Effect of n-3 long-chain polyunsaturated fatty acid intake during pregnancy on maternal, infant, and child health outcomes: a systematic review

Evidence from observational studies and randomised trials has suggested a potential association between intake of n-3 long-chain polyunsaturated fatty acids (LCPUFA) during pregnancy and certain pregnancy and birth outcomes. Marine foods (e.g. fatty sea fish, algae) and select freshwater fish contain pre-formed n-3 LCPUFA, which serve as precursors for bioactive molecules (e.g. prostaglandins) that influence a variety of biological processes. The main objective of this analysis was to summarise evidence of the effect of n-3 LCPUFA intake during pregnancy on select maternal and child health outcomes. Searches were performed in PubMed, EMBASE, and other electronic databases to identify trials where n-3 LCPUFA were provided to pregnant women for at least one trimester of pregnancy. Data were extracted into a standardised abstraction table and pooled analyses were conducted using RevMan software. Fifteen randomised controlled trials were eligible for inclusion in the meta-analysis, and 14 observational studies were included in the general review. n-3 LCPUFA supplementation during pregnancy resulted in a modest increase in birthweight (mean difference = 42.2 g; [95% CI 14.8, 69.7]) and no significant differences in birth length or head circumference. Women receiving n-3 LCPUFA had a 26% lower risk of early preterm delivery (<34 weeks) (RR = 0.74; [95% CI 0.58, 0.94]) and there was a suggestion of decreased risk of preterm delivery (RR = 0.91; [95% CI 0.82, 1.01]) and low birthweight (RR = 0.92; [95% CI 0.83, 1.02]). n-3 LCPUFA in pregnancy did not influence the occurrence of pre-eclampsia, high blood pressure, infant death, or stillbirth. Our review of observational studies revealed mixed findings, with several large studies reporting positive associations between fish intake and birthweight and several reporting no associations. In conclusion, n-3 LCPUFA supplementation during pregnancy resulted in a decreased risk of early preterm delivery and a modest increase in birthweight. More studies in low- and middle-income countries are needed to determine any effect of n-3 LCPUFA supplementation in resource-poor settings, where n-3 PUFA intake is likely low.     

首次急症剖宫产术从决定手术至切皮时间间期与母婴结局的关系

目的:研究急症剖宫产术从决定手术至切皮时间间期(DII)与母婴结局的相关性,评估昆明医学院第一附属医院目前对产科急症的应急能力。方法:对2000年1月1日~2006年9月30日期间在产科住院分娩的部分急症剖宫产术(ECS)进行回顾性队列研究,比较不同DII时间段ECS母婴的不良妊娠结局。结果:在纳入本研究的735例首次ECS病例中,DII的分布范围为10~310 min,仅9例(1.2%)的ECS达到DII≤30 min;ECS的指征按照构成比依次为:活跃期头位难产383例(52.2%),胎儿窘迫320例(43.8%),脐带脱垂12例(1.6%),胎盘早剥10例(1.4%),前置胎盘10例(1.4%),本研究病例中无子宫破裂和剖宫产术中脏器损伤者;以DII 30 min为组距将病例分为6组,各组间母亲和新生儿不良结局的发生率均无统计学显著差异;将相同病例分为DII≤75 min和DII>75 min两组,两组间母亲和新生儿不良结局的发生率也没有显著统计学差异;以活跃期头位难产为指征的383例以及以胎儿宫内窘迫为指征的320例病例分为DII≤75 min和DII>75 min两组,两组间母亲和新生儿不良结局的发生率均无显著统计学差异。结论:该院真实医疗现状极难达到DII≤30 min的国际标准。在以非危急ECS指征为主的一般急症剖宫产中,未发现DII>75 min增加母婴不良结局。     

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.     

