Duration of second stage of labor and instrumental delivery as risk factors for severe perineal lacerations: population-based study

BMC Pregnancy and Childbirth

Research Article

Marija Simic¹  Sven Cnattingius¹  Gunnar Petersson¹  Olof Stephansson²  Anna Sandström² 

[1] Clinical Epidemiology Unit, T2, Department of Medicine Solna, Karolinska University Hospital and Institutet, SE 171 76, Stockholm, Sweden;Clinical Epidemiology Unit, T2, Department of Medicine Solna, Karolinska University Hospital and Institutet, SE 171 76, Stockholm, Sweden;Department of Women’s and Children’s Health, Division of Obstetrics and Gynecology, Karolinska University Hospital and Institutet, SE-171 76, Stockholm, Sweden;

关键词: Pregnancy;    Second stage of labor;    Perineal lacerations;    Instrumental delivery;    Episiotomy;    Occiput posterior position;    Macrosomia;    Partograph;    Obstetric anal sphincter injury;   

DOI  :  10.1186/s12884-017-1251-6

 received in 2015-09-08, accepted in 2017-02-11,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundWe sought to investigate the impact of the duration of second stage of labor on risk of severe perineal lacerations (third and fourth degree).MethodsThis population based cohort study was conducted in the Stockholm/Gotland region, Sweden, 2008–2014. Study population included 52 211 primiparous women undergoing vaginal delivery with cephalic presentation at term. Unconditional logistic regression analysis was used to calculate crude and adjusted odds ratios (OR), using 95% confidence intervals (CI). Main exposure was duration of second stage of labor, and main outcome was risks of severe perineal lacerations (third and fourth degree).ResultsRisk of severe perineal lacerations increased with duration of second stage of labor. Compared with a second stage of labor of 1 h or less, women with a second stage of more than 2 h had an increased risk (aOR 1.42; 95% CI 1.28–1.58). Compared with non-instrumental vaginal deliveries, the risk was elevated among instrumental vaginal deliveries (aOR 2.24; 95% CI 2.07–2.42). The risk of perineal laceration increased with duration of second stage of labor until less than 3 h in both instrumental and non-instrumental vaginal deliveries, but after 3 h, the ORs did not further increase. After adjustments for potential confounders, macrosomia (birth weight > 4 500 g) and occiput posterior fetal position were risk factors of severe perineal lacerations.ConclusionsThe risk of severe perineal laceration increases with duration until the third hour of second stage of labor. Instrumental delivery is the most significant risk factor for severe lacerations, followed by duration of second stage of labor, fetal size and occiput posterior fetal position.

【 授权许可】

CC BY   
© The Author(s). 2017