ORIGINAL ARTICLE
Trans R Soc Trop Med Hyg 2014; 108: 380–384 doi:10.1093/trstmh/tru044 Advance Access publication 30 March 2014
Helicobacter pylori, anemia, iron deficiency and thrombocytopenia among pregnant women at Khartoum, Sudan Nahla Mubaraka, Gasim I. Gasimb, Khalifa E. Khalafallac, Naj I. Alid and Ishag Adama,* a
Department of Obstetrics and Gynecology, Faculty of Medicine, University of Khartoum, PO Box 102, Khartoum, Sudan; bQassim College of Medicine, Kingdom of Saudi Arabia; cRayan Specified laboratory Khartoum, Sudan; dSudan Academy of Science, Khartoum, Sudan
Received 14 October 2013; revised 20 February 2014; accepted 24 February 2014 Background: Helicobacter pylori is a common gut pathogen that is linked to many complications of pregnancy such as iron deficiency anemia, pre-eclampsia and thrombocytopenia. There are no published data on H. pylori in Sudan. Methods: A cross-sectional study was conducted during the period May–June 2012 at the antenatal care unit of Khartoum Hospital, Sudan, to investigate prevalence of H. pylori and its association, if any, with anemia and thrombocytopenia. Obstetric and medical histories were gathered using questionnaires. Hemoglobin and serum ferritin were measured and H. pylori antibodies (IgA and IgG) investigated using ELISA. Results: Among 179 women, rates of positivity for specific IgG formed against H. pylori were 69.8% (125/179), 94.0% (168/179) and 5.6% (10/179) for IgA, IgG and both IgG and IgA, respectively. There was no association between the expected risk factors (age, parity, education) and H. pylori seropositivity. Of these women, 42/179 (24.3%), 50/179 (28.9%) and 19/179 (11%), respectively, were anemic (hemoglobin ,11 g/dl) or had iron deficiency (serum ferritin ,15 mg/l) or iron deficiency anemia. There was no association between H. pylori infection and anemia (OR¼1.0, 95% CI¼0.3–3.2, p¼1.0), iron deficiency (OR¼0.6, 95% CI¼0.1–3.8, p¼0.367) or thrombocytopenia (OR¼2.0, 95% CI¼0.4–8.4, p¼0.322). Conclusion: There is a high prevalence of H. pylori infection among pregnant women in Khartoum, Sudan, and it is not associated with anemia or thrombocytopenia. Keywords: Anemia, Helicobacter pylori, Pregnancy, Sudan, Thrombocytopenia
Introduction Helicobacter pylori infection is the most common bacterial infection worldwide, with almost half of people in developed countries and three-quarters of people in developing countries infected. 1 Although many infected individuals are asymptomatic, H. pylori is an important health problem. A high prevalence of H. pylori has been observed among pregnant women, e.g. 44.8% and 88%, respectively, in Turkey and Egypt.2,3 H. pylori infection in pregnancy is associated with many adverse effects, such as hyperemesis gravidarum (extreme, persistent nausea and vomiting), congenital malformations e.g. neural tube defects in newborns, pre-eclampsia with intrauterine fetal growth restriction and miscarriage, and thrombocytopenia.4–7 Furthermore, pregnant women infected with H. pylori infection are at increased risk of anemia.8,9 There is a high rate of anemia during pregnancy in Sudan, where pregnant women are more susceptible to anemia (especially iron-deficiency anemia), regardless of their age or
parity.10–12 Furthermore anemia is a leading cause of maternal– fetal morbidity and mortality in Sudan.10,13–16 There are few published data on H. pylori infection among pregnant women in Africa,3,8 and none are available for Sudan. Such data would be useful to care givers and health planners, and would add to our knowledge of anemia and its risk factors and prevention, and of how best to manage the condition during pregnancy in order to enhance maternal and perinatal outcomes (i.e. to minimize maternal anemia, still birth, low birth weight, and maternal and perinatal mortality). Therefore the current study was conducted to investigate the epidemiology (prevalence and predictors) of H. pylori infection and its effect, if any, on anemia, together with its association with thrombocytopenia, among women attending for antenatal care at Khartoum Hospital, Sudan.
Materials and methods A cross-sectional study was conducted during the period May–June 2012 at the antenatal care unit of Khartoum
