This is a cross - sectional study to determine the prevalence of GBS infection and associated factors in preterm labor women conceived through ART.

221 subjects will be involved.

Pregnant women at 20 0/7 to 36 6/7 weeks of gestation, conceived through ART, with signs and symptoms of preterm labor will be recruited.

Anal - vaginal fluid samples will be taken by 2 cotton swabs from each participant for culture. Digital examination will be performed after that. Only participants fulfilling all the study's eligible criteria will be interviewed face-to-face with a questionnaire.

The samples will be sent immediately to My Duc hospital laboratory or will be stored in Stuart-Amies medium in < 4 hours. All culture results are interpreted based on Clinical and Laboratory Standards Institute (CLSI) in 2012.

Statistical analysis was performed by Statistical Package for the Social Sciences (SPSS) v.20 and chi-square test. A p-value of < 0.05 was considered as statistically significant.

* Inclusion Criteria:

To be eligible for enrolment into this trial, subject must fulfil all of the following criteria, unless specified otherwise

• Being conceived through IVF

• Moderate uterine contractions (2 contractions per 10 minutes, duration < 30 seconds)

• 20 0/7 to 36 6/7 weeks of gestation

• Intact membrane

• Cervical dilation ≤ 3 cm

• Willing to participate into the study

  • Exclusion Criteria:

To be eligible for enrolment in this study each subject must not meet any of the following criteria:

• Having had intercourse during 24 hours before
• Being suspected of amniotic leakage
• Rupture of membrane identified by direct observation through speculum examination of amniotic fluid flow from cervix
• Vaginal bleeding
• Being suspected of placenta abruption, placenta previa
• Having been treated with antibiotics within 1 week before
• Vaginal douche within 48 hours before
• Having used vaginal medicines during 48 hours before
• Having vaginal ultrasound shortly before
• Urine culture positive with GBS