Obstetric anal sphincter injuries during instrumental vaginal delivery: An observational study based on 18-years of real-world data.

OBJECTIVE: To determine the prevalence and secular trends of obstetric anal sphincter injuries (OASIS) in vacuum and forceps deliveries in Norway, both with and without episiotomy. DESIGN: Population-based real-world data collected during 2001-2018. SETTING: Medical Birth Registry Norway. POPULATION OR SAMPLE: Nulliparous women with singleton foetuses in a cephalic presentation delivered by either vacuum or forceps (n = 70 783). METHODS: Logistic regression analyses were applied to the OASIS prevalence in six 3-year time periods. Both crude odds ratios and adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were determined. MAIN OUTCOME MEASURES: OASIS prevalence. RESULTS: The OASIS prevalence in vacuum and forceps deliveries decreased from 14.8% during 2001-2003 to 5.2% during 2016-2018. The overall reduction between the first and last 3-year time period was 61% (aOR = 0.39, 95% CIs = 0.35-0.43). The only exception to this decreasing trend in OASIS was found in forceps deliveries performed without an episiotomy. The OASIS prevalence was approximately twofold higher in forceps compared to vacuum deliveries (aOR = 1.92, 95% CIs = 1.79-2.05). Performing either a mediolateral or lateral episiotomy was associated with a 45% decrease in the prevalence of OASIS relative to no episiotomy (aOR = 0.55, 95% CIs = 0.52-0.58). CONCLUSIONS: Opting for vacuum rather than forceps delivery in conjunction with a mediolateral or lateral episiotomy could significantly lower the OASIS prevalence in nulliparous women.

Different pathways for preterm birth between singleton and twin pregnancies: a population-based registry study of 481 176 nulliparous women.

OBJECTIVE: To explore the contribution of pregnancy-related complications on the prevalence of extremely, very and late preterm births in singleton and twin pregnancies. To study the risk of spontaneous preterm birth in twin pregnancies compared with singleton pregnancies. DESIGN: Population-based registry study. SETTING: Medical birth registry of Norway and Statistics Norway. POPULATION: Nulliparous women with singleton (n = 472 449) or twin (n = 8727) births during 1999-2018. METHODS: Prevalence rates of pregnancy-related complications for extremely, very and late preterm birth in twin and singleton pregnancies were calculated with 95% confidence intervals. Multivariable logistic regression was applied to assess odds ratios for preterm birth, adjusted for obstetric and socio-economic factors. MAIN OUTCOME MEASURES: Extremely preterm (<28+0  weeks of gestation), very preterm (28+0 -33+6  weeks of gestation) and late preterm (34+0 -36+6  weeks of geatation) birth. RESULTS: Preterm birth was significantly more prevalent in twin pregnancies than in singleton pregnancies in all categories: all preterm (54.7% vs 6.1%), extremely preterm (3.6% vs 0.4%), very preterm (18.2% vs 1.4%) and late preterm (33.0% vs 4.3%) births. Stillbirth, congenital malformation and pre-eclampsia were more prevalent in twin pregnancies than in singleton pregnancies, but the prevalence of complications differed in the three categories of preterm birth. Pre-eclampsia was more prevalent in singleton than in twin pregnancies ending in extremely and very preterm birth. The adjusted odds of spontaneous preterm live birth were between 19- and 54-fold greater in twin pregnancies than in singleton pregnancies. CONCLUSIONS: Singleton and twin pregnancies seem to have different pathways leading to extremely, very and late preterm birth.

Exploring the impact of indication on variation in rates of intrapartum caesarean section in six Palestinian hospitals: a prospective cohort study.

