Obstetric anal sphincter injury by maternal origin and length of residence: a nationwide cohort study.

OBJECTIVE: To estimate the association between maternal origin and obstetric anal sphincter injury (OASI), and assess if associations differed by length of residence. DESIGN: Population-based cohort study. SETTING: The Medical Birth Registry of Norway. POPULATION: Primiparous women with vaginal livebirth of a singleton cephalic fetus between 2008 and 2017 (n = 188 658). METHODS: Multivariable logistic regression models estimated adjusted odds ratios (aORs) for OASI with 95% CI by maternal region of origin and birthplace. We stratified models on length of residence and paternal birthplace. MAIN OUTCOME MEASURES: OASI. RESULTS: Overall, 6373 cases of OASI were identified (3.4% of total cohort). Women from South Asia were most likely to experience OASI (6.2%; aOR 2.24, 95% CI 1.87-2.69), followed by those from Southeast Asia, East Asia & the Pacific (5.7%; 1.59, 1.37-1.83) and Sub-Saharan Africa (5.2%; 1.85, 1.55-2.20), compared with women originating from Norway. Among women born in the same region, those with short length of residence in Norway (0-4 years), showed the highest odds of OASI. Migrant women across most regions of origin had the lowest risk of OASI if they had a Norwegian partner. CONCLUSIONS: Primiparous women from Asian regions and Sub-Saharan Africa had up to two-fold risk of OASI, compared with women originating from Norway. Migrants with short residence and those with a foreign-born partner had higher risk of OASI, implying that some of the risk differential is due to sociocultural factors. Some migrants, especially new arrivals, may benefit from special attention during labour to reduce morbidity and achieve equitable outcomes. TWEETABLE ABSTRACT: Anal sphincter injury during birth is more common among Asian and Sub-Saharan migrants and particularly among recent arrivals.

Prelabour uterine rupture: characteristics and outcomes.

OBJECTIVE: To describe the characteristics and outcomes of prelabour uterine ruptures. DESIGN: Descriptive study based on population data from the Medical Birth Registry of Norway, the Patient Administration System and medical records. SAMPLE: Maternities with uterine rupture before start of labour in Norway during the period 1967-2008 (8 complete ruptures among 2 334 712 women with unscarred uteri, and 22 complete and 45 partial ruptures among 121 085 women with scarred uteri). METHOD: We measured the rate of perinatal deaths and peripartum hysterectomy following ruptures. In addition, we studied the characteristics of ruptures. RESULTS: The eight complete ruptures in women with unscarred uteri were associated with trauma from traffic accidents (n = 3; 37.5%), previous curettage (n = 3; 37.5%) and congenital uterine malformations (n = 2; 25%), resulting in seven perinatal deaths and two hysterectomies. The 22 complete ruptures in scarred uteri were mostly outside the lower uterine segment (n = 17; 72.7%). Abnormally invasive placenta (AIP) and previous rupture were present in four (18.2%) and three women (13.6%), respectively. They resulted in nine perinatal deaths (39.1%) and two hysterectomies (9.1%). The 45 partial ruptures involved mostly scars in the lower uterine segment (n = 39; 86.7%). None of them resulted in perinatal death or hysterectomy. Perinatal deaths have decreased dramatically in recent years, despite increasing prelabour rupture rates. CONCLUSION: Although complete uterine ruptures before labour start were rare, they often resulted in catastrophic outcomes, such as perinatal death. Scars outside the lower segment were associated with a higher percentage of catastrophic prelabour ruptures compared with scars in the lower segment (Video S1). TWEETABLE ABSTRACT: Complete prelabour uterine ruptures were rare, but resulted in high perinatal deaths, especially if they were in scars outside the lower segment.

Reproductive factors and risk of melanoma: a population-based cohort study.

