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Biomedical subjects

S F Olsen

Publications and source records attributed to S F Olsen.

At least 19 recordsLinked to original sources
PubMed2006

Marine oil, and other prostaglandin precursor, supplementation for pregnancy uncomplicated by pre-eclampsia or intrauterine growth restriction.

BACKGROUND: Population studies have shown that higher intakes of marine foods during pregnancy are associated with longer gestations, higher infant birthweights and a low incidence of pre-eclampsia. It is suggested that the fatty acids of marine foods may be the underlying cause of these associations. OBJECTIVES: To estimate the effects of marine oil, and other prostaglandin precursor, supplementation during pregnancy on the risk of pre-eclampsia, preterm birth, low birthweight and small-for-gestational age. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group Trials Register (December 2005), The Cochrane Central Register of Controlled Trials (The Cochrane Library 2005, Issue 2) and MEDLINE (1966 to April 2005). SELECTION CRITERIA: All randomised trials comparing oral marine oil, or other prostaglandin precursor, supplementation during pregnancy with either placebo or no treatment. Trials were excluded if their aim was to treat women with established pre-eclampsia or suspected intrauterine growth restriction. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion, data extraction and trial quality. MAIN RESULTS: Six trials, involving 2783 women, are included in this review. Three of these were rated as high quality, including the largest trial with 1477 women. Women allocated a marine oil supplement had a mean gestation that was 2.6 days longer than women allocated to placebo or no treatment (weighted mean difference (WMD), 2.55 days, 95% confidence interval (CI) 1.03 to 4.07 days; 3 trials, 1621 women). This was not reflected in a clear difference between the two groups in the relative risk (RR) of birth before 37 completed weeks, although women allocated marine oil did have a lower risk of giving birth before 34 completed weeks' gestation (RR 0.69, 95% CI 0.49 to 0.99; 2 trials, 860 women). Birthweight was slightly greater in infants born to women in the marine oil group compared with control (WMD 47 g, 95% CI 1 g to 93 g; 3 trials, 2440 women). However, there were no overall differences between the groups in the proportion of low birthweight or small-for-gestational age babies. There was no clear difference in the relative risk of pre-eclampsia between the two groups. AUTHORS' CONCLUSIONS: There is not enough evidence to support the routine use of marine oil, or other prostaglandin precursor, supplements during pregnancy to reduce the risk of pre-eclampsia, preterm birth, low birthweight or small-for-gestational age.

Dietary Supplements↗
PubMed2006

Fish oil in various doses or flax oil in pregnancy and timing of spontaneous delivery: a randomised controlled trial.

OBJECTIVES: To test the earlier suggested hypothesis that intake of long-chain n-3 fatty acids from fish oil may delay the timing of spontaneous delivery and to test if alpha-linolenic acid, provided as flax oil capsules, shows the same effect. DESIGN: Randomised controlled trial including women reporting low dietary fish intake. The women were allocated in the proportions of 1:1:1:1:1:1:2 into six treatment groups and a control group, respectively, from week 17-27 of gestation. The treatment groups received fish oil, in various doses, or flax oil, and the control group did not receive any treatment. SETTING: The Danish National Birth Cohort. SAMPLE: A total of 3098 women allocated into six treatment groups and one control group. METHODS: The six intervention groups were offered fish oil capsules in doses of 0.1, 0.3, 0.7, 1.4 and 2.8 g of eicosapentaenoic acid and docosahexaenoic acid per day or 2.2 g of alpha-linolenic acid (ALA) per day from week 17-27 of gestation until delivery. MAIN OUTCOME MEASURES: Timing of spontaneous delivery. RESULTS: No differences in timing of spontaneous delivery was detected in the fish oil groups or the flax oil group, compared with the control group. The difference in timing of spontaneous delivery in the group receiving the highest fish oil dose compared with the control group was 0.8 days (95% CI: -2.3 to 1.0). Only a minority of the women in the intervention groups took capsules until delivery. CONCLUSION: Possible explanations for these findings include no true effect of n-3 fatty acids on spontaneous delivery or a quick-acting effect not detectable in this trial.

Biomarkers↗
PubMed2003

Breastfeeding and allergic disease: a multidisciplinary review of the literature (1966-2001) on the mode of early feeding in infancy and its impact on later atopic manifestations.

