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.

Pre-pregnant body mass index and recreational physical activity: effects on perinatal mortality in a prospective pregnancy cohort.

OBJECTIVE: To examine the effect of maternal pre-pregnant body mass index (BMI) and recreational physical activity on perinatal mortality. DESIGN: A prospective cohort study. SETTING: The Norwegian Mother and Child Cohort (MoBa), 1999-2008. POPULATION: Singleton pregnancies without congenital anomalies (n = 77 246). METHODS: Pre-pregnant BMI was classified as underweight (<18.5), normal weight (18.5-24.9), overweight (25-29.9), obese (30-34.9) or morbidly obese (BMI ≥ 35). Risk estimates were obtained by logistic regression and adjusted for confounders. MAIN OUTCOME MEASURES: Perinatal death (stillbirth ≥ 22 weeks plus early neonatal death 0-7 days after birth). RESULTS: An increased risk of perinatal death was seen in obese [odds ratio (OR) 2.4, 95% CI (confidence interval) 1.7-3.4] and morbidly obese women (OR 3.3, 95% CI 2.1-5.1) as compared with normal weight women. In the group participating in recreational physical activity during pregnancy, obese women had an OR of 3.2 (95% CI 2.2-4.7) for perinatal death relative to non-obese women. In the non-active group the corresponding OR was 1.8 (95% CI 1.1-2.8) for obese women compared with non-obese women. The difference in perinatal mortality risk related to obesity between the active and non-active groups was statistically significant (P-value for interaction = 0.046, multiplicative model). CONCLUSIONS: Maternal obesity was associated with a two- to three-fold increased risk of perinatal death when compared with normal weight. For women with a BMI <30 the lowest perinatal mortality was seen in those performing recreational physical activity at least once a week.

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.

Leisure time physical activity and the risk of pre-eclampsia: a systematic review.

Today, pre-eclampsia (PE) is one of the leading causes of maternal and perinatal morbidity and mortality. It has been proposed that leisure time physical activity (LTPA) is associated with a decreased risk of PE. The objective of this study was to perform a systematic literature review examining the association between LTPA before and/or during pregnancy and the risk of PE. A systematic search of the EMBASE and PUBMED databases from inception to November 17, 2011 was conducted by two independent reviewers. Only studies describing the association between the intensity or amount of LTPA before and/or during pregnancy and the risk of PE were included. A narrative synthesis of the results was undertaken following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A quality assessment was performed using the Newcastle Ottawa Scale. Eleven studies were included. None of the studies found light- or moderate-intensity LTPA to be associated with PE. Three studies reported that vigorous-intensity LTPA before and/or during pregnancy may reduce the risk of PE. One study reported a reduced risk among women who participated in LTPA at least 25 times per month or more than 4 h per week. However, one study found an elevated risk of severe PE with high amounts of LTPA, defined as 4.5 h per week or more. Results are mixed, but high intensity LTPA before and/or during pregnancy or more than 4 h per week of LTPA may reduce the risk of PE. However, an urgent need remains for high-quality studies including different ethnicities to further explore this relationship.

Validation of self-reported recreational exercise in pregnant women in the Norwegian Mother and Child Cohort Study.

We compared the self-reported frequency of recreational exercise and corresponding metabolic equivalent (MET)-minutes with physical activity measured with a position and motion sensor in pregnant women. One hundred and twelve women in the Norwegian Mother and Child Cohort Study (MoBa) completed questions about weekly participation in recreational exercise by week 17 of pregnancy and participated in the validation study around week 20. Data from a validated motion sensor (ActiReg) that measures physical activity and total energy expenditure (TEE) served as the "gold standard." Self-reported recreational exercise was compared with the following ActiReg-based measures: physical activity energy expenditure (PAEE), minutes of vigorous physical activity (VPA), physical activity level (PAL) and TEE. Pearson's correlations between self-reported weekly exercise and the objectively assessed variables were: rPAEE=0.26, rVPA=0.32, rPAL=0.30 (all P<0.01) and rTEE=0.17 (P=0.07). The partial correlation coefficients between the questionnaire responses and the ActiReg measurements were similar after adjusting for parity, body mass index, education, age, height and smoking, but rTEE increased (r=0.27, P<0.01). We observed significant positive associations between self-reported exercise activities and motion sensor measurements of physical activity, indicating that the questions used for exercise assessment in MoBa may be useful for ranking pregnant women according to the recreational exercise level.

Correlates of regular exercise during pregnancy: the Norwegian Mother and Child Cohort Study.

The aims of this study were to describe the level of exercise during pregnancy and to assess factors associated with regular exercise. Using data from the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health, 34 508 pregnancies were included in the present study. Data were collected by self-completed questionnaires in gestational weeks 17 and 30, and analyzed by logistic regression analysis. The results are presented as adjusted odds ratios (aOR) with a 95% confidence interval. The proportion of women exercising regularly was 46.4% before pregnancy and decreased to 28.0 and 20.4% in weeks 17 and 30, respectively. Walking and bicycling were the most frequently reported activities before and during pregnancy. The prevalence of swimming tended to increase from prepregnancy to week 30. Exercising regularly prepregnancy was highly related to regular exercise in week 17, aOR=18.4 (17.1-19.7) and 30, aOR 4.3 (4.1-4.6). Low gestational weight gain was positively associated with regular exercise in week 30, aOR=1.2 (1.1-1.4), whereas being overweight before pregnancy was inversely associated with regular exercise in week 17, aOR=0.8 (0.7-0.8) and 30, aOR=0.7 (0.6-0.7). Also, women experiencing a multiple pregnancy, pelvic girdle pain, or nausea were less likely to exercise regularly.