The effects of maternal and infant vitamin A supplementation on vitamin A status: a randomised trial in Kenya

Postpartum vitamin A supplementation of mothers and infants is recommended, but the efficacy has been questioned. In this double-blind, placebo-controlled trial, Kenyan mother-infant pairs were randomised to maternal vitamin A (400,000 IU) or placebo <24 h postpartum, and infant vitamin A (100,000 IU) or placebo at 14 weeks. Milk retinol was determined at weeks 4, 14 and 26, and maternal and infant serum retinol at weeks 14 and 26. Infant retinol stores were assessed at week 26, using a modified relative dose response (MRDR) test. Among 564 women, serum retinol at 36 weeks gestation was 0.81 (SD 0.21) micromol/l, and 33.3% were<0.7 micromol/l. Maternal serum retinol was not different between groups, but milk retinol was higher in the vitamin A group: (0.67 v. 0.60 micromol/l; 0.52 v. 0.44 micromol/l; 0.50 v. 0.44 micromol/l at 4, 14 and 26 weeks, respectively). When expressed per gram fat, milk retinol was higher in the vitamin A group only at 4 weeks. Infant serum retinol was not different between groups. However, although most infants had deficient vitamin A stores (MRDR>0.06%) at 26 weeks, vitamin A to infants, but not mothers, resulted in a lower proportion of infants with deficient vitamin A stores (69 v. 78 %). High-dose postpartum vitamin A supplementation failed to increase serum retinol and infant stores, despite modest effects on milk retinol. Infant supplementation, however, increased stores. There is a need for a better understanding of factors affecting absorption and metabolism of vitamin A.     

Effect of zinc supplementation on pregnancy and infant outcomes: a systematic review

Poor maternal zinc status has been associated with foetal loss, congenital malformations, intra-uterine growth retardation, reduced birth weight, prolonged labour and preterm or post-term deliveries. A meta-analysis completed in 2007 showed that maternal zinc supplementation resulted in a small but significant reduction in preterm birth. The purposes of this analysis are to update that previous review and expand the scope of assessment to include maternal, infant and child health outcomes. Electronic searches were carried out to identify peer-reviewed, randomised controlled trials where daily zinc supplementation was given for at least one trimester of pregnancy. The co-authors applied the study selection criteria, assessed trial quality and abstracted data. A total of 20 independent intervention trials involving more than 11,000 births were identified. The 20 trials took place across five continents between 1977 and 2008. Most studies assessed the zinc effect against a background of other micronutrient supplements, but five were placebo-controlled trials of zinc alone. The provided dose of supplemental zinc ranged from 5 to 50 mg/day. Only the risk of preterm birth reached statistical significance (summary relative risk 0.86 [95% confidence interval 0.75, 0.99]). There was no evidence that supplemental zinc affected any parameter of foetal growth (risk of low birth weight, birth weight, length at birth or head circumference at birth). Six of the 20 trials were graded as high quality. The evidence that maternal zinc supplementation lowers the risk of preterm birth was graded low; evidence for a positive effect on other foetal outcomes was graded as very low. The effect of zinc supplementation on preterm birth, if causal, might reflect a reduction in maternal infection, a primary cause of prematurity. While further study would be needed to explore this possibility in detail, the overall public health benefit of zinc supplementation in pregnancy appears limited.     

n-3多不饱和脂肪酸对消化系统肿瘤病人临床结局的影响和安全性评估的Meta分析

目的:系统评价补充n-3多不饱和脂肪酸(PUFA)的营养支持对消化系统肿瘤病人临床结局的影响以及安全性评估. 方法:文献检索数据库选择MEDLINE、EMBASE、Cochrane对照试验中心数据库(CENTRAL),(CNKI)、中国生物医学数据库(CBM).检索起止时间为数据库默认时间.检索主题词选择Omega-3 fatty acids,fish oil,cancer,turmor,neoplasms,n-3多不饱和脂肪酸,鱼油,癌症,恶性肿瘤.按照纳入与排除标准筛选出高质量随机对照试验.采用Cochrane协作网提供的RevMan 5.2统计软件进行分析. 结果:本研究通过严格的质量控制,最终纳入585例病人11项高质量随机对照试验,来自5个不同国家不同种族.大部分临床结局分析指标与安全性评估指标合并后异质性较低,漏斗图对称,说明各研究间偏倚小,合并结果可信度高.Meta分析结果显示,补充n-3 PUFA组病人的总住院天数短于对照组,肝功能指标好于对照组,但感染等并发症以及肾功能指标两组间无统计学差异. 结论:n-3 PUFA可改善消化系统肿瘤病人的某些指标,且安全性良好.     