BACKGROUND: Strategies to prevent children from developing allergy have been elaborated on the basis of state-of-the-art reviews of the scientific literature regarding pets and allergies, building dampness and health, and building ventilation and health. A similar multidisciplinary review of infant feeding mode in relation to allergy has not been published previously. Here, the objective is to review the scientific literature regarding the impact of early feeding (breast milk and/or cow's milk and/or formula) on development of atopic disease. The work was performed by a multidisciplinary group of Scandinavian researchers. METHODS: The search in the literature identified 4323 articles that contained at least one of the exposure and health effect terms. A total of 4191 articles were excluded mainly because they did not contain information on both exposure and health effects. Consequently, 132 studies have been scrutinized by this review group. RESULTS: Of the 132 studies selected, 56 were regarded as conclusive. Several factors contributed to the exclusions. The studies considered conclusive by the review group were categorized according to population and study design. CONCLUSIONS: The review group concluded that breastfeeding seems to protect from the development of atopic disease. The effect appears even stronger in children with atopic heredity. If breast milk is unavailable or insufficient, extensively hydrolysed formulas are preferable to unhydrolysed or partially hydrolysed formulas in terms of the risk of some atopic manifestations.

Animals↗
PubMed2001

[Does alcohol increase the risk of preterm delivery?].

INTRODUCTION: The aim was to assess the association between alcohol intake during pregnancy and preterm delivery. MATERIALS AND METHODS: Women attending routine antenatal care at Aarhus University Hospital, Denmark, from 1989-1991 and 1992-1996 were eligible for the study. Our analyses included 18,228 singleton pregnancies. We obtained prospective information on alcohol intake at about 16 and 30 weeks of gestation, other lifestyle factors, maternal characteristics, and obstetrical risk factors from questionnaires completed by the women and hospital files. RESULTS: For women with an alcohol intake of 1-2, 3-4, 5-9, and > or = 10 drinks/week, the risk ratio (RR) of preterm delivery was 0.91 (95% CI: 0.76-1.08), 0.86 (0.64-1.15), 0.89 (0.52-1.52), and 2.93 (1.52-5.63) respectively, compared with an intake of < 1 drink/week at about 16 weeks of gestation, and 0.69 (0.56-0.86), 0.82 (0.60-1.13), 0.97 (0.58-1.64), and 3.56 (1.78-7.13) at about 30 weeks. Adjustment for smoking habits, caffeine intake, age, height, prepregnant weight, marital status, occupational status, education, parity, chronic diseases, previous preterm delivery, mode of initiation of labour, and sex of the child did not alter the conclusions, nor did restriction of the highest intake group to women drinking 10-14 drinks/week (RR = 3.41 (1.71-6.81) at 16 weeks and RR = 3.47 (1.64-7.35) at 30 weeks). DISCUSSION: The association between alcohol intake and preterm delivery appeared to be J-shaped, with a threshold for adverse effect at a level of about 10-14 drinks/week.

Alcohol Drinking↗
PubMed2001

Exposure to tobacco smoke in utero and the risk of stillbirth and death in the first year of life.

The authors examined the association between exposure to tobacco smoke in utero and the risk of stillbirth and infant death in a cohort of 25,102 singleton children of pregnant women scheduled to deliver at Aarhus University Hospital, Aarhus, Denmark, from September 1989 to August 1996. Exposure to tobacco smoke in utero was associated with an increased risk of stillbirth (odds ratio = 2.0, 95% confidence interval: 1.4, 2.9), and infant mortality was almost doubled in children born to women who had smoked during pregnancy compared with children of nonsmokers (odds ratio = 1.8, 95% confidence interval: 1.3, 2.6). Among children of women who stopped smoking during the first trimester, stillbirth and infant mortality was comparable with that in children of women who had been nonsmokers from the beginning of pregnancy. Conclusions were not changed after adjustment in a logistic regression model for the sex of the child; parity; or maternal age, height, weight, marital status, years of education, occupational status, and alcohol and caffeine intake during pregnancy. Approximately 25% of all stillbirths and 20% of all infant deaths in a population with 30% pregnant smokers could be avoided if all pregnant smokers stopped smoking by the sixteenth week of gestation.

Denmark↗
PubMed2001

Self reported alcohol intake in pregnancy: comparison between four methods.

