Archive
Search

In this section, you can search articles in the system.

Journal Information

Online ISSN (English)
1305-3124

Print ISSN (Turkish)
1300-5251

Online ISSN (Turkish)
1305-3132

Established
1993

Editor-in-Chief
Cihat Şen

Editors
Murat Yayla, Oluş Api, Resul Arısoy

Hepatitis B seropositivity of pregnant women and the review of Turkish literature

Rabia Zehra Bakar, Banu Dane

Article info

Hepatitis B seropositivity of pregnant women and the review of Turkish literature. Perinatal Journal 2016;24(2):83-88 DOI: 10.2399/prn.16.0242005

Author(s) Information

Rabia Zehra Bakar1,
Banu Dane2

  1. İstanbul Kanuni Sultan Süleyman Eğitim ve Araştırma Hastanesi Kadın Hastalıkları ve Doğum Kliniği, İstanbul
  2. Bezmialem Vakıf Üniversitesi Tıp Fakültesi Kadın Hastalıkları ve Doğum Anabilim Dalı, İstanbul
Correspondence

Rabia Zehra Bakar, İstanbul Kanuni Sultan Süleyman Eğitim ve Araştırma Hastanesi Kadın Hastalıkları ve Doğum Kliniği, İstanbul, [email protected]

Publication History

Manuscript Received: February 13, 2016

Manuscript Accepted: June 06, 2016

Earlyview Date: June 25, 2016

Publication date: September 25, 2018

Conflicts of Interest

Conflicts of Interest: No conflicts declared.

Objective
The aim of the study was to show the progress of hepatitis B seropositivity rates of pregnant women in Turkey for the last two decades by regions and years and to evaluate the current condition in consideration of the studies published.
Methods
The studies investigating hepatitis B seropositivity of pregnant women in Turkey were analyzed by reviewing the databases and the literature. On this topic, 64 studies performed between 1975 and 2016 were found. The studies published within the last 2 decades (1996–2016) were arranged by their publication years. Additionally, the data of the women delivered in our clinic between 2012 and 2015 were reviewed retrospectively and the result of HBsAg seropositivity rate was determined.
Results
It was seen that the rate of HBsAg seropositivity in the studies published in Turkey was between 1.2 and 19.2%. Considering the studies performed within the last two decades, the highest rate was 9.3%, and no HBsAg seropositivity higher than 6% was found in the studies performed in the last 7 years with the contribution of vaccine program carried out throughout the country. In the study we performed in our clinic, we found the rate 2.16% in 4037 pregnant women.
Conclusion
In Turkey, it is fought against the perinatal contagion of hepatitis B virus by antenatal HBsAg screening, routine hepatitis B virus vaccine of newborns and passive and active immunization practices applied on newborns of the mothers who are positive for HBsAg. In addition, high risk groups are vaccinated against hepatitis B and with all these methods, it is expected to decrease the rate of hepatitis B in future years in Turkey.
Keywords

Hepatitis B, pregnancy, seropositivity, Turkey.

