Randomised controlled trial of effect of fish-oil supplementation on pregnancy duration

American gastroenterological association institute technical review on the use of gastrointestinal medications in pregnancy

This literature review and the recommendations therein were prepared for the American Gastroenterological Association Institute Clinical Practice and Economics Committee. The paper was approved by the Committee on February 22, 2006 and by the AGA Institute Governing Board on April 20, 2006.

Effect of n-3 long-chain polyunsaturated fatty acid supplementation of women with low-risk pregnancies on pregnancy outcomes and growth measures at birth: a meta-analysis of randomized controlled trials

BACKGROUND

It is hypothesized that the intake of long-chain polyunsaturated fatty acids (LC-PUFAs) throughout pregnancy is important to maternal health and fetal and infant development.

OBJECTIVE

The objective was to evaluate systematically the effect of LC-PUFA supplementation of pregnant women's diets on pregnancy outcomes and growth measures at birth.

DESIGN

We searched MEDLINE, EMBASE, CINAHL, and the Cochrane Library through August 2005 and also searched the references in reviewed articles for randomized controlled trials (RCTs) comparing LC-PUFA supplementation with placebo or no supplementation.

RESULTS

Of 6 included RCTs, only 1 was judged to be at low risk of bias. Supplementation with n-3 LC-PUFAs in these 6 RCTs (1278 infants) was associated with a significantly greater length of pregnancy [weighted mean difference (WMD): 1.57 d; 95% CI: 0.35, 2.78 d; findings stable on sensitivity analysis] than in control subjects. We found no evidence that supplementation influenced the percentage of preterm deliveries, the rate of low-birth-weight infants, or the rate of preeclampsia or eclampsia. We found no significant difference in the 6 RCTs (1278 infants) in birth weight (WMD: 54 g; 95% CI: -3.1, 111 g) and no significant difference in 5 RCTs (1262 infants) in birth length (WMD: 0.23 cm; 95% CI: -0.04, 0.5 cm), but, in 4 RCTs (729 infants), there was a significant increase in head circumference (WMD: 0.26 cm; 95% CI: 0.02, 0.49 cm; significance was lost on sensitivity analysis).

CONCLUSIONS

n-3 LC-PUFA supplementation during pregnancy may enhance pregnancy duration and head circumference, but the mean effect size is small. The implications of these findings for later growth and development remain to be elucidated.

Effects of n-3 fatty acids during pregnancy and lactation

n-3 Fatty acids exert important effects on eicosanoid metabolism, membrane properties, and gene expression and therefore are biologically important nutrients. One n-3 fatty acid, docosahexaenoic acid, is an important component of neural and retinal membranes and accumulates rapidly in the brain and retina during the later part of gestation and early postnatal life. It is reasonable to hypothesize that maternal n-3 fatty acid intakes might have significant effects on several pregnancy outcomes as well as on subsequent infant visual function and neurodevelopmental status. Studies, both observational and interventional, assessing the influence of n-3 fatty acids during pregnancy or the early postpartum period on duration of gestation and infant size at birth, preeclampsia, depression, and infant visual function and neurodevelopment have been reported. n-3 Fatty acid intakes (both in terms of absolute amounts of docosahexaenoic acid and eicosapentaenoic acid and the ratio of these 2 fatty acids) varied widely in these studies, however, and no clear consensus exists regarding the effects of n-3 fatty acids on any of these outcomes. The available data suggest a modest effect of these fatty acids on increasing gestational duration and possibly enhancing infant neurodevelopment. Although data from earlier observational studies suggested a potential role of these fatty acids in decreasing the incidence of preeclampsia, this has not been confirmed in randomized, prospective trials. Because of the paucity of data from randomized, prospective, double-blind trials, the effect of n-3 fatty acids on depression during pregnancy or the early postpartum period remains unresolved.

Maternal folic acid supplementation to dams on marginal protein level alters brain fatty acid levels of their adult offspring

Studies on fetal programming of adult diseases have highlighted the importance of maternal nutrition during pregnancy. Folic acid and long-chain essential polyunsaturated fatty acids (LC-PUFAs) have independent effects on fetal growth. However, folic acid effects may also involve alteration of LC-PUFA metabolism. Because marginal deficiency of LC-PUFAs during critical periods of brain growth and development is associated with risks for adult diseases, it is highly relevant to investigate how maternal supplementation of such nutrients can alter brain fatty acid levels. We examined the impact of folic acid supplementation, conventionally used in maternal intervention, on brain essential fatty acid levels and plasma corticosterone concentrations in adult offspring at 11 months of age. Pregnant female rats from 4 groups (6 in each) were fed with casein diets either with 18 g protein/100 g diet (control diet) or treatment diets that were marginal in protein (MP), such as 12 g protein/100 g diet supplemented with 8 mg folic acid (FAS/MP), 12 g protein/100 g diet without folic acid (FAD/MP), or 12 g protein/100 g diet (MP) with 2 mg folic acid. Pups were weaned to a standard laboratory diet with 18 g protein/100 g diet. All male adult offspring in the FAS/MP group showed lower docosahexaenoic acid (P<.05) as compared with control adult offspring (6.04+/-2.28 vs 10.33+/-0.86 g/100 g fatty acids) and higher n-6/n-3 ratio (P<.05). Docosahexaenoic acid levels in FAS/MP adult offspring were also lower (P<.05) when compared with the MP group. Plasma corticosterone concentrations were higher (P<.05) in male adult offspring from the FAS/MP group compared with control as well as the MP adult offspring. Results suggest that maternal folic acid supplementation at MP intake decreased brain docosahexaenoic acid levels probably involving corticosterone increase.

General obstetrics: 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.

Differential Effects of n-3 and n-6 Fatty Acids on Prostaglandin F2 Production by Bovine Endometrial Cells

Recent studies have implicated n-3 polyunsaturated fatty acids in the reduction of eicosanoid production in the bovine uterus. The objective of this study was to determine whether the effect of eicosapentaenoic acid (EPA; C(20:5), n-3) on PGF2alpha production by bovine endometrial (BEND) cells is influenced by the quantity of linoleic acid (C(18:2), n-6) in the incubation medium. Confluent BEND cells were incubated in the absence (control) or presence of 100 microM of EPA for 24 h. After incubation, cells were rinsed and then stimulated with phorbol 12,13-dibutyrate (PDBu; 100 ng/mL) for 6 h. Additional sets of culture dishes were treated with a combination of EPA and increasing n-6/n-3 fatty acid ratios for 24 h and then challenged with PDBu for 6 h. The PDBu stimulated PGF2alpha secretion and upregulated steady-state concentrations of prostaglandin endoperoxide synthase-2 and peroxisome proliferator-activated receptor delta mRNA within 6 h. Preincubation of BEND cells with EPA for 24 h decreased PGF2alpha response to phorbol ester, but had no detectable effects on prostaglandin endoperoxide synthase-2 or peroxisome proliferator-activated receptor delta mRNA abundance in PDBu-stimulated BEND cells. The inhibitory effect of EPA on PGF2alpha production was reverted in BEND cells treated with an increasing n-6-to-n-3 fatty acid ratio. Findings indicate that the net inhibition of endometrial PGF2alpha bioynthesis by n-3 fatty acids may vary depending on the ratio of n-6 to n-3 fatty acids in the uterus.

