Abnormally invasive placenta-prevalence, risk factors and antenatal suspicion: results from a large population-based pregnancy cohort study in the Nordic countries.

OBJECTIVE: The objective was to investigate prevalence, estimate risk factors, and antenatal suspicion of abnormally invasive placenta (AIP) associated with laparotomy in women in the Nordic countries. DESIGN: Population-based cohort study. SETTING AND POPULATION: A 3-year Nordic collaboration among obstetricians to identify and report on uterine rupture, peripartum hysterectomy, excessive blood loss, and AIP from 2009 to 2012 The Nordic Obstetric Surveillance Study (NOSS). METHODS: In the NOSS study, clinicians reported AIP cases from maternity wards and the data were validated against National health registries. MAIN OUTCOME MEASURES: Prevalence, risk factors, antenatal suspicion, birth complications, and risk estimations using aggregated national data. RESULTS: A total of 205 cases of AIP in association with laparotomy were identified, representing 3.4 per 10 000 deliveries. The single most important risk factor, which was reported in 49% of all cases of AIP, was placenta praevia. The risk of AIP increased seven-fold after one prior caesarean section (CS) to 56-fold after three or more CS. Prior postpartum haemorrhage was associated with six-fold increased risk of AIP (95% confidence interval 3.7-10.9). Approximately 70% of all cases were not diagnosed antepartum. Of these, 39% had prior CS and 33% had placenta praevia. CONCLUSION: Our findings indicate that a lower CS rate in the population may be the most effective way to lower the incidence of AIP. Focused ultrasound assessment of women at high risk will likely strengthen antenatal suspicion. Prior PPH is a novel risk factor associated with an increased prevalence of AIP. TWEETABLE ABSTRACT: An ultrasound assessment in women with placenta praevia or prior CS may double the awareness for AIP.

Caesarean section in nulliparous women of advanced maternal age has been reduced in Sweden and Norway since the 1970s: a register-based study.

OBJECTIVE: To investigate rates of caesarean delivery in Sweden and Norway from 1973 to 2008 in relation to advanced and very advanced maternal age. DESIGN: Register study. SETTING: Sweden and Norway. SAMPLE: All nulliparous women aged over 30 years with a singleton pregnancy, with the fetus in a cephalic presentation, and delivering at term between 1973 and 2008 were evaluated. The study population comprised 329 824 women in Sweden and 127 810 women in Norway. METHODS: Data from the national Medical Birth Registers were used to describe caesarean section rates in three age groups: 30-34 years (reference group); 35-39 years (advanced age group); and ≥ 40 years (very advanced age group). Logistic regression analyses estimated the risk in each age group over four decades, in each of the two national samples. RESULTS: Caesarean delivery decreased from 1973-1979 to 2000-2008 in the two oldest age groups in Sweden (35-39 years, OR = 0.53, 95% CI = 0.50-0.58; ≥ 40 years, OR = 0.36, 95% CI = 0.30-0.43) and Norway (35-39 years, OR = 0.61, 95% CI = 0.54-0.68; ≥ 40 years, OR = 0.45, 95% CI = 0.34-0.58), but increased in women aged 30-34 years. The caesarean delivery rate in the two oldest groups peaked in the second half of the 1970s. Regardless of time point, the caesarean delivery rate was always highest in women aged ≥ 40 years, followed by women aged 35-39 years and lowest in women aged 30-34 years. CONCLUSIONS: Caesarean delivery in nulliparous women of advanced and very advanced age peaked by end of the 1970s in Sweden and Norway. The subsequent reduction was contemporaneous with the introduction of electronic fetal monitoring and a more consistent use of the partogram, suggesting that more effective surveillance of labour increased the chance of a vaginal birth in these high-risk women.

Risk factors for anal sphincter tears: the importance of maternal position at birth.

OBJECTIVE: To assess the role of birth position in the occurrence of anal sphincter tears (AST). DESIGN: Observational cohort study. SETTING: South Hospital in Stockholm, a teaching hospital with around 5700 births per year. POPULATION: Among all 19,151 women who gave birth at the South Hospital during the study period 2002-05, 12,782 women met the inclusion criteria of noninstrumental, vaginal deliveries. METHODS: Data on birth position and other obstetric factors were analysed in relation to occurrence of AST. MAIN OUTCOME MEASURE: Third- and fourth-degree AST. RESULTS: AST occurred in 449 women (3.5%). The trauma was more frequent in primiparous (5.8%) than in multiparous women (1.7%). The highest proportion of AST was found among women who gave birth in lithotomy position (6.9%), followed by squatting position (6.4%). Logistic regression analyses showed that lithotomy (adjusted OR 2.02, 95% CI 1.58-2.59) and squatting positions (adjusted OR 2.05, 95% CI 1.09-3.82) were associated with a significantly increased risk for AST. Other major risk factors for anal sphincter trauma were primiparity (adjusted OR 3.29, 95% CI 2.55-4.25), prolonged second stage of labour >1 hour (adjusted OR 1.52, 95% CI 1.11-2.10), infant birthweight more than 4 kg (adjusted OR 2.12, 95% CI 1.64-2.72) and large infant head circumference (adjusted OR 1.57, 95% CI 1.23-1.99). CONCLUSION: Lithotomy and squatting position at birth were associated with an increased risk for AST also after control for other risk factors.

A randomized trial of birthing stool or conventional semirecumbent position for second-stage labor.

Two hundred ninety-four women were randomly allocated to a group in which the use of a birthing stool (experimental group) or a conventional semirecumbent position (control group) was encouraged. The birthing stool was 32 cm high and allowed the parturient to sit upright and to squat. The husband could sit close behind his wife and support her back. No differences were observed between the two groups regarding mode of delivery, length of the second stage of labor, oxytocin augmentation, perineal trauma, labial lacerations, or vulvar edema. Infant outcome measured by Apgar scores at 1 and 5 minutes postpartum and numbers of neonatal intensive care unit transfers was the same in both groups. Mean estimated blood loss and the number of mothers with a postpartum hemorrhage 600 ml or more were greater in the experimental group than in the control group. Women in the experimental group reported less pain during the second stage of labor, and they and their spouses were more satisfied with the birth position than were parents in the control group. Midwives were less satisfied with their working posture in the experimental group.