Introduction
The infection of hepatitis B virus is still considered as one of the leading public health problems in the world. According to the recent data of WHO, there are about 240 millions of individuals have been exposed to the chronic hepatitis B infection worldwide. The incidence of hepatitis B varies according to the geographical regions and they are classified as high, medium and low endemic regions. According to this classification, Turkey is among the medium endemic regions.
Hepatitis B virus seropositivity is evaluated with hepatitis B surface antigen (HBsAg) and HBsAg seropositivity rate is 5% in women in the world which varies between 0.6 and 20% according to the endemic regions.[1]
Hepatitis B virus (HBV) is transmitted by body fluids such as infectious blood, saliva and vaginal fluid/semen or percutaneous or mucosal contact. On the other hand, perinatal contagion is blamed particularly in the high endemic regions. Infection contagion from HBsAg positive mother to baby can occur during intrauterine, intrapartum or postpartum period. While contagion during intrauterine period is rare, it is more frequent during intrapartum or postpartum period when baby may contact with infected maternal fluids.
It was found that hepatitis B e antigen (HBeAg) and serum HBV DNA levels of mother are effective in the contagion of the infection from HBV carrier mother to the baby during perinatal period.[2] It was reported in a study that the risk of contagion from mothers negative for HBeAg was 10–40% and that the risk increases to 70–90% in positive women.[3] When it is transmitted from mothers positive for HBeAg, it is considered that the rate of the disease being chronic in the infected baby also increases.[4] Thanks to the active and passive immunization applied together with the birth, the risk of contagion to babies born from mothers positive for HBsAg/HBeAg is decreased. In Turkey, all newborns have been vaccinated routinely for hepatitis B since 1998.
As the perinatal contagion of hepatitis B is still important today, we aimed in this study to explain the seropositivity of hepatitis B virus of pregnant women in the light of the studies carried out in Turkey and to show the progress of HBsAg seropositivity rate by regions and years.
Methods
The studies on HBV seropositivity in pregnant women were screened in the databases of ULAKBIM Medical Database (Turkish Medical Index), TürkMedline and Turkish Citation Index. The studies were researched by using the keywords “hepatit B” (hepatitis B), “HBsAg”, “gebe enfeksiyon” (infection in pregnant women), “gebe hepatit B” (hepatitis B in pregnant women), and “gebe HBsAg” (HBsAg in pregnant women). Other studies were found by analyzing the studies found in the databases. Except the theses published in Turkey, the theses found during the database investigation were reviewed in terms of the literature. On this topic, 64 studies performed between 1975 and 2016 were found. The studies performed within the last 2 decades (1996–2016) were arranged by their publication years (Table 1).
Additionally, the data of the women delivered in our clinic between 2012 and 2015 were reviewed retrospectively and the result of HBsAg seropositivity rate was determined in our study.
Results
There are more than 60 studies, investigating HBsAg seropositivity of pregnant women in Turkey, performed in different years and in the same and different cities. While these studies show that HBsAg seropositivity varies between 1.2 and 19.2% in Turkey, no higher positivity was found in other studies after the study reporting the rate as 19.2%. It is seen that the highest rate reported by the studies performed within the last two decades is 9.3% (Table 1). It is seen that the rate is less than 6% in the studies performed in the last 7 years with the contribution of vaccine program carried out throughout the country.
In our study that we investigated the rate of HBsAg seropositivity of pregnant women, we found this rate as 2.16% in 4037 pregnant women. In the study, we retrospectively analyzed the data of pregnant women who delivered at our clinic between 2012 and 2015 and found that 8.22% of the pregnant women were of foreign nationality, the mean age was 28.64 (±5.77), mean week of gestation was 38.57 (±2.72), gravida was 2.51 (±1.44) and parity was 1.20 (±1.16).
Discussion
Hepatitis B virus is an infectious agent which progress with mortality and may cause chronic liver diseases, cirrhosis and hepatocellular carcinoma. HBV is transmitted essentially by infected blood and body fluids as well as percutaneous or mucosal contact. On the other hand, perinatal contagion is blamed particularly for the incidence of hepatitis B in the high endemic regions. The presence of this infection is important in terms of obstetrics as it is considered that HBV infection has adverse effects on gestational outcomes. Infection contagion from carrier mother to baby can occur during intrauterine, intrapartum or postpartum period. It is thought that the reasons such as skin scars, mucosal penetration, swallowing maternal blood and fetomaternal bleeding due to placental injury have a role in the intrapartum contagion.[5]