An open trial of Omega-3 fatty acids for depression in pregnancy

OBJECTIVE

In this flexible-dose, open-label trial, we examined the efficacy of omega-3 fatty acids for the treatment of depression during pregnancy.

METHODS

Fifteen pregnant women with major depressive episodes participated. Subjects initially received two capsules per day [0.93 g of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)]; the dose could be increased by one capsule per day every 2 weeks to a maximal dose of 2.8 g. Subjects were assessed with the Edinburgh Postnatal Depression Scale (EPDS) and Hamilton Rating Scale for Depression (HRSD).

RESULTS

Average duration of participation in this treatment trial was 8.3 weeks (SD ± 7.1). Average final dose of EPA + DHA in this flexible dose trial was 1.9 g per day (±0.5). The mean reduction in EPDS scores was 40.9% (SD ± 21.9); the mean decrease in HRSD score was 34.1% (SD ± 27.1).

CONCLUSIONS

This open trial provides data to support the need for randomized controlled dose-finding trials of omega-3 fatty acids in major depressive episodes during pregnancy.

Changes in dietary intake from the first to the second trimester of pregnancy

Maternal diet may influence outcomes of pregnancy and childhood. Diet in the first trimester may be more important to development and differentiation of various organs, whereas diet later in pregnancy may be important for overall fetal growth as well as for brain development. To our knowledge, no studies have examined individual-level changes in food and nutrient intake from the 1st to 2nd trimester of pregnancy. The objective of this study was to examine changes in dietary intake from the 1st to 2nd trimester of pregnancy. As part of the ongoing US prospective cohort study, Project Viva, we studied 1543 women who completed food-frequency questionnaires that assessed dietary intakes during the 1st and 2nd trimester of pregnancy. For both foods and energy-adjusted nutrients, we examined changes in dietary intake from 1st to 2nd trimester. Reported mean energy intake was similar for the 1st (2046 kcal) and 2nd (2137 kcal) trimesters. Foods and energy-adjusted nutrients from foods whose overall mean intakes increased more than 5% from 1st to 2nd trimester were skim or 1% dairy foods (22%), whole-fat dairy foods (15%), red and processed meat (11%), saturated fat (6%) and vitamin D (7%). Intake of caffeinated beverages (-30%) and alcoholic beverages (-88%) decreased more than 5%. Because mean multivitamin intake increased by 35% from the 1st to 2nd trimester, total micronutrient intake increased appreciably more than micronutrient intake from foods only. Correlations across trimesters ranged from 0.32 for vitamin B12 to 0.68 for fruit and vegetables. In conclusion, for many outcomes of pregnancy and childhood, the incremental information obtained from assessing complete diet in both early and late pregnancy may not outweigh the burden to participants and investigators. However, investigators should assess caffeine, alcohol, and vitamin and supplement use in both the 1st and 2nd trimester, and consider doing so for foods and nutrients for which trimester-specific hypotheses are well substantiated.

Randomized dose-ranging pilot trial of omega-3 fatty acids for postpartum depression

OBJECTIVE

Postpartum depression (PPD) affects 10-15% of mothers. Omega-3 fatty acids are an intriguing potential treatment for PPD.

METHOD

The efficacy of omega-3 fatty acids for PPD was assessed in an 8-week dose-ranging trial. Subjects were randomized to 0.5 g/day (n = 6), 1.4 g/day (n = 3), or 2.8 g/day (n = 7).

RESULTS

Across groups, pretreatment Edinburgh Postnatal Depression Scale (EPDS) and Hamilton Rating Scale for Depression (HRSD) mean scores were 18.1 and 19.1 respectively; post-treatment mean scores were 9.3 and 10.0. Percent decreases on the EPDS and HRSD were 51.5% and 48.8%, respectively; changes from baseline were significant within each group and when combining groups. Groups did not significantly differ in pre- or post-test scores, or change in scores. The treatment was well tolerated.

CONCLUSION

This study was limited by small sample size and lack of placebo group. However, these results support further study of omega-3 fatty acids as a treatment for PPD.

Effect of a cholesterol-lowering diet on maternal, cord, and neonatal lipids, and pregnancy outcome: a randomized clinical trial

OBJECTIVE

We assessed the effect of a cholesterol-lowering diet on maternal, cord, and neonatal plasma lipids and pregnancy outcome.

STUDY DESIGN

Nonsmoking white women with singleton pregnancies (n = 290), aged 21 to 38 years, and with no previous pregnancy-related complications, were randomized to either continue their usual diet or to adopt a diet that promoted fish, low-fat meats and dairy products, oils, whole grains, fruits, vegetables, and legumes from gestational week 17 to 20 to birth.

RESULTS

Maternal total and low-density lipoprotein cholesterol levels were lowered in the intervention compared with the control group (P < .01). Lipid levels in cord blood and in neonates born to mothers in the intervention versus the control groups did not differ. In the intention-to-treat cohort 1 (0.7%) of 141 women in the intervention group versus 11 (7.4%) of 149 women in the control group delivered before 37 weeks (RR 0.10; 95% CI 0.01-0.77). The incidence of other pregnancy complications and birth weight was similar in both groups.

CONCLUSION

A cholesterol-lowering diet may modify maternal lipid levels but not cord and neonatal lipids. The marked observed effect of this diet on the reduction of preterm delivery in low-risk pregnancies should encourage future larger studies to clarify the role of such a diet in the prevention of preterm birth.

Gestational age and birth weight in relation to n-3 fatty acids among Inuit (Canada)

Seafood consumption during pregnancy carries both benefits (high n-3 FA intake) and risks (exposure to environmental contaminants) for the developing fetus. We determined the impacts of marine n-3 FA and environmental contaminants on gestational age (GA) of Nunavik women and the anthropometric characteristics of their newborns. FA and contaminant (polychlorinated biphenyls and mercury) concentrations were measured in cord plasma of Nunavik newborns (n = 454) and compared with those of a group of newborns (n = 29) from southern Québec. Data were collected from hospital records and birth certificates. In Nunavik newborns, arachidonic acid (AA) was two times lower (P < 0.0001), whereas DHA concentration, the sigman-3 / sigman-6 ratio, and the percentage of n-3 highly unsaturated FA (HUFA) (of the total HUFA) were three times higher (P < 0.0001) compared with southern Québec newborns. After controlling for confounders, GA and birth weight were higher by 5.4 d [95% confidence interval (CI): 0.7-10.1] and 77 g (95% CI: -64 to 217) in the third tertile of percentage of n-3 HUFA (of the total HUFA) as compared with the first tertile. There was no evidence that contaminants had negative effects on GA or birth weight. In this seafood-eating population, an increase in the proportion of n-3 HUFA (of the total HUFA), measured in umbilical cord plasma phospholipids, was associated with a significantly longer GA.