# The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: [email protected].
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*Corresponding author: Tel: +249 912168988; Fax: +249 1 83771211; E-mail: [email protected]
Transactions of the Royal Society of Tropical Medicine and Hygiene
Mean (SD)
Age (years) Parity Gravidity Gestational age (weeks) Weight (kg) Hemoglobin (gm/dl) Body mass index (weight [kg]/height [m]2)
26.0 (6.8) 1.6 (1.8) 3.13 (2.34) 25.1 (2.6) 73.6 (16.4) 11.7 (1.29) 28.8 (6.32)
Statistics The collected data were analyzed using SPSS V.16.0 (SPSS Inc., Chicago, IL, USA). Continuous data were checked for normality; Student’s t test was used to compare normally distributed data, and the Mann–Whitney U test to compare non-parametric data between two groups, while categorized data were compared using the x2 test. Univariate and multivariate analyses were performed where H. pylori IgA seropositivity (another model was set for anemia and iron deficiency) was the dependent variable and expected risk factors (age, parity, gestational age, education, etc.) were the independent variables. Odds ratio (OR) with a 95% confidence interval (CI) was calculated and statistical significance defined as p,0.05
Results We had complete data and enough sera for analysis for 179 of the 190 women. The basic characteristics of the women are shown in Table 1. Among these 179 women the rates of positivity for specific IgG formed against H. pylori were 69.8% (125/179), 94.0% (168/179) and 5.6% (10/179) for IgA, IgG and both IgG and IgA, respectively. There was no association between the expected risk factors (age, parity, and education) and H. pylori seropositivity (Table 2). Of the 179 women, 42/179 (24.3%), 50/179 (28.9%) and 19/179 (11%), respectively, were anemic, had iron deficiency and iron-deficiency anemia, respectively. H. pylori seropositivity (IgA) was not different in anemic women vs non-anemic women (29/42 [69.0%] vs 96/137 [70.0%], p¼1.000) and women who had iron deficiency vs women who did not (33/50 [66.0%] vs 92/129 [71.3%], p¼0.586. There was no association between H. pylori infection and anemia (OR¼1.0, 95% CI¼0.3– 3.2, p¼1.0) or iron deficiency (OR¼0.6, 95% CI¼0.1–3.8,
Table 1. Basic characteristics of the pregnant women included in the study at Khartoum Teaching Hospital, Sudan Variables
Anemia was defined as hemoglobin ,11 g/dl, iron deficiency as serum ferritin ,15 mg/L. Iron-deficiency anemia was defined as hemoglobin ,11 g/dl and serum ferritin ,15 mg/L. Thrombocytopenia was defined as a platelet count ,150×109/L.
Table 2. Factors associated with anti-Helicobacter pylori IgA seropositivity among pregnant women at Khartoum, Sudan, using univariate and multivariate analyses Variable
Age (years) Gravidity Gestational age (weeks) Interpregnancy interval (months) Rural residency Education (,secondary level) Pica Antibiotic use during index pregnancy Body mass index (weight [kg]/height [m]2)
Univariate analyses
Multivariate analyses
OR
95% CI
p-value
OR
95% CI
p-value
1.0 0.8 0.9 1.0 0.8 1.1 2.0 1.1 1.0
0.9–1.0 0.7–0.9 0.8–1.2 0.8–1.4 0.4–1.6 0.7–1.7 0.7–5.2 0.5–2.4 0.9–1.0
0.829 0.032 0.921 0.577 0.637 0.604 0.151 0.673 0.437
1.0 1.1 0.8 1.1 0.7 1.2 4.7 3.0 1.0
0.9–1.0 0.8–1.4 0.6–1.1 0.8–1.6 0.2–1.9 0.6–2.5 0.9–24.4 0.8–11.2 0.9–1.1
0.945 0.280 0.315 0.330 0.527 0.454 0.064 0.089 0.375
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Hospital, Sudan. We used pretested questionnaires to collect obstetric and medical histories from 190 women, who each signed to indicate their informed consent. Thereafter, maternal weight and height were measured and body mass index (BMI) calculated; BMI¼weight (kg) divided by height (m2). A blood sample (7 ml) was taken from the antecubital vein of each participant. A 2 ml portion of each sample was placed in a container with ethylenediaminetetraacetic acid (EDTA) and immediately analysed to obtain a complete blood count including haemoglobin, white blood count (WBC), and platelet count, using an automated hematology analyzer (Sysmex XN-9000; Sysmex, Hyogo, Japan). The remaining portion of each sample was centrifuged and the serum separated and kept at 2228C for measurement of serum ferritin by immunofluorescent assay (Immulite kits, Siemens, Los Angeles, CA, USA). Specific H. pylori antibody profiles were analyzed using commercial H. pylori-specific ELISA (Euroimmun, Lu¨beck, Germany) to detect seroposivity for IgG (indicating chronic infection) and IgA (indicating new infection), the tests being performed as per the manufacturers’ instructions. Results of ≥1.1 were considered to be positive, those of 0.9–1.1 were considered to be weakly positive and those ≤0.9 were recognized as negative.
