Liraglutide and Liver Injury: Rare Case Report with Literature Review.

BACKGROUND: Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist used for the treatment of type 2 diabetes mellitus (T2DM). So far, few severe side effects have been reported for it. CASE PRESENTATION: A 41-year-old woman was admitted to the Emergency Room with diffuse abdominal pain. The patient had a known case of T2DM, fatty liver disease, and hypertension and was treated with Metformin, Liraglutide, and Losartan. Her liver functional test (LFT) was consistent with hepatocellular injury; however, laboratory tests and abdominal ultrasound were used to rule out autoimmune hepatitis. Due to concerns for drug-induced liver injury (DILL), liraglutide was discontinued and N-acetyl cysteine was prescribed. On the fifth day of hospitalization, the patient's symptoms resolved and his LFT started to decrease on the sixth day after 2 months, the patient's liver enzyme levels returned to normal. CONCLUSION: Liraglutide is one of the most important drugs in the treatment of T2DM.The most common side effects of this drug are constipation, nausea, vomiting, diarrhea, indigestion, and loss of appetite. In rare cases, symptoms of thyroid cancer, pancreatitis, and hypoglycemia have been reported, however, DILL is one of the extremely rare side effect of Liraglutide. It is important to increase the awareness of physicians about the liver injury of Liraglutide.

The environmental risk factors associated with ectopic pregnancy: An umbrella review.

INTRODUCTION: Ectopic pregnancy(EP) is the implantation of a fertilized ovum outside of the uterine cavity. The incidence of EP has steadily increased around the world. The present umbrella review evaluated risk factors prior to conception associated with EP based on meta-analyses and systematic reviews. METHODS: We searched PubMed, Scopus, and Web of Science until June 25, 2021. All meta-analyses that had focused on assessing the risk factors associated with EP were included. We calculated summary effect estimates, 95% CI, heterogeneity I², 95% prediction interval, small-study effects, excess significance biases, and sensitive analysis. The quality of the meta-analyses was evaluated with A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2). RESULTS: Two risk factors including chlamydia trachomatis (OR: 3.03) and smoking (OR: 1·77) were graded as suggestive evidence (class III). IUD with pregnant control (OR: 10.63) and endometriosis for case-control studies (OR: 2·66) and tubal ligation with pregnant control (OR: 9.3) were graded as risk factors with weak evidence (class IV). Tubal ligation with non-pregnant control was a protective factor (class IV). IUD with non-pregnant control and endometriosis for cohort studies were not as risk factors for EP. CONCLUSION: Two risk factors including chlamydia trachomatis and smoking were graded as suggestive evidence. IUD with pregnant control and endometriosis for case-control studies and tubal ligation with pregnant control were graded as risk factors with weak evidence. Strong evidence for risk factors of EP was not achieved, indicating the degree of uncertainty and bias, which bring an emergency to conduct further no-bias studies. SYSTEMATIC REVIEW REGISTRATION: PROSPERO (CRD42021281632).

Predictive factors of Sexual Quality of Life in women with polycystic ovary syndrome: a path analysis.

Polycystic ovarian syndrome (PCOS) is one of the common endocrine disorders. This study aimed to assess predictive factors of sexual quality of life among Iranian women with PCOS. A cross-sectional study was conducted on 100 women with PCOS in Hamadan, Iran, from July to October 2021. Data was collected using The Sexual Quality of Life-Female (SQOL-F) questionnaire, The Hurlbert Index of Sexual Compatibility, hirsutism, and a general health questionnaire (GHQ-28). Data were analyzed using descriptive statistics, Bivariate Pearson correlations, and a path model by the SPSS, Version 16, and LISREL software version 8.5. The average age of participants was 32.80 years. The mean (SD) of the total SQOL-F, sexual compatibility, and GHQ were 69.36 (18.78), 55.44 (7.07), and 58.06 (12.87), respectively. Our results showed that hirsutism score, GHQ, and sexual compatibility were the main predictors of the SQOL-F. Sexual compatibility has an indirect effect on the SQOL-F through the GHQ. The findings of the present study suggest that women with PCOS should be routinely screened for sexual quality of life by qualified health professionals. In addition, the necessary medical interventions and counseling should be done for improving sexual compatibility, mental health, and clinical manifestation of these women.

The environmental risk factors related to uterine leiomyoma: An umbrella review.

