CC BY-NC-ND 4.0 · AJP Rep 2019; 09(03): e302-e309
DOI: 10.1055/s-0039-1697655
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The Accuracy of Group Beta Streptococcus Rectovaginal Cultures at 35 to 37 Weeks of Gestation in Predicting Colonization Intrapartum

Farrah N. Hussain
1  Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Mount Sinai West, Icahn School of Medicine at Mount Sinai, New York, New York
,
Zainab Al-Ibraheemi
1  Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Mount Sinai West, Icahn School of Medicine at Mount Sinai, New York, New York
,
Stephanie Pan
2  Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, New York
,
Antonia P. Francis
3  Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, New York University Langone Health, New York, New York
,
Dyese Taylor
1  Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Mount Sinai West, Icahn School of Medicine at Mount Sinai, New York, New York
,
Melissa Chu Lam
1  Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Mount Sinai West, Icahn School of Medicine at Mount Sinai, New York, New York
,
Dawnette Lewis
1  Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Mount Sinai West, Icahn School of Medicine at Mount Sinai, New York, New York
› Author Affiliations
Further Information

Publication History

06 May 2019

28 June 2019

Publication Date:
23 September 2019 (online)

  

Abstract

Objective This study aims to investigate accuracy of group beta Streptococcus (GBS) rectovaginal cultures at 35 to 37 weeks in predicting intrapartum colonization.

Study Design Institutional review board (IRB) approved prospective cohort study of 302 women from October 2015 to May 2017. Patients had the following tests for GBS: first trimester urine culture, rectovaginal culture at 35 to 37 weeks, and intrapartum rectovaginal culture. Outcomes included accuracy of 35- to 37-week GBS rectovaginal culture in detecting results intrapartum, and accuracy of first trimester urine culture in comparison to intrapartum rectovaginal cultures.

Results There was sufficient evidence of agreement between results at 35 to 37 weeks with intrapartum cultures (p = 0.001). However, agreement was weak, 11 patients (3.7%) were GBS positive intrapartum but negative at 35 to 37 weeks; and 33 patients (11%) were initially GBS positive but were negative intrapartum. Sensitivity and specificity of the 35- to 37-week culture was 69% (95% confidence interval [CI]:54–84%) and 87% (95% CI: 83–91%), respectively. There was also weak agreement between first trimester urine culture and intrapartum rectovaginal culture. Specificity for this assessment was 98% (95% CI: 97–100%) and was significantly different compared with antepartum GBS culture (p < 0.001). Accuracy between antepartum GBS rectovaginal culture and urine culture was similar (85 vs. 87%, p = 0.47).

Conclusion The 35- to 37-week GBS rectovaginal culture might be a poor predictor for intrapartum colonization.

Condensation

Group beta Streptococcus (GBS) rectovaginal cultures at 35 to 37 weeks of gestation may be a poor predictor for GBS colonization in labor.


Note

This study was presented at the Society for Maternal-Fetal Medicine 38th annual Pregnancy Meeting, Dallas, TX, January 29 to February 3, 2018.


Financial Supportl

No financial support was obtained for this study.