PubMed Central, : RMMJ Rambam Maimonides Medical Journal Rambam Health Care Campus 2017 April; 8(2): e0018. ISSN: 2076-9172Published online 2017 April 28. doi: 10.5041/RMMJ.10295.

Study	Risk Factors
Sheiner et al. (2005)¹⁶	Forceps delivery (OR, 26.7; 95% CI, 8.0–88.5) Vacuum extraction (OR, 8.2; 95% CI, 4.7–14.5) Fetal macrosomia (>4,000 g) (OR, 2.5; 95% CI, 1.2–4.9)
Groutz et al. (2011)¹³	Asian ethnicity (OR, 8.9; 95% CI, 4.2–18.9) Vacuum delivery (OR, 2.7; 95% CI, 1.6–4.6) Primiparity (OR, 2.4; 95% CI, 1.5–3.7) Persistent occipito-posterior position (OR, 2.1; 95% CI, 1–4.5) Birthweight ≥4,000 g (OR, 1.001; 95% CI, 1–1.001)
Zafran & Salim (2012)¹⁷	Primiparity (OR, 11.75; 95% CI, 3.10–44.60) Vacuum extraction (OR, 4.21; 95% CI, 1.31–13.53)
Melamed et al. (2013)¹⁵	Forceps delivery (OR, 5.5; 95% CI, 3.9–7.8) Precipitate labor (OR, 5.2; 95% CI, 2.9–2.9) Persistent occiput-posterior position (OR, 2.6; 95% CI, 1.6–4.3) Vacuum extraction (OR, 1.9; 95%CI, 1.4–2.6) Large for gestational age (>90th percentile) (OR, 1.5; 95% CI, 1.1–2.0) Gestational age >40 weeks (OR, 1.4; 95% CI, 1.1–1.7)
Loewenberg-Weisband et al. (2014)¹⁴	Primiparity (OR, 3.19; 95% CI, 2.23–4.55) Instrumental delivery (OR, 1.82; 95% CI, 1.25–2.65) Prolonged second stage of labor (OR, 1.77; 95% CI, 1.19–2.61) Episiotomy (OR, 1.69; 95% CI, 1.18–2.40)
Garmi et al. (2016)¹²	Vaginal birth after cesarean section (OR, 13.6; 95% CI, 4.7–39.3) Primiparity (OR, 7.6; 95% CI, 3.5–16.3) Prolonged second stage of labor (OR, 1.5; 95% CI, 1.1–2.1)
Krissi et al. (2016)⁶	Type 2 diabetes mellitus (OR, 24.5; 95% CI, 2.55–236.40) Severe preeclampsia (OR, 9.53; 95% CI, 1.17–77.55) Vaginal birth after cesarean section (OR, 3.65; 95% CI, 1.49–9.12) Higher neonatal birthweight (OR, 1.01; 95% CI, 1.01–1.02)
Mizrachi et al. (2017)⁴	Nulliparity (OR, 6.08; 95% CI, 2.30–16.02) Fetal macrosomia (OR, 4.17; 95% CI 1.36–12.75)