BACKGROUND: Uterine leiomyoma (UL) is the most common benign tumor of the reproductive period and become a major health problem. The present umbrella review assessed the environmental risk factors associated with UL based on meta-analyses studies. MATERIALS AND METHODS: We searched three Major databases until February 2022. The meta-analyses that had focused on evaluating the environmental risk factors associated with the UL were included. The summary effect estimates, 95% CI, heterogeneity I², 95% prediction interval, small-study effects, excess significance biases, and sensitive analysis were applied. We used A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2) for assessing the quality of the meta-analyses. RESULT: The risk factor of chronic psychological stress (OR 1.24, 95% CI: 1.15, 1.34) and obesity (OR 1.19, 95% CI: 1.09, 1.29) was graded as suggestive evidence (class III). The current alcohol intake (OR 1.33, 95% CI: 1.01, 1.76) was graded as the risk factor with weak evidence (class IV). Current oral contraceptive (OCP) use (RR 0.43, 95% CI: 0.25, 0.73) (class IV), and former smokers (OR 0.93, 95% CI: 0.88, 0.99) (class IV) were as the protective factors. CONCLUSION: The current alcohol intake, chronic psychological stress, and obesity were risk factors for the UL, but current OCP use and former smokers were the protective factors.

Maternal Smoking and the Risk of Placenta Accreta Spectrum: A Systematic Review and Meta-Analysis.

Background: This is the first meta-analysis that assessed the association between maternal smoking and the risk of placenta accreta spectrum (PAS), so this study was aimed at investigating the association between maternal smoking and PAS based on observational studies. PAS is defined as a severe obstetric complication due to the abnormal invasion of the chorionic villi into the myometrium and uterine serosa. Methods: We searched electronic bibliographic databases including PubMed, Web of Science, Scopus, Science Direct, and Google Scholar until January 2022. The results were reported using a random effect model. The chi-square test and the I 2 statistic were used to assess heterogeneity. Egger's and Begg's tests were used to examine the probability of publication bias. All statistical analyses were performed at a significance level of 0.05 using Stata software, version 11. Results: Based on the random effect model, the estimated OR of the risk of PAS associated with smoking was 1.21 (95% CI: 1.02, 1.41; I 2 = 4.7%). Subgroup analysis was conducted based on study design, and the result showed that the association between smoking and PAS among cohort studies was significant 1.35 (95% CI: 1.15, 1.55; I 2 = 0.0%). Conclusion: Our results suggested that maternal smoking is a risk factor for the PAS. There was no heterogeneity among studies that reported an association between smoking and the PAS. The Newcastle-Ottawa Scale (NOS) was used to measure study quality.

Pregnancy-Associated Sacroiliitis following an Uncomplicated Pregnancy.

Pregnancy-associated sacroiliitis is infrequent during the peripartum period. Although pregnancy-associated pyogenic sacroiliitis rarely occurs, it is associated with significant morbidity and mortality. A timely diagnosis of the disease is challenging due to its nonspecific clinical symptoms. We reviewed a case that experienced an acute illness during pregnancy. The illness was manifested by localized pain in the hips or buttocks, sacroiliac joint tenderness, and debilitating hip pain during ambulation. Magnetic resonance imaging revealed little joint involvement, and the patient was treated with antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDs), and glucocorticoids. The patient responded well to the therapy with marked improvement in her ambulation. Septic sacroiliitis should be considered in peripartum patients presenting with increased inflammatory markers and severe localized pain. Medical management is usually curative and without an adverse effect on pregnancy. Although we could not perform a biopsy to verify the cause of the disease, the patient's excellent response to the treatment confirmed our diagnosis.

The environmental risk factors prior to conception associated with placental abruption: an umbrella review.

