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Bjørn Backe

Publications and source records attributed to Bjørn Backe.

13 recordsLinked to original sources
PubMed2006

Term prediction with ultrasound: evaluation of a new dating curve for biparietal diameter measurements.

BACKGROUND: In Norway, routine ultrasound examination with assessment of gestational age was included in the standard antenatal care program in 1985. Until presently, a dating chart introduced in 1983 has been used throughout the country. New national normal values are now developed. The aim of the study was to compare the performance of the two sets of normal values; both are based on measurement of fetal biparietal diameter in the second trimester. MATERIAL AND METHOD: We analyzed a cohort of 11,238 singleton deliveries with spontaneous onset of labor. All had reliable last menstrual period and all had a routine ultrasound examination in the second trimester with measurement of fetal biparietal diameter. We calculated the expected day of delivery both according to the old (method A) and the new (method B) reference values. RESULTS: The prediction error (the difference between observed and expected day of delivery) for the last menstrual period method was -0.1 days, for method A -3.5 days, and for method B -0.7 days. The prediction error for method A increased up to 7 days when ultrasound measurements were obtained in gestational week 14-15. CONCLUSION: The old ultrasound method leads to a systematic underestimation of fetal age, and the prediction error increases notably when the ultrasound measurements are performed in the early second trimester. Gestational age is more precisely assessed with the new reference values.

Analysis of Variance↗
PubMed2006

Pregnancy risk increases from 41 weeks of gestation.

BACKGROUND: The aim of this study was to evaluate the mortality and morbidity of conservatively managed post-term pregnancies (gestation 294 days and beyond). MATERIALS AND METHODS: This is a population-based prospective study. The sample was comprised of all women (N=17,493) with a singleton pregnancy in one Norwegian county from 1989 to 1999, with a second-trimester ultrasound examination and delivery after 37 completed gestational weeks. RESULTS: One thousand three hundred and thirty-six (7.6%) of the deliveries were post-term. In this group, the increase in perinatal mortality reached borderline significance [relative risk (RR) 2.0; 95% confidence interval 0.9-4.6]. Perinatal morbidity expressed as Apgar score <7 at 5 min (RR 2.0; 95% confidence interval 1.2-3.3), and transferal to neonatal intensive care unit (RR 1.6; 95% confidence interval 1.3-2.0) were significantly more frequent. However, RR for perinatal death calculated per 1000 ongoing pregnancies increased significantly from 0.2 in week 37-3.7 in week 42, using perinatal mortality in gestational week 41 as a reference. CONCLUSIONS: Our results indicate that expectant management of post-term pregnancies allowing pregnancies to continue up to week 43 carries a risk for perinatal mortality and morbidity. The risk increases already from gestational week 41. The guidelines for management of post-term pregnancies should be revised.

Apgar Score↗
PubMed2005

Routine ultrasound screening and detection of congenital anomalies outside a university setting.

BACKGROUND: To assess the sensitivity for detecting fetal congenital anomalies by a routine ultrasound examination program at midtrimester performed in an unselected population by midwives and specialists in obstetrics and gynecology. METHODS: Six hundred seventy-six of the pregnancies had the midtrimester ultrasound examinations performed outside the county. Three hundred seventeen of the women had midtrimester ultrasound examinations performed in the county, but delivered outside the county. A total of 18 181 pregnancies were eligible for the study. RESULTS: Altogether there were 267 fetuses and newborns with anomalies, which gives a prevalence of 1.5%. One hundred three of the 267 anomalies were detected at the midtrimester ultrasound examination, yielding a sensitivity of 39.0%. There were 11 false positives and 163 remained undiagnosed (false negatives), which gives a specificity of 99.9% and a positive predictive value of 90.4%. The sensitivity for detecting anomalies ranged from 74.4 to 8.3% according to the organ system of the fetus. CONCLUSIONS: Our study shows that midtrimester routine ultrasound examination in district hospitals can achieve a detection rate of congenital anomalies comparable with tertiary centers. One-stage ultrasound examination at midtrimester gives acceptable results concerning congenital anomalies with few false-positive results.

Chromosome Aberrations↗
PubMed2003

[Mifepristone for induction of second trimester abortion].

