@2024 Afarand., IRAN

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ISSN: 2251-8215    Sarem Journal of Reproductive Medicine 2019;3(1):1-4

Background
Group B Streptococcus (GBS) is a gram-positive and encapsulated diplococcus, and in most cases it forms a colony in a digestive tract and human reproductive system[1]. This bacterium is an important cause of infection in newborns, pregnant women, and adults with underlying diseases[2]. In pregnant women, Streptococcus Group B, produces bacteriuria and chorioamnionitis and can cause pneumonia, meningitis, endocarditis, sepsis, and bacteremia in newborns. These infections sometimes begin the uterus[3-6]. Severe infections of pregnant women with GBS in some cases also cause failure of pregnancy[7].
Previous Studies
Research findings have shown that the vaginal colonization of mother with GBS is infectious to infants [8]. Infection transmission from mother to fetus is transmitted vertically and usually occurs after preterm rupture of membranes[9]. However, in some cases, infections of infants with GBS occur without preterm rupture of membranes in the uterus and before the onset of labor[10]. Neonatal infections occur in two ways: 1) Early infection which occurs 24 to hours to 6 days after birth, and 2) Late infection which occurs 6 to 90 days after birth. Studies have shown that vaginal infection with GBS during pregnancy increases the risk of vertical transmission of infection to infant and the probability of late infection[11, 12]. Late infection is common in forms of meningitis, sepsis, and pneumonia in newborns and in 90% of cases, it manifests itself in the first 24 hours[13]. In studies conducted on infants whose mother with GBS-positive and not treated, in half of the cases, one complication was reported such as fetal death, infant infections and neonatal death[10]. If the infection is diagnosed during pregnancy and mothers are treated with antibiotics, the infectious outbreak decreases in the infant. In recent years, due to timely treatment, the prevalence of infection in newborns had decreased as well as neonatal lethargic complications[13].
Aim(s)
Because of the importance of neonatal GBS infections and the lethality of septicemia caused by this bacterium, studies are needed in this regard, given that the treatment of mothers carrying these bacteria prevents infants. The purpose of this study was to determine the prevalence of B-streptococcus in pregnant women in the gestational age of 35-37 weeks of gestation.
Research type
This study is descriptive type.
Research society, place and time
In this study, during the 18 month period, from the beginning of 2011 to the middle of 2012, pregnant women who referred to Prenatal Clinic at Sarem Hospital in Tehran were investigated.
Sampling method and number
A total of 1610 women were divided into 5 groups based on their place of residence, including residents of northern Tehran, central Tehran, southern Tehran, Tehran suburb, and outside Tehran. Then, vaginal discharge was sampled from the middle third vaginal area to examine GBS with sterilized swabs and sent to microbiological lab of Sarem Hospital in tube containing sterile physiology for vaginal culture.
Used devices&materials
In the laboratory, samples were cultured on Blood Agar medium. Beta hemolysis was induced on the medium, followed by catalase and CAMP tests. Also, a range of vaginal discharge was investigated to examine the gram-positive coccus of the pair or chains by gram staining. Finally, the prevalence of GBS and its relation with demographic variables of the place of residence, level of education, occupation of pregnant women, husband›s occupation, age, frequency of pregnancy, interval between marriage and pregnancy, proper weight gain during pregnancy, abortion rate and infertility, history of underlying illness, and smoking, alcohol and drugs were studied. Data were analyzed using SPSS software.
Findings by Text
The prevalence of GBS among pregnant women was 119 (7.4%) in the 35-37 weeks of gestation. The mean age of the subjects with GBS was 29.93±5.70 years. The minimum and maximum ages were 19 and 46 years. 96.5% of the GBS carriers were in the age range of 21-45 years old. 57% of the cases were over 30 years old and 43% were below 30 years old. Most pregnant women who came from other cities were Karaj residents. The level of education of 90% of women with GBS, was bachelor and lower (Table 1) In 97% of pregnant women carrying GBS, no underlying disease was observed, and only 3% of them had underlying disease. None of the patients consumed cigarettes, alcohol or drug. All 119 patients who were gram positive for GBS had a good weight gain during pregnancy. In GBS pregnant women, 91% had no history of infertility and only 9% had a history of infertility. Most women (48.7%) weighed less than 67 kg. In 64.7% of the cases, the interval between the marriage and the gestational age was less 5 years (Table 2).
Main comparison to the similar studies
Compared to the findings of the present study, a prevalence of GBS colonization in pregnant women in three hospital was reported to be about 20% in Taiwan in 2004-2005[14]. In another similar study in the Netherland, about 21% of pregnant women were positive for GBS bacteria[15]. Of conducted studies in Iran, one study from University of Ardabil indicated that the prevalence of GBS in vaginal and rectum samples of 420 pregnant women was about 3.5% in the 35-37 weeks. Compared to studies from other countries, it seems that the prevalence of streptococcus B in pregnant women in Iran is lower. It is important to note that our study was conducted in a private hospital and was based only on vaginal culture, while in other countries, vaginal and rectal cultivation (two samples taken together) had been studied. This difference in samples, can be justification for lower prevalence of GBS in this study, compared to other countries.
Suggestions
In studying the demographic findings, low level of education and living in areas outside or suburb of Tehran with a low level of health and culture were among the issues that were related to the prevalence of GBS and the need for study in these areas are emphasized. Therefore, it is necessary that the individual and environmental factors affecting the prevalence of GBS be carefully examined and more extensive studies be done with generalizability.
Limitations
Because our study was conducted in a private hospital, and naturally those who come to such hospitals have higher education, culture and economic status, the findings of this study cannot be generalized to the society.
Conclusions
The prevalence of B group streptococcus in pregnant women is %7.4 in the week 37-35 of the pregnancy that is lower than the other countries.
Acknowledgments
Non-declared by the authors.
Conflict of interest
Non-declared by the authors.
Ethical Permissions
Non-declared by the authors.
Funding Sources
Non-declared by the authors.

TABLES and CHARTS

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