BACKGROUND: The present umbrella review evaluated risk factors prior to conception associated with placental abruption based on meta-analyses and systematic reviews. METHODS: We searched PubMed, Scopus, and Web of Science until June 25, 2021. All meta-analyses that had focused on assessing the risk factors associated with placental abruption were included. We calculated summary effect estimates, 95% CI, heterogeneity I2, 95% prediction interval, small-study effects, excess significance biases, and sensitive analysis. The quality of the meta-analyses was evaluated with A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2). RESULTS: There was no risk factor in the present umbrella review with the high level of evidence (class I or II). Eight risk factors including maternal asthma (RR 1.29 95% CI 1.14, 1.47), prior cesarean section (RR 1.38, 95% CI 1.35-1.42), cocaine using (RR 4.55, 95% CI 1.78-6.50), endometriosis (OR 1.40, 95% CI 1.12-1.76), chronic hypertension (OR 3.13, 95% CI 2.04-4.80), advanced maternal age (OR 1.44, 95% CI 1.35-1.54), maternal smoking (OR 1.80, 95% CI 1.75-1.85) (RR 1.65, 95% CI 1.51-1.80), and use of assisted reproductive techniques (ART) (OR 1.87, 95% CI 1.70-2.06) were graded as suggestive evidence (class III). The other four risk factors including pre-pregnancy underweight (OR 1.38, 95% CI 1.12-1.70), preeclampsia (OR 1.73, 95% CI 1.47-2.04), uterine leiomyoma (OR 2.63, 95% CI 1.38-3.88), and marijuana use (OR 1.78, 95% CI 1.32-2.40) were graded as risk factors with weak evidence (class IV). CONCLUSION: Maternal asthma, prior cesarean section, cocaine use, endometriosis, chronic hypertension, advanced maternal age, maternal smoking, and use of ART, pre-pregnancy underweight, preeclampsia, uterine leiomyoma, and marijuana use were risk factors associated with placental abruption. Although factors associated with placental abruption have been investigated, the current meta-analytic associations cannot disentangle the complex etiology of placental abruption mainly due to their low quality of evidence.

Effectiveness of sodium bicarbonate and zinc chloride mouthwashes in the treatment of oral mucositis and quality of life in patients with cancer under chemotherapy.

AIM: The purpose of the study is to evaluate the effectiveness of sodium bicarbonate and zinc chloride mouthwashes on oral mucositis and quality of life in patients undergoing chemotherapy. DESIGN: The present study was a randomized controlled trial study. METHODS: One hundred forty-four patients with a cancer diagnosis were randomly assigned into three groups: sodium bicarbonate mouthwash (n = 48), zinc chloride mouthwash (n = 48) and placebo group (n = 48). The severity of mucositis and quality of life were examined blindly at the baseline and 3-week follow-up. RESULTS: The grade of oral mucositis decreased at the end of the third weeks in the sodium bicarbonate and zinc chloride groups rather than the placebo group (p < .001). The severity of oral mucositis in the sodium bicarbonate and zinc chloride groups decreased from end of the first week until third week (p < .001). In addition, there was significant difference in the severity of oral mucositis among the groups at the end of the second (p = .014) and the third weeks (p < .001). Also, there was a statistically significant difference in quality of life scores between the sodium bicarbonate and zinc chloride mouthwash with the placebo group (p < .001). CONCLUSION: Zinc chloride and sodium bicarbonate mouthwashes were effective in treating and reducing the severity of oral mucositis, and subsequently improving quality of life in patients with cancer under chemotherapy. Therefore, we can recommend zinc chloride and sodium bicarbonate at the beginning of chemotherapy to improve oral health and promoting quality of life in these patients.

The risk factors associated with placenta previa: An umbrella review.

We evaluated in this umbrella review a systematic collection from meta-analyses conducted on risk factors associated with placenta previa. We searched PubMed, Scopus, and Web of Science until April 2021 assessing the risk factors associated with placenta previa. We calculated summary effect estimates odds ratio, relative risk, 95% CI, heterogeneity I2, 95% prediction interval, small-study effects, excess significance biases, and sensitive analysis. The quality of the meta-analyses was evaluated with AMSTAR 2. We included nine studies in the present umbrella review. Seven risk factors including prior induced abortion (OR 1·36, 95% CI: 1·02, 1·69), prior spontaneous abortion (OR 1·77, 95% CI: 1·60, 1·94), male fetus (OR 1·2, 95% CI: 1·2, 1·3), smoking (OR 1·42, 95% CI 1·30, 1·54) (RR 1·27, 95% CI: 1·18, 1·35) advanced maternal age (OR 3·16, 95% CI: 2·79, 3·57), cesarean (OR 1·60, 95% CI: 1·44, 1·76) and ART (singleton pregnancy) (RR 3·71, 95% CI: 2·67, 5·16) were graded as highly suggestive evidence (class III). Endometriosis (OR 3·03, 95% CI: 1·50, 6·13) and maternal cocaine use (OR 2·9, 95% CI: 1·9, 4·3) were graded as risk factors with weak evidence (class IV). This study provides suggestive evidence about prior spontaneous abortion, prior induced abortion, male fetus, smoking, advanced maternal age, cesarean section, and assisted reproductive techniques (singleton pregnancy) as risk factors associated with placenta previa.