A randomized controlled trial of the effect of fish oil supplementation in late pregnancy and early lactation on the n-3 fatty acid content in human breast milk

The aim of this research was to investigate the effect of fish oil supplementation, in the third trimester of pregnancy and early lactation period of healthy pregnant Danish women. Forty-four pregnant women were randomly allocated to fish oil supplementation (1.3 g EPA and 0.9 g DHA per day) from week 30 of gestation (FO-group) or to a control regimen (olive oil or no oil; controls). The FO-group was randomly subdivided into women stopping fish oil supplementation at delivery IFO(pregn)], and women continuing supplementation for an additional 30 d [FO(pregn/lact)]. Thirty-six women agreed to collect milk samples at days 4, 16, and 30 postpartum. The FA composition of the milk samples was determined by GLC. At days 4, 16, and 30 in lactation, FO(pregn/lact) women (n = 12) had, respectively 2.3 (P = 0.001), 4.1 (P = 0.001), and 3.3 (P = 0.001) times higher mean contents of LCPUFA(n-3) in their breast milk compared with controls (n = 13), and 1.7 (P = 0.005), 2.8 (P = 0.001), and 2.8 (P = 0.001) times higher LCPUFA(n-3) contents, respectively, at these days compared with FO(pregn) women (n = 11). The latter group did not differ significantly from controls with regard to LCPUFA(n-3) content in the breast milk. Similar results were obtained when analyzing separately for effects on the milk content of DHA. Dietary supplementation with 2.7 g LCPUFA(n-3) per day from week 30 of gestation and onward more than tripled the LCPUFA(n-3) content in early breast milk; supplementation limited to pregnancy only was much less effective.

Omega-3 for Baby and Me: Material Development for a WIC Intervention to Increase DHA Intake during Pregnancy

OBJECTIVE

The purpose of this project was to develop educational materials for a Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) program intervention in Denver, Colorado. Despite accumulating evidence of the importance of docosahexaenoic acid (DHA) during pregnancy, there has been no attempt to develop a targeted nutrition intervention to improve birth outcomes among high-risk women. The goal of the Omega-3 for Baby and Me intervention, for which these materials were developed, is to increase the consumption of DHA-rich foods to decrease the risk for premature delivery and low-birth weight babies among this population.

METHOD

Following collection of data from eight focus groups among the target audience, the principles of the Health Belief Model were used to develop materials to address the needs, barriers, and motivators of this audience. In addition, process evaluation pilot testing was used to evaluate recipes and logos during the material development.

RESULTS

Materials developed for this intervention include a logo, 9-month calendar, stickers, shopping lists, recipes, recipe holder, magnetic clip, nylon pouch, and recruitment materials.

CONCLUSION

The use of focus groups and pilot testing increased the target audience acceptance of education materials that are being used for the Omega-3 for Baby and Me intervention. Successful outcomes from the Omega-3 for Baby and Me intervention, i.e., decreasing the incidence of preterm birth and low-birth weight, will have implications for supplemental food policies at state and national levels.

Relationship between dietary intake of cod liver oil in early pregnancy and birthweight

OBJECTIVE

To investigate the possible association between birth outcome and marine food and cod liver oil intake of healthy women in early (prior to 15 weeks of gestation) pregnancy.

DESIGN

An observational study.

SETTING

Free-living conditions in a community with traditional fish and cod liver oil consumption.

POPULATION

Four hundred and thirty-five healthy pregnant Icelandic women without antenatal and intrapartum complications.

METHODS

Dietary intake of the women was estimated with a semi-quantitative food frequency questionnaire (FFQ) covering food intake together with lifestyle factors for the previous three months. Questionnaires were filled out at between 11 and 15 weeks and between 34 and 37 weeks of gestation. The estimated intake of marine food and cod liver oil was compared with birthweight by linear and logistic regression controlling for potential confounding.

MAIN OUTCOME MEASURES

Birthweight, cod liver oil intake, lifestyle factors (alcohol, smoking).

RESULTS

Fourteen percent of the study population used liquid cod liver oil in early pregnancy. Regression analysis shows that these women gave birth to heavier babies (P < 0.001), even after adjusting for the length of gestation and other confounding.

CONCLUSIONS

Maternal intake of liquid cod liver oil early in pregnancy was associated with a higher birthweight. Higher birthweight has been associated with a lower risk of diseases later in life and maternal cod liver oil intake might be one of the means for achieving higher birthweight.

Raised dietary n-6 polyunsaturated fatty acid intake increases 2-series prostaglandin production during labour in the ewe

Preterm labour is the major cause of perinatal morbidity and mortality in humans. The incidence is around 10% and the causes are often unknown. Consumption of dietary n-6 polyunsaturated fatty acids (PUFAs) in western societies is increasing. These are metabolized to arachidonic acid, the precursor for 2-series prostaglandins (PGs), major signalling molecules during labour. This study investigated the effect of dietary supplementation with linoleic acid (LA, 18: 2, n-6) on parturition. Ewes were fed a control or LA-supplemented diet from 100 days gestation. Labour was induced using a standardized glucocorticoid challenge (dexamethasone, Dex) to the fetus, starting on day 139. Electromyographic (EMG) activity and fetal and maternal circulating PG concentrations were monitored. One third of LA-fed ewes delivered early (pre-Dex) although basal uterine EMG activity preceding Dex was higher in control ewes (P < 0.05). A steep increase in EMG activity occurred 18-38 h after the start of Dex infusion. Twice basal EMG activity (defined as established labour) occurred on average 7 h earlier in the LA-supplemented ewes (P < 0.05). The basal concentrations of maternal and fetal PGFM and fetal PGE(2) were approximately doubled in LA-supplemented ewes before the start of Dex infusion (P < 0.01). The rise in fetal PGE(2) and maternal oestradiol concentrations post-Dex occurred earlier in the LA-supplemented ewes. All PG measurements remained significantly higher in the LA-supplemented ewes during labour onset. This study suggests that consumption of a high LA diet in late pregnancy can enhance placental PG production and may thus increase the risk of preterm labour.

An introduction to dietary/supplemental omega-3 fatty acids for general health and prevention: Part II

The correction of a subtle nutritional deficiency that may reduce the risk of a future chronic disease is indeed a challenge. However, some specific examples in the past, such as the addition of folic acid to prevent neural tube defects and calcium and vitamin D to prevent osteoporosis, should provide some encouragement that some conditions can be prevented with the appropriate addition of a deficient compound. One of the most intriguing current and future impacts on public health may come from a higher intake of omega-3 fatty acids, such as alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). The omega-3 fatty acids continue to accumulate research that suggests that they may prevent a variety of diverse chronic diseases and potentially some acute clinical scenarios. In the first part of this article, the potential for these compounds to prevent certain cardiovascular conditions are discussed. In the second part, the potential for an impact in arthritis, numerous areas of cancer research, depression, maternal and child health, neurologic diseases, osteoporosis, and other medical disciplines are also briefly covered. The future appears bright for these agents, but specifically which conditions, who qualifies, testing, frequency, adequate sources, future trials, and numerous other questions need to be addressed and answered before the potential impact can catch up to the recent hype.