STUDY OBJECTIVE: To assess the agreement between four different measures of alcohol intake in pregnancy. DESIGN AND SETTING: Danish speaking pregnant women referred to the Midwife Centre in Aarhus, Denmark, for routine antenatal care were contacted at their first visit at approximately 15-16 weeks gestation from October to December 1998. The women were interviewed about current average alcohol intake and intake within the previous week, and subsequently filled in a two week diary on alcohol intake. When booking for delivery at the end of the first trimester the women were also asked to complete a questionnaire including a one item question on current average alcohol intake. PARTICIPANTS: Participants were 441 pregnant women. MAIN RESULTS: Per cent agreement +/- 1 category ranged between 73 and 82. Mean (SD) intake ranged between 1.09 (1.35) drinks/week for diaries, and 0.69 (0.85) for questionnaires. Mean differences between methods were all close to zero. Three of the four measures yielded comparable distributions of average alcohol intake, but reports of intake within the past seven days seemed to be an inappropriate measure of average intake, yielding three times as many abstainers as expected when combining the methods. CONCLUSIONS: When assessing the distribution of alcohol intake in pregnancy or when studying adverse pregnancy outcomes that are probably caused mainly by sustained exposure it seems that for pregnant women with low to moderate alcohol intake diaries or an average measure from interviews or a simple one item questionnaire may be applied. A measure of intake for the previous week seems to be a relevant measure only when studying adverse pregnancy outcomes that are most probably caused by binge-like exposure.

Adult↗
PubMed2001

The Danish National Birth Cohort--its background, structure and aim.

BACKGROUND: It is well known that the time from conception to early childhood has importance for health conditions that reach into later stages of life. Recent research supports this view, and diseases such as cardiovascular morbidity, cancer, mental illnesses, asthma, and allergy may all have component causes that act early in life. Exposures in this period, which influence fetal growth, cell divisions, and organ functioning, may have long-lasting impact on health and disease susceptibility. METHODS: To investigate these issues the Danish National Birth Cohort (Better health for mother and child) was established. A large cohort of pregnant women with long-term follow-up of the offspring was the obvious choice because many of the exposures of interest cannot be reconstructed with sufficient validity back in time. The study needs to be large, and it is aimed to recruit 100,000 women early in pregnancy, and to continue follow-up for decades. The Nordic countries are better suited for this kind of research than most other countries because of their population-based registers on diseases, demography and social conditions, linkable at the individual level by means of the unique ID-number given to all citizens. Exposure information is mainly collected by computer-assisted telephone interviews with the women twice during pregnancy and when their children are six and 18 months old. Participants are also asked to fill in a self-administered food frequency questionnaire in mid-pregnancy. Furthermore, a biological bank has been set up with blood taken from the mother twice during pregnancy and blood from the umbilical cord taken shortly after birth. Data collection started in 1996 and the project covered all regions in Denmark in 1999. By August 2000. a total of 60,000 pregnant women had been recruited to the study. It is expected that a large number of gene-environmental hypotheses need to be based on case-control analyses within a cohort like this.

Cohort Studies↗
PubMed2000

Does alcohol increase the risk of preterm delivery?

We evaluated the association between alcohol intake during pregnancy and preterm delivery. Women attending routine antenatal care at Aarhus University Hospital, Denmark, from 1989-1991 and 1992-1996 were eligible. We included 18,228 singleton pregnancies in the analyses. We obtained prospective information on alcohol intake at 16 and 30 weeks of gestation, other lifestyle factors, maternal characteristics, and obstetrical risk factors from self-administered questionnaires and hospital files. For women with alcohol intake of 1-2, 3-4, 5-9, and > or =10 drinks/week the risk ratio (RR) of preterm delivery was 0.91 (95% CI = 0.76-1.08), 0.86 (95% CI = 0.64-1.15), 0.89 (95% CI = 0.52-1.52), and 2.93 (95% CI = 1.52-5.63), respectively, compared with intake of <1 drink/week at 16 weeks gestation, and 0.69 (95% CI = 0.56-0.86), 0.82 (95% CI = 0.60-1.13), 0.97 (95% CI = 0.58-1.64), and 3.56 (95% CI = 1.78-7.13) at 30 weeks. Adjustment for smoking habits, caffeine intake, age, height, pre-pregnant weight, marital status, occupational status, education, parity, chronic diseases, previous preterm delivery, mode of initiation of labor, and sex of the child did not change the conclusions, nor did restriction of the highest intake group to women drinking 10-14 drinks/week (RR = 3.41 (1.71-6.81) at 16 weeks and RR = 3.47 (1.64-7.35) at 30 weeks).

Alcohol Drinking↗
PubMed2000

Randomised clinical trials of fish oil supplementation in high risk pregnancies. Fish Oil Trials In Pregnancy (FOTIP) Team.

