Omega-3 long-chain polyunsaturated fatty acids and fish oil supplementation during pregnancy: which evidence?

Objective: The aim of this study was to provide evidence-based recommendations for omega-3 supplementation during pregnancy through a systematic review of level-1 data published on this topic.

Methods: We reviewed all randomized-controlled trials (RCTs) including women who were randomized to treatment with either omega-3 supplementation or control (placebo or no treatment) during pregnancy and analyzed all the outcomes reported in the trials, separately. We planned to evaluate the effect of omega-3 on: preterm birth (PTB); pre-eclampsia (PE) and intrauterine growth restriction (IUGR); gestational diabetes; perinatal mortality; small for gestational age (SGA) and birth weight; infant eye and brain development; and postpartum depression.

Results: We identified 34 RCTs including 14 106 singletons and 2578 twins. These level-1 data showed that omega-3 was not associated with prevention of PTB, PE, IUGR, gestational diabetes, SGA, post-partum depression or better children development. Data about birth weight, perinatal mortality and childhood cognitive outcome were limited. Women with gestational diabetes who received omega-3 had significantly lower serum C-reactive protein concentrations, low incidence of hyperbilirubinemia in newborns and decreased newborns’ hospitalization rate.

Conclusions: There was not enough evidence to support the routine use of omega-3 supplementation during pregnancy. Given the 73% significant decrease in perinatal death in the singleton gestations who started omega-3 supplementation ≤?20 weeks, further research is needed. Large RCTs in multiple gestations and longer follow-up are also required.     

Use of herbal preparations during pregnancy: Focus group discussion among expectant mothers attending a hospital antenatal clinic in Norwich,UK

BackgroundThe extent of herbal medicine use in pregnancy has been widely researched throughout the world but little research has been published about the motivations for this use.MethodsFocus group discussion. Women who participated in a survey at an antenatal clinic were asked to participate in a focus group discussion to elaborate further on some of the results from the survey. Six women participated.ResultsThe major themes identified were: the “underground” nature of taking herbal remedies, reliance on family and friends for information, perceived safety of herbal remedies whilst acknowledging the lack of trial evidence and a desire for the NHS to be more open minded.ConclusionHerbal medicines are pharmacologically active and pregnant women frequently take these without informing their pregnancy care provider. If doctors want to obtain a full medical picture which includes herb use then non-judgemental responses to such behaviour is required.     

Use of embryo culture supernatant to improve clinical outcomes in assisted reproductive technology: a systematic review and meta-analysis

We planned a systematic review and meta-analysis of randomized clinical trials (RCTs) to examine the best available evidence regarding the intrauterine instillation of embryo culture supernatant prior to embryo transfer in ART. The outcomes were: (i) live birth; (ii) clinical pregnancy; (iii) multiple pregnancy; and (iv) miscarriage rates. Five RCTs were considered eligible and available for qualitative synthesis. Due to clinical heterogeneity, results from only two trials were combined for the meta-analysis. The live birth rate (risk ratio [RR], 0.47; 95% confidence interval [CI] 0.22–0.98; one study, 60 participants, low-quality evidence) was found to be significantly lower with intrauterine instillation of embryo culture supernatant compared to no intervention. The clinical pregnancy rate was similar between the embryo culture supernatant group and the control group (RR 1.02 RR, 95% CI 0.77–1.36; two trials, 156 participants, I²?=?0%). To conclude, this review did not find any improvement in clinical pregnancy rate with the intrauterine instillation of embryo culture supernatant prior to embryo transfer compared to no intervention in women undergoing ART and we remain uncertain regarding its effect on live birth rate.     