Including walnuts in a low-fat/modified-fat diet improves HDL cholesterol-to-total cholesterol ratios in patients with type 2 diabetes

OBJECTIVE

The aim of this study was to examine the effect of a moderate-fat diet inclusive of walnuts on blood lipid profiles in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

This was a parallel randomized controlled trial comparing three dietary advice groups each with 30% energy as fat: low fat, modified low fat, and modified low fat inclusive of 30 g of walnuts per day. Fifty-eight men and women, mean age 59.3 +/- 8.1 years, started the trial. Dietary advice was given at baseline with monthly follow-up and fortnightly phone calls for support. Body weight, percent body fat, blood lipids, HbA1c, total antioxidant capacity, and erythrocyte fatty acid levels were measured at 0, 3, and 6 months. Data were assessed by repeated-measures ANOVA with an intention-to-treat model.

RESULTS

The walnut group achieved a significantly greater increase in HDL cholesterol-to-total cholesterol ratio (P=0.049) and HDL (P=0.046) than the two other treatment groups. A 10% reduction in LDL cholesterol was also achieved in the walnut group, reflecting a significant effect by group (P=0.032) and time (P=0.036). There were no significant differences between groups for changes in body weight, percent body fat, total antioxidant capacity, or HbA1c levels. The higher dietary polyunsaturated fat-to-saturated fat ratio and intakes of omega-3 fatty acids in the walnut group were confirmed by erythrocyte biomarkers of dietary intake.

CONCLUSIONS

Structured "whole of diet" advice that included 30 g of walnuts/day delivering substantial amounts of polyunsaturated fatty acid improved the lipid profile of patients with type 2 diabetes.

Nutrients, neurodevelopment, and mood

Human neurodevelopment is the result of genetic and environmental interactions. This paper examines the role of prenatal nutrition relative to psychiatric disorders and explores the relationship among nutrients, mood changes, and mood disorders. Epidemiologic studies have found that adults who were born with a normal, yet low birth weight have an increased susceptibility to diseases such as coronary heart disease, diabetes, and stroke in adulthood. Prenatal caloric malnutrition, low birth weight, and prematurity also increase the risk for neurodevelopmental disorders, schizophrenia, affective disorders, and schizoid and antisocial personality disorders. Placebo-controlled studies in medicated patients suggest that add-on treatment with omega-3 fatty acids, particularly eicosapentaenoic acid, may ameliorate symptoms of major depressive disorder. Additional studies are necessary to confirm any benefits for bipolar disorders.

Epidemiological evidence on reproductive effects of persistent organochlorines in humans

Organochlorines are widespread pollutants in humans. Concern about adverse reproductive effects of these compounds arises from accidental exposure of humans and experimental studies. Recently, this issue has been addressed by a number of studies of exposed populations and hospital-based case-referent studies. These studies indicate that high concentrations of persistent organochlorines may adversely affect semen quality and cause testicular cancer in males, induce menstrual cycle abnormalities and spontaneous abortions in females, and cause prolonged waiting time pregnancy, reduced birth weight, skewed sex ratio, and altered age of sexual development. However, most effects have been demonstrated at exposure levels above the present day exposure level in European and North American populations. Due to inherent methodological problems in several of the available studies, additional research is needed to fully elucidate the possible adverse effects of organochlorines on human reproductive health.

Associations of seafood and elongated n-3 fatty acid intake with fetal growth and length of gestation: results from a US pregnancy cohort

Previous studies, mainly among populations with high consumption of seafood, have suggested that increased marine n-3 polyunsaturated fatty acid (PUFA) intake during pregnancy promotes longer gestation and higher birth weight. Few studies have isolated the contribution of fetal growth to birth weight. Using data from 2,109 pregnant women in Massachusetts enrolled in Project Viva from 1999 to 2002, the authors examined associations of marine n-3 PUFA and seafood intake with birth weight and birth-weight-for-gestational-age z value (fetal growth) using linear regression; length of gestation using median regression; and low birth weight, preterm delivery, and being small for gestational age using logistic regression. After adjustment for maternal and child factors, birth weight was 94 (95% confidence interval: 23, 166) g lower and fetal growth z value 0.19 (95% confidence interval: 0.08, 0.31) units lower in the highest compared with the lowest quartile of first-trimester n-3 PUFA intake. Results for the second and third trimesters were similar, and findings for seafood paralleled those for n-3 PUFA. Elongated n-3 PUFA intake and seafood intake were not associated with length of gestation or risk of preterm birth. Results from this US cohort support the conclusion that seafood intake during pregnancy is associated with reduced fetal growth.

Women and Omega-3 Fatty Acids

Omega-3 fatty acids (omega-3 FA) are constituents of the membranes of all cells in the body and are precursors of locally produced hormones, eicosanoids, which are important in the prevention and treatment of various diseases, especially in women. Omega-3 FA are of interest in some of the most common conditions affecting women. One mechanism underlying dysmenorrhea is a disturbed balance between antiinflammatory, vasodilator eicosanoids derived from omega-3 FA and proinflammatory, vasoconstrictor eicosanoids derived from omega-6 FA. Increased intake of omega-3 FA can reverse the symptoms in this condition by decreasing the amount of omega-6 FA in cell membranes. An increased prostacyclin/thromboxane ratio induced by omega-3 FA can facilitate pregnancy in women with infertility problems by increasing uterine blood flow. Supplementation with omega-3 FA during pregnancy lowers the risk of premature birth and can increase the length of pregnancy and birth weight by altering the balance of eicosanoids involved in labor and promote fetal growth by improving placental blood flow. Intake of omega-3 FA during pregnancy and breast feeding may facilitate the child's brain development. There is also some evidence that supplementation with omega-3 FA might help to prevent preeclampsia, postpartum depression, menopausal problems, postmenopausal osteoporosis, and breast cancer. Furthermore, because elevated triglyceride levels are associated with cardiovascular disease, especially in women; and because omega-3 FA have powerful effects on triglycerides, women in particular gain from an increased intake of these fatty acids. This is especially important in women receiving hormone therapy, which can increase triglyceride levels. The quality of the omega-3 FA preparation is important. It should have an appropriate antioxidant content not to induce lipid peroxidation, and its content of dioxin and polychlorinated biphenyls (PCBs) should be well below the established safe limit.

Maternal fish intake in late pregnancy and the frequency of low birth weight and intrauterine growth retardation in a cohort of British infants

OBJECTIVE

To investigate the relation between maternal fish intake in late pregnancy and the frequency of low birth weight and intrauterine growth retardation (IUGR).

PARTICIPANTS

11 585 pregnant women in south west England.