N. Mubarak et al.
Table 3. Factors associated with anemia and iron deficiency among pregnant women at Khartoum, Sudan, using logistic regression Variable
Iron deficiency
OR
95% CI
p-value
OR
95% CI
p-value
1.0 1.1 1.0 0.9 1.2 2.3 0.6 0.1 0.6 1.0 1.0
0.9–1.0 0.9–1.4 0.8–1.4 0.6–1.4 0.4–3.5 1.1–4.7 0.1–2.0 0.01–1.2 0.2–1.2 0.3–3.2 0.9–1.1
0.844 0.158 0.544 0.877 0.699 0.023 0.414 0.075 0.194 0.975 0.323
0.9 1.1 0.9 1.0 2.0 0.4 0.7 0.4 0.9 0.6 1.0
0.8–1.1 0.8–1.5 0.6–1.3 0.7–1.6 0.4–9.2 0.1–1.2 0.1–3.9 0.04–4.8 0.4–2.0 0.1–3.8 0.9–1.0
0.752 0.269 0.724 0.726 0.368 0.109 0.712 0.523 0.945 0.367 0.628
Figure 1. Serum ferritin levels and Helicobacter pylori-IgA serology among pregnant women at Khartoum, Sudan.
p¼0.367) among these pregnant women (Table 3). Likewise there was no significant difference in mean (SD) hemoglobin concentration (11.8 [1.2] vs 11.7 [1.3] g/dl, p¼0.879) and median (interquartile) serum ferritin (22.6 [13.7–30.8] vs 20.6 [14.0–34.7) mg/ L, p¼0.866) between women who were H. pylori (IgA) seropostive (n¼125) and women who were H. pylori seronegative (n¼54), (Figure 1). Twenty-four (13.4%) of the 179 women had thrombocytopenia. There was no significant difference in the prevalence of H. pylori IgA positivity between women with thrombocytopenia and women who had no thrombocytopenia (13/24 [54.2%] vs 112/155 [72.3%], p¼0.094). Moreover, there was no difference in the median (quartile) platelet level (207×109/L [171.5–261) vs 200×109/L (156–239.5), p¼0.175] between women who were H. pylori (IgA) seropostive (n¼125) and those who were H. pylori seronegative (n¼54) (Figure 2). There was no association between
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Figure 2. Platelet count and Helicobacter pylori-IgA serology among pregnant women at Khartoum, Sudan.
H. pylori seropositivity and thrombocytopenia (OR¼2.0, 95% CI¼0.4–8.4, p¼0.322) (Table 4).
Discussion The main findings of the current study were that there was a high prevalence of H. pylori infection (94.2 and 68.8%, respectively, for chronic and new infection) among women attending for prenatal care, regardless of their age and parity, and that H. pylori infection was not a risk factor for anemia, nor for thrombocytopenia. A previous report from Khartoum, Sudan, showed that H. pylori was detected in 59.6% of individuals with gastroesophageal reflux disease and that 80% of non-pregnant patients with Barrett esophagus were positive for H. pylori. 17 The high rate of H. pylori infection in this study mirrors the observation of an
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Age (years) Gravidity Gestational age (weeks) Interpregnancy interval (months) Rural residency Education (,secondary level) Pica Iron-folic acid usage Antibiotic use during index pregnancy Anti-H. pylori IgA seropositivity Body mass index (weight [kg]/height [m]2)
Anemia
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Table 4. Factors associated with thrombocytopenia among pregnant women at Khartoum, Sudan, using univariate and multivariate analyses Variable
Multivariate analyses
OR
95% CI
p-value
OR
95% CI
p-value
0.9 0.8 1.0 1.5 1.8 0.7 0.5 2.2 0.9
0.9–1.0 0.6–1.0 0.8–1.3 1.1–2.2 0.7–5.0 0.4–1.4 0.1–1.5 0.9–5.2 0.9–1.0
0.777 0.194 0.541 0.011 0.206 0.441 0.240 0.077 0.220
0.9 0.8 1.0 1.3 2.3 0.6 0.5 2.0 0.9
0.8–1.0 0.5–1.2 0.6–1.5 0.9–1.9 0.5–10.5 0.2–1.6 0.1–2.7 0.4–8.4 0.9–1.0
0.471 0.322 0.902 0.085 0.259 0.384 0.460 0.322 0.327
88% rate of H. pylori infection in neighboring Egypt.3 A contrasting low prevalence of H. pylori infection (17.5%) observed among pregnant women in the African island of Zanzibar18 might reflect a difference in hygienic practices or other sociodemographic characteristics, while a high prevalence (74%) of H. pylori infection was reported among pregnant women at the US–Mexico border.19 In the present study, none of the known predictors was associated with H. pylori infection. In contrast, Hanafi et al. found that, in Saudi Arabia, rural residence, crowded housing, low socioeconomic status, using tanks for drinking water supply, eating raw vegetables, and eating spicy food were the risk factors for H. pylori.20 In the present study there was no association between H. pylori infection and anemia. This result was in contrast to previous results: in Zanzibar, pregnant women with H. pylori were at an eight times (OR¼7.63) higher risk of severe anemia, and H. pylori infection with a low bacterial load was associated with a lower hemoglobin concentration.8 Likewise there was a strong relationship between H. pylori infection and iron deficiency anemia among Turkish women with uncomplicated pregnancy.9 In Germany, Weyermann et al. observed that, compared with uninfected mothers, mothers with H. pylori infection had a lower mean hemoglobin level early in pregnancy and a more unfavorable change in hemoglobin level during pregnancy.21 In addition, a recent randomized