BACKGROUND: The association between reproductive factors and risk of cutaneous melanoma (CM) is unclear. We investigated this issue in the Norwegian Women and Cancer cohort study. OBJECTIVES: To examine the association between the reproductive factors age at menarche, menstrual cycle length, parity, age at first and last birth, menopausal status, breastfeeding duration and length of ovulatory life, and CM risk, overall and by histological subtypes and anatomical site. METHODS: We followed 165 712 women aged 30-75 years at inclusion from 1991-2007 to the end of 2015. Multivariable Cox regression was used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). RESULTS: The mean age at cohort enrolment was 49 years. During a median follow-up of 18 years, 1347 cases of CM were identified. No reproductive factors were clearly associated with CM risk. When stratifying by histological subtype we observed significant heterogeneity (P = 0·01) in the effect of length of ovulatory life on the risk of superficial spreading melanoma (HR 1·02, 95% CI 1·01-1·04 per year increase) and nodular melanoma (HR 0·97, 95% CI 0·94-1·01 per year increase). When stratifying by anatomical site, menopausal status (HR 0·54, 95% CI 0·31-0·92, postmenopausal vs. premenopausal) and menstrual cycle length (HR 1·07, 95% CI 1·01-1·13, per day increase) were associated with CM of the trunk, and significant heterogeneity between anatomical sites was observed for menopausal status (P = 0·04). CONCLUSIONS: In this large population-based Norwegian cohort study, we did not find convincing evidence of an association between reproductive factors and risk of CM.

The effectiveness of surgical interventions for women with FGM/C: a systematic review.

BACKGROUND: Female genital mutilation/cutting (FGM/C) changes normal genital functionality and can cause complications. There is an increasing demand for treatment of FGM/C-related complications. OBJECTIVES: We conducted a systematic review of empirical quantitative research on the outcomes of interventions for women with FGM/C-related complications. SEARCH STRATEGY: A search specialist searched 16 electronic databases. SELECTION CRITERIA: Selection was performed independently by two researchers. We accepted quantitative studies that examined the outcome of an intervention for an FGM/C-related concern. DATA COLLECTION AND ANALYSIS: We extracted data into a pre-designed form, calculated effect estimates, and performed meta-analyses. MAIN RESULTS: We included 62 studies (5829 women), which investigated the effect of defibulation, excision of cysts, and clitoral reconstruction. Meta-analyses of defibulation versus no defibulation showed a significantly lower risk of caesarean section (relative risk, RR: 0.33; 95% confidence interval, 95% CI: 0.25-0.45) and perineal tears with defibulation: second-degree tear (RR: 0.44, 95% CI: 0.24-0.79), third-degree tear (RR: 0.21, 95% CI: 0.05-0.94), fourth-degree tear (RR: 0.06, 95% CI: 0.01-0.41). The meta-analyses detected no significant differences in obstetric outcomes of antenatal versus intrapartum defibulation. Except for one study, none of the studies on the excision of cysts indicated any complications, and the results were deemed favourable. Reconstructive surgery resulted in a visible clitoris in about 77% of women. Most women self-reported improvements in their sexual life, but up to 22% experienced a worsening in sexuality-related outcomes after reconstruction. CONCLUSIONS: Women with FGM/C who seek therapeutic surgery should be informed about the scarcity of evidence for benefits and the potential harms of the available procedures. TWEETABLE ABSTRACT: Systematic review shows defibulation after FGM/C has obstetric benefits; effect of reconstruction is uncertain.

Assisted reproductive technology and severe postpartum haemorrhage: a case-control study.