There are many studies in the literature investigating the effects of HBV infection on gestational outcomes. In a study, it was reported that preterm labor rate is higher in pregnant women positive for HBsAg than the pregnant women in the control group and that the rates of gestational diabetes, preterm labor and low birth weight are higher in carrier women positive for HBsAg than the carrier women negative for HBsAg.[6] In another study, it is claimed that HBsAg seropositivity is associated with antepartum hemorrhage and low APGAR scores.[7]
There are more than 60 studies, investigating HBsAg seropositivity of pregnant women in Turkey, performed in different years and in the same and different cities. While these studies show that HBsAg seropositivity is between 1.2 and 19.2% in Turkey, the study of Turhanoğlu et al. in 1987 which was conducted on pregnant women in Diyarbakır found the rate 19.2%[8] and no such positivity has been seen in all other studies published afterwards.[8] When we evaluate the studies performed in the last two decades (Table 1),[9–49] we see that the highest rate is 9.3%.[26] It is seen that HBsAg seropositivity rate is lower in the studies performed with high number of pregnant women than those with less number of pregnant women. In the first three studies with the highest pregnant woman population, the rates of HBsAg seropositivity were 2.1% (90,351 pregnant women),[24] 3.5% (56,275 pregnant women)[41] and 2.1% (11,840 pregnant women).[37] It is remarkable in this regard that the numbers of pregnant women in studies with the rate above 7% are 397, 312 and 136.[26,12,21] The variety among the rates of HBsAg positivity in the studies shown in Table 1 may have many reasons. While some of these studies were carried out in reference centers such as university and training and research hospitals, some of them were performed in rural areas and maternal-pediatric health centers.[38,13] In this regard, it should be remembered that the studies carried out in the clinics which are reference centers cannot reflect the entire society. The rates also vary by regions and years. In recent years, HBsAg seropositivity rates tend to decrease in pregnant women as in the general population. With the help of country-wide vaccination program which has been conducted since 1998, no HBsAg seropositivity over 6% has been found in the studies carried out in the last 7 years.
In the studies investigating perinatal contagion, cord blood of babies of HBsAg seropositive mothers was checked and while a study found 45% HBsAg seropositivity in cord blood,[50] another study found no HBsAg seropositivity in the cord blood.[40] Kuru et al.[51] conducted screenings on the children as well as husbands of HBsAg seropositive cases and they found anti-Hbs rate over 20%. In the same study, there was no statistically significant difference between seropositive and seronegative cases in terms of age, number of pregnancy, socioeconomical status, intravenous injection, and applying blood and blood products.
We found the rate of HBsAg seropositivity of pregnant women in our clinic 2.16% in 4037 pregnant women. In this study, we retrospectively analyzed the data of pregnant women who delivered at our clinic between 2012 and 2015, and investigated HBsAg results checked with ELISA method in the peripheral blood samples collected routinely from the pregnant women at antenatal period. Of the pregnant women, 8.22% were foreign. Of those included in the study, mean age was 28.64 (±5.77), mean week of gestation was 38.57 (±2.72), gravida was 2.51 (±1.44) and parity was 1.20 (±1.16). We found that the HBsAg seropositivity rate in our clinic was consistent with the rates found in similar studies conducted in Istanbul in recent years.
When we look at the Table 1 which shows the progress of HBsAg seropositivity in different cities within last 20 years, we see that the rate is slightly above 4% in Istanbul for the first 10 years while it decreases to the level below 4% in the last 10 years. Although the rate reported in the study of Doğan et al. published in 2014 decreases to 1.2%,[47] the reasons for the slight increase in our study are considered to be the increased migration to Istanbul from other cities and the Middle East, and our clinic being one of the reference centers.
When we look at the distribution among the reasons, we see that there is a clear decrease in HBsAg seropositivity of pregnant women in Marmara, Mediterranean/Aegean and Eastern Anatolia regions while the rates fluctuate in Central and Southeastern Anatolia regions. On the other hand, the rate in Black Sea region increased from 2.2% to 5.1% in the last 10 years (Fig. 1). This result shows that further studies are required to investigate the reasons for the increase in Black Sea region.
Conclusion
As perinatal contagion maintains its importance in the endemic regions, it is necessary to investigate HBV of pregnant women in these regions and to take protective precautions against this infection. In Turkey, it is fought against the perinatal contagion of HBV by antenatal HBsAg screening, routine HBV vaccine of newborns and passive and active immunization practices applied on newborns of the mothers who are positive for HBsAg. In addition, high risk groups are vaccinated against HPV and with all these methods, it is expected to decrease the rate of hepatitis B in future years in Turkey.
References
  1. Lee CY, Huang LM, Chang MH, Hsu CY, Wu SJ, Sung JL, et al. The protective efficacy of recombinant hepatitis B vaccine in newborn infants of hepatitis B e antigen-positive-hepatitis B surface antigen carrier mothers. Pediatr Infect Dis J 1991;10:299–303. [PubMed