placebo-controlled double blind clinical trial (a pilot study) of H. pylori eradication has indicated that eradication (plus iron and folic acid supplement) can increase hemoglobin levels among pregnant women.22 Moreover, meta-analyses of randomized control trials of H. pylori eradication have indicated that eradication can increase hemoglobin levels among the nonpregnant population.23 Surprisingly, H. pylori seropositivity was inversely associated with anemia among adults.24 The current study failed to show an association between H. pylori IgA seropositivity and thrombocytopenia among pregnant Sudanese women. This finding is in line with that of a recent study by Epstein et al., who found no association between H. pylori and thrombocytopenia in the pregnant Hispanic population.25 Likewise Mulayim et al. failed to show an association between H. pylori infection and thrombocytopenia among Turkish pregnant women.9 Yet in a recent review there was a strong association of H. pylori with immune thrombocytopenia.26
The current study had some limitations. We did not investigate the risk factors for H. pylori, e.g. crowded housing, socioeconomic status, drinking water supply, eating raw vegetables and eating spicy food,20 neither did we consider other infections, such as malaria and schistosomiasis, which are endemic in the area and were previously reported as a cause of anemia among pregnant women.10,11 The prevalence of H. pylori infection among pregnant Sudanese women is high. Nevertheless, it is not associated with iron deficiency nor with any of the known risk factors for such deficiency among the study population; moreover, anemia among the study group was associated with level of education. No links were found between H. pylori and thrombocytopenia in the pregnant Sudanese population.
Authors’ contributions: NM, GIG, NIA and IA conceived the study; KEK, NM and IA designed the study; GIG and IA analyzed and interpreted the data; KEK interpreted the data. All authors drafted and critically revised the manuscript for intellectual content, and approved the final version of the paper. NM and IA are guarantors of the paper. Funding: None. Competing interests: None declared. Ethical approval: The study received ethical approval from the Research and Ethics Committee of Khartoum University.
References 1 Go MF. Review article. Natural history and epidemiology of Helicobacter pylori infection. Aliment Pharmacol Ther 2002;16 (Suppl 1):3–15. 2 Koc¸ak I, Akcan Y, Ustu¨n C et al. Helicobacter pylori seropositivity in patients with hyperemesis gravidarium. Int J Gynaecol Obstet 1999;66:251–4. 3 Bassily S, Frenck RW, Mohareb EW et al. Seroprevalence of Helicobacter pylori among Egyptian newborns and their mothers: a preliminary report. Am J Trop Med Hyg 1999;61:37–40.
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Age (years) Gravidity Gestational age (weeks) Interpregnancy interval (months) Rural residency Education (,secondary level) Pica Anti-H. pylori IgA seropositivity Body mass index (weight [kg]/height [m]2)
Univariate analyses
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4 Mansour GM, Nashaat EH. Role of Helicobacter pylori in the pathogenesis of hyperemesis gravidarum. Arch Gynecol Obstet 2011;284:843–7. 5 Golalipour MJ, Sedehi M, Qorbani M. Does maternal Helicobacter pylori infection increase the risk of occurrence of neural tube defects in newborns in Northern Iran? Neurosciences (Riyadh) 2012;17:219–25. 6 Cardaropoli S, Rolfo A, Piazzese A et al. Helicobacter pylori’s virulence and infection persistence define pre-eclampsia complicated by fetal growth retardation. World J Gastroenterol 2011; 17:5156–65.
8 Farag TH, Stoltzfus RJ, Khalfan SS, Tielsch JM. Helicobacter pylori infection is associated with severe anemia of pregnancy on Pemba Island, Zanzibar. Am J Trop Med Hyg 2007;76:541–8. 9 Mulayim B, Celik NY, Yanik FF. Helicobacter pylori infection detected by 14C-urea breath test is associated with iron deficiency anemia in pregnant women. J Obstet Gynaecol Res 2008;34:980–5. 10 Adam I, Elhassan EM, Haggaz AE et al. A perspective of the epidemiology of malaria and anaemia and their impact on maternal and perinatal outcomes in Sudan. J Infect Dev Ctries 2011;25:83–7. 11 Abdelgadir MA, Khalid AR, Ashmaig AL et al. Epidemiology of anaemia among pregnant women in Geizera, central Sudan. J Obstet Gynaecol 2012;32:42–4. 12 Adam I, Khamis AH, Elbashir MI. Prevalence and risk factors for anaemia in pregnant women of eastern Sudan. Trans R Soc Trop Med Hyg 2005;99:739–43. 13 Ali AA, Adam I. Lack of antenatal care, education, and high maternal mortality in Kassala hospital, eastern Sudan during 2005–2009. J Matern Fetal Neonatal Med 2011;24:1077–8. 14 Ali AA, Rayis DA, Abdallah TM et al. Severe anaemia is associated with a higher risk for preeclampsia and poor perinatal outcomes in Kassala hospital, eastern Sudan. BMC Res Notes 2011;264:311.