Effect of multiple micronutrient supplementation on pregnancy and infant outcomes: a systematic review

Supplementation with multiple micronutrients (MM) during pregnancy may result in improved pregnancy and infant outcomes. We conducted meta-analyses of randomised controlled trials that evaluated the effects of prenatal supplementation with MM (defined as containing at least five micronutrients and typically included iron or iron and folic acid). The outcomes of interest were low birthweight (<2500 g), birthweight, small-for-gestational age (SGA), gestational age, preterm birth (<37 weeks' gestation), stillbirth and neonatal death, maternal morbidity and mortality. We identified eligible studies through PubMed and EMBASE database searches. Meta-analyses were performed by pooling results for outcomes that were reported from more than one trial and sub-analyses were conducted to evaluate the effect of timing of intervention and amount of iron. We included published results from 16 trials in this review. Compared with control supplementation that was usually iron plus folic acid in most studies, MM supplementation resulted in a significant reduction in the incidence of low birthweight [pooled risk ratio (RR) 0.86; 95% confidence interval (CI) 0.81, 0.91] and SGA (pooled RR 0.83 [95% CI 0.73, 0.95]) and an increase in mean birthweight (weighted mean difference (WMD) 52.6 g [95% CI 43.2 g, 62.0 g]). There was no significant difference in the overall risk of preterm birth, stillbirth, and maternal or neonatal mortality, but we found an increased risk of neonatal death for the MM group compared with iron-folate in the subgroup of five trials that began the intervention after the first trimester (RR 1.38 [95% CI 1.05, 1.81]). None of the studies evaluated maternal morbidity. Compared with iron plus folic acid supplementation alone, prenatal maternal supplementation with MM resulted in a reduction in the incidence of low birthweight and SGA but increased risk of neonatal death in the subgroup of studies that began the intervention after the first trimester.     

n-3 Fatty acid supplementation and regular moderate exercise: differential effects of a combined intervention on neutrophil function

CVD is associated with a cellular inflammatory/immune response. n-3 PUFA and moderate aerobic exercise independently alter cytokine production and leucocyte function. There is limited evidence for the combined effect of these treatments on immune function, particularly in patients with risk factors for CVD. We hypothesised that exercise would enhance the anti-inflammatory effects of n-3 PUFA. In a randomised, placebo-controlled study, fifty volunteers were allocated double-blind to consume either sunflower oil (6 g/d, placebo) or DHA-rich fish oil (6 g/d; about 2 g n-3 PUFA; 1.6 g DHA /d) for 12 weeks. Volunteers were further randomised to undertake regular exercise (walking 3 d/week for 45 min at 75 % of maximum heart rate) or maintain their usual physical activity for 12 weeks. Immune functions were assessed in blood taken initially and after 12 weeks. There was no effect on cytokine production by T cells and monocytes. Superoxide anion production from stimulated blood neutrophils was decreased by fish oil (19.5 (sem 8.5) %, P = 0.016) but not by exercise, and this change was negatively correlated with the incorporation of DHA into erythrocytes (r-0.385, P = 0.047). Participation in regular exercise maintained neutrophil bactericidal activity, which decreased in non-exercising subjects (2.9 (sem 0.7) %, P = 0.013). Neutrophil chemotaxis and adherence were not significantly affected by exercise, oil, or the combination of the two. Thus the combination of moderate exercise and fish-oil supplementation, which reduces cardiovascular risk, may also help to counteract inflammation.     