  2. Dwivedi M, Misra SP, Misra V, Pandey A, Pant S, Singh R, et al. Seroprevalence of hepatitis B infection during pregnancy and risk of perinatal transmission. Indian J Gastroenterol 2011;30:66–71. [PubMed] [CrossRef

  3. Kölgelier S, Demir LS, Demir NA, Ozcimen S, Tabak S. Seropositivity of HBsAg and anti-HCV in pregnant women in Adıyaman. [Article in Turkish] Viral Hepatitis Journal 2012;18:98–101. [CrossRef

  4. Behrman RE, Kliegman RM, Jenson HB. Nelson textbook of pediatrics. 17th ed. Philadelphia: WB Saunders; 2004. p. 1327–9. 

  5. Comella LT, Cunnigham MD, Eyal FG. Infection diseases. Norwalk, CT: Appleton and Lange; 1992. p. 348–9. 

  6. Sirilert S, Traisrisilp K, Sirivatanapa P, Tongsong T. Pregnancy outcomes among chronic carriers of hepatitis B virus. Int J Gynaecol Obstet 2014;126:106–10. [PubMed] [CrossRef

  7. Tse KY, Ho LF, Lao T. The impact of maternal HBsAg carrier status on pregnancy outcomes: a case-control study. J Hepatol 2005;43:771–5. [PubMed] [CrossRef

  8. Turhanoğlu M, Arıkan E. HBsAg and antibody incidence in different groups in the Southeast Turkey. [Article in Turkish] Dicle Üniversitesi Tıp Fakültesi Dergisi 1987;4:28–31. 

  9. Çepni İ, Bese T, Çetinkaya M, Gezer A, Altınok T, Aksu F. Prevalence of hepatitis B surface antigen in pregnant women attending to obstetrics and gynecology department. [Article in Turkish] Viral Hepatitis Journal 1996;2:80–3. 

  10. Kuru U, Turan O, Kuru N, Saglam Z, Ceylan Y, Nurluoglu M, Agacfidan A. Prevalence of hepatitis B virus infection in pregnant Turkish women and their families. Eur Clinical Microbiol Infect Dis 1996;15:248–51. [PubMed] [CrossRef

  11. Kadanalı A, Çelebi S, Aydos SK, Kadanalı S, Ayyıldız A. Perinatal transmission of hepatit B virus in Erzurum. [Article in Turkish] Atatürk Üniversitesi Tıp Dergisi 1997;29:450–2. 

  12. Kaleli B, Kaleli İ, Aktan E, Özen N, Akşit F. HBsAg in pregnants and in the cord blood of their infants. [Article in Turkish] Perinatoloji Dergisi 1997;5:42–4. 

  13. Akın N, Dilek S, Bilgel N. Screening for hepatitis B virus (HBV) seropositivity among pregnant women in the maternal child health and family planning (MCHFP) center in Bursa (Turkey). [Article in Turkish] Aile Hekimliği Dergisi 1997;1:86–9. 

  14. Gül A, Türkdoğan MK, Zeteroğlu S. The prevalance of hepatitis B and hepatitis C in a group of pregnant women. [Article in Turkish] Perinatoloji Dergisi 1998;6:67–9. 

  15. Biri A, Kilic G, Bozdayi G, Tezcan S. Prevalence of hepatitis B, hepatitis C and human immunodeficiency viruses during pregnancy. Turkiye Klinikleri Journal of Case Reports 2001;19:100–3. 

  16. Aslan G, Ulukanlıgil M, Seyrek A. Seroprevalance of HBsAg, anti-HBs and anti-HCV in Şanlıurfa. [Article in Turkish] Viral Hepatitis Journal 2001;7:408–11. 

  17. Yücel A, Bozdayı G, Turgut I. Serological profile of hepatitits B, hepatitis C and human immunodeficiency viruses among pregnant women. [Article in Turkish] Gazi Medical Journal 2001;12:103–5. 

  18. Sağsöz N, Apan T. The rates of tetanus, hepatitis B and Rubella seropositivity in pregnants. [Article in Turkish] Turkiye Klinikleri Journal of Gynecology and Obstetrics 2002;12:52–5. 

  19. Karaca Ç, Karaca N, Usta T, Demir K, Kaymakoğlu S, Beşışık F, et al. The frequencies of hepatitis B, C, D virus infection in the pregnant population and the rate of perinatal transmission of hepatitis C virus. [Article in Turkish] Akademik Gastroenteroloji Dergisi 2003;2:122–4. 

  20. Yegane Tosun S, Erensoy S, Özacar T, Yücebilgin S, Bilgiç A. The investigation and follow-up of pregnant women and their children for hepatitis virus infections. [Article in Turkish] Türk Mikrobiyol Cemiyeti Dergisi 2003;33:153–9. 

  21. Harma M, Harma M, Kafalı H, Güngen N, Demir N. Hepatitis B carrier status of pregnant women and vertical transmission to the newborn. [Article in Turkish] Perinatoloji Dergisi 2003;11:29–32. 

