Preeclampsia by maternal reasons for immigration: a population-based study.

BACKGROUND: To investigate whether the occurrence of preeclampsia varied by maternal reasons for immigration. METHODS: We included 1,287,270 singleton pregnancies (163,508 to immigrant women) in Norway during 1990-2013. Individual data were obtained through record linkage between the Medical Birth Registry of Norway and Statistics Norway. Analyses were performed for preeclampsia overall and in combination with preterm birth < 37 and < 34 weeks of gestation, referred to as preterm and very preterm preeclampsia. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using logistic regression with robust standard errors, adjusted for relevant covariates, including maternal income and education. RESULTS: Preeclampsia was reported in 3.5% of Norwegian women and 2.5% of immigrants. Compared with Norwegian women, the adjusted OR for preeclampsia was lowest in labour immigrants (adjusted OR 0.55 [95% CI 0.49-0.62]), followed by family immigrants (0.62 [0.59-0.65]), immigrant students (0.75 [0.65-0.86]), refugees (0.81 [0.75-0.88]), and immigrants from other Nordic countries (0.87 [0.80-0.94]). Compared with Norwegian women, labour immigrants also had lower adjusted odds of preterm and very preterm preeclampsia, whereas refugees had increased adjusted odds of preterm and very preterm preeclampsia (< 37 weeks: 1.18 [1.02-1.36], and < 34 weeks: 1.41 [1.15-1.72]). CONCLUSIONS: The occurrence of preeclampsia was lower overall in immigrants than in non-immigrants, but associations varied by maternal reasons for immigration. Maternity caregivers should pay increased attention to pregnant women with refugee backgrounds due to their excess odds of preterm preeclampsia.

Folic acid and multivitamin supplement use and risk of placental abruption: a population-based registry study.

The authors investigated a possible association of supplemental folic acid and multivitamin use with placental abruption by using data on 280,127 singleton deliveries recorded in 1999-2004 in the population-based Medical Birth Registry of Norway. Odds ratios, adjusted for maternal age, marital status, parity, smoking, pregestational diabetes, and chronic hypertension, were estimated with generalized estimating equations for logistic regression models. Use of folic acid and/or multivitamin supplements before or any time during pregnancy was reported for 36.4% of the abruptions (0.38% of deliveries) and 44.4% of the nonabruptions. Compared with no use, any supplement use was associated with a 26% risk reduction of placental abruption (adjusted odds ratio = 0.74, 95% confidence interval: 0.65, 0.84). Women who had taken folic acid alone had an adjusted odds ratio of 0.81 (95% confidence interval: 0.68, 0.98) for abruption, whereas multivitamin users had an adjusted odds ratio of 0.72 (95% confidence interval: 0.57, 0.91), relative to supplement nonusers. The strongest risk reduction was found for those who had taken both folic acid and multivitamin supplements (adjusted odds ratio = 0.68, 95% confidence interval: 0.56, 0.83). These data suggest that folic acid and other vitamin supplementation during pregnancy may be associated with reduced risk of placental abruption.

Norwegian midwives and doctors have increased cesarean section rates.

BACKGROUND: Increasing cesarean section (CS) rates over the last 3 decades may, in part, be explained by improved obstetric procedures, but socio-economic factors also play a major role. Much attention has been given to professionals' attitudes to operative delivery, and several studies have been performed to clarify the issue. The present study explored CS rates among Norwegian doctors and midwives, compared to other professionals with an education of 17-18 years (doctors) and 15-16 years (midwives). METHODS: Data on mode of delivery notified to the Medical Birth Registry of Norway for 1969-1998 (n=1,733,665) were linked with data on formal education from Statistics Norway. CS rates and crude and adjusted odds ratios (ORs) were calculated for the observation period. RESULTS: Female doctors and midwives had higher CS rates; the crude ORs were 1.18 (95% CI: 1.12-1.28) for doctors, and 1.35 (95% CI: 1.21-1.49) for midwives. Adjusted for age and birth order, the ORs were 1.22 (95% CI: 1.12-1.33) for doctors and 1.14 (95% CI: 1.03-1.27) for midwives. CONCLUSION: From 1969 to 1998, Norwegian female doctors and midwives had higher CS rates than other professionals with an education of comparable duration.

A validation of the diagnosis of obstetric sphincter tears in two Norwegian databases, the Medical Birth Registry and the Patient Administration System.

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.