The factors associated with the quality of life among postmenopausal women.

OBJECTIVE: The present work aimed at determining the prevalence of menopausal symptoms and factors associated with the Quality of life among postmenopausal women. MATERIALS AND METHODS: This cross-sectional work was carried out on 270 postmenopausal females referring to health centers of Hamadan city chosen by stratified random sampling. A questionnaire of the Menopausal Quality of Life Questionnaire (MENQOL) was used as the data collection method. Although, the Mann-Whitney test and the Kruskal-Wallis tests were used to compare MENQOL item scores. The significance level of statistical tests was regarded as less than 0.05. RESULTS: The mean MENQOL Score in menopausal was 2.45 ± 1.04. Also, vasomotor symptoms had the highest score, and sexual symptoms had the lowest score rather than other dimensions. There was a significant association between the total menopausal quality of life score and job, economy status, smoking, exercise, supplemental Omega-3 s intake, and Postmenopausal stage (p < 0.01). As smokers, women had increasing levels of bother experienced from the MENQOL symptom than non-smokers (mean = 3.67 ± 0.85 vs. 2.36 ± 0.99; p < 0.001). While the MENQOL scores for menopausal females who exercised more often (mean = 1.56 ± 0.7) had lower than those who exercised less than 3 times per week (mean = 3.27 ± 0.9; p < 0.001). However the lowest score was menopausal females who had taking supplemental Omega-3 s than those who hadn't taken it (mean = 2.15 ± 1.06 vs. 2.65 ± 0.97; p < 0.001). Though women who had postmenopausal stage less than 5 years stage (mean = 2.28 ± 0.87) had significantly lower MENQOL scores from those who had postmenopausal stage 5 or more years (mean = 2.63 ± 1.16; p < 0.001). CONCLUSION: Based on the results, vasomotor symptoms were the most dominant symptom. Therefore, it is necessary to improve physical activity levels, focusing on job status, recommend taking an omega 3 s supplement, and planning education and promotion intervention for cessation or prevention of smoking among postmenopausal women to increase the MENQOL is essential.

Pelvic Hydatid Cyst with Hydroureteronephrosis: A Rare Case Report.

Hydatid cyst is a parasitic disease caused by Echinococcus granulosus or Echinococcus multilocularis. Humans are accidentally infected with the parasite. The cyst is usually found in the liver and lungs and rarely occurs in other body parts. The present article describes a rare case of pelvic hydatid cyst in a young man who presented with nausea, vomiting, and right abdominal pain. Two large cystic masses were discovered during a CT scan in the patient's pelvic region, resulting in right urinary tract hydroureteronephrosis. Additionally, the antibody index was used to confirm the presence of a primary hydatid cyst.

Environmental and ecological factors of stomach cancer incidence and mortality: a systematic review study on ecological studies.

OBJECTIVES: Stomach cancer (SC) is one of the most common and deadly types of cancer. It is the third leading cause of cancer deaths worldwide. The effect of environmental and ecological factors in SC have been assessed in some studies. Thus, we aimed to synthesize the environmental and ecological factors of SC incidence and mortality. CONTENT: In this systematic review study, the scientific databases, including Web of Science, Scopus and PubMed, were searched from inception to November 2019 for all primary articles written in English by using relevant Medical Subject Heading (Mesh) terms. Two independent authors conducted the screening process to decide on the eligibility and inclusion of the articles in the study. The third author acted as an arbiter to resolve any disagreements. SUMMARY AND OUTLOOK: A total of 157 potentially relevant articles were identified from the initial search 38 of which met the eligibility criteria; finally, 34 articles were included in the systematic review. The results revealed that soil arsenic exposure, coal and other opencast mining installations, living near incinerators and installations for the recovery or disposal of hazardous waste, installations for the production of cement, lime, plaster, and magnesium oxide, proximity to a metal industry sources, dietary iron, ingested asbestos, farming, arsenic in soil, altitude, organochlorines and environmental exposure to cadmium and lead have positive associations with SC incidence or death. Most of the ecological and environmental factors such as living near the mineral industries, the disposal of hazardous waste, metal industry sources and environmental exposure to cadmium and lead are positively related to SC mortality and incidence. However, solar UV-B, heat index and dietary zinc can be taken into account as protective factors against SC mortality and incidence.