BACKGROUND: Caesarean section rates are rising globally. No specific caesarian section rate at either country-level or hospital-level was recommended. In Palestinian government hospitals, nearly one-fourth of all births were caesarean sections, ranging from 14.5 to 35.6%. Our aim was to assess whether variation in odds for intrapartum caesarean section in six Palestinian government hospitals can be explained by differences in indications. METHODS: Data on maternal and fetal health were collected prospectively for all women scheduled for vaginal delivery during the period from 1st March 2015 to 30th November 2016 in six government hospitals in Palestine. Comparisons of proportions in sociodemographic, antenatal obstetric characteristics and indications by the hospital were tested by χ2 test and differences in means by one-way ANOVA analysis. The odds for intrapartum caesarean section were estimated by logistic regression. The amount of explained variance was estimated by Nagelkerke R square. RESULTS: Out of 51,041 women, 4724 (9.3%) underwent intrapartum caesarean section. The prevalence of intrapartum caesarean section varied across hospitals; from 7.6 to 22.1% in nulliparous, and from 5.8 to 14.1% among parous women. The most common indications were fetal distress and failure to progress in nulliparous, and previous caesarean section with an additional obstetric indication among parous women. Adjusted ORs for intrapartum caesarean section among nulliparous women ranged from 0.42 (95% CI 0.31 to 0.57) to 2.41 (95% CI 1.70 to 3.40) compared to the reference hospital, and from 0.50 (95% CI 0.40-0.63) to 2.07 (95% CI 1.61 to 2.67) among parous women. Indications explained 58 and 66% of the variation in intrapartum caesarean section among nulliparous and parous women, respectively. CONCLUSION: The differences in odds for intrapartum caesarean section among hospitals could not be fully explained by differences in indications. Further investigations on provider related factors as well as maternal and fetal outcomes in different hospitals are necessary.

Association between maternal country of birth and preterm birth: A population-based register study of 910,752 deliveries.

Aims: The aim of this study was to analyse associations between maternal country of birth and preterm birth among women giving birth in Norway. Methods: A population-based register study was conducted employing official national databases in Norway. All singleton births, with neonates without major anomalies, between 1999 and 2014 were included (N=910,752). We estimated odds ratios (ORs) for extremely preterm birth (<28 weeks gestation), very preterm birth (28-33 weeks gestation) and late preterm birth (34-36 weeks gestation) by maternal country of birth. We conducted multivariable regression analyses, adjusting for maternal, obstetric and socio-economic confounders. Results: For extremely preterm births (0.4% of the study population), women with an unknown country of birth (adjusted OR (aOR)=3.09; 95% confidence interval (CI) 2.26-4.22) and women born in sub-Saharan Africa (aOR=1.66; CI 1.40-1.96) had the highest ORs compared to Norwegian-born women. For very preterm births (1.2% of the study population), women with an unknown country of birth (aOR=1.72; CI 1.36-2.18) and women born in South Asia (aOR=1.48; CI 1.31-1.66) had the highest ORs. For late preterm births (3.8% of the study population), women born in East Asia Pacific/Oceania (aOR=1.33; CI 1.25-1.41) and South Asia (aOR=1.30; CI 1.21-1.39) had the highest ORs. Conclusions: After adjusting for maternal, obstetric and socio-economic risk factors, maternal country of birth remained significantly associated with preterm birth. Women with an unknown country of birth and women born in sub-Saharan Africa were found to be at increased risk of extremely preterm birth.

Impact of animated instruction on tablets and hands-on training in applying bimanual perineal support on episiotomy rates: an intervention study.

INTRODUCTION AND HYPOTHESIS: In Palestine, episiotomy is frequently used among primiparous women.This study assesses the effect of training birth attendants in applying bimanual perineal support during delivery by either animated instruction on tablets or hands-on training on episiotomy rates among primiparous women. METHODS: An interventional cohort study was performed from 15 October 2015 to 31 January 2017, including all primiparous women with singletons and noninstrumental vaginal deliveries at six Palestinian hospitals. Intervention 1 (animated instructions on tablets) was conducted in Hospitals 1, 2, 3, and 4. Intervention 2 (bedside hands-on training) was applied in Hospitals 1 and 2 only. Hospitals 5 and 6 did not receive interventions. Differences in episiotomy rates in intervention and nonintervention hospitals were assessed before and after the interventions and presented as p values using chi-square test, and odds ratios (OR) with 95% confidence intervals (CI). Differences in the demographic and obstetric characteristics were presented as p values using the Kruskal-Wallis test. RESULTS: Of 46,709 women, 12,841 were included. The overall episiotomy rate in the intervention hospitals did not change significantly after intervention 1, from 63.1 to 62.1% (OR = 0.96, 95% CI 0.84-1.08), but did so after intervention 2, from 61.1 to 38.1% (OR = 0.39, 95% CI 0.33-0.47). Rates after Intervention 2 changed from 65.0 to 47.3% (OR = 0.52, 95% CI 0.40-0.67) in Hospital 1 and from 39.4 to 25.1% (OR = 0.49, 95% CI 0.35-0.68) in Hospital 2. CONCLUSIONS: Hands-on training of bimanual perineal support during delivery of primiparous women was significantly more effective in reducing episiotomy rates than animated instruction videos alone.