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16 Elhassan EM, Abbaker AO, Haggaz AD et al. Anaemia and low birth weight in Medani, Hospital Sudan. BMC Res Notes 2010;3:181. 17 Ahmed HH, Mudawi HM, Fedail SS. Gastro-oesophageal reflux disease in Sudan a clinical endoscopic and histopathological study. Trop Gastroenterol 2004;25:135–8. 18 Farag TH, Stoltzfus RJ, Khalfan SS, Tielsch JM. Unexpectedly low prevalence of Helicobacter pylori infection among pregnant women on Pemba Island, Zanzibar. Trans R Soc Trop Med Hyg 2007; 101:915–22. 19 Goodman KJ, O’Rourke K, Day RS et al. Helicobacter pylori infection in pregnant women from a US–Mexico border population. J Immigr Health 2003;5:99–107. 20 Hanafi MI, Mohamed AM. Helicobacter pylori infection: seroprevalence and predictors among healthy individuals in Al Madinah, Saudi Arabia. J Egypt Public Health Assoc 2013;88:40–45. 21 Weyermann M, Rothenbacher D, Gayer L et al. Role of Helicobacter pylori infection in iron deficiency during pregnancy. Am J Obstet Gynecol 2005;192:548–53. 22 Malik R, Guleria K, Kaur I, Sikka M, Radhakrishnan G. Effect of Helicobacter pylori eradication therapy in iron deficiency anaemia of pregnancy–a pilot study. Indian J Med Res 2011;134:224–31. 23 Yuan W, Li Y, Yang K, Ma B, Guan Q, Wang D, Yang L. Iron deficiency anemia in Helicobacter pylori infection: meta-analysis of randomized controlled trials. Scand J Gastroenterol 2010;45: 665–76. 24 Shak JR, Sodikoff JB, Speckman RA et al. Anemia and Helicobacter pylori seroreactivity in a rural Haitian population. Am J Trop Med Hyg 2011;85:913–8. 25 Epstein A, Wing DA, Ouzounian JG et al. Helicobacter pylori and thrombocytopenia in the pregnant hispanic population. J Matern Fetal Neonatal Med 2012;25:2588–90. 26 Hasni SA. Role of Helicobacter pylori infection in autoimmune diseases. Curr Opin Rheumatol 2012;24:429–34.
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7 Hajishafiha M, Ghasemi-Rad M, Memari A et al. Effect of Helicobacter pylori infection on pregnancy rates and early pregnancy loss after intracytoplasmic sperm injection. Int J Womens Health 2011; 3:329–35.
15 Ali AA, Adam I. Anaemia and stillbirth in Kassala Hospital, Eastern Sudan. J Trop Pediatr 2011;57:62–64.
Trans R Soc Trop Med Hyg 2014; 108: 380–384 doi:10.1093/trstmh/tru044 Advance Access publication 30 March 2014
Helicobacter pylori, anemia, iron deficiency and thrombocytopenia among pregnant women at Khartoum, Sudan Nahla Mubaraka, Gasim I. Gasimb, Khalifa E. Khalafallac, Naj I. Alid and Ishag Adama,* a
Department of Obstetrics and Gynecology, Faculty of Medicine, University of Khartoum, PO Box 102, Khartoum, Sudan; bQassim College of Medicine, Kingdom of Saudi Arabia; cRayan Specified laboratory Khartoum, Sudan; dSudan Academy of Science, Khartoum, Sudan
Received 14 October 2013; revised 20 February 2014; accepted 24 February 2014 Background: Helicobacter pylori is a common gut pathogen that is linked to many complications of pregnancy such as iron deficiency anemia, pre-eclampsia and thrombocytopenia. There are no published data on H. pylori in Sudan. Methods: A cross-sectional study was conducted during the period May–June 2012 at the antenatal care unit of Khartoum Hospital, Sudan, to investigate prevalence of H. pylori and its association, if any, with anemia and thrombocytopenia. Obstetric and medical histories were gathered using questionnaires. Hemoglobin and serum ferritin were measured and H. pylori antibodies (IgA and IgG) investigated using ELISA. Results: Among 179 women, rates of positivity for specific IgG formed against H. pylori were 69.8% (125/179), 94.0% (168/179) and 5.6% (10/179) for IgA, IgG and both IgG and IgA, respectively. There was no association between the expected risk factors (age, parity, education) and H. pylori seropositivity. Of these women, 42/179 (24.3%), 50/179 (28.9%) and 19/179 (11%), respectively, were anemic (hemoglobin ,11 g/dl) or had iron deficiency (serum ferritin ,15 mg/l) or iron deficiency anemia. There was no association between H. pylori infection and anemia (OR¼1.0, 95% CI¼0.3–3.2, p¼1.0), iron deficiency (OR¼0.6, 95% CI¼0.1–3.8, p¼0.367) or thrombocytopenia (OR¼2.0, 95% CI¼0.4–8.4, p¼0.322). Conclusion: There is a high prevalence of H. pylori infection among pregnant women in Khartoum, Sudan, and it is not associated with anemia or thrombocytopenia. Keywords: Anemia, Helicobacter pylori, Pregnancy, Sudan, Thrombocytopenia
