BACKGROUND: Thus far, few factors with a causal relation to preterm birth have been identified. Many studies have focused on the woman's diet, but most have been discouraging. The aim of the present study was to examine if maternal intake of a Mediterranean-type diet (MD) is associated with reduced risk of preterm birth. METHODS: The Danish National Birth Cohort assessed diet in mid-pregnancy by food frequency questionnaires (FFQ). Women consuming MD were those who ate fish twice a week or more, used olive or rape seed oil, consumed 5+ fruits and vegetables a day, ate meat (other than poultry and fish) at most twice a week, and drank at most 2 cups of coffee a day. RESULTS: Of 35,530 non-smoking women, 1,137 (3.2%) fulfilled all MD criteria, and 540 (1.5%) none. Odds ratios for preterm birth and early preterm birth were 0.61 (95% Confidence Interval (CI): 0.35-1.05) and 0.28 (0.11-0.76), respectively, in MD women compared to women fulfilling none of the MD criteria. CONCLUSION: Shifting towards a MD during pregnancy may reduce the risk of early delivery in Danish women.
OBJECTIVE: To examine whether fruit and vegetable consumption in pregnancy is associated with birth weight in a Western population. DESIGN: Prospective cohort study based on telephone interviews, a food frequency questionnaire (FFQ), and extractions of birth characteristics from national health registries. SUBJECTS AND SETTING: The 43,585 Danish women from the Danish National Birth Cohort who had completed the FFQ in mid-pregnancy and on whom information about birth outcome was available. The exposures were frequency of green leafy vegetable (GLV) intake and quantified intake of fruit, fruit and vegetables, and fruit and vegetables and juice. The outcomes were birth weight and z-score for expected birth weight adjusted for sex and gestation week. Information on maternal height, weight, smoking, and other potential confounders was obtained through telephone interviews. RESULTS: Significant associations were found for all exposures to fruit and vegetable intake with birth weight and most with z-score. The strongest association was found for fruit intake in which case birth weight increased by 10.7 g (95% CI 7.3-14.2) per quintile. All associations were stronger among lean women (BMI
The timing and frequency of periconceptional multivitamin use may be related to the risk of preeclampsia. Women in the Danish National Birth Cohort (1997-2003) reported multivitamin or folate-only supplement use during a 12-week periconceptional period (from 4 weeks prior to 8 weeks after the last menstrual period). Preeclampsia cases were identified by using International Classification of Diseases, Tenth Revision, codes. Cox regression was used to estimate the association of frequency (weeks of use) and timing (preconception and postconception) of use with preeclampsia risk. Overall, there were 668 cases of preeclampsia (2.3%), and 18,551 women (65%) reported periconceptional multivitamin use. After adjustment, regular use (12 of 12 weeks) was related to a reduced risk of preeclampsia among normal-weight women. Compared with nonusers with a body mass index of 22 kg/m(2), regular multivitamin users with the same body mass index had a 20% reduced risk of preeclampisa (hazard ratio = 0.78, 95% confidence interval: 0.60, 0.99). In addition, regular use in the postconception period only was associated with reduced risk, a relation that also appeared to be limited to women with a body mass index of
BACKGROUND: Few studies have examined the overall effect of maternal fish intake during pregnancy on child development or examined whether the developmental benefits of maternal fish intake are greater in infants breastfed for a shorter duration. OBJECTIVE: We aimed to study associations of maternal prenatal fish intake and breastfeeding duration with child developmental milestones. DESIGN: We studied 25 446 children born to mothers participating in the Danish National Birth Cohort, a prospective population-based cohort study including pregnant women enrolled between 1997 and 2002. Mothers reported child development by a standardized interview, which we used to generate developmental scores at ages 6 and 18 mo. We used multivariate cumulative ordinal logistic regression to evaluate the odds of higher developmental scores associated with maternal fish intake and breastfeeding, after adjustment for child age, sex, and growth; maternal size and pregnancy characteristics; and parental education and social status. RESULTS: Higher maternal fish intake and greater duration of breastfeeding were associated with higher child developmental scores at 18 mo [odds ratio: 1.29 (95% CI: 1.20, 1.38) for the highest versus the lowest quintile of fish intake, and 1.28 (1.18, 1.38) for breastfeeding for > or =10 mo compared with breastfeeding for
This study investigated the association between dietary variables and plasma levels of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) among 1076 pregnant women. Diet was assessed at midpregnancy by a food-frequency questionnaire. Mean first trimester plasma PFOS and PFOA levels were 35.1 and 5.6 ng/mL respectively. PFOS levels were positively associated (p or =75th percentile) vegetable intake and women reporting low vegetable and high red meat intake resulted in differences in plasma PFOS and PFOA concentrations equal to 31% and 18% of mean levels, respectively. Studies quantifying levels of perfluorinated compounds in food have suggested that diet could be an important route of human exposure. The observed associations in our study between dietary variables and maternal exposure further support that conclusion.