Influence of Calcium on Vascular Reactivity in Pregnant Rats

Objective: To examine fetal (FHR) and neonatal heart rate patterns following use of common oral antihypertensives in pregnancy. Methods: A systematic review of randomized controlled trials (RCTs), observational studies (N ≥ 6 women), and animal studies. Data were abstracted (two reviewers) to determine relative risk (RR) (or risk difference (RD) for low event rates) and 95% CI. Results: Eighteen RCTs (1858 women), one controlled observational study (N = 22), and seven case series (N = 117) were reviewed. Most hypertension was pregnancy‐induced (N = 14 studies). The FHR was assessed by cardiotocogram (CTG) (N = 17 studies (visual interpretation); 1 study (computerized CTG), or umbilical artery velocimetry (N = 4). Four studies examined neonatal heart rate. In placebo‐controlled RCTs (N = 192 women), adverse FHR effects did not differ between groups [9/101 (drugs) vs. 7/91 (placebo); RD 0.02, 95% CI (? 0.06, 0.11); χ² = 1.02]. In six drug vs. drug RCTs (295 women), adverse FHR effects did not differ between groups [29/144 (methyldopa) vs. 42/151 (other drugs); RR 0.72, 95% CI (0.49, 1.07); χ² = 0.69]. In one labetalol vs. placebo trial, neonatal bradycardia did not differ between groups [4/70 (labetalol) vs. 4/74 (placebo); OR 1.06, 95% CI (0.26, 4.39)], while in three drug vs. drug RCTs, neonatal bradycardia was not observed (0/24 vs. 0/26). Conclusions: Available data are inadequate to conclude whether oral methyldopa, labetalol, nifedipine, or hydralazine adversely affect fetal or neonatal heart rate and pattern. Until definitive data are available, FHR changes cannot be reliably attributed to drug effect, but may be due to progression of the underlying maternal or placental disease.     

Does Acupuncture Have a Place as an Adjunct Treatment During Pregnancy? A Review of Randomized Controlled Trials and Systematic Reviews

Background: Complementary medicine has become popular throughout many Western countries and is widely used by women across all stages of their life cycle. Acupuncture is used by women during their pregnancy, and research suggests that acupuncture may be used as an adjunct to their existing conventional care. The aim of this paper was to summarize the evidence examining the effectiveness of acupuncture during pregnancy and birthing, and to discuss its role as an adjunct treatment. Methods: We conducted a systematic literature search using several electronic databases. We included all placebo‐controlled randomized trials of parallel design, and systematic reviews that evaluated the role of acupuncture during pregnancy and birthing. A critical appraisal of clinical trials and systematic reviews was undertaken. Results: The summarized findings indicated a small but growing body of acupuncture research, with some evidence suggesting a benefit from acupuncture to treat nausea in pregnancy. Findings from the review also highlighted promising evidence for the effectiveness of acupuncture to manage back and pelvic pain, acupuncture‐type interventions to induce change in breech presentation, and pain relief in labor. The methodological quality of recent trials has improved, and the quality of systematic reviews was high. Conclusions: Interest is growing in the use of acupuncture to treat some complaints during pregnancy and childbirth, and evidence is beginning to consolidate that acupuncture may assist with the management of some complaints during pregnancy. However, definitive conclusions about its effectiveness cannot be reached and further research is justified.     

Bed rest following embryo transfer might negatively affect the outcome of IVF/ICSI: a systematic review and meta-analysis

The majority of patients undergoing in vitro fertilization (IVF) and intracytoplasmatic sperm injection (ICSI) treatment will reach the stage of embryo transfer (ET), but only a small proportion of transferred embryos implant. Bed rest following ET has been recommended as a way to prevent embryo expulsion by gravity. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) published prior to May 2014 reporting the effect of bed rest following ET, and irrespective of language, country of origin, blinding or sample size. Four RCTs, including 757 women met the inclusion criteria. Bed rest following ET did not improve clinical pregnancy and live birth rates, but reduced the implantation rate. The quality of the trials included was moderate because of attrition bias and possible reporting bias. The findings of this systematic review and meta-analysis are concordant with previously published literature and suggest that bed rest is not beneficial following ET. Moreover, it might negatively affect the outcome of IVF/ICSI cycles via stress/anxiety mechanisms.     

Effect of folic acid supplementation during pregnancy on gestational hypertension/preeclampsia: A systematic review and meta-analysis

Objective: To evaluate the effect of folic acid supplementation during pregnancy on the risk of gestational hypertension/preeclampsia. Methods: A systematic review and meta-analysis were conducted. Medline, Embase, Scopus, and the Web of Science were searched from inception to December 2014. Results: Out of 1224 potentially relevant studies, 13 studies met our inclusion criteria (2 randomized controlled trials (RCTs), 10 cohort studies, and 1 case–control study). The pooled relative risk (RR) and 95% confidence interval (CI) of the two RCTs were 0.62 (0.45–0.87) in the trial arm as compared with the placebo arm. The pooled RR was 0.92 (95% CI: 0.79–1.08) for nine cohort studies with available data on folic acid supplementation in pregnancy and gestational hypertension/preeclampsia. Pooled RR was 0.88 (95% CI: 0.76–1.02) for eight cohort studies with available data on folic acid supplementation and preeclampsia. Conclusion: Whether folic acid supplementation in pregnancy can prevent the occurrence of gestational hypertension/preeclampsia remains uncertain.     