METHODS

Information on fish intake was obtained from a food frequency questionnaire sent to the women at 32 weeks' gestation, and used to calculate n-3 fatty acid (n-3FA) intake from fish. IUGR was defined as a birth weight for gestational age and sex below the 10th centile. Confounding variables considered included maternal age, height, weight, education, parity, smoking and drinking in pregnancy, and whether the mother was living with a partner. Only singleton, liveborn infants were included.

MAIN RESULTS

Mean daily intakes of fish and n-3FAs were 32.8 g and 0.147 g respectively. In unadjusted analyses there were positive associations between mean birth weight and fish intake or n-3FA intake, but these disappeared on adjustment for potential confounders. The frequency of IUGR decreased with increasing fish intake-the OR (95%CI) of IUGR in those eating no fish was 1.85 (1.44 to 2.38) compared with those in the highest fish intake group. On adjustment this relation was attenuated (adjusted OR 1.37 (1.02 to 1.84)), but the decline in the frequency of IUGR with increasing fish intake remained statistically significant. No relation was observed between mean gestation and fish or n-3FA intake.

CONCLUSIONS

These results lend some support to the hypothesis that raising fish or n3-FA intake during pregnancy may increase fetal growth rate. However, they provide no evidence that increasing fish consumption is associated with an increase in mean gestation.

Changes of Fatty Acid Composition of Human Milk during the First Month of Lactation: A Day-to-Day Approach in the First Week

BACKGROUND

Fatty acid composition of human milk (HM) is known to change considerably during lactation. However, we were unable to find data on changes of fatty acid composition of HM during the very early phase of lactation, i.e. in the first week of life.

SUBJECTS AND METHODS

HM samples were obtained from 18 healthy lactating women every day during the first week and thereafter on the 14th and 28th days of lactation. Fatty acid composition of colostrum and mature HM samples was determined by high-resolution capillary gas-liquid chromatography.

RESULTS

Values of the n-6 essential fatty acid, linoleic acid, in HM did not change significantly during the first month of lactation, whereas values of the n-3 essential fatty acid, alpha-linolenic acid, showed significant increases during the first 2 weeks of lactation (1st day: 0.49 [0.12], % weight/weight, median [ranges from the 1st to the 3rd quartile], 14th day: 0.69 [0.31], p < 0.05). In contrast, values of the n-6 long-chain metabolites, eicosadienoic-, dihomo-gamma-linolenic- and arachidonic acid, as well as the values of the n-3 long-chain metabolites, eicosatrienoic-, and eicosapentaenoic acid exhibited significant decreases during the entire period investigated. The principal n-3 long-chain metabolite, docosahexaenoic acid, showed a significant increase between the 3rd and 14th days, but a significant decrease between the 14th and 28th days (3rd day: 0.15 [0.13], 14th day: 0.28 [0.11], p < 0.05, 28th day: 0.19 [0.12], p < 0.01). There were statistically significant positive correlations between arachidonic and docosahexaenoic acid values on the 1st (r = 0.67, p < 0.01), 5th (r = 0.56, p < 0.05) and the 6th (r = 0.53, p < 0.05) days of lactation.

CONCLUSION

Fatty acid composition of HM changes significantly even during the first week of lactation. The lack of positive correlation between essential fatty acids and their long-chain metabolites suggests that it is not only the availability of essential fatty acids that influences the fatty acid composition of human colostrum.

Differential effects of fish oil and folic acid supplementation during pregnancy in rats on cognitive performance and serum glucose in their offspring

OBJECTIVE

We studied the effect of folic acid and polyunsaturated fatty acid supplementation during pregnancy in Wistar albino rats on cognitive performance and serum glucose concentrations in their pups.

METHODS

Pregnant female rats from four groups (n = 6/group) were fed casein diets with 18% protein and 2 mg of folic acid/kg of diet (group I), 12% protein and no folic acid (group II), 12% protein and 8 mg of folic acid/kg of diet (group III), or 12% protein and 70 g of cod liver oil/kg of diet (group IV). All pups were weaned on standard control diet with 18% protein. Cognitive performance, brain fatty acid profile, and serum glucose concentrations were studied in offspring at age 6 mo.

RESULTS

There was no significant difference in length of gestation or litter size, but the litter weight for group IV was lower (P = 0.047) than that for group I. After weaning, males in group II had lower (P < 0.05) body weights, but those in group III had weights comparable to those in group I for both sexes. In group IV, body weights were lower beyond 15 wk (P < 0.05). Relative brain weight and cognitive performance were significantly higher (P < 0.05) in group IV males and showed higher levels of brain gamma-linolenic acid. Further, these animals had serum glucose levels comparable to those of control animals at age 6 mo, whereas serum glucose levels were higher in males from groups II (P = 0.01) and III (P = 0.01).

CONCLUSION

Fish oil supplementation during pregnancy improved cognitive performance and maintained glucose levels into adulthood, unlike folic acid supplementation, which supported only fetal growth and did not maintain glucose levels.

Fat-modified diets during pregnancy and lactation and serum lipids after birth

OBJECTIVE

This study investigated the influence of modifying the maternal dietary fat on the serum lipids of infants at birth and at one year of age.

METHODS

This single-blind randomized clinical trial was done on 180 4-month-pregnant women. All subjects proved to have a fat-unmodified diet through a 4-day food record dietary questionnaire. They were divided randomly into two groups. The intervention group was kept on a fat-modified diet including saturated fatty acid (SFA) < 10%, monounsaturated fatty acids: (MUFA) 10-5%, polyunsaturated fatty acid (PUFA) upto 10% and cholesterol < 300 mg/day with dietary advice for the pregnancy period. The control group was given only the latter advice. All subjects were followed up monthly. The serum lipids including total cholesterol (T.cho), triglyceride (TG), and HDL cholesterol (HDL-C) were analyzed through enzymatic methods. The level of LDL-cholesterol (LDL-C) was calculated by Friedewald formula. The comparison of mean cord and one-year-old infant serum lipids were done through unpaired T-test in two groups.

RESULTS

The mean level of T.cho in the intervention and control group was (70.3+/-15.9, vs 81.4+/-17.2, P< 0.009), TG (85.3 +/- 16.7 vs 97.5 +/- 18.2, P< 0.007), LDL-C (27.8 +/- 15.2 vs 34.8 +/- 17.1, P< 0.04) and non-HDL-C (44.5+/-7.2 vs 54.5 +/- 8.1, P< 0.02) and in one year old infant the comparison of serum lipids were as follows. T.cho (145.7 +/- 51.4 vs 161.4 +/- 56.2, P< 0.003), TG (90.1 +/- 31.8 vs 98.3 +/- 33.1, P< 0.02), LDL-C (85.6 +/- 20.4 vs 92.3 +/- 19.6, P< 0,05) and non-HDL-C (113.6 +/- 30.2 vs 128.8 +/- 34.8, P< 0.04). However, there was no significant difference in HDL-C of both groups.