Introduction Helicobacter pylori infection is the most common bacterial infection worldwide, with almost half of people in developed countries and three-quarters of people in developing countries infected. 1 Although many infected individuals are asymptomatic, H. pylori is an important health problem. A high prevalence of H. pylori has been observed among pregnant women, e.g. 44.8% and 88%, respectively, in Turkey and Egypt.2,3 H. pylori infection in pregnancy is associated with many adverse effects, such as hyperemesis gravidarum (extreme, persistent nausea and vomiting), congenital malformations e.g. neural tube defects in newborns, pre-eclampsia with intrauterine fetal growth restriction and miscarriage, and thrombocytopenia.4–7 Furthermore, pregnant women infected with H. pylori infection are at increased risk of anemia.8,9 There is a high rate of anemia during pregnancy in Sudan, where pregnant women are more susceptible to anemia (especially iron-deficiency anemia), regardless of their age or
parity.10–12 Furthermore anemia is a leading cause of maternal– fetal morbidity and mortality in Sudan.10,13–16 There are few published data on H. pylori infection among pregnant women in Africa,3,8 and none are available for Sudan. Such data would be useful to care givers and health planners, and would add to our knowledge of anemia and its risk factors and prevention, and of how best to manage the condition during pregnancy in order to enhance maternal and perinatal outcomes (i.e. to minimize maternal anemia, still birth, low birth weight, and maternal and perinatal mortality). Therefore the current study was conducted to investigate the epidemiology (prevalence and predictors) of H. pylori infection and its effect, if any, on anemia, together with its association with thrombocytopenia, among women attending for antenatal care at Khartoum Hospital, Sudan.
Materials and methods A cross-sectional study was conducted during the period May–June 2012 at the antenatal care unit of Khartoum
# The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: [email protected].
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*Corresponding author: Tel: +249 912168988; Fax: +249 1 83771211; E-mail: [email protected]
Transactions of the Royal Society of Tropical Medicine and Hygiene
Mean (SD)
Age (years) Parity Gravidity Gestational age (weeks) Weight (kg) Hemoglobin (gm/dl) Body mass index (weight [kg]/height [m]2)
26.0 (6.8) 1.6 (1.8) 3.13 (2.34) 25.1 (2.6) 73.6 (16.4) 11.7 (1.29) 28.8 (6.32)
Statistics The collected data were analyzed using SPSS V.16.0 (SPSS Inc., Chicago, IL, USA). Continuous data were checked for normality; Student’s t test was used to compare normally distributed data, and the Mann–Whitney U test to compare non-parametric data between two groups, while categorized data were compared using the x2 test. Univariate and multivariate analyses were performed where H. pylori IgA seropositivity (another model was set for anemia and iron deficiency) was the dependent variable and expected risk factors (age, parity, gestational age, education, etc.) were the independent variables. Odds ratio (OR) with a 95% confidence interval (CI) was calculated and statistical significance defined as p,0.05
Results We had complete data and enough sera for analysis for 179 of the 190 women. The basic characteristics of the women are shown in Table 1. Among these 179 women the rates of positivity for specific IgG formed against H. pylori were 69.8% (125/179), 94.0% (168/179) and 5.6% (10/179) for IgA, IgG and both IgG and IgA, respectively. There was no association between the expected risk factors (age, parity, and education) and H. pylori seropositivity (Table 2). Of the 179 women, 42/179 (24.3%), 50/179 (28.9%) and 19/179 (11%), respectively, were anemic, had iron deficiency and iron-deficiency anemia, respectively. H. pylori seropositivity (IgA) was not different in anemic women vs non-anemic women (29/42 [69.0%] vs 96/137 [70.0%], p¼1.000) and women who had iron deficiency vs women who did not (33/50 [66.0%] vs 92/129 [71.3%], p¼0.586. There was no association between H. pylori infection and anemia (OR¼1.0, 95% CI¼0.3– 3.2, p¼1.0) or iron deficiency (OR¼0.6, 95% CI¼0.1–3.8,
Table 1. Basic characteristics of the pregnant women included in the study at Khartoum Teaching Hospital, Sudan Variables
Anemia was defined as hemoglobin ,11 g/dl, iron deficiency as serum ferritin ,15 mg/L. Iron-deficiency anemia was defined as hemoglobin ,11 g/dl and serum ferritin ,15 mg/L. Thrombocytopenia was defined as a platelet count ,150×109/L.