Letrozole versus clomiphene citrate in polycystic ovary syndrome: systematic review and meta-analysis

Abstract

The objective of the present systematic review and meta-analysis was to examine the literature and to identify the results of randomized controlled trials (RCTs) comparing the use of letrozole to clomiphene citrate (CC) for ovulation induction in patients with polycystic ovary syndrome (PCOS). An exhaustive electronic literature search was performed using the MEDLINE and EMBASE databases until October 2014. Seven prospective RCTs comparing the use of letrozole to CC in PCOS patients met the inclusion criteria. Overall, the seven included studies accounted for 1833 patients (906 in the letrozole group and 927 in the CC group) and for 4999 ovulation induction cycles (2455 in the letrozole group and 2544 in the CC group). Five of the included studies reported data on live birth rates. There was a statistically significant increase in the live birth and pregnancy rates in the letrozole group when compared to the CC group, with a relative risk (RR)?=?1.55 (95% confidence interval (CI): 1.26–1.90; I^2?=?0%) and RR?=?1.38 (95% CI: 1.05–1.83; I^2?=?61%), respectively. There were no differences in the multiple pregnancy, miscarriage and ovulation rates between the two groups. Our study found that letrozole is superior to CC when considering the live birth and pregnancy rates in patients with PCOS.     

Follicular flushing during oocyte retrieval: a systematic review and meta-analysis

Purpose

The purpose of this systematic review and meta-analysis was to examine the literature and identify randomized controlled trials (RCTs), in order to answer if performing follicular flushing during the oocyte retrieval may improve the assisted reproductive technologies (ART) outcomes.

Methods

An exhaustive electronic search was performed using MEDLINE and EMBASE databases. Only RCTs comparing follicular flushing to aspiration only during ART, were included. We included 5 trials, with a total of 482 patients randomized, with median ages ranging from 30.5 to 37.1.

Results

The data analyses did not show significant differences regarding live birth rate, clinical pregnancies rates, and the number of oocytes retrieved. The duration of oocyte retrieval was significantly increased in the follicular flushing group.

Conclusions

The results from this systematic review and meta-analysis suggest that there is no advantage to use of routine follicular flushing during OR in an unselected group of patients.     

Use of herbal medicines among pregnant women attending family health centers in Alexandria

ObjectiveThe aim of the study is to elucidate the use of herbal medicines in pregnant women and to explore patterns of herbal medication use including dietary supplements in pregnant women in Alexandria, Egypt.MethodologyA cross sectional study of pregnant females was conducted in a family health center in Alexandria between March and June 2011 utilizing a sample of 300 pregnant women (100 pregnant women in each trimester). A specially designed self administered questionnaire was used to collect the data.ResultsThe mean age of studied pregnant women was 26.9 ± 4.9 years. Only 27.3% of the studied pregnant women reported the use of herbal medicines during pregnancy while 89% reported the use of dietary supplements.The majority of pregnant women resorted to (family/friends) as primary source of information of herbal medicines (42.7% and 28%, respectively), while the majority of women using dietary supplements resorted to (physicians) as primary source of information (76%).52.4% of the studied pregnant women reported that they use ginger during the 1st trimester of pregnancy while 51.6% reported that they use fenugreek during the 3rd trimester of pregnancy.More than half of the studied pregnant women (64.6%) reported the efficacy of herbal medicines in relieving their complaints during pregnancy.ConclusionThe use of herbal medicines during pregnancy in Alexandria was uncommon while the use of dietary supplements was very common.About three quarters of studied sample reported that the physician was the person to recommend dietary supplement usage while the physician was rarely cited as the person recommending herbal usage.The most common herbs used by pregnant women were aniseed, fenugreek, ginger, while the least used was peppermint.Ginger was found to be used by a significantly higher percentage of pregnant women in the first trimester; on the other hand, fenugreek was used by a significantly higher percentage of pregnant women in the third trimester.RecommendationsResults of the following study suggest the following recommendations:General recommendationsGeneral health education for pregnant women about benefits and harms of herbal use during pregnancy in ante-natal care especially for herbs commonly used in Egypt.Specific recommendations

• ACare providers:

Training of family physicians in the family health centers on the use of herbal medicines in pregnancy and possible effects on the fetus.