OBJECTIVE: To investigate the association between assisted reproductive technology and severe postpartum haemorrhage. DESIGN: Case-control study. SETTING: The study was conducted in Norway; Division of Gynaecology and Obstetrics at Oslo University Hospital and Department of Obstetrics and Gynaecology at Drammen Hospital. POPULATION: A source population including all women admitted for delivery at Oslo University Hospital and Drammen Hospital during the time period 1 January 2008 to 31 December 2011. The study population consisted of all cases of severe postpartum haemorrhage (n = 1064) and a random sample of controls (n = 2059). METHODS: We used an explanatory strategy in the analysis, with multivariable logistic regression. MAIN OUTCOME MEASURES: Severe postpartum haemorrhage; defined as blood loss ≥1500 ml or need for blood transfusion. RESULTS: Assisted reproductive technology was associated with an increased risk of severe postpartum haemorrhage (crude OR = 2.92; 95% CI 2.18-3.92, P < 0.001). Mode of delivery and anticoagulant medication had significant confounding effects. Strong interaction was found for multiple pregnancies. After adjusting for confounding and interaction, an increased risk was observed both in the strata of multiple pregnancies (adjusted OR = 7.00, 95% CI 2.70-18.12, P < 0.001), and in the strata of single gestation (adjusted OR = 1.58, 95% CI 1.12-2.24, P = 0.010). CONCLUSIONS: Our findings warrant an increased awareness of the risk of severe postpartum haemorrhage in women conceiving with assisted reproductive technology. Furthermore, the high risk of severe postpartum haemorrhage in the presence of a twin or triplet pregnancy is an additional argument for single embryo transfer. TWEETABLE ABSTRACT: Assisted reproductive technology is associated with an increased risk of severe postpartum haemorrhage.

Uterine rupture: trends over 40 years.

OBJECTIVE: To follow trends of uterine rupture over a period of 40 years in Norway. DESIGN: Population-based study using data from the Medical Birth Registry, the Patient Administration System, and medical records. SETTING: Norway. SAMPLE: Women giving birth in 21 maternity units in Norway during the period 1967-2008 (n = 1 441 712 maternities). METHODS: The incidence and outcomes of uterine rupture were compared across four decades: 1967-1977; 1978-1988; 1989-1999; and 2000-2008. Multivariable logistic regression was used to determine the odds ratio (OR) for uterine rupture in each decade compared with the second decade. MAIN OUTCOME MEASURE: Trends in uterine rupture. RESULTS: We identified 359 uterine ruptures. The incidence rates per 10 000 maternities in the first, second, third, and fourth decade were 1.2, 0.9, 1.7, and 6.1, respectively. The ORs for complete and partial ruptures in the fourth versus the second decade were 6.4 (95% confidence interval, 95% CI 3.8-10.8) and 7.2 (95% CI 4.2-12.3), respectively. Significant contributing factors to this increase were the higher rates of labour augmentation with oxytocin, scarred uteri from a previous caesarean section, and labour induction with prostaglandins or prostaglandins combined with oxytocin. After adjusting for risk factors, the ORs for complete and partial ruptures were 2.2 (95% CI 1.3-3.8) and 2.8 (95% CI 1.6-4.8), respectively. Severe postpartum haemorrhage, hysterectomy, intrapartum death and infant death after complete uterine ruptures decreased significantly over time. CONCLUSIONS: A sharply increasing trend of uterine rupture was found. Obstetric interventions contributed to this increase, but could not explain it entirely. TWEETABLE ABSTRACT: A sharply increasing trend of uterine ruptures has been found in Norway in recent years.

Cancer risk among parous women following assisted reproductive technology.