孕期体质指数增量对母婴结局的影响

目的:探讨孕期体质指数(BMI)增长对母婴结局的影响。方法:回顾性收集2018年1月-2019年3月本院产检并分娩孕妇347例临床资料,根据孕期BMI增量分为轻度组(增量<5kg/m2)、中度组(5 kg/m2≤增量≤10 kg/m2)和重度组(增量>10 kg/m2),比较各组母婴结局。结果:重度组总产程(12.19±1.99h)高于轻度组和中度组,宫口扩张速度(0.80±0.17cm/h)低于轻度组和中度组,剖宫产(47.8%)和产钳助产比例(20.9%)高于轻度组(P<0.05),与中度组比较无差异(P>0.05);巨大儿(20.9%)、新生儿窒息(11.9%)发生率高于轻度组(P<0.05),与中度组比较无差异(P>0.05);妊娠期糖尿病(17.9%)、妊娠期高血压(19.4%)和产后出血(17.9%)发生高于轻度组(P<0.05),与中度组比较无差异(P>0.05)。结论:临床应针对孕期BMI增量≥5 kg/m2孕妇,积极给予干预措施。     

高龄产妇妊娠期并发症及母婴结局分析

目的探讨高龄初产妇及经产妇妊娠期并发症及妊娠结局。方法回顾性分析2012年3月至2016年10月在山西医科大学第一医院住院分娩的10248例孕产妇病历资料,高龄产妇组1460例,适龄产妇组8788例,比较两组产妇的妊娠期并发症及母婴结局。同时按照初产妇、经产妇进行分层分析,比较高龄对初产妇及经产妇的不同影响。结果高龄组发生妊娠期糖尿病、妊娠期高血压疾病、前置胎盘、产后大出血、剖宫产、巨大儿、早产的发生风险是适龄产妇的1.485倍、1.320倍、1.409倍、1.642倍、1.670倍、1.299倍、1.440倍和1.233倍。按照初产妇和经产妇进行分层分析,初产妇高龄组发生妊娠期糖尿病、前置胎盘、胎盘早剥、产后大出血、剖宫产和早产的发生风险是适龄产妇的2.754倍、1.436倍、2.309倍、2.728倍、1.993倍和1.233倍。经产妇高龄组发生妊娠期糖尿病、妊娠期高血压疾病、前置胎盘、产后大出血、剖宫产、巨大儿和早产的发生风险是适龄产妇的1.356倍、1.326倍、1.452倍、1.505倍、1.571倍、1.351倍和1.266倍。结论高龄产妇妊娠期并发症及母婴不良结局的发生风险高于适龄妊娠产妇,高龄初产妇较适龄初产妇更容易发生胎盘早剥,高龄经产妇早产的发生风险较高。     

Evaluation of breed effects on n-3 PUFA metabolism with dietary flaxseed oil supplementation in dogs

PUFA are important for human and animal health. To our knowledge, previous studies investigating the metabolism of PUFA in dogs have not examined breed differences. The aim of the present study was to evaluate the potential to elongate PUFA in two pure breeds of dogs. Plasma fatty acid composition (%) was measured in dogs during 3 weeks supplementation with flaxseed oil (57 % α-linolenic acid (ALA) and 17 % linolenic acid (LA)) at the rate of 100 ml/kg food following 4 months of feeding an identical standard basal diet. Plasma extracted at fasting state from five beagles and five greyhounds was analysed by GC. Plasma ALA, EPA and LA increased steadily and significantly from days 0 to 22 (P < 0.05); however, no significant breed differences were shown. Plasma DHA levels, on the other hand, showed no significant increase over time, but a significant breed difference was observed, with beagles having higher plasma level from day 0 (P = 0.002). This breed difference requires further investigation. Levels of ALA and EPA were still rising significantly between days 15 and 22, indicating that PUFA levels in plasma had not stabilised in 3 weeks. These findings together suggest that flaxseed oil could be a useful source of PUFA in dogs, especially ALA and EPA, and that breed differences may be important.     