  22. Yılmazer M, Altındiş M, Çevrioğlu S, Fenkçi V, Aktepe O, Sırthan E. Toxoplasma, Cytomegalovirus, Rubella, Hepatitis B and Hepatitis C seropositivity rates in pregnant women who live in Afyon region. [Article in Turkish] Kocatepe Tıp Dergisi 2004;5:49–53. 

  23. Tekay F, Özbek E. Short communication: hepatitis B, hepatitis C and human immunodeficiency virus seropositivities in women admitted to Sanliurfa Gynecology and Obstetrics Hospital. [Article in Turkish] Mikrobiyol Bult 2006;40:369–73. [PubMed

  24. Madendağ Y, Çöl Madendağ İ, Çelen Ş, Ünlü S, Danışman N. Seroprevalence of hepatitis B, hepatitis C and HIV at whole obstetric and gynecologic patients who applied our hospital. [Article in Turkish] Turkiye Klinikleri Journal of Gynecology and Obstetrics 2007;17:442–6. 

  25. Cakmak B, Yoruk P, Elmas B. Niğde bölgesinde doğum yapan kadınlarda hepatit B seropozitiflik oranı, risk faktörleri ve yenidoğan sonuçları. 6. Ulusal Jinekoloji Obstetrik Kongresi, 14 Mayıs 2008, Antalya. Türk Jinekoloji ve Obstetrik Derneği Dergisi Kongre Özel Sayısı 2008;5:115–6. 

  26. Sirmatel F, Bozkurt AI, Karsligil T, Cakmak A, Geyikli I. Hepatitis B in pregnant women and results of follow up of immunized children whose mothers are hepatitis B surfage antigen positive. [Article in Turkish] Bakırköy Tıp Dergisi (BTDMJB) 2008;4:31–3. 

  27. Uyar Y, Cabar C, Balci A. Seroprevalence of hepatitis B virus among pregnant women in northern Turkey. Hepat Mon 2009;9:146–9.
  28. Atilgan R, Kavak SB, Celik A. The ratio of hepatitis B and hepatitis C seropositivity in pregnants. [Article in Turkish] Turkiye Klinikleri Journal of Gynecology and Obstetrics 2009;19:34–7. 

  29. Dündar Ö, Çelik S, Tütüncü L, Ergür AR, Atay V, Müngen E. The prevalence of hepatitis B, hepatitis C, HIV, toxoplasmosis and rubella among pregmant women delivered in our clinic between 2000 and 2005. [Article in Turkish] Zeynep Kamil Tıp Bülteni 2009;40:1–9. 

  30. Kölgelier S, Güler D, Demiraslan H. The prevalence of HBsAg and anti-HCV in pregnant women in Adıyaman. [Article in Turkish] Dicle Tıp Dergisi 2009;36:191–4. [CrossRef

  31. Api O, Bektas M, Akil A, Api M, Batirel A, Bayer F, et al. Hepatitis B Virus seroprevalence in the pregnant population admitting to an Education and Research Hospital in Istanbul. TJOD Dergisi 2009;6:103–10. 

  32. Altinbas S, Erdogan M, Danisman N. The seroprevalences of HBsAg and anti-HCV in pregnant women in Ankara. Arch Gynecol Obstet 2010;281:371. [PubMed] [CrossRef

  33. Köksaldı Motor V, Evirgen Ö, Aksakal M, İnci M, Önlen Y. Seropositivity of Hepatitis B and Hepatitis C in women who were admitted to Hatay Maternity and Children’s Hospital. [Article in Turkish] Viral Hepatitis Journal 2010;16:53–6. 

  34. Akdemir N, Bilir C, Akarsu S, Gürsoy AY. Hepatitis B and Hepatitis C seroprevalence follow up and awareness rates of pregnant; Ankara-Kecioren Region. [Article in Turkish] Ortadoğu Tıp Dergisi 2010;1:22–5. 

  35. Karlıdağ GE. HBsAg seroprevalence in pregnant women admitted to a hospital in centrum Elazig. [Article in Turkish] Fırat Üniversitesi Sağlık Bilimleri Tıp Dergisi 2011;25:111–3. 

  36. Coşkun Eİ, Dinçgez B, Koyucu RG, Ayanoglu YT, Ender Yumru A. The incidence of HBsAg, anti-HBs and anti-HCV in pregnant women. Perinatal Journal 2011;19:71–5. [CrossRef

  37. Araz NC, Dikensoy E. Seroprevalence of hepatitis B among pregnant women in Southern Turkey. J Pak Med Assos 2011;61:176–7. [PubMed

  38. Gönen İ. The frequency of HBV and HCV in pregnant women in rural areas. [Article in Turkish] Viral Hepatitis Journal 2011;17:66–8. 