The association Between Occupational Exposure to silica and Risk of Developing Rheumatoid Arthritis: A Meta-Analysis.

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune disease with systemic inflammatory arthritis. This meta-analysis was conducted to examine the association between occupational exposure to silica and the risk of developing RA among different workers. METHODS: In this meta-analysis, we searched relevant published studies using major electronic databases including Scopus, PubMed, ISI Web of Science, and Google Scholar search engine up to October 2019, and the references of retrieved articles were also checked for further possible sources. A random-effects model was used to account for heterogeneity among the results of the studies using the pooled odds ratios (ORs) and their 95% confidence intervals (CIs). The Q-statistic and I2 tests were calculated to assess heterogeneity between the studies. RESULTS: The pooled calculation of OR indicated a significant association between occupational exposure to silica and risk of developing RA among different workers (OR = 2.59, 95% CI = 1.73 to 3.45). In addition, the pooled estimates of OR in smokers were statistically significant (OR = 2.49, 95% CI = 1.13 to 3.86). CONCLUSIONS: The findings of the present study reveal that occupational exposure to silica may be associated with increased risk of developing RA.

The uterine leiomyoma and placenta previa: a meta-analysis.

Background: Some epidemiological studies have reported that uterine leiomyoma may increase the risk of placenta previa. To date, the meta-analysis has not been carried out for assessing the relationship between uterine leiomyoma and placenta previa. This meta-analysis was carried out to estimate the association between uterine leiomyoma and the risk of placenta previa. Methods: A systematic search was conducted out in major databases PubMed, Web of Science, and Scopus from the earliest possible year to June 2017. The heterogeneity across studies was explored by Q-test and I2 statistic. The publication bias was assessed by Begg's and Egger's tests. The results were showed using odds ratio (OR) estimate with its 95% confidence intervals (CI) using a random-effects model. Results: The literature search included 1218 articles until to June 2017 with 255,886 women. Based on OR estimates obtained from case-control and cohort studies, there was significant association between uterine leiomyoma and placenta previa in studies adjusted (2.21; 95%CI: 1.48, 2.94). Conclusions: We showed based on reports in observational studies that uterine leiomyoma is a risk factor for placenta previa in studies adjusted.

Effect of prenatal smoking cessation interventions on birth weight: meta-analysis.

BACKGROUND: Smoking is preventable factor for pregnancy outcomes such as low birth weight (LBW). In this study, we assessed the effects of smoking cessation in pregnancy period on the birth weight in Randomized Controlled Trial studies (RCTs). METHODS: International databases of Pub Med, Scopus, and Web of Science, by the MeSH heading and/or additional terms, were searched to assess relevant studies in systematic possess. I2 statistics was used to assess of heterogeneity. Pooled effects size was obtained by random effects model. Meta-regression was used to explore of heterogeneity using Stata software version 12 (Stata Corp, College Station, TX). RESULTS: A total 16 RCTs, 6192 women were enrolled to assess of smoking cessation in pregnancy period on the birth weight. Relative risk (RR) of not smoking at the end of pregnancy in intervention group was 2.47 (95% CI: 1.73-3.20). The odds ratio (OR) for effect of smoking cessation on LBW was 0.65 (95% CI: 0.42-0.88) and standardized mean difference (SMD) was significantly increased in the intervention group, 0.28 (95% CI: 0.05-0.50). CONCLUSIONS: Results of this study approve results of previous RCTs that smoking cessation in pregnancy is a good practical action to prevention of LBW in infants.

The relationship between smoking and dysmenorrhea: A meta-analysis.

Many studies have investigated the potential association between smoking and dysmenorrhea. However, results from such studies have been inconsistent. In this study, we assessed the association between smoking and dysmenorrhea by meta-analysis. We performed a systematic search of the international databases, including PubMed, Scopus, Web of Science, EBSCO and Google Scholar by the MeSH heading and/or additional terms to obtain relevant studies published from 1990 until 2017. I2 statistics were used to assess heterogeneity. Pooled effects size was obtained using a random effects model. Subgroup analyses were also conducted. Data were analyzed through Stata software version 12 (Stata Corp, College Station, TX, USA). A total of fourteen studies were included in meta-analysis. A significant positive association was observed between current smoking and dysmenorrhea in both the unadjusted (odds ratio [OR] = 1.60; 95 percent confidence interval [CI]: 1.35, 1.85) and adjusted models (AOR = 1.44; 95 percent CI: 1.18, 1.69). Also, the association between current smoking and primary dysmenorrhea was significant only in the unadjusted model (OR = 1.53; 95 percent CI: 1.21, 1.85). The pooled effects size showed a significant association between smoking and dysmenorrhea in the fourteen eligible studies. This provides a new approach for prevention from dysmenorrhea in females for policymakers.