Routine iron/folate supplementation during pregnancy: effect on maternal anaemia and birth outcomes

Iron deficiency is the most common nutritional deficiency globally. Children and women of reproductive age are at a particular risk of iron deficiency. Anaemia during pregnancy is a specific risk factor for adverse maternal and perinatal outcomes. The objective of this review was to assess the impact of routine iron supplementation on maternal anaemia and perinatal outcomes. A literature search was conducted for published randomised and quasi-randomised trials on PubMed and the Cochrane Library. Only those studies were included in the review that assessed the preventive effect of iron supplementation during pregnancy. Data from selected studies were double abstracted in a standardised excel sheet. The studies were graded according to study design, limitations, intervention specifics and outcome effects. Meta-analyses were conducted where data were available from more than one study for an outcome. After screening 5209 titles, 30 studies were selected for inclusion in this review. Daily iron supplementation resulted in 69% reduction in incidence of anaemia at term in the intervention group compared with control [relative risk (RR) 0.31 [95% confidence interval (CI) 0.22, 0.44]] and 66% reduction in iron deficiency anaemia at term (RR 0.44 [95% CI 0.28, 0.68]; random model) compared with no intervention/placebo. The quality grade for these outcomes was that of 'moderate' level. Routine daily iron supplementation during pregnancy resulted in a significant reduction of 20% in incidence of low birthweight in the intervention group compared with control (RR 0.80 [95% CI 0.71, 0.90]). Preventive iron supplementation during pregnancy has a significant benefit in reducing incidence of anaemia in mothers and low birthweight in neonates.     

三组不同分娩体位对孕产妇母儿结局的影响

目的探讨仰卧位、侧卧位和俯卧位三组不同分娩体位对孕产妇母儿结局的影响。方法选择2018年3月-2019年3月在佛山市南海区第六人民医院选择自然分娩的产妇300例,随机分为仰卧位组、侧卧位组和俯卧位组,每组100例。比较三组产妇妊娠结局(顺产率、剖宫产率、第二产程时间、产后2 h出血量)、产妇疼痛及焦虑感和胎儿心率,评价不同的分娩体位对孕产妇的影响。结果比较三组产妇的顺产率,发现俯卧位和侧卧位产妇顺产率均显著高于仰卧位,差异具有统计学意义(P <0.05);比较三组产妇的疼痛及焦虑情况发现,侧卧位和俯卧位分娩可以降低产妇的疼痛感和焦虑感,差异具有统计学意义(P<0.05);比较三组产妇的第二产程时间和产后2 h出血量发现,侧卧位和俯卧位分娩的产妇第二产程时间稍高于仰卧位组产妇,侧卧位和俯卧位分娩的产妇产后2 h出血量稍低于仰卧位组产妇,但差异均无统计学意义(P>0.05);比较三组产妇胎儿胎心正常率发现,侧卧位分娩和俯卧位分娩胎儿胎心正常率显著高于仰卧位,差异具有统计学意义(P <0.05)。结论产妇在第二产程分娩的过程中采取俯卧位和侧卧位分娩,可以提高孕产妇的顺产率,降低产妇分娩过程中的疼痛感和焦虑感,胎儿胎心的正常发生率也显著升高,达到改善孕产妇母儿结局的目的,是促进自然分娩的有效方式,值得在临床上进一步推广应用。     

A short-term n-3 DPA supplementation study in humans

Purpose

Despite the detailed knowledge of the absorption and incorporation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into plasma lipids and red blood cells (RBC) in humans, very little is known about docosapentaenoic acid (DPA, 22:5 n-3). The aim of this study was to investigate the uptake and incorporation of pure DPA and EPA into human plasma and RBC lipids.