• BPregnant women:

Health education program directed toward pregnant women to increase their awareness about the effects of herbal medicines.     

Dietary supplements and herbal remedies for premenstrual syndrome (PMS): a systematic research review of the evidence for their efficacy

Many women with PMS use alternative therapies, although there has been little research to demonstrate their efficacy. This systematic review provides a comprehensive discussion of dietary supplements and herbal remedies commonly used for premenstrual syndrome (PMS), including calcium, magnesium, vitamin B6, evening primrose oil, Vitex agnus castus, ginkgo biloba and St John's Wort. Randomized controlled trials of magnesium and evening primrose oil have produced conflicting results, in contrast to the substantial evidence for the efficacy of calcium and vitamin B6. There are insufficient data to advocate the use of ginkgo biloba, Vitex agnus castus and St John's Wort, although preliminary data seem supportive. Greater standardization of PMS diagnosis and assessment, with randomized, double‐blind, placebo‐controlled trials using larger, representative samples, strict, prospectively confirmed diagnostic criteria and assessment of treatment efficacy, would help to clarify the role of these alternative PMS treatments. Although much of the clinical research is preliminary and/or inadequately controlled, this review will be relevant to the practicing clinician looking for greater understanding of the alternative therapies available to their patients with PMS.     

Use of herbal drugs during pregnancy among 600 Norwegian women in relation to concurrent use of conventional drugs and pregnancy outcome

Purpose

The purpose of this study was to investigate the use of herbal drugs by pregnant women in relation to concurrent use of conventional drugs, delivery, and pregnancy outcome.

Method

600 women at Stavanger University Hospital Norway were interviewed using a structured questionnaire within five days after delivery. Medical birth charts were reviewed with respect to pregnancy outcome.

Results

In all, 39.7% of the women reported having used herbal drugs during pregnancy, most commonly ginger, iron-rich herbs, echinacea and cranberry. Although 86.3% of the women reported having used conventional drugs during pregnancy there were few potential interactions between herbal drugs and conventional drugs. There was a significant association between the use of iron-rich herbs during pregnancy and high birthweight, and use of raspberry leaves and caesarean delivery.

Conclusion

Use of herbal drugs is common during pregnancy and indicates a need for documentation about their safety in pregnancy.     

Use of anti-emetic herbs in pregnancy: women's choices, and the question of safety and efficacy

The majority of North American pregnant women experience some degree of nausea and vomiting, usually in the first few months of pregnancy. Women utilize many coping strategies, including self-treatment with herbal medicine and other alternative therapies. In a qualitative study of self-care in pregnancy, birth and lactation within a non-random sample of 27 women in British Columbia, Canada, 20 women (74%) experienced pregnancy-induced nausea. Ten of these women used anti-emetic herbal remedies, which included ginger, peppermint, and Cannabis. The safety and efficacy of each of these herbal remedies is discussed here. Only ginger has been subjected to clinical trials among pregnant women, though all three herbs were clinically effective against nausea and vomiting in other contexts, such as chemotherapy-induced nausea and post-operative nausea. While safety concerns exist in the literature for all three herbs with regards to their use by pregnant women, clinical evidence of harm is lacking.     

Retrospective evaluation of pregnancy outcomes in women with familial Mediterranean fever

Abstract

Aim: Familial Mediterranean fever (FMF) is an autosomal recessive condition characterized by periodic attacks of fever, aseptic serositis and synovitis. In this study, we investigated maternal and neonatal outcomes in pregnant patients with FMF.

Methods: This retrospective study consisted of 46 pregnant patients with FMF who attended the perinatology clinic of Dr Zekai Tahir Burak Research and Training Hospital between January 2008 and December 2012. The following clinical and demographic data were obtained by reviewing the patients’ medical records: maternal age, colchicine use during pregnancy, obstetric history, pregnancy outcome and maternal and neonatal complications during the current pregnancy.