Maternal body mass index as a predictor for delivery method.

INTRODUCTION: High maternal body mass index (BMI) is associated with complications during pregnancy and delivery such as gestational diabetes, hypertensive disorders, perineal injuries and macrosomia. The aim of this study was to assess the association between maternal BMI and delivery method in non-breech, singleton deliveries, after 36 weeks of gestation, in women with no more than one previous cesarean section, in Oslo University Hospital, Ullevål. MATERIAL AND METHODS: This retrospective register study used data from the hospital obstetrical database in 2011-2012, forming a cohort of 8821 women. Women were categorized into five different BMI classes and stratified into subgroups according to parity and previous cesarean delivery. Mode of delivery was categorized to spontaneous delivery, instrumental vaginal delivery, planned cesarean section and emergency cesarean section. RESULTS: Incidence of emergency cesarean delivery increased with increasing maternal BMI. Among primiparous women with overweight or obesity, the caesarean delivery rate was doubled (23.2 and 29.1%, respectively), compared with women with underweight or normal weight (12.5 and 13.7%). Also among parous women, maternal BMI ≥30 doubled the risk for cesarean delivery. The strongest risk factor for planned or emergency cesarean delivery was previous cesarean section [adjusted odds ratio 16.41 (confidence interval 12.19-22.08) and 8.72 (6.33-12.02), respectively]. Maternal BMI ≥30 increased the risk of planned cesarean delivery by 77%, and doubled the risk of emergency cesarean delivery. CONCLUSIONS: Prepregnancy BMI ≥30 was an independent risk factor for delivery by emergency cesarean section for both primiparous and parous women.

The association of maternal country of birth and education with hypertensive disorders of pregnancy: A population-based study of 960 516 deliveries in Norway.

INTRODUCTION: Previous studies estimating the association of maternal country of birth and education with hypertensive disorders of pregnancy (HDP) have shown conflicting results. The aim of the study was to assess the prevalence of HDP and estimate the association of maternal country of birth and education level with preeclampsia/eclampsia and gestational hypertension in Norway. MATERIAL AND METHODS: We performed a population-based observational cohort study linking two population datasets: The Medical Birth Registry of Norway and Statistics Norway (SSB). Singleton deliveries in Norway between 1999 and 2014 (907 048 deliveries) were stratified by parity. Multiple regression analysis was performed. RESULTS: In 20% of the deliveries the woman was born outside of Norway. Foreign-born women had lower risk of preeclampsia/eclampsia and gestational hypertension compared with Norwegian-born women. High education reduced the risk for preeclampsia/eclampsia by 34% (adjusted odds ratio 0.66, 95% CI 0.62-0.69), compared with women with secondary education among nulliparous women, and by 39% (adjusted odds ratio 0.61, 95% CI 0.57-0.65) among parous women. Poorly educated women had no increased risk of HDP compared with women with secondary education. Among highly educated nulliparous women the risk of preeclampsia/eclampsia was lower but the risk of gestational hypertension higher compared with women of similar parity with secondary education. Adjustment for confounding variables had minimal effect on these estimates. CONCLUSIONS: Maternal country of birth and education were associated with HDP. Women with higher education had the lowest risk of HDP, and Norwegian-born women had the highest risk of HDP, regardless of parity and other confounding factors.

Impact of electronic and blended learning programs for manual perineal support on incidence of obstetric anal sphincter injuries: a prospective interventional study.