CONCLUSION

There is a significant decrease of T.cho, TG, LDL-C and non-HDL-C levels with no significant increase of HDL-C in the intervention group with the fat-modified diet. Maternal fat-modified diet could be suitable way to prevent cardiovascular disease among infants from the beginning of the life.

Fish and shellfish as dietary sources of methylmercury and the omega-3 fatty acids, eicosahexaenoic acid and docosahexaenoic acid: risks and benefits

Fish and shellfish supply the human diet with not only complex nutrients including the omega-3 fatty acids, but also highly toxic chemicals including methylmercury. The dietary essential fatty acids are linoleic and alpha-linolenic acid. Two omega-3 fatty acids with longer carbon chains, eicosahexaenoic acid (EPA) and docosahexaenoic acid (DHA), can be synthesized in humans from alpha-linolenic precursors. Though not required in the diet per se, EPA and DHA have important roles in metabolism. The almost exclusive source of preformed dietary DHA is fish and shellfish. These foods are also an important source of EPA. In marked contrast to the benefits of fish and shellfish as sources of preformed omega-3 fatty acids, fish and shellfish are almost exclusively the dietary source of methylmercury. Fortunately, these chemicals are not uniformly distributed across many species of fish and shellfish. The purpose of this article is to provide information on the comparative distribution of these chemicals and nutrients to help groups formulating dietary recommendations.

Influence of Trans Fatty Acids on Health

The contribution of dietary trans fatty acids (TFAs) on the risk of ischemic heart disease (IHD) has recently gained further support due to the results from large, prospective, population-based studies. Compared to saturated fat, TFAs are, gram to gram, associated with a considerably (2.5- to >10-fold) higher risk increment for IHD. A negative effect on the human fetus and on newborns and an increase in colon cancer risk in adults are possible but, however, still equivocal. Recent findings justify further studies concerning the effect of TFAs on allergic diseases in children and on the risk of type-2 diabetes in adults. The intake of industrially produced TFAs in European countries is decreasing. However, determination of the TFA content in various popular food items collected in Danish shops showed that it is likely that persons with a frequent intake of, e.g., French fries, microwave oven popcorn, chocolate bars, fast food, etc., consume industrially produced TFAs in amounts far exceeding the average intake, and are thereby exposed to an unnecessary health risk. The Danish government has decided that oils and fats containing more than 2% industrially produced TFAs will not be sold in Denmark after the January 1, 2004.

The Effects of Feeding Fish Oil on Uterine Secretion of PGF2α, Milk Composition, and Metabolic Status of Periparturient Holstein Cows

The objectives were to determine the effect of dietary fish oil (FO) on uterine secretion of PGF2alpha, milk production, milk composition, and metabolic status during the periparturient period. Holstein cows were assigned randomly to diets containing FO (n = 13) or olive oil (OO, n = 13). Cows were fed prepartum and postpartum diets that provided approximately 200 g/d from 21 d before the expected parturition until 21 d after parturition. The FO used contained 36% eicosapentaenoic acid (EPA, C20:5, n-3) and 28% docosahexaenoic acid (DHA, C22:6, n-3). Blood samples were obtained from 14 d before the due date until d 21 postpartum. A total of 6 FO and 8 OO cows without periparturient disorders were used in the statistical analyses of PGF2alpha-metabolite (PGFM) and metabolite concentrations. Length of prepartum feeding with OO or FO did not differ. Proportions of individual and total n-3 fatty acids were increased in caruncular tissue and milk of cows fed FO. The combined concentrations of EPA and DHA in caruncular tissue were correlated positively with the number of days supplemented with FO. Cows fed FO had reduced concentrations of plasma PGFM during the 60 h immediately after parturition compared with cows fed OO. Concentrations of prostaglandin H synthase-2 mRNA and protein in caruncular tissue were unaffected by diet. Production of milk and FCM were similar between cows fed the two oil diets. However, cows fed FO produced less milk fat. Feeding FO reduced plasma concentrations of glucose. Dietary fatty acids given during the periparturient period can reduce the uterine secretion of PGF2alpha in lactating dairy cows and alter the fatty acid profile of milk fat.

Effects of n-3 polyunsaturated fatty acid supplementation in pregnancy on maternal and fetal erythrocyte fatty acid composition

OBJECTIVE

The aim of this study was to assess the effects of fish oil supplementation in pregnancy on maternal erythrocyte fatty acid composition at different stages of pregnancy and in the post-partum period, and on neonatal erythrocyte fatty acid composition.

DESIGN

A double-blind, randomised, placebo-controlled study.

SETTING

: Subiaco, Western Australia.

SUBJECTS

In all, 98 women booked for delivery at St John of God Hospital, Subiaco, were recruited from private rooms of obstetricians. In total, 83 women and their healthy full-term babies completed the study.

INTERVENTION

Women received either 4 g of fish oil (n=52) (56% docosahexaenoic acid (DHA) and 28% eicosapentaenoic acid (EPA) or placebo (olive oil) (n=46) per day from 20 weeks gestation until delivery.

MAIN OUTCOME MEASURES

Erythrocyte phospholipid fatty acids were measured in maternal peripheral blood at 20, 30 and 37 weeks of pregnancy and at 6 weeks post partum, and from cord blood collected at birth.

RESULTS

Compared to the control group, maternal EPA and DHA were significantly higher in the fish oil group at 30 and 37 weeks gestation, and remained elevated at 6 weeks post partum (P<0.001). The proportions of n-6 polyunsaturated (arachidonic acid, 22:3n-6 and 22:4n-6) were significantly lower in the fish oil supplemented group at the same time periods (P<0.001). Similarly, the proportions of EPA and DHA were significantly higher (P<0.001), and those of n-6 polyunsaturated fatty acids arachidonic acid, 20:3n-6, 22:3n-6 and 22:4n-6 were significantly lower (P<0.001), in erythrocytes from neonates in the fish oil group, compared to those in the control group.

CONCLUSION

Fish oil supplementation from 20 weeks of pregnancy until birth is an effective means of enhancing n-3 fatty acid status of both mothers and neonates. Furthermore, the changes in maternal erythrocyte fatty acid composition are retained until at least 6 weeks post partum. It is essential to assess the effects of concomitant decreases in arachidonic acid status before any dietary recommendations can be made.

SPONSORSHIP

The study was supported by grants from the NH & MRC and Raine Medical Research Foundation, Australia.

Prostaglandin endoperoxide H synthase inhibitors and other tocolytics in preterm labour

Preterm delivery (<37 weeks of gestation) is the major obstetrical complication in developed countries, yet attempts to delay labour and prolong pregnancy have largely been unsuccessful. One of the many reasons it is so difficult to prevent preterm birth is that the nature of preterm labour changes as a function of gestational age, maternal lifestyle factors or infection, to list a few of the reasons. The inhibitors of prostaglandin endoperoxide H synthase (PGHS), known as the Non-steroidal Antiinflammatory Drugs, have been viewed with interest as tocolytics with promising effectiveness under most conditions of preterm labour. Three isoforms of PGHS exist; the first two, PGHS-1 and -2, have been studied for their catalytic activity, X-ray crystallographic structure, and physiological roles in the adult and the foetus. Mixed inhibitors and isoform-specific inhibitors of PGHS have been developed, and their roles in delaying preterm labour are examined and compared to other tocolytics.