Results: The patients with FMF had higher rates of premature rupture of membranes (PROM) and Cesarean delivery as well as low birth weight infants; however, rates of stillbirth, gestational diabetes, preeclampsia did not differ between the groups. Preterm delivery rates were higher in the study group, but this difference did not reach statistical significance. Patients with pregnancy complications had significantly more basal proteinuria than did patients without complications.

Nine patients did not receive colchicine therapy in the previous or current pregnancies. Within this subgroup, four (44.4%) of the patients had a history of two or more previous miscarriages. However, there were only three cases (8.1%) of two or more miscarriages among 37 patients who received colchicine; this difference was statistically significant

Conclusions: FMF leads to higher rates of PROM, recurrent miscarriage and preterm deliveries. Colchicine treatment is safe in pregnancy and may lead to a decreased miscarriage rate.     

Effect of nonsurgical periodontal therapy during gestation period on adverse pregnancy outcome: a systematic review

Abstract

Objective: To confirm effectiveness of nonsurgical periodontal treatment during pregnancy on pregnancy outcome in terms of preterm birth and low birth weight (LBW).

Method: We searched for Randomized controlled trials in MEDLINE, CINAHL and EMBASE. from January 2000 to October 2012. References of included studies were hand searched. Studies which measured incidence of either preterm labor (PTL), LBW or both were included. Information on study design, population, risk of bias, periodontal parameters, time and type of periodontal treatment given and pregnancy outcome were abstracted independently by three reviewers.

Results: Total thirteen studies were included. Five studies had low risk of bias. Conclusive results could not be obtained for incidence of PTL or LBW because of heterogeneity in results due to various reasons, but all studies which assessed PTL and LBW combined showed significant difference in incidence of same in group which received non surgical periodontal treatment.

Conclusion: Our study suggests that treatment of periodontitis during gestation improves pregnancy outcome in terms of PTLBW, a fact which may be used for health and economical benefits but better RCTs with adequate sample size are required for conclusive evidence.     

Efficacy of dehydroepiandrosterone (DHEA) supplementation for in vitro fertilization and embryo transfer cycles: a systematic review and meta-analysis

Dehydroepiandrosterone (DHEA) supplementation might hold some promise in vitro fertilization and embryo transfer cycles. However, the results remain controversial. We conducted a systematic review and meta-analysis to evaluate the efficacy of DHEA in patients for in vitro fertilization. PubMed, EMbase, Web of science, EBSCO and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) assessing the effect of DHEA versus placebo on in vitro fertilization were included. Two investigators independently searched articles, extracted data and assessed the quality of included studies. The primary outcomes were clinical pregnancy and live birth rate. Meta-analysis was performed using random-effect model. Six RCTs involving 745 patients were included in the meta-analysis. Overall, compared with placebo, DHEA supplementation was associated with the significant increase in clinical pregnancy (OR?=?1.45; 95% CI?=?1.04–2.03; p?=?.03), live birth rate (OR?=?2.70; 95% CI?=?1.24–5.85; p?=?.01) and endometrial thickness (Std. mean difference?=?0.67; 95% CI?=?0.02–1.32; p?=?.04) but showed no influence on E₂ on hCG day (Std. mean difference?=?0.69; 95% CI?= ?0.46 to 1.85; p?=?.24), embryos transferred (Std. mean difference?=?0.42; 95% CI?= ?0.04 to 0.88; p?=?.07) and miscarriage rate (OR?=?0.43; 95% CI?=?0.03–6.66; p?=?.55). DHEA supplementation could significantly improve clinical pregnancy, live birth rate, endometrial thickness and retrieved oocytes but failed to alter E₂ on hCG day, embryos transferred and miscarriage rate.     

Effective management and intrauterine treatment of congenital cytomegalovirus infection: review article and case series

Abstract

Objective: Human Cytomegalovirus (CMV) infection during pregnancy is the most frequent viral cause of intrauterine infection and responsible for various cerebral and other ultrasound abnormalities of the fetus. It is the leading infectious cause of mental retardation and sensorineural deafness in affected newborns and infants.