We examined the association between exposure to seafood intake during two periods of pregnancy on the one hand and risks of preterm delivery and postterm delivery on the other. In a prospective cohort of 8729 pregnant Danish women, we assessed frequency of fish meals during the first and second trimester of pregnancy by questionnaires completed around gestation weeks 16 and 30, respectively. When fish intake was based solely on intake reported for the early period of pregnancy, mean gestation length was shorter by 3.91 (95% CI: 2.24-5.58) days and odds of preterm delivery were increased 2.38 (1.23-4.61) times in those who never consumed fish (n = 308) vs. those who consumed both fish as main meal and fish in sandwiches at least once per week (n = 785). These measures were similar when fish intake was based solely on intake reported for mid-pregnancy. In the subgroup of women reporting same intake in the two trimesters, those who never consumed fish (n = 165) had 8.57 (5.46-11.7) days shorter mean gestation and 19.6 (2.32-165) times increased odds of preterm delivery, compared to high fish consumers (n = 127); odds of elective and postterm delivery were reduced by a factor 0.33 (0.11-1.02) and 0.34 (0.12-0.95), respectively, in zero fish consumers. All analyses were adjusted for potential confounding by factors such as maternal smoking, height, and prepregnant weight. We conclude that never consuming fish in the first two trimesters of pregnancy was an extremely strong risk factor for preterm delivery but was also associated with reduced risks of elective delivery and postterm delivery.
BACKGROUND: Atopic dermatitis has been related to a disturbed metabolism of polyunsaturated fatty acids (PUFAs). OBJECTIVE: We tested whether the PUFA composition of breast milk differs significantly between mothers with atopic dermatitis, mothers with other types of atopy, and nonatopic mothers. We also investigated whether differences in diet can explain possible observed differences. DESIGN: Mothers with current or previous asthma (n = 396) were divided into 3 groups according to history of atopic dermatitis and allergic rhinitis. Breast-milk samples were collected from 314 women approximately 3 wk after delivery. The habitual diet of the women was assessed with food-frequency questionnaires in the 25th week of gestation (n = 207). Breast-milk samples and simultaneous dietary data from 14 nonatopic mothers were used for comparison. RESULTS: Compared with the milk of nonatopic mothers, that of atopic mothers had significantly higher concentrations of 22:5n-6 and lower concentrations of 20:5n-3; moreover, 20:4n-6/20:5n-3, 22:5n-6/22:6n-3, and long-chain n-3 PUFA/18:3n-3 were shifted toward n-6 PUFA and 18:3n-3 in nonatopic and atopic mothers, respectively. No differences in breast-milk PUFA composition were evident between the subject groups. The diets of the groups differed only slightly with respect to protein intake. However, the PUFA composition of the breast milk was associated with diet and time of milk sampling, and the above difference in milk PUFAs disappeared when those factors were taken into account. CONCLUSION: Our data do not support the possibility that the fatty acid composition of breast milk is affected by atopic dermatitis or atopy in general, because most differences in breast-milk PUFA composition appear to be explained by the diet.
