiles ≥10 for both. Similarly, the effect of adding an SGA niece/nephew was twofold (RR 2.3; 95% CI 1.3-3.9), whereas the combined effect of SGA in the mother, her sibling and her niece/nephew was fourfold (RR 3.6; 95% CI 1.9-6.8)., Conclusions: Women who were born SGA have an increased risk of severe placental abruption. The corresponding paternal effect was modest. A history of SGA in other family members increases the generational effect., Tweetable Abstract: Women born small for gestational age have excess risk of placental abruption., (© 2017 Royal College of Obstetricians and Gynaecologists.)

Introduction: Trial of labor (TOL) is an option in most deliveries after a previous cesarean section (CS). The Medical Birth Registry of Norway (MBRN) has received compulsory notification of all deliveries in the country since 1967, including data that could identify TOL in epidemiologic research. The objective of this study was to validate MBRN data for identification of TOL deliveries after a previous cesarean section (CS)., Material and Methods: The MBRN provided a random national sample of 500 birth order two deliveries during 1989-2012 in women with a registered birth order one CS delivery. The reporting maternity units were asked to complete a questionnaire on data items in both deliveries, using hospital record data as the gold standard., Results: Completed questionnaires were returned for 477 women (95.5%) with data on both deliveries. An algorithm to identify TOL using MBRN data from the birth order two delivery had a positive predictive value of 93.2%, a negative predictive value of 93.5%, a sensitivity of 96.1%, and a specificity of 88.8%. Validity of MBRN data on mode and onset of delivery, CS subtype, and planned mode of delivery is also reported., Conclusions: MBRN data on planned and actual mode of delivery, CS subtype, and the algorithm to identify TOL in deliveries after a previous CS had satisfactory quality for a registry-based study of TOL., (© 2017 Nordic Federation of Societies of Obstetrics and Gynecology.)

Background: Out-of-pocket payments are the main sources of healthcare financing in most developing countries. Healthcare services can impose a massive cost burden on households, especially in developing countries. The purpose of this study was to calculate households encountered with catastrophic healthcare expenditures in Ferdows, Iran., Materials and Methods: The sample included 100 households representing 20% of all households in Ferdows, Iran. The data were collected using self-administered questionnaire. The ability to pay of households was calculated, and then if costs of household health were at least 40% of their ability to pay, it was considered as catastrophic expenditures., Results: Rate of households encountered to catastrophic health expenditures was estimated to be 24%, of which dentistry services had the highest part in catastrophic health expenditures., Conclusion: Low ability to pay of households should be supported against these expenditures. More equitable health system would solve the problem, although more financial aid should be provided for households encountered to catastrophic costs.

Objective: To investigate the aggregation of obstetric anal sphincter injuries (OASIS) in relatives., Design: Population-based cohort study., Setting: The Medical Birth Registry of Norway from 1967 to 2008., Population: All singleton, vertex-presenting infants weighing 500 g or more. Through linkage by national identification numbers, 393 856 mother-daughter pairs, 264 675 mother-son pairs, 134 889 mothers whose sisters later became mothers, 132 742 fathers whose brothers later became fathers, 131 702 mothers whose brothers later became fathers and 88 557 fathers whose sisters later became mothers were provided., Methods: Comparison of women with and without a history of OASIS in their relatives., Main Outcome Measure: Relative risk of OASIS after a previous OASIS in the family., Results: The risk of OASIS was increased if the woman's mother or sister had OASIS in a delivery (aRR 1.9, 95% CI 1.6-2.3; aRR 1.7, 95% CI 1.6-1.7, respectively). If OASIS occurred in one brother's partner at delivery, the risk of OASIS in the next brother's partner was modestly increased (aRR 1.2, 95% CI 1.1-1.4). If OASIS occurred in one sister at delivery, the risk of OASIS in the brother's partner was also increased a little (aRR 1.2, 95% CI 1.1-1.4). However, there was no excess occurrence in sisters whose brothers' partners had previously had OASIS (aRR 1.1, 95% CI 0.9-1.3)., Conclusions: There appears to be increased familial aggregation of OASIS. These risks are stronger through the maternal rather than the paternal line of transmission, suggesting a strong genetic role that shapes aggregation of OASIS within families. These observations must be cautiously interpreted because of bias from unmeasured confounding factors may have impacted the findings., (© 2013 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2013 RCOG.)