Table 2. Factors associated with anti-Helicobacter pylori IgA seropositivity among pregnant women at Khartoum, Sudan, using univariate and multivariate analyses Variable
Age (years) Gravidity Gestational age (weeks) Interpregnancy interval (months) Rural residency Education (,secondary level) Pica Antibiotic use during index pregnancy Body mass index (weight [kg]/height [m]2)
Univariate analyses
Multivariate analyses
OR
95% CI
p-value
OR
95% CI
p-value
1.0 0.8 0.9 1.0 0.8 1.1 2.0 1.1 1.0
0.9–1.0 0.7–0.9 0.8–1.2 0.8–1.4 0.4–1.6 0.7–1.7 0.7–5.2 0.5–2.4 0.9–1.0
0.829 0.032 0.921 0.577 0.637 0.604 0.151 0.673 0.437
1.0 1.1 0.8 1.1 0.7 1.2 4.7 3.0 1.0
0.9–1.0 0.8–1.4 0.6–1.1 0.8–1.6 0.2–1.9 0.6–2.5 0.9–24.4 0.8–11.2 0.9–1.1
0.945 0.280 0.315 0.330 0.527 0.454 0.064 0.089 0.375
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Hospital, Sudan. We used pretested questionnaires to collect obstetric and medical histories from 190 women, who each signed to indicate their informed consent. Thereafter, maternal weight and height were measured and body mass index (BMI) calculated; BMI¼weight (kg) divided by height (m2). A blood sample (7 ml) was taken from the antecubital vein of each participant. A 2 ml portion of each sample was placed in a container with ethylenediaminetetraacetic acid (EDTA) and immediately analysed to obtain a complete blood count including haemoglobin, white blood count (WBC), and platelet count, using an automated hematology analyzer (Sysmex XN-9000; Sysmex, Hyogo, Japan). The remaining portion of each sample was centrifuged and the serum separated and kept at 2228C for measurement of serum ferritin by immunofluorescent assay (Immulite kits, Siemens, Los Angeles, CA, USA). Specific H. pylori antibody profiles were analyzed using commercial H. pylori-specific ELISA (Euroimmun, Lu¨beck, Germany) to detect seroposivity for IgG (indicating chronic infection) and IgA (indicating new infection), the tests being performed as per the manufacturers’ instructions. Results of ≥1.1 were considered to be positive, those of 0.9–1.1 were considered to be weakly positive and those ≤0.9 were recognized as negative.
N. Mubarak et al.
Table 3. Factors associated with anemia and iron deficiency among pregnant women at Khartoum, Sudan, using logistic regression Variable
Iron deficiency
OR
95% CI
p-value
OR
95% CI
p-value
1.0 1.1 1.0 0.9 1.2 2.3 0.6 0.1 0.6 1.0 1.0
0.9–1.0 0.9–1.4 0.8–1.4 0.6–1.4 0.4–3.5 1.1–4.7 0.1–2.0 0.01–1.2 0.2–1.2 0.3–3.2 0.9–1.1
0.844 0.158 0.544 0.877 0.699 0.023 0.414 0.075 0.194 0.975 0.323
0.9 1.1 0.9 1.0 2.0 0.4 0.7 0.4 0.9 0.6 1.0
0.8–1.1 0.8–1.5 0.6–1.3 0.7–1.6 0.4–9.2 0.1–1.2 0.1–3.9 0.04–4.8 0.4–2.0 0.1–3.8 0.9–1.0
0.752 0.269 0.724 0.726 0.368 0.109 0.712 0.523 0.945 0.367 0.628
Figure 1. Serum ferritin levels and Helicobacter pylori-IgA serology among pregnant women at Khartoum, Sudan.
p¼0.367) among these pregnant women (Table 3). Likewise there was no significant difference in mean (SD) hemoglobin concentration (11.8 [1.2] vs 11.7 [1.3] g/dl, p¼0.879) and median (interquartile) serum ferritin (22.6 [13.7–30.8] vs 20.6 [14.0–34.7) mg/ L, p¼0.866) between women who were H. pylori (IgA) seropostive (n¼125) and women who were H. pylori seronegative (n¼54), (Figure 1). Twenty-four (13.4%) of the 179 women had thrombocytopenia. There was no significant difference in the prevalence of H. pylori IgA positivity between women with thrombocytopenia and women who had no thrombocytopenia (13/24 [54.2%] vs 112/155 [72.3%], p¼0.094). Moreover, there was no difference in the median (quartile) platelet level (207×109/L [171.5–261) vs 200×109/L (156–239.5), p¼0.175] between women who were H. pylori (IgA) seropostive (n¼125) and those who were H. pylori seronegative (n¼54) (Figure 2). There was no association between
382
Figure 2. Platelet count and Helicobacter pylori-IgA serology among pregnant women at Khartoum, Sudan.