BACKGROUND: Obstetric anal sphincter injuries (OASIS) are associated with anal incontinence, dyspareunia and perineal pain. Bimanual perineal support technique (bPST) prevents OASIS. The aim of this study was to assess the effect of two different bPST training-methods on OASIS incidence. METHODS: This is a prospective-interventional quality improvement study conducted in two Palestinian maternity units between June 1 2015 and December 31 2016. Women having spontaneous or operative vaginal-delivery at ≥24 gestational-weeks or a birthweight of ≥1000 g (n = 1694) were recruited and examined vaginally and rectally immediately after vaginal birth by a trained assessor. Data on baseline OASIS incidence were collected during Phase-1 of the study. Subsequently, birth attendants in both maternity units were trained in bPST using two training modalities. A self-directed electronic-learning (e-learning) using an animated video was launched in phase-2 followed by a blended learning method (the animated e-learning video+ structured face-to-face training) in phase-3. OASIS incidence was monitored during phases-2 and 3. Variations in OASIS incidence between the three phases were assessed using Pearson-χ2-test (or Fisher's-Exact-test). The impact of each training-method on OASIS incidence was assessed using logistic-regression analysis. RESULTS: A total of 1694 women were included; 376 in phase-1, 626 in phase-2 and 692 in phase-3. Compared to Phase-1, OASIS incidence was reduced by 45% (12.2 to 6.7%, aOR: 0.56, CI; 0.35-0.91, p = 0.018) and 74% (12.2 to 3.2%, aOR, 0.29, CI; 0.17-0.50, p < 0.001) in phases-2 and 3, respectively. There was also a significant reduction in OASIS incidence by 52% from phase-2 to phase-3 (6.7% (42/626) to 3.2% (22/692), p = 0.003). These reductions reached statistical significance among parous-women only (aOR: 0.18, CI; 0.07-0.49, p = 0.001) after the first training method tested in phase-2. However, the reduction was significant among both primiparous (aOR: 0.39, CI; 0.21-0.74, p = 0.004) and parous-women (aOR: 0.11, CI; 0.04-0.32, p < 0.001) after implementing the blended learning method in phase-3. CONCLUSION: The animated e-learning video had a positive impact on reducing OASIS incidence. However, this reduction was enhanced by the use of a blended learning program combining both e- learning and face-to-face training modalities. STUDY REGISTRATION NUMBER: ClinicalTrialo.gov identifier: NCT02427854 , date: 28 April 2015.

Building a research registry for studying birth complications and outcomes in six Palestinian governmental hospitals.

BACKGROUND: Electronic-health (e-health) provides opportunities for quality improvement of healthcare, but implementation in low and middle income countries is still limited. Our aim was to describe the implementation of a registration (case record form; CRF) for obstetric interventions and childbirth events using e-health in a prospective birth cohort study in Palestine. We also report the completeness and the reliability of the data. METHODS: Data on maternal and fetal health was collected prospectively for all women admitted to give birth during the period from 1st March 2015 to 31st December 2015 in three governmental hospitals in Gaza and three in the West Bank. Essential indicators were noted in a case registration form (CRF) and subsequently entered into the District Health Information Software 2 (DHIS 2) system. Completeness of registered cases was checked against the monthly hospital birth registries. Reliability (correct information) of DHIS2 registration and entry were checked for 22 selected variables, collected during the first 10 months. In the West Bank, a comparison between our data registration and entry and data obtained from the Ministry of Health patient electronic records was conducted in the three hospitals. RESULTS: According to the hospital birth registries, a total of 34,482 births occurred in the six hospitals during the study period. Data on the mothers and children registered on CRF was almost complete in two hospitals (100% and 99.9%); in the other hospitals the completeness ranged from 72.1% to 98.7%. Eighty birth events were audited for 22 variables in the three hospitals in the West Bank. Out of 1760 registrations in each hospital, the rates of correct data registration ranged from 81% to 93.2% and data entry ranged from 84.5% to 93.1%. CONCLUSIONS: The registered and entered data on birth events in six hospitals was almost complete in five out of six hospitals. The collected data is considered reliable for research purposes.

Sexual activity and dyspareunia the first year postpartum in relation to degree of perineal trauma.