We present three cases of primary cytomegalovirus infection in pregnancy and demonstrate three different scenarios of the disease with regard to clinical outcome and therapy options. We first report on CMV related phospho- and glycoprotein-specific antibody reactivities in amnion fluid that have not been reported earlier in literature.

Case presentation: Case 1: A 33-year-old Gravida II Para I was referred for primary CMV infection at 15 weeks gestation presenting with a history of fever. HIG therapy was performed resulting in good neonatal outcome.

Case 2: A 23-year-old Gravida I was referred for targeted ultrasound at 23 weeks of gestation presenting with intrauterine growth retardation, multiple fetal hepatic echodensities and thickened placenta. Termination of pregnancy was initiated.

Case 3: A 29-year-old Gravida II Para I was referred for primary CMV infection at 16 weeks gestation presenting with no clinical symptoms of CMV. HIG therapy was performed, resulting in good neonatal outcome.

Conclusion: We want to stress the potential benefit of an off label use of CMV-specific hyperimmune globulin (HIG) therapy, present an algorithm for the management of affected pregnancies and review current literature on this issue.     

Effect of exercise during pregnancy to prevent gestational diabetes mellitus: a systematic review and meta-analysis

Introduction: Exercise showed some potential in preventing gestational diabetes mellitus. However, the results remained controversial. We conducted a systematic review and meta-analysis to evaluate the impact of exercise during pregnancy on gestational diabetes mellitus.

Methods: PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) assessing the influence of exercise during pregnancy on gestational diabetes mellitus were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcome was the incidence of gestational diabetes mellitus. Meta-analysis was performed using random-effect model.

Results: Six RCTs involving 2164 patients were included in the meta-analysis. Compared with control intervention, exercise intervention was associated with significantly decreased incidence of gestational diabetes mellitus (Std. mean difference?=?0.59; 95%CI?=?0.39–.88; p?=?.01), but had no effect on gestational age at birth (Std. mean difference?=??0.03; 95%CI?=??0.12 to 0.07; p?=?.60), the number of preterm birth (OR?=?0.85; 95%CI?=?0.43–1.66; p?=?.63), glucose 2-h post-OGTT (Std. mean difference?=??1.02; 95%CI?=??2.75 to 0.71; p?=?.25), birth weight (Std. mean difference?=??0.13; 95%CI?=??0.26 to 0.01; p?=?.06), and Apgar score less than 7 (OR?=?.78; 95%CI?=?0.21–2.91; p?=?.71).

Conclusions: Compared to control intervention, exercise intervention could significantly decrease the risk of gestational diabetes mellitus, but showed no impact on gestational age at birth, preterm birth, glucose 2-h post-OGTT, birth weight, and Apgar score less than 7.     

Association between wood cooking fuel and maternal hypertension at delivery in central East India

Objective: Smoke from burning of biomass fuels has been linked with adverse pregnancy outcomes and hypertension among nonpregnant subjects; association with hypertension during pregnancy has not been well studied. We evaluated whether the use of wood cooking fuel increases the risk of maternal hypertension at delivery compared to gas which burns with less smoke. Methods: Information on fuel use and blood pressure was available for analysis from a cross-sectional survey of 1369 pregnant women recruited at delivery in India. Results: Compared to gas users, women using wood as fuel had on average lower mean arterial pressure (adjusted effect size???2.0?mmHg; 95% CI: ?3.77, ?0.31) and diastolic blood pressure (adjusted effect size ?1.96?mmHg; 95% CI: ?3.60, ?0.30) at delivery. Risk of hypertension (systolic >139?mmHg or diastolic >89?mmHg) was 14.6% for wood users compared to 19.6% for gas users although this did not reach significance after adjustment, using propensity score techniques, for factors that make wood and gas users distinct (adjusted prevalence ratio 0.76; 95% CI: 0.49, 1.17). Conclusions: Combustion products from the burning of biomass fuels are similar to those released with tobacco smoking, which has been linked with a reduced risk for preeclampsia. The direction of our findings suggests the possibility of a similar effect for biomass cook smoke. Whether clean cooking interventions being promoted by international advocacy organizations will impact hypertension in pregnancy warrants further analysis as hypertension remains a leading cause of maternal death worldwide and cooking with biomass fuels is widespread.