The Relationship Between Human Development Index and Its Components with Thyroid Cancer Incidence and Mortality: Using the Decomposition Approach.

BACKGROUND: The link between age specific-rates of thyroid cancer (TC) and human development index (HDI) and also its components can be a new direction for planning by policy makers. OBJECTIVES: This study aimed at identifying the relationship between TC rates by gender, and HDI and its components in different regions of the world. METHODS: An ecological study was conducted; the data was obtained from the GLOBOCAN project in 2012. Inequality in TC estimates (age-specific incidence and mortality rates), according to the HDI and its components was calculated. Concentration index (CI) was used to estimate inequality and CI was decomposed to determine contribution of HDI and its components in inequality. RESULTS: The inequality index (CI) was 0.29 (95% CI: 0.21 - 0.38) and -0.15 (95% CI: -0.23 - 0.06) for incidence and mortality of TC by HDI, respectively. The important contributors in inequality for incidence rates of TC were life expectancy at birth (0.30), mean years of schooling (0.26), and expected years of schooling (0.18). The important contributors in inequality of mortality rates were mean years of schooling (0.19), expected years of schooling (0.17), and urbanization (0.17). CONCLUSIONS: According to the findings of this study, global inequalities exist in the TC incidence and mortality rates; incidence rates of TC are more concentrated in countries with high HDI, yet inequality index showed that deaths occurred more in disadvantaged countries.

The effect of uterine leiomyoma on the risk of malpresentation and cesarean: a meta-analysis.

BACKGROUND: some epidemiological studies have found that uterine leiomyoma can increase the risk of cesarean and malpresentation at term. To date, the meta-analysis has not been conducted for assessing the relationship between uterine leiomyoma and cesarean/malpresentation. This meta-analysis was conducted to estimate the association between uterine leiomyoma and the risk of cesarean/malpresentation. METHODS: A literature search was conducted out in major databases PubMed, Web of Science, and Scopus up to September 2016. The heterogeneity across studies was conducted by Q-test and I2 statistic. The publication bias was assessed by Begg's and Egger's tests. The results were shown using odds ratio (OR) estimate with 95% confidence intervals (CI) conducting a random-effect model. RESULTS: The literature search included 1244 articles until September 2016 with 232,177 participants. Based on OR estimates obtained from case-control and cohort studies, there was significant association between uterine leiomyoma and cesarean (2.60; 95% CI: 2.02, 3.18) and between leiomyoma and malpresentation at term (2.65; 95% CI: 1.60, 3.70). CONCLUSIONS: We showed based on reports in observational studies that uterine leiomyoma increased the risk of cesarean and malpresentation at term.

The association between maternal smoking and hyperemesis gravidarum: a meta-analysis.

BACKGROUND: The majority of studies have not found hyperemesis to be a protective and some others have not. To date, no meta-analysis has quantitatively assessed the association between smoking and risk of hyperemesis gravidarum. To help close that research gap, we performed meta-analysis of the association between smoking and risk of hyperemesis gravidarum. METHODS: A literature search was carried out in PubMed, Web of Science, and Scopus from the earliest possible year to January 2016. The heterogeneity across studies was explored by Q-test and I2 statistic. The possibility of publication bias was assessed using Begg's and Egger's tests. The results were reported using odds ratio (OR) estimate with its 95% confidence intervals (CI) using a random-effects model. RESULTS: The literature search yielded 607 publications until January 2016 with 1 400 000 participants. Based on the random-effects model, compared to nonsmoker people, the estimated OR of hyperemesis gravidarum was 0.40 (95% CI: 0.24, 0.56). CONCLUSIONS: We showed based on reports in epidemiological studies that smoking before and during pregnancy is not a risk factor for hyperemesis gravidarum but also can reduce the risk of it.