INTRODUCTION AND HYPOTHESIS: Knowledge on sexual complaints and time to sexual resumption after obstetric anal sphincter injury (OASI) is scarce. The aim of the study was to investigate self-reported sexual activity and coital problems 1 year postpartum in relation to perineal trauma, in addition to delivery mode. METHODS: Among 2,846 women recruited during pregnancy, all women who delivered with OASI (n = 42, all third-degree perineal tears), in addition to 20 randomly selected controls per OASI case, a total of 882 women, were sent a self-administered questionnaire addressing time to coital resumption after delivery and potential coital difficulty 1 year postpartum. RESULTS: By 8 weeks, half of the 561 responders (51.4 %) had resumed intercourse, increasing to 75.2 % by 12 weeks and 94.7 % 1 year postpartum. In multivariate regression analysis OASI was the strongest predictor for postponed coital onset, defined as after 8 weeks (aOR 5.52, CI 1.59-19.16). OASI was also the only significant predictor for dyspareunia 1 year after delivery (aOR 3.57, CI 1.39-9.19). Episiotomy was neither a risk factor for postponed coital onset nor for dyspareunia. There were no differences between episiotomy and second-degree laceration injury groups regarding postponed coital onset (p = 0.45) or dyspareunia (p = 0.67) 1 year postpartum. CONCLUSIONS: Obstetric anal sphincter injury was a strong and independent predictor for both postponed coital resumption after delivery and for dyspareunia 1 year postpartum, whereas episiotomy and spontaneous second-degree lacerations were not. Our main finding of affected sexual activity after OASI further supports the need to reduce the rates of this obstetric injury to a minimum.

Episiotomy preferences, indication, and classification--a survey among Nordic doctors.

INTRODUCTION: Episiotomy performance impacts perineal health and rates of obstetric anal sphincter injuries (OASIS). Our objective was to assess self-reported episiotomy practice and opinions on clinical indication for episiotomy among Nordic physicians and to investigate potential misclassification. MATERIAL AND METHODS: A survey was conducted among doctors attending the 2012 Nordic obstetrical and gynecological conference. Participants were asked to draw an episiotomy on a photo of a perineum with a crowning fetal head similarly to their clinical practice if an episiotomy was clinically indicated, and to name the technique drawn. Differences in outcome measures were compared by country of practice and seniority. RESULTS: The majority of the 297 participants (47%) drew a lateral episiotomy according to our classification by incision point and angle, but as many as 64% of these 138 doctors misclassified this as mediolateral episiotomy. Only 20% drew a mediolateral episiotomy, the great majority classifying it accurately, but 8% misclassified their mediolateral cut as a lateral episiotomy. One-third of episiotomies were nonclassifiable. In general, doctors in Finland, Sweden, and Norway more often favored lateral episiotomies compared with doctors in Denmark and Iceland. There were significant differences between Finnish and Norwegian vs. Danish and Swedish doctors in perception of clinical indications for episiotomy. CONCLUSIONS: The great variation in self-reported episiotomy performance between Nordic physicians and large misclassification rates indicate that educational programs are warranted. Use of uniform classification and appropriate techniques may be crucial to investigate the role of episiotomies in preventing OASIS.

Effect of different episiotomy techniques on perineal pain and sexual activity 3 months after delivery.

INTRODUCTION AND HYPOTHESIS: The effect of different episiotomy techniques on pain perception 3 months after delivery is unknown. Study aims were to explore the association between different episiotomy techniques and perineal pain 3 months after delivery and to assess female sexual activity in relation to episiotomy technique. METHODS: This is a prospective observational study, designed to investigate short- and long-term complications of different episiotomy techniques. All 300 participants were recruited and clinically examined during their postpartum hospital stay in order to evaluate episiotomy performance. A 3-month follow-up questionnaire addressing pain, sexual activity, and puerperal wound infection was distributed to 208 women who had scored perineal pain in a personal interview the first day after delivery. RESULTS: A response rate of 87.7 % was obtained. We found no difference in pain score distribution by Visual Analogue Scale (VAS) when comparing midline, mediolateral, and lateral episiotomy techniques (p = 0.32) or between midline and lateral incision points (p = 0.58). Dyspareunia was reported by 33 out of 179 women, but no difference between episiotomy techniques (p = 0.90), or between episiotomy incision points (p = 0.14), was found. Perineal wound infection was reported by 9.5 %, but there was no significant difference between episiotomy techniques (p = 0.73). CONCLUSIONS: No difference was found in perineal pain perception 3 months postpartum between different episiotomy techniques or when comparing midline and lateral incision points. Dyspareunia was not associated with any particular episiotomy technique or incision point.

Modeling manual perineal protection during vaginal delivery.