Fish Oil Supplementation of Rats during Pregnancy Reduces Adult Disease Risks in Their Offspring

Metabolic programming in utero due to maternal undernutrition is considered to increase the risk of adult diseases in offspring. It is therefore of relevance to investigate how dietary supplementation of specific nutrients can ameliorate the negative effects of maternal malnutrition. We examined the effects of supplementing fish oil or folic acid, both of which are conventional supplements in maternal intervention, on risk factors in the offspring as adults. Pregnant female rats from 4 groups (n = 6/group) were fed casein diets with 18 g/100 g protein (control diet), 12 g/100 g protein supplemented with 8 mg folic acid/kg diet (0.08 mg/kg diet) (FAS), 12 g/100 g protein without folic acid (FAD) or 12 g/100 g protein supplemented with 7 g/100 g fish oil (FOIL). Pups were weaned to a standard laboratory diet with 18 g/100 g protein. Serum glucose, insulin and cholesterol and plasma homocysteine levels were measured in the offspring at 6 and 11 mo of age. Serum glucose in 11-mo-old male and female pups was greater (P < 0.05) in both the FAS (males 2.46 +/- 0.51, females 2.49 +/- 0.29 mmol/L) and FAD groups (2.48 +/- 0.28 and 2.67 +/- 0.41 mmol/L) than in controls (2.03 +/- 0.15 and 2.02 +/- 0.18 mmol/L). Serum insulin concentrations were higher (P < 0.05) in the FAD group (males 1476 +/- 317, females 1441 +/- 220 pmol/L) but were lower in males from the FAS group (483 +/- 165 pmol/L) compared with controls (males 917 +/- 373, females 981 +/- 264 pmol/L). Glucose and insulin concentrations did not differ between the control and FOIL groups. Plasma homocysteine levels were lower (P < 0.05) only in 11-mo-old folate-deficient males; none of the other groups differed from the controls. Maternal supplementation of fish oil to a diet containing marginal protein was beneficial in maintaining circulating glucose, insulin, cholesterol and homocysteine levels in the offspring as adults.

Will feeding mothers prevent the Asian metabolic syndrome epidemic?

Evolutionary pressures have probably amplified the mechanisms for minimizing the impact of environmental factors through compensatory maternal mechanisms. Nevertheless, experimentally there are clear long-term programming effects of manipulations to the maternal diet on the likelihood of neural-tube defects associated with folate deficiency The fat/lean ratios of the newborn, and subsequent development, seem to be linked to amino acid or folate supply. An altered balance in the hypothalamic-pituitary-adrenal axis, which experimentally has profound effects on brain development, is induced by low-protein maternal diets. Such diets are linked to a reduced pancreatic capacity for insulin production and to an altered hepatic architecture, with a change in the control of glucose metabolism. Human studies suggest that what happens in pregnancy is modified by the child's diet in the first months of life. Low birthweight is linked to early stunting, and predisposes to abdominal obesity and metabolic syndrome in later life. Metabolic syndrome amplifies the risks of diabetes, hypertension, coronary heart disease and probably some cancers. Mothers with gestational diabetes are themselves prone to early type 2 diabetes and produce heavier babies prone to childhood obesity and adolescent type 2 diabetes. There is increasing evidence of an intergenerational effect, with big babies being prone to excess weight gain, which then, in girls, predisposes them to diabetes in pregnancy, which, in turn, promotes an accelerating cycle of early diabetes in subsequent generations. Essential fatty acids and fat soluble vitamins are important, but we need early interventions and monitoring systems to justify coherent policies.

Third World adversity: African infant precocity and the role of environment

The war against illiteracy has not been won. The number of illiterates approaches a billion. Most reside in Third World countries--former colonies--where they are caught in a poverty trap of disease, low agricultural production and environmental adversity requiring technology beyond their means. I argue against the commonly held view that this is mainly attributable to the four hundred years of traffic in men. According to the late K.O. Dike, middle men along the African coast barred foreign merchants from the hinterland, and because of this the social, political structure and sovereignty of the African states remained fundamentally unchanged during the period 1400-1807, whereas a few decades after colonisation the socio-political system collapsed and was replaced by a small rich elite and many poor, while resources were taken out of Africa. Present poverty and underdevelopment represent as great a challenge as the trade in slaves. As did the African Middle-Men of that time, African leaders now must unite in an ambitious and confident Pan-African Union demonstrating strength. Western countries should focus on reducing poverty and improving nutrition. This also makes terrorism and legal and illegal migration less likely. Education is important, but the West should not limit its effort to fighting illiteracy but should also support the establishment of institutions for higher education. Africa possessed optimal conditions and an enriched environment for human evolution. African Infant Precocity is a persistent example. The human brain, like other brains, consists 60% of poly-unsaturated fatty acids (Marine-Fat), the rest being water. A sufficient amount is required to secure optimal brain growth. It normalizes brain function, and prevents sudden cardiac and infant death, which have been increasing in Western societies. Humans are unique in having a mismatch between the need for brain food--marine fat--and our common high protein diet. Nowhere is the neglect of the brain greater than in pregnancy when protein is the only major nutrient considered. Declining levels of polyunsaturated fatty acids have been observed in human milk. Deficient intake could, if not corrected, gradually impair brain function as has been seen in animal experiments.

Micronutrient status during pregnancy and outcomes for newborn infants in developing countries

More than 9 million neonatal deaths occur each year, 98% of them in developing countries. Neonatal deaths account for two-thirds of deaths in infancy and 40% of deaths before age 5 y. The major direct causes of neonatal death are infections, preterm delivery and asphyxia. Important indirect causes include low birth weight and hypothermia. The present body of work on multiple micronutrient interventions is not sufficient for us to draw conclusions on their effects on neonatal well-being. Because studies have generally concentrated on single micronutrients and a range of outcomes, this paper reviews the findings for individual nutrients and then summarizes the situation. The evidence for the contribution of micronutrient deficiencies to perinatal mortality and duration of gestation is limited, and the evidence base for individual micronutrient effects on neonatal mortality and morbidity is patchy. To translate knowledge into policy, community evaluations of effect and an expanded evidence base that includes affordability, acceptability and scalability are also required. A balance between supply-side and demand-side interventions must be struck, with an emphasis on effect and sustainability. Among the key requirements are randomized, controlled community effectiveness trials of the effect of micronutrient supplementation in pregnancy on perinatal mortality and neurodevelopment, studies on improving adherence and studies on the relation between micronutrient deficiencies and sepsis and neonatal encephalopathy. It would also be helpful to look at mechanisms for bringing the periconceptional period within the ambit of trials.