STUDY QUESTION: Do women who give birth after assisted reproductive technology (ART) have an increased risk of cancer compared with women who give birth without ART? SUMMARY ANSWER: Without correction, the results indicate an increase in overall cancer risk, as well as a 50% increase in risk of CNS cancer for women giving birth after ART, however the results were not significant after correcting for multiple analyses. WHAT IS KNOWN ALREADY: Studies regarding the effects of hormonal treatments involved with ART on subsequent cancer risk have provided inconsistent results, and it has also been suggested that infertility itself could be a contributory factor. STUDY DESIGN, SIZE, DURATION: A population-based cohort consisting of all women registered in the Medical Birth Registry of Norway as having given birth between 1 January 1984 and 31 December 2010 was assembled (n = 812 986). Cancers were identified by linkage to the Cancer Registry of Norway. Study subjects were followed from start of first pregnancy during the observational period until the first cancer, death, emigration, or 31 December 2010. PARTICIPANTS/MATERIALS, SETTING, METHODS: Of the total study population (n = 806 248), 16 525 gave birth to a child following ART. Cox regression analysis computed hazard ratios (HR) and 95% confidence intervals (CI) comparing cancer risk between ART women and non-ART women; for overall cancer, and for cervical, ovarian, uterine, central nervous system (CNS), colorectal and thyroid cancers, and for malignant melanoma. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 22 282 cohort members were diagnosed with cancer, of which 338 were ART women and 21 944 non-ART women. The results showed an elevated risk in one out of seven sites for ART women. The HR for cancer of the CNS was 1.50 (95% CI 1.03- 2.18), and among those specifically subjected to IVF (without ICSI) the HR was 1.83 (95% CI 1.22-2.73). Analysis of risk of overall cancer gave an HR of 1.16 (95% CI 1.04-1.29). Among those who had delivered only one child by the end of follow-up, the HR for ovarian cancer was 2.00 (95% CI 1.08-3.65), and for those nulliparous at entry the HR was 1.80 (95% CI 1.04-3.11). However, all findings became non-significant after correcting for multiple analyses. LIMITATIONS, REASONS FOR CAUTION: The results of elevated risk of overall cancer and CNS cancer lost significance when adjusting for multiple analyses, implying an important limitation of the study. The follow-up time was relatively short, especially for ART women. In addition, as the cohort was relatively young, there were few incident cancers, especially for some rarer cancer forms, such as uterine cancer. Risk assessments according to different causes of infertility could not be done. WIDER IMPLICATIONS OF THE FINDINGS: In light of the findings in the present study, further studies should be made on risk of CNS and ovarian cancer, and continued monitoring of all those treated with ART is encouraged. Our findings may only be generalizable to women who give birth after ART, and the risk for women who remain nulliparous after ART remains to be assessed. STUDY FUNDING/COMPETING INTEREST: The study was funded by the Norwegian National Advisory Unit on Women's Health. All authors claim no competing interests.

Breastfeeding and pelvic girdle pain: a follow-up study of 10,603 women 18 months after delivery.

OBJECTIVE: To study the associations of patterns and duration of breastfeeding with the persistence of pelvic girdle pain 18 months after delivery. DESIGN: Longitudinal population study. SETTING: Norway, for the period 1999-2011. POPULATION: A follow-up of 10 603 women with singleton deliveries in the Norwegian Mother and Child Cohort Study who reported pelvic girdle pain at 0-3 months postpartum. METHODS: Data were obtained by four self-administered questionnaires and linked to the Medical Birth Registry of Norway. MAIN OUTCOME MEASURE: Pelvic girdle pain, defined as combined anterior and bilateral posterior pelvic pain, 18 months after delivery. RESULTS: Eighteen months after delivery, 7.8% of respondents (829/10,603) reported pelvic girdle pain. Breastfeeding patterns at 5 months after delivery were not associated with persistence of pelvic girdle pain. The proportion of women with pelvic girdle pain 18 months after delivery increased as the duration of breastfeeding decreased (test for trend, P < 0.001). The estimated associations attenuated after adjustment for educational level, smoking status, and body mass index, but remained statistically significant for the association between 0 and 2 months of breastfeeding and persistent pelvic girdle pain (adjusted odds ratio 1.34; 95% confidence interval 1.03-1.75). The association of short breastfeeding duration with persistent pelvic girdle pain was only present in women with body mass index ≥25 kg/m(2) . CONCLUSIONS: Breastfeeding was associated with a small beneficial effect on the recovery process of pelvic girdle pain in women with a body mass index ≥25 kg/m(2) . Among women with pelvic girdle pain, breastfeeding should be encouraged in accordance with the existing child-feeding recommendations.