Objective: To investigate the recurrence risk, the likelihood of having further deliveries and mode of delivery after third to fourth degree obstetric anal sphincter injuries (OASIS)., Design: Population-based cohort study., Setting: The Medical Birth Registry of Norway., Population: A cohort of 828,864 mothers with singleton, vertex-presenting infants, weighing 500 g or more, during the period 1967-2004., Methods: Comparison of women with and without a history of OASIS with respect to the occurrence of OASIS, subsequent delivery rate and planned caesarean rate., Main Outcome Measures: OASIS in second and third deliveries, subsequent delivery rate and mode of delivery., Results: Adjusted odds ratios of the recurrence of OASIS in women with a history of OASIS in the first, and in both the first and second deliveries, were 4.2 (95% CI 3.9-4.5; 5.6%) and 10.6 (95% CI 6.2-18.1; 9.5%), respectively, relative to women without a history of OASIS. Instrumental deliveries, in particular forceps deliveries, birthweights of 3500 g or more and large maternity units were associated with a recurrence of OASIS. Instrumental delivery did not further increase the excess recurrence risk associated with high birthweight. A man who fathered a child whose delivery was complicated by OASIS was more likely to father another child whose delivery was complicated by OASIS in another woman who gave birth in the same maternity unit (adjusted OR 2.1; 95% CI 1.2-3.7; 5.6%). However, if the deliveries took place in different maternity units, the recurrence risk was not significantly increased (OR 1.3; 95% CI 0.8-2.1; 4.4%). The subsequent delivery rate was not different in women with and without previous OASIS, whereas women with a previous OASIS were more often scheduled to caesarean delivery., Conclusion: Recurrence risks in second and third deliveries were high. A history of OASIS had little or no impact on the rates of subsequent deliveries. Women with previous OASIS were delivered more frequently by planned caesarean delivery., (© 2011 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2011 RCOG.)

Objective: To investigate risk factors for obstetric anal sphincter injuries in a large population-based data set, and to assess to what extent changes in these risk factors could account for trends in obstetric anal sphincter injuries., Methods: This is a population-based cohort study on data from the Medical Birth Registry of Norway between 1967 and 2004, including all vaginal singleton deliveries of vertex-presenting fetuses weighing 500 g or more. Women with their first birth before 1967 and births with previous obstetric anal sphincter injuries were excluded, leaving 1,673,442 births for study. The outcome variable was third- and fourth-degree obstetric anal sphincter injuries. The associations of obstetric anal sphincter injuries with possible risk factors were estimated by odds ratios (ORs) obtained by logistic regression., Results: The occurrence of obstetric anal sphincter injuries increased from 0.5% in 1967 to 4.1% in 2004. After adjusting for demographic and other risk factors, as well as possible confounders, the increase of obstetric anal sphincter injuries persisted, although reduced (unadjusted OR 7.1; 95% confidence interval [CI] 6.8-7.4; adjusted OR 5.6; 95% CI 5.3-5.9). Obstetric anal sphincter injuries were significantly associated with maternal age 30 years or older, vaginal birth order of one, previous cesarean delivery, instrumental delivery, episiotomy, type 1 diabetes, gestational diabetes, induction of labor by prostaglandin, size of maternity unit, birth weight 3,500 g or more, head circumference 35 cm or more, and African or Asian country of birth., Conclusion: Risk of obstetric anal sphincter injuries considerably increased in Norway in 1967 to 2004. Changes in the risk factors studied could only partially explain this increase., Level of Evidence: II.

Background: The purpose of the present study was to validate the registration of obstetric sphincter tears in 2 registers, the Medical Birth Registry of Norway [MBRN] and Patient Administration System [PAS]., Methods: A retrospective cohort study of all obstetric sphincter tears that occurred in our department in 1990-1992 and 2000-2002 was performed. The case records of all patients registered either in MBRN, PAS or the birth logs were compared with the information in the medical records, which constituted the 'golden standard'., Results: The incidence of obstetric sphincter tears in 1990-1992 was 5.8% (774/13381), 5.6% (745/13381) had a perineal tear of third degree and 0.2% (29/13381) of fourth degree. In 2000-2002, the total incidence was 6.6% (813/12380), 5.9% (731/12380) was a third degree perineal tear and 0.7% (82/12380) fourth degree, respectively. The sensitivity and specificity of the MBRN database to detect obstetric sphincter tears was 85.3 and 99.5% in 1990-1992, and 91.8 and 99.7% in 2000-2002, respectively. The positive and negative predictive values of a MBRN-registered diagnosis of obstetric sphincter tears in 1990-1992 were 91.4 and 99.1%, while the corresponding percentages in 2000-2002 were 95.4 and 99.4%, respectively. The sensitivity and specificity of the PAS database was correspondingly 52.1 and 99.0% in 1990-1992, and 84.6 and 98.5% in 2000-2002. The positive and negative predictive values of a PAS-diagnosis of obstetric sphincter tears were 75.8 and 97.1% in 1990-1992. In 2000-2002, they were 92.7 and 98.9%, respectively., Conclusion: The validity of a diagnosis of obstetric sphincter tears, based on the MBRN, is sufficiently high to justify future large-scale epidemiologic studies based on this database, while the validity of a PAS diagnosis is lower, but improves.