High-DHA eggs: feasibility as a means to enhance circulating DHA in mother and infant

Dietary DHA enhances infant attention and visual development. Because the DHA content of red blood cells and plasma lipids varies approximately threefold in pregnancy, maternal DHA status may influence subsequent infant function. It would be feasible to study the effects of higher maternal DHA intake on infant development if dietary intake of DHA could be increased by a reliable means. This study was designed to determine whether women provided with one dozen high-DHA hen eggs (135 mg DHA/egg) would consume the eggs and have higher blood DHA levels than women consuming ordinary eggs (18 mg DHA/egg). The study was a randomized, double-masked comparison of the effect of eggs with different concentrations of DHA on intake and blood lipid DHA content of women and their infants. A third nonrandomized group ate few eggs. In this study, DHA intake reported from eggs was eightfold higher in the high-DHA egg group compared to the ordinary egg group. Including all groups, DHA intake ranged from 0 to 284 mg/d. In this intake range, maternal blood lipid DHA content at enrollment best predicted DHA content at delivery, accounting for 36.5 and 51.7% of the variance in ordinary and high-DHA egg intake groups, respectively. The high-DHA vs. ordinary egg groups had similar maternal and cord blood lipid DHA, but there was a positive relationship between maternal plasma phospholipid DHA and daily DHA intake from eggs controlled for study duration (r = 0.278, P = 0.048). DHA intake and birth weight were also correlated (r = 0.299, P = 0.041). High-DHA eggs were well accepted and increased DHA intake. Other benefits of DHA intake during pregnancy were also suggested.

Maternal and umbilical cord erythrocyte omega-3 and omega-6 fatty acids and haemorheology in singleton and twin pregnancies

BACKGROUND

Being devoid of both nuclei and mitochondria, mature human erythrocytes provide an opportunity to study membrane structure and function outwith the restrictions of genetic control. With its unique rapid increase in vascularisation, pregnancy is considered the most opportune period in which to investigate blood rheology.

METHODS

Maternal and fetal (cord) bloods were retained at delivery from 32 (25 singleton and seven twin) normal pregnancies at two maternity hospitals in the Glasgow area over a nine month period. Erythrocyte fatty acid compositions were assessed by mass spectroscopy, and corresponding membrane deformabilities measured by ultrafiltration through a membrane of 5 micro m diameter pore size, to mimic placental microcirculation.

RESULTS

Significant direct correlations (Spearman rank) were found between erythrocyte membrane omega-3 docosahexaenoic acid concentrations and corresponding deformabilities in maternal and cord blood from both singleton and twin pregnancies, whereas greater omega-6 arachidonic acid content was associated with increased maternal membrane rigidity. Membrane concentrations of omega-3 fatty acids only correlated strongly both within and between maternal and cord bloods. Mean cord erythrocyte docosahexaenoic acid concentration was higher than maternal in singletons but lower in twins. When maternal erythrocyte concentrations exceeded about 7% (of total fatty acids), resistance to erythrocyte flow was virtually eliminated.

CONCLUSIONS

It may be that a greater maternal intake of docosahexaenoic acid should be encouraged in some pregnancies for optimal tissue perfusion. Fetal demand for docosahexaenoic acid may not be entirely satisfied in multiple pregnancies.

Erythrocyte cell membrane phospholipid levels compared against reported dietary intakes of polyunsaturated fatty acids in pregnant Mexican women

OBJECTIVE

To evaluate the validity of a food-frequency questionnaire (FFQ) for assessment of the dietary intakes of polyunsaturated fatty acids (PUFAs) against a biochemical marker of fat intake, erythrocyte cell membrane phospholipid levels, during pregnancy.

DESIGN

Cross-sectional analysis.

SETTING

Developmental Neurobiology Department, National Institute of Perinatology, Mexico City.

SUBJECTS

One hundred forty-six healthy pregnant women during the last trimester of pregnancy. Among women enrolled, the first 35 pregnant women (24%) had their erythrocytes analysed for fatty acid status.

METHODS

We administered an FFQ and compared intakes of PUFAs against their erythrocyte cell membrane concentrations, processed by gas chromatography.

RESULTS

Pearson correlation coefficients among alpha-linolenic acid (ALN), docosahexaenoic acid (DHA) and eicosapentaenoic acid in erythrocyte cell membranes against their crude dietary counterparts were 0.32, 0.35 and 0.36 (each P < 0.05). In a simple linear regression, erythrocyte DHA and arachidonic acid (AA) were significantly related to their respective dietary intakes (beta = 0.30, 95% confidence interval (CI): 0.007-0.60, P=0.045 for DHA; beta = 0.49, 95% CI: 0.010-0.98, P=0.044 for AA). Erythrocyte cell membrane ALN concentration (%/total) was only marginally related to ALN dietary intake (mg day-1) (beta = 0.52, 95% CI: -0.020-1.10, P=0.061). However, after adjustment for long-chain n-3 PUFA/AA, this association reached significance (beta = 0.44, 95% CI: 0.026-0.825, P=0.038). Main dietary sources for n-3 PUFAs were canned tuna fish and fresh catfish; for n-6 these were eggs and cow's milk. The use of this FFQ in these pregnant Mexican women provided estimates of average long-term intakes of PUFAs and correlated reasonably well with their erythrocyte cell membrane phospholipid status. However, we need to consider that, during pregnancy, there is a faster turnover of PUFAs from fat storage that may modify the profile of erythrocyte PUFAs and lower the correlation between dietary intake and erythrocyte PUFAs.

Seafood consumption, the DHA content of mothers' milk and prevalence rates of postpartum depression: a cross-national, ecological analysis

BACKGROUND

Mothers selectively transfer docosahexaenoic acid (DHA) to their fetuses to support optimal neurological development during pregnancy. Without sufficient dietary intake, mothers become depleted of DHA and may increase their risk of suffering major depressive symptoms in the postpartum period. We postulated that the DHA content of mothers' milk and seafood consumption would both predict prevalence rates of postpartum depression across countries.

METHODS

Published prevalence data for postpartum depression were included that used the Edinburgh Postpartum Depression Scale (n=14532 subjects in 41 studies). These data were compared to the DHA, eicosapentaenoic acid (EPA) and arachidonic acid (AA) content in mothers' milk and to seafood consumption rates in published reports from 23 countries.

RESULTS

Higher concentrations of DHA in mothers' milk (r=-0.84, p<0.0001, n=16 countries) and greater seafood consumption (r=-0.81, p<0.0001, n=22 countries) both predicted lower prevalence rates of postpartum depression in simple and logarithmic models, respectively. The AA and EPA content of mothers' milk were unrelated to postpartum depression prevalence.

LIMITATIONS

These findings do not prove that higher omega-3 status cause lower prevalence rates of postpartum depression. Data on potentially confounding factors were not uniformly available for all countries.

CONCLUSIONS

Both lower DHA content in mothers' milk and lower seafood consumption were associated with higher rates of postpartum depression. These results do not appear to be an artifact of cross-national differences in well-established risk factors for postpartum depression. Interventional studies are needed to determine if omega-3 fatty acids can reduce major postpartum depressive symptoms.