BACKGROUND: We wanted to assess the effect of changing the regimen for termination from gemeprost to mifepristone and misoprostol. METHOD: The study was prospective from 1994 to 2001 and included 179 women who had a second trimester termination of pregnancy because of fetal malformations. Three different regimens were used: The traditional regimen with vaginal application of gemeprost (77 patients), pretreatment with mifpristone followed by gemeprost (40 patients), and pretreatment with mifepristone followed by misoprostol (62 patients). RESULTS: The induction-to-abortion interval was significantly shorter in the two groups receiving pretreatment with mifepristone than in the group treated solely with gemeprost, on average 9.7 and 9.5 hours compared to 22.7 hours (p < 0.001). All patients who received mifepristone aborted within 24 hours of start of induction, compared to 80 % of patients treated solely with gemeprost. INTERPRETATION: The combination of mifepristone and misoprostol provides a non-invasive and effective regimen for second trimester termination of pregnancy. Pretreatment with mifepristone represents a major improvement. Misoprostol is cheaper than gemeprost, is stored in room temperature, and can be used orally as well as vaginally.

Abortifacient Agents, Nonsteroidal↗
PubMed2003

[The epidemic of Caesarean section: has it reached Norway?].

BACKGROUND: Women's right to decide on the mode of delivery is discussed, as well as the management of term breech deliveries. Obstetric practice may have changed as a consequence of ongoing debates. National caesarean section rates were stable at 12-13% during the 1990s, but no information has been provided about the development over the last two years. MATERIAL AND METHODS: Information about deliveries in obstetrical units in Norway, 1999 to 2002, was extracted from the Norwegian Patient Register. The number of deliveries was validated against information from Statistics Norway. The numbers of caesarean sections in 1999 and 2000 were validated against information from the Medical Birth Registry of Norway. RESULTS: The caesarean section rate increased slightly from 12.8% in 1999 to 13.0% in 2000. In 2001, there was a considerable increase to 14.9%; during the first 8 months of 2002, the rate was 15.1%. The change in practice appeared in the last months of 2000, coinciding with the publication of the term breech trial. However, only about one third of the increase can be attributed to a change in breech delivery. COMMENTS. Caesarean section is the most frequent major surgical procedure performed on hospitalised patients. In times of rapid changes in obstetric practice, monitoring of the development without time delay is called for.

Breech Presentation↗
PubMed2002

[Antenatal care in Norway--many unnecessary check ups].

BACKGROUND: Until recently antenatal care in Norway has been provided solely by general practitioners. In 1995, it was laid down in law that the communities should offer antenatal care provided by midwives in community health centers. The resulting conflict between midwives and disagreeing general practitioners may have led to an increase in the number of antenatal visits. Also, the utilization of midwife-based antenatal care is unknown. MATERIAL AND METHODS: National cross-sectional study including all 54 hospital departments of obstetrics. For all patients number of antenatal visits and parity were recorded. The study included 1,780 women giving birth during the two-week registration period. RESULTS: The mean number of antenatal care visits was 12.0 (range 0-44). The difference between primiparous (mean 12.4) and parous women (mean 11.7) was minor. Midwives provided 44% and doctors 56% of the antenatal visits. A total of 279 women (16%) had not seen a midwife during pregnancy; 3% had only seen a midwife and no doctor. INTERPRETATION: The recommended reduction in the frequency of antenatal visits is not followed up. The proportion of visits performed by midwives is approaching the 50% level suggested in the guidelines for antenatal care.

Cross-Sectional Studies↗
PubMed2002

Adverse obstetric outcome in fetuses that are smaller than expected at second trimester routine ultrasound examination.

BACKGROUND: Adverse obstetric outcome in fetuses that are smaller than expected at second trimester routine ultrasound examination. AIM: To assess the obstetric outcome when the interval between the estimated date of delivery by last menstrual period and the estimated date of delivery by second trimester ultrasound exceeds 14 days. MATERIALS AND METHODS: Population-based prospective cohort study. Included were all women (n = 16 302) with a singleton pregnancy, in one Norwegian county from 1989 to 1999, with a reliable menstrual history and whose second trimester ultrasound examination was conclusive with a 35-60-mm biparietal diameter. RESULTS: Adverse outcome was defined as preterm birth (< 37 weeks), perinatal death, low birthweight (< 2500 g) and small-for-gestational age (< 2 standard deviation). The risk for perinatal death (odds ratio = 2.3), preterm birth (odds ratio = 1.7), low birth weight (odds ratio = 1.5), and small-for-gestational age (odds ratio = 1.5) was highly significantly increased in deliveries where the discrepancy between the two terms was more than 14 days. The increased risk is not explained by differences in parity, maternal age, smoking, fetal malformations, or use of oral contraceptives before pregnancy. CONCLUSION: Fetuses that are smaller than expected at the mid-second trimester ultrasound corresponding to a discrepancy of more than 14 days have an increased risk for adverse obstetric outcome.

Adult↗