BACKGROUND: Mothers may be reluctant to receive medical treatment of postpartum depression (PPD), despite the detrimental consequences the disorder can impose on mother and child. Research on alternative methods of prevention and treatment of PPD is warranted. Previous studies have suggested that long-chain n-3 polyunsaturated fatty acids (PUFAs) might have a beneficial effect on depression. OBJECTIVE: The objective was to explore the association between intake of fish and n-3 PUFAs during pregnancy and PPD in the Danish National Birth Cohort (DNBC). DESIGN: Exposure information from the DNBC was linked to the Danish patient and prescription registries for data on clinically identified cases of depression up to 1 y postpartum. Intake of fish and n-3 PUFAs was assessed in midpregnancy with a food-frequency questionnaire. Admission to the hospital for PPD (PPD-admission) and prescription of antidepressants (PPD-prescription) were treated as separate outcomes. A total of 54,202 women were included in the present study sample. RESULTS: Rates of depression were 0.3% (PPD-admission) and 1.6% (PPD-prescription). No association was observed between fish intake and risk of PPD-admission [crude odds ratio of 1.01 (95% CI: 0.52, 1.97) and adjusted odds ratio of 0.82 (95% CI: 0.42, 1.64)], whereas a higher risk of PPD-prescription was found for the lowest compared with the highest fish intake group [crude odds ratio of 1.61 (95% CI: 1.26, 2.06) and adjusted odds ratio of 1.46 (95% CI: 1.12, 1.90)]. No association was observed with respect to n-3 PUFA intake. CONCLUSION: Overall, our data from a large prospective cohort linked with high-quality registers showed little evidence to support an association between intake of fish or n-3 PUFAs and PPD.
Evidence from controlled trials suggests that ingestion of 0.4 mg of folic acid per day in the periconceptional period is effective in preventing neural tube defects (NTD). For this reason, most countries recommend that women planning pregnancy take folic acid supplements in the periconceptional period, and some countries even fortify stable foods with folic acid. Denmark exemplifies a country with a relatively conservative attitude with respect to taking action in these matters. In 1999, a national information campaign was launched that recommended women planning pregnancy take 0.4 mg of folic acid periconceptionally, but with the moderation that women who eat a healthy diet do not need to take folic acid supplement. The campaign was repeated during 2001. The results of the latter campaign were evaluated by using data from a national survey among pregnant women conducted simultaneously with the campaign by the Danish National Birth Cohort. An increase in the proportion of folic acid users took place concomitantly with the launching of the information events, but the increase was limited. Among women who did not plan their pregnancy, a small proportion had taken folic acid supplements periconceptionally, and this proportion did not change concomitantly with the campaign. Young age and low education were factors associated with low likelihood of taking folic acid. It seems that different and more efficient actions are needed if a more substantial proportion of Danish women and their fetuses are going to benefit from the knowledge that folic acid supplementation in the periconceptional period can prevent NTD.
OBJECTIVES: To evaluate compliance with the national recommendation on supplemental iron to all pregnant women in Denmark and to explore differences between compliers and non-compliers with respect to dietary habits and other lifestyle factors. DESIGN: Intake of supplemental iron from pure iron supplements and from multivitamin and mineral preparations was estimated in mid-pregnancy. SETTING: Nationwide cohort study, the Danish National Birth Cohort (DNBC), comprising more than 100,000 women recruited in early pregnancy. SUBJECTS: Information on diet and dietary supplements was available for 54,371 women. Of these, information on lifestyle factors was available for 50,902 women. RESULTS: A high compliance with the recommendation was found, as approximately 77% of the women reported use of iron supplements during pregnancy. However, many of the compliers did not obtain the recommended doses of iron, which can partly be explained by the lack of iron preparations of appropriate doses available on the Danish market. Compliance with the recommendation was associated with age above 20 years, primiparity, body mass index