  39. Varol FG, Sayın NC, Soysüren S. Seroprevalance of toxoplasma gondii antibodies in antenatal population of Trakya region. Journal of Turkish Society of Obstetrics and Gynecology 2011;8:93–9. [CrossRef

  40. Deveci Ö, Yula E, Özer TT, Tekin A, Kurkut B, Durmaz S. Investigation of intrauterine transmission of hepatitis B virus to children from HBsAg-positive pregnant women. J Microbiol Infect Dis 2011;1:14–6. [CrossRef

  41. Cicek AC, Duygu F, Inakci IH. Hepatitis B and hepatitis C seropositivities in women admitted to gynecology and obstetrics hospital in Şanlıurfa city: a 3-year evaluation. [Article in Turkish] Viral Hepatitis Journal 2012;18:15–8. [CrossRef

  42. Çakmak B, Karataş A. Sero-positivity ratios of hepatitis B and C in pregnant women living in Kocaeli region. [Article in Turkish] Selçuk Tıp Dergisi 2012;28:80–2. 

  43. Yıldız B, Bucaktepe PGE, Yıldız İ, Kara İH. The ratio of HBsAg and antiHCV seropozitivity in pregnant and other patients admitted to department of obstetrics and gynecology and their relationships with the other risk factors. [Article in Turkish] Konuralp Tıp Dergisi 2012;4(3):27–34. 

  44. Ozlu T, Tas T, Mengeloglu FZ, Kocoglu E, Donmez ME. Frequency of HBsAg, anti-HCV and anti-HIV in pregnant women and/or patients with gynecologic diseases in tertiary hospital. [Article in Turkish] J Clin Exp Invest 2013;4:166–70. [CrossRef

  45. Balık G, Üstüner I, Kağıtçı M, Ural ÜM, Tekin YB, Şentürk Ş, et al. HBsAg, AntiHBs and Anti-HCV seroprevalance in pregnant women living in Rize region. [Article in Turkish] Dicle Tıp Dergisi 2013;40:254–7. [CrossRef

  46. Koruk İ, Koruk ST, Demir C, Şeyhanoğlu AS, Kara B. HbsAg seropositivity and other related factors among pregnant women in crowded living conditions in a health district where seasonal farmworkers live in Şanlıurfa. [Article in Turkish] Turk J Public Health 2013;11:149–59. 

  47. Dogan K, Guraslan H, Ozel G, Aydan Z, Yasar L. Seroprevalence rates of toxoplasma gondii, rubella, cytomegalovirus, syphilis, and hepatitis B, seroprevalences rate in the pregnant population in Istanbul. [Article in Turkish] Türkiye Parazitoloji Dergisi 2014;38:228–33. [CrossRef

  48. Özcan Dağ Z, Gül S, Işık Y, Tulmaç ÖB, Şimşek Y. Hepatitis B and hepatitis C seropositivity rates in pregnants who live in Kırıkkale region. [Article in Turkish] Bozok Tıp Dergisi 2015;5(3):1–4. 

  49. Aynıoğlu A, Aynıoğlu Ö, Akar T, Aydın M, Altunok ES. HBsAg, anti-HBs and anti-HCV seropositivity rates among pregnant women attending a University Hospital in Zonguldak. Viral Hepatitis Journal 2015;21:31–4. [CrossRef

  50. Olgun N, Dirik E, Kavukçu S, Şaşmaz E, Bahar H, Güner S, Okuyan M. İzmir yöresinde HBV’nin perinatal geçiş sıklığı. İnfeksiyon Dergisi 1991;5:117–20. [PubMed] [CrossRef

  51. Kuru Ü, Turan Ö, Ceylan Y, Nurluoğlu M, Önür C, Ağaçfidan A, Biçici D ve ark. Incidence of HBsAg positivity in pregnancy. [Article in Turkish] Klimik Dergisi 1992;5:83–6. [PubMed] [CrossRef
File/Dsecription
Table 1.
The studies carried out on HBsAg seropositivity of pregnant women in Turkey within the last 20 years.
Fig. 1.
Distribution of HBsAg seropositivity of pregnant women within the last 20 years by regions and years.