INTRODUCTION AND HYPOTHESIS: We compared hands-on manual perineal protection (MPP) and hands-off delivery techniques using the basic principles of mechanics and assessed the tension of perineal structures using a novel biomechanical model of the perineum. We also measured the effect of the thumb and index finger of the accoucheur's dominant-posterior hand on perineal tissue tension when a modified Viennese method of MPP is performed. METHODS: Hands-off and two variations of hands-on manual perineal protection during vaginal delivery were simulated using a biomechanical model, with the main outcome measure being strain/tension throughout the perineal body during vaginal delivery. RESULTS: Stress distribution with the hands-on model shows that when using MPP, the value of highest stress was decreased by 39 % (model B) and by 30 % (model C) compared with the hands-off model A. On the cross section there is a significant decrease in areas of equal tension throughout the perineal body in both hands-on models. Simulation of the modified Viennese MPP significantly reduces the maximum tension on the inner surface of the perineum measured at intervals of 2 mm from the posterior fourchette. CONCLUSIONS: In a biomechanical assessment with a finite element model of vaginal delivery, appropriate application of the thumb and index finger of the accoucheur's dominant-posterior hand to the surface of the perineum during the second stage of delivery significantly reduces tissue tension throughout the entire thickness of the perineum; thus, this intervention might help reduce obstetric perineal trauma.

Different episiotomy techniques, postpartum perineal pain, and blood loss: an observational study.

INTRODUCTION AND HYPOTHESIS: The lateral episiotomy technique has been postulated to cause more postpartum perineal pain and blood loss compared to the midline and mediolateral episiotomy technique. The aim of the study was to explore the association with postpartum perineal pain and blood loss between different episiotomy techniques. METHODS: Clinical evaluation of episiotomy was performed 0-3 days after delivery on 300 participating women. Episiotomy technique was classified by millimeter distance from the incision point to the posterior fourchette and by angle from the sagittal plane in degrees. Postpartum perineal pain was scored on a visual analogue scale (VAS) the first day after delivery. Blood loss data were collected from medical charts. Different episiotomy techniques and different episiotomy incision point groups were compared in relation to perineal pain perception and blood loss. RESULTS: We found no difference between midline, mediolateral, and lateral episiotomy techniques in perineal pain perception the first postpartum day (p = 0.74) or in estimated blood loss (p = 0.38). No differences were found in perineal pain or blood loss between midline and lateral incision points. Mediolateral angles were significantly narrower than lateral angles (p < 0.005). Physicians performed longer episiotomies than midwives (p < 0.005), but episiotomy angle did not vary between professions (p = 0.075). CONCLUSIONS: No differences in perineal pain perception the first postpartum day and no differences in estimated blood loss were found when comparing different episiotomy techniques or when comparing midline and lateral incision points.

Are obstetric anal sphincter ruptures preventable?-- large and consistent rupture rate variations between the Nordic countries and between delivery units in Norway.

OBJECTIVE: To study changes in the incidence of obstetric anal sphincter rupture (OASR) during recent years in Denmark, Finland, Sweden and Norway and hospital-based incidence in recent years in Norway. DESIGN: Retrospective birth register study. SETTING: Unselected population of delivering women in four Nordic countries. SAMPLE: All deliveries (574 175) registered in Denmark, Finland, Norway and Sweden, 2004-2010. METHODS: Parity data, including maternal, obstetrical and fetal characteristics, were obtained. The incidence of OASR was calculated from vaginal deliveries. A chi-squared test was used to analyse differences between countries and time periods. MAIN OUTCOME MEASURES: Incidence of OASR. RESULTS: During the study period, the OASR incidence in Finland was notably lower (0.7-1.0%) than in the other three Nordic countries (4.2-2.3%). A significant and constant reduction in OASR incidence was observed in Norway only (from 4.1 to 2.3%, from 2004 to 2010, p < 0.001). This reduction occurred simultaneously with introduction of a national intervention program of improved delivery techniques that aimed to reduce the incidence of OASR. No major alterations in maternal or fetal risk factors for OASR or registration routines could explain this rapid reduction in the rate of OASR. Differences in the incidence of OASR between Norwegian delivery units were significant, with a threefold difference when comparing the units with lowest and highest incidences. CONCLUSIONS: Obstetric anal sphincter rupture seems to be preventable to a considerable extent, as indicated by the rapid and lasting reduction of OASR incidence after implementation of perineal protection programs in Norway. Improved delivery techniques should be implemented in all delivery units to prevent OASR as much as possible.

Time trends in caesarean section rates and associations with perinatal and neonatal health: a population-based cohort study of 1 153 789 births in Norway.