OBJECTIVE: To test the postulated preventive effects of dietary n-3 fatty acids on pre-term delivery, intrauterine growth retardation, and pregnancy induced hypertension. DESIGN: In six multicentre trials, women with high risk pregnancies were randomly assigned to receive fish oil (Pikasol) or olive oil in identically-looking capsules from around 20 weeks (prophylactic trials) or 33 weeks (therapeutic trials) until delivery. SETTING: Nineteen hospitals in Europe. SAMPLES: Four prophylactic trials enrolled 232, 280, and 386 women who had experienced previous pre-term delivery, intrauterine growth retardation, or pregnancy induced hypertension respectively, and 579 with twin pregnancies. Two therapeutic trials enrolled 79 women with threatening pre-eclampsia and 63 with suspected intrauterine growth retardation. INTERVENTIONS: The fish oil provided 2.7 g and 6.1 g n-3 fatty acids/day in the prophylactic and therapeutic trials, respectively. MAIN OUTCOME MEASURES: Preterm delivery, intrauterine growth retardation, pregnancy induced hypertension. RESULTS: Fish oil reduced recurrence risk of pre-term delivery from 33% to 21% (odds ratio 0.54 (95% CI 0.30 to 0.98)) but did not affect recurrence risks for the other outcomes (OR 1.26; 0.74 to 2.12 and 0.98; 0.63 to 1.53, respectively). In twin pregnancies, the risks for all three outcomes were similar in the two intervention arms (95% CI for the three odds ratios were 0.73 to 1.40, 0.90 to 1.52, and 0.83 to 2.32, respectively). The therapeutic trials detected no significant effects on pre-defined outcomes. In the combined trials, fish oil delayed spontaneous delivery (proportional hazards ratio 1.22; 1.07 to 1.39, P = 0.002). CONCLUSIONS: Fish oil supplementation reduced the recurrence risk of pre-term delivery, but had no effect on pre-term delivery in twin pregnancies. Fish oil had no effect on intrauterine growth retardation and pregnancy induced hypertension, affecting neither recurrence risk nor risk in twin pregnancies.

Delivery, Obstetric↗
PubMed2000

A prospective study of smoking during pregnancy and SIDS.

AIMS: To study the association between smoking during pregnancy and sudden infant death syndrome (SIDS) using prospectively collected data, making it possible to account for a number of potential confounders. DESIGN: Prospective follow up study (n = 24 986). RESULTS: The overall rate of SIDS was 0.80 per 1000 live births (n = 20). Children of smokers had more than three times the risk of SIDS compared with children of non-smokers (OR = 3.5; 95% CI 1.4-8.7), and the risk of SIDS increased with the number of cigarettes smoked per day (p < 0.05). Adjustment for parity, alcohol, and caffeine intake during pregnancy, maternal height and weight before pregnancy, years of school, occupational status, marital status, and number of antenatal care visits did not change the results. Adjustment for mother's age marginally reduced the risk of SIDS associated with smoking (OR = 3.0; 95% CI 1.2-7.3). CONCLUSIONS: Given the prospective nature of the study, the number of deaths is small; however, if our results reflect a true association between smoking during pregnancy and SIDS, approximately 30-40% of all cases of SIDS could be avoided if all pregnant women stopped smoking in a population with 30% pregnant smokers. Our study adds to earlier evidence for an association between smoking during pregnancy and SIDS. The strengths of the study are the possibility to adjust for a number of potential confounders and the fact that information about smoking habits during pregnancy was prospectively collected.

Adolescent↗
PubMed2000

Perinatal deaths in the Faroe Islands during 1986-95.

OBJECTIVE: To examine causes of perinatal mortality in the Faroe Islands, where it has been increased compared to other Nordic societies. METHOD: Cases were classified according to a fetal/obstetric, a fetal/neonatal, and a fetal/obstetric/neonatal classification (classifications C1, C2, and C3, respectively). SETTING: The Faroe Islands 1986-1995; as reference materials were used a) the preceding decade in the Faroes and b) a parallel period in Denmark. SUBJECTS: We examined all available information regarding each case from hospital records, midwife records, birth certificates, death certificates and autopsy records. RESULTS: The perinatal mortality was 10.3 per 1,000 total births (83/8,096) compared with 13.7 (102/7,458) in the preceding decade; the fall could be attributed to fewer cases with preeclampsia, antepartum bleedings (C1) and antepartum asphyxia (C2) and the number fell despite an increased occurrence of cases attributed to congenital malformations. Perinatal mortality in Denmark was 8.3 (4,574/550,971), where rates were lower of cases with congenital malformations and fetoplacental dysfunction, but where the rate was higher of cases related to preterm birth (C3). CONCLUSIONS: Although the perinatal mortality rate still is higher in the Faroes than Denmark, the rate had fallen in the Faroes from 1976-85 to 1986-1995. The fall was mainly due to fewer cases attributable to antepartum asphyxia, preeclampsia, antepartum bleedings, and hyaline membrane disease, a pattern compatible with a more efficient perinatal service in the Faroes in the latter period.

Birth Certificates↗