Methods

Ten female participants received 8 g of pure DPA or pure EPA in randomized crossover double-blinded manner over a 7-day period. The placebo treatment was olive oil. Blood samples were collected at days zero, four and seven, following which the plasma and RBC were separated and used for the analysis of fatty acids.

Results

Supplementation with DPA significantly increased the proportions of DPA in the plasma phospholipids (PL) (by twofold) and triacylglycerol (TAG) fractions (by 2.3-fold, day 4). DPA supplementation also significantly increased the proportions of EPA in TAG (by 3.1-fold, day 4) and cholesterol ester (CE) fractions (by 2.0-fold, day 7) and of DHA in TAG fraction (by 3.1-fold, day 4). DPA proportions in RBC PL did not change following supplementation. Supplementation with EPA significantly increased the proportion of EPA in the plasma CE and PL fractions, (both by 2.7-fold, day 4 and day 7) and in the RBC PL (by 1.9-fold, day 4 and day 7). EPA supplementation did not alter the proportions of DPA or DHA in any lipid fraction. These results showed that within day 4 of supplementation, DPA and EPA demonstrated different and specific incorporation patterns.

Conclusion

The results of this short-term study suggest that DPA may act as a reservoir of the major long-chain n-3 fatty acids (LC n-3 PUFA) in humans.     

Effects of calcium supplementation during pregnancy on maternal, fetal and birth outcomes

Gestational hypertensive disorders are the second leading cause of maternal death worldwide. Epidemiological and clinical studies have shown that an inverse relationship exists between calcium intake and development of hypertension in pregnancy. The purpose of this review was to evaluate preventive effect of calcium supplementation during pregnancy on gestational hypertensive disorders and related maternal and neonatal morbidity and mortality. A literature search was carried out on PubMed, WHOLIS, PAHO and Cochrane Library. Only randomised trials were included in the review. Data were extracted into a standardised Excel sheet. Primary outcomes were pre-eclampsia, preterm birth and birthweight. Other neonatal outcomes such as neonatal mortality, small-for-gestational age and low birthweight were also evaluated. A total of 15 randomised controlled trials were included in this review. Pooled analysis showed that calcium supplementation during pregnancy reduced risk of pre-eclampsia by 52% [relative risk (RR) 0.48; 95% confidence interval (CI) 0.34, 0.67] and that of severe pre-eclampsia by 25% (RR 0.75 [95% CI 0.57, 0.98]). There was no effect on incidence of eclampsia (RR 0.73 [95% CI 0.41, 1.27]). There was a significant reduction for risk of maternal mortality/severe morbidity (RR 0.80 [95% CI 0.65, 0.97]). Calcium supplementation during pregnancy was also associated with a significant reduction in risk of pre-term birth (RR 0.76 [95% CI 0.60, 0.97]). There was an extra gain of 85 g in the intervention group compared with control (mean difference 85 g [95% CI 37, 133]). There was no effect of calcium supplementation on perinatal mortality (RR 0.90 [95% CI 0.74, 1.09]). There was a statistically non-significant increased risk of urolithiasis in the intervention group compared with control (RR 1.52 [95% CI 0.06, 40.67]). In conclusion, calcium supplementation during pregnancy is associated with a reduction in risk of gestational hypertensive disorders and pre-term birth and an increase in birthweight. There is no increased risk of kidney stones.     