OBJECTIVES: To study caesarean section (CS) rates and associations with perinatal and neonatal health in Norway during 1999-2018. DESIGN: Population-based cohort study. SETTING: Medical Birth Registry of Norway. PARTICIPANTS: 1 153 789 births and 1 174 066 newborns. METHODS: CS, intrapartum, perinatal and neonatal mortality rates expressed as percentages (%) or per mille (‰) with 95% CIs. PRIMARY AND SECONDARY OUTCOME MEASURES: CS rates in the Robson Ten-Group Classification System; intrapartum, perinatal and neonatal mortality rates. RESULTS: The overall CS rate increased from 12.9% in 1999 to 16.7% in 2008 (p<0.001), and then reduced to 15.8% in 2018 (p<0.001). The largest reductions were observed in Robson groups 2 and 4. In Robson group 2, the planned CS rate decreased from 9.6% in 2007-2008 to 4.6% in 2017-2018, the intrapartum CS rate decreased from 26.6% in 2007-2008 to 22.3% in 2017-2018. In Robson group 4, the planned CS rate decreased from 16.1% in 2007-2008 to 7.6% in 2017-2018, and the intrapartum CS rate decreased from 7.8% in 2007-2008 to 5.2% in 2017-2018.The intrapartum fetal mortality rate decreased from 0.51 per 1000 (‰) in 1999-2000 to 0.14‰ in 2017-2018. Neonatal mortality decreased from 2.52‰ to 1.58‰. CONCLUSIONS: CS rates in Norway increased between 1999 and 2008, followed by a significant reduction between 2008 and 2018. At the same time, fetal and neonatal mortality rates decreased. Norwegian obstetricians and midwives have contributed to maintaining a low CS rate under 17%. These findings indicate that restricting the use of CS is a safe option for perinatal health.

Trends in Term Intrapartum Stillbirth in Norway.

Importance: Fetal death during labor at term is a complication that is rarely studied in high-income countries. There is a need for large population-based studies to examine the rate of term intrapartum stillbirth in high-income countries and the factors associated with its occurrence. Objective: To evaluate trends in term intrapartum stillbirth over time and to investigate the association between the trends and term intrapartum stillbirth risk factors from 1999 to 2018 in Norway. Design, Setting, and Participants: This cohort study used data from the Medical Birth Registry of Norway from 1999 to 2018 to examine rates of term intrapartum stillbirth and risk factors associated with this event. A population of 1 021 268 term singleton pregnancies without congenital anomalies or antepartum stillbirths was included in analyses, which were performed from September 2022 to February 2023. Exposure: The main exposure variable was time, which was divided into four 5-year periods: 1999 to 2003, 2004 to 2008, 2009 to 2013, and 2014 to 2018. Main Outcomes and Measures: The primary study outcome was term intrapartum stillbirth. Risk ratios were calculated, and multivariable logistic regression analyses were conducted to identify factors associated with secular trends of term intrapartum stillbirth. Results: The study population consisted of 1 021 268 term singleton births (maternal mean [SD] age, 29.72 [5.01] years; mean [SD] gestational age, 39.69 [1.27] weeks). During the study period, there were 95 term intrapartum stillbirths (0.09 per 1000 births). Maternal age, the proportion of individuals born in a country other than Norway, and the prevalence of gestational diabetes, labor induction, operative vaginal delivery, and previous cesarean delivery increased over the course of the study period. Conversely, the prevalence of infants large for gestational age, hypertensive disorder in pregnancy, and spontaneous vaginal delivery and the proportion of individuals who smoked decreased. The term intrapartum stillbirth rate decreased by 87% (95% CI, 68%-95%) from 0.15 per 1000 births in 1999 to 2008 to 0.02 per 1000 births in 2014 to 2018. Three in 4 term intrapartum stillbirths (70 of 95) occurred during intrapartum operative deliveries. The increased prevalence of older maternal age and obstetric risk factors were not associated with the variation in intrapartum stillbirth rates among the time periods. The prevalence of term intrapartum stillbirth was higher for individuals who gave birth in maternity units with fewer than 3000 annual births (adjusted odds ratio, 1.67; 95% CI, 1.07-2.61) than for those who gave birth in units with 3000 or more annual births. Conclusions and Relevance: Findings of this study suggest that, despite increases in maternal and obstetric risk factors, term intrapartum stillbirth rates substantially decreased during the study period. Reasons for this decrease may be due to improvements in intrapartum care.