H. pylori seropositivity and thrombocytopenia (OR¼2.0, 95% CI¼0.4–8.4, p¼0.322) (Table 4).
Discussion The main findings of the current study were that there was a high prevalence of H. pylori infection (94.2 and 68.8%, respectively, for chronic and new infection) among women attending for prenatal care, regardless of their age and parity, and that H. pylori infection was not a risk factor for anemia, nor for thrombocytopenia. A previous report from Khartoum, Sudan, showed that H. pylori was detected in 59.6% of individuals with gastroesophageal reflux disease and that 80% of non-pregnant patients with Barrett esophagus were positive for H. pylori. 17 The high rate of H. pylori infection in this study mirrors the observation of an
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Age (years) Gravidity Gestational age (weeks) Interpregnancy interval (months) Rural residency Education (,secondary level) Pica Iron-folic acid usage Antibiotic use during index pregnancy Anti-H. pylori IgA seropositivity Body mass index (weight [kg]/height [m]2)
Anemia
Transactions of the Royal Society of Tropical Medicine and Hygiene
Table 4. Factors associated with thrombocytopenia among pregnant women at Khartoum, Sudan, using univariate and multivariate analyses Variable
Multivariate analyses
OR
95% CI
p-value
OR
95% CI
p-value
0.9 0.8 1.0 1.5 1.8 0.7 0.5 2.2 0.9
0.9–1.0 0.6–1.0 0.8–1.3 1.1–2.2 0.7–5.0 0.4–1.4 0.1–1.5 0.9–5.2 0.9–1.0
0.777 0.194 0.541 0.011 0.206 0.441 0.240 0.077 0.220
0.9 0.8 1.0 1.3 2.3 0.6 0.5 2.0 0.9
0.8–1.0 0.5–1.2 0.6–1.5 0.9–1.9 0.5–10.5 0.2–1.6 0.1–2.7 0.4–8.4 0.9–1.0
0.471 0.322 0.902 0.085 0.259 0.384 0.460 0.322 0.327
88% rate of H. pylori infection in neighboring Egypt.3 A contrasting low prevalence of H. pylori infection (17.5%) observed among pregnant women in the African island of Zanzibar18 might reflect a difference in hygienic practices or other sociodemographic characteristics, while a high prevalence (74%) of H. pylori infection was reported among pregnant women at the US–Mexico border.19 In the present study, none of the known predictors was associated with H. pylori infection. In contrast, Hanafi et al. found that, in Saudi Arabia, rural residence, crowded housing, low socioeconomic status, using tanks for drinking water supply, eating raw vegetables, and eating spicy food were the risk factors for H. pylori.20 In the present study there was no association between H. pylori infection and anemia. This result was in contrast to previous results: in Zanzibar, pregnant women with H. pylori were at an eight times (OR¼7.63) higher risk of severe anemia, and H. pylori infection with a low bacterial load was associated with a lower hemoglobin concentration.8 Likewise there was a strong relationship between H. pylori infection and iron deficiency anemia among Turkish women with uncomplicated pregnancy.9 In Germany, Weyermann et al. observed that, compared with uninfected mothers, mothers with H. pylori infection had a lower mean hemoglobin level early in pregnancy and a more unfavorable change in hemoglobin level during pregnancy.21 In addition, a recent randomized placebo-controlled double blind clinical trial (a pilot study) of H. pylori eradication has indicated that eradication (plus iron and folic acid supplement) can increase hemoglobin levels among pregnant women.22 Moreover, meta-analyses of randomized control trials of H. pylori eradication have indicated that eradication can increase hemoglobin levels among the nonpregnant population.23 Surprisingly, H. pylori seropositivity was inversely associated with anemia among adults.24 The current study failed to show an association between H. pylori IgA seropositivity and thrombocytopenia among pregnant Sudanese women. This finding is in line with that of a recent study by Epstein et al., who found no association between H. pylori and thrombocytopenia in the pregnant Hispanic population.25 Likewise Mulayim et al. failed to show an association between H. pylori infection and thrombocytopenia among Turkish pregnant women.9 Yet in a recent review there was a strong association of H. pylori with immune thrombocytopenia.26
The current study had some limitations. We did not investigate the risk factors for H. pylori, e.g. crowded housing, socioeconomic status, drinking water supply, eating raw vegetables and eating spicy food,20 neither did we consider other infections, such as malaria and schistosomiasis, which are endemic in the area and were previously reported as a cause of anemia among pregnant women.10,11 The prevalence of H. pylori infection among pregnant Sudanese women is high. Nevertheless, it is not associated with iron deficiency nor with any of the known risk factors for such deficiency among the study population; moreover, anemia among the study group was associated with level of education. No links were found between H. pylori and thrombocytopenia in the pregnant Sudanese population.
Authors’ contributions: NM, GIG, NIA and IA conceived the study; KEK, NM and IA designed the study; GIG and IA analyzed and interpreted the data; KEK interpreted the data. All authors drafted and critically revised the manuscript for intellectual content, and approved the final version of the paper. NM and IA are guarantors of the paper. Funding: None. Competing interests: None declared. Ethical approval: The study received ethical approval from the Research and Ethics Committee of Khartoum University.
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