慢性乙型肝炎及HBeAg状态对母婴结局的影响研究

目的 探讨妊娠合并乙肝病毒（hepatitis B virus,HBV）感染及乙型肝炎E抗原（hepatitis B e antigen,HBeAg）阳性状态对母婴结局的影响。方法 选取2008年6月~2017年9月于武汉市妇女儿童医疗保健中心分娩的1 463例乙肝孕妇作为病例组,另按照1 ∶1个体匹配的方式选取前后一月时间内在该机构分娩的1 463例健康孕妇作为对照组。在此基础上,按照乙肝血清学标志物结果,将所有纳入的研究对象分成正常对照组、乙肝表面抗原（hepatitis B surface antigen,HBsAg）（+）和HBeAg（-）组（单阳性组）、HBsAg（+）和HBeAg（+）组（双阳性组）。收集孕产妇一般信息、妊娠并发症情况以及新生儿信息,分别比较上述三组的一般情况、各项妊娠不良结局的发生情况。结果 单阳性组妊娠高血压的发生风险是正常对照的2.74倍（95%CI：1.09～6.90,P=0.033）;双阳性组妊娠期高血压的发生风险是正常对照的6.67倍（95%CI：1.29～34.48,P=0.023）。单阳性组剖宫产的发生风险是正常对照的1.15倍（95%CI：1.03～1.29,P=0.010）;双阳性组则为正常对照的1.53倍（95%CI：1.24～1.88,P<0.001）。结论 乙肝感染会增加孕妇妊娠期高血压和以剖宫产作为其分娩方式的风险。     

The effects of maternal smoking on fetal and infant mortality

Although maternal cigarette smoking has been shown to reduce the birth weight of an infant, previous findings on the relation between smoking and fetal and infant mortality have been inconsistent. This study used the largest data base ever available (360,000 birth, 2,500 fetal death, and 3,800 infant death certificates for Missouri residents during 1979-1983) to assess the impact of smoking on fetal and infant mortality. Multiple logistic regression was used to estimate the joint effects of maternal smoking, age, parity, education, marital status, and race on total mortality (infant plus fetal deaths). Compared with nonsmoking women having their first birth, women who smoked less than one pack of cigarettes per day had a 25% greater risk of mortality, and those who smoked one or more packs per day had a 56% greater risk. Among women having their second or higher birth, smokers experienced 30% greater mortality than nonsmokers, but there was no difference by amount smoked. The prevalence of smoking in this population was 30%. It was estimated that if all pregnant women stopped smoking, the number of fetal and infant deaths would be reduced by approximately 10%. The higher rate of mortality among blacks compared with whites could not be attributed to differences in smoking or the other four maternal characteristics studied. In fact, the black-white difference was greater among low-risk women (e.g., married multiparas aged 20 and over with high education) than among high-risk women (e.g., unmarried teenagers with low education).     

Ethnic differences in early pregnancy maternal n-3 and n-6 fatty acid concentrations: an explorative analysis

Ethnicity-related differences in maternal n-3 and n-6 fatty acid status may be relevant to ethnic disparities in birth outcomes observed worldwide. The present study explored differences in early pregnancy n-3 and n-6 fatty acid composition of maternal plasma phospholipids between Dutch and ethnic minority pregnant women in Amsterdam, the Netherlands, with a focus on the major functional fatty acids EPA (20 : 5n-3), DHA (22 : 6n-3), dihomo-gamma-linolenic acid (DGLA; 20 : 3n-6) and arachidonic acid (AA; 20 : 4n-6). Data were derived from the Amsterdam Born Children and their Development (ABCD) cohort (inclusion January 2003 to March 2004). Compared with Dutch women (n 2443), Surinamese (n 286), Antillean (n 63), Turkish (n 167) and Moroccan (n 241) women had generally lower proportions of n-3 fatty acids (expressed as percentage of total fatty acids) but higher proportions of n-6 fatty acids (general linear model; P < 0.001). Ghanaian women (n 54) had higher proportions of EPA and DHA, but generally lower proportions of n-6 fatty acids (P < 0.001). Differences were most pronounced in Turkish and Ghanaian women, who, by means of a simple questionnaire, reported the lowest and highest fish consumption respectively. Adjustment for fish intake, however, hardly attenuated the differences in relative EPA, DHA, DGLA and AA concentrations between the various ethnic groups. Given the limitations of this observational study, further research into the ethnicity-related differences in maternal n-3 and n-6 fatty acid patterns is warranted, particularly to elucidate the explanatory role of fatty acid intake v. metabolic differences.