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Updated: May 1, 2026
Anogenital Distance and Perineal Measurements of the Pelvic Organ Prolapse POP Quantification System
Published on: September 20, 2018
Racial/ethnic variations in perineal length and association with perineal lacerations: a prospective cohort study
Amanda Yeaton-Massey1, Luchin Wong, Teresa N Sparks
1Department of Obstetrics & Gynecology, Stanford Hospital & Clinics , Stanford, CA , USA .
Objective:
To examine the association between race/ethnicity, perineal length and the risk of perineal laceration.
Methods:
This is a prospective cohort study of a diverse group of women with singleton gestations in the third trimester of pregnancy. Perineal length was measured and mean values calculated for several racial/ethnic groups. Chi-squared analyses were used to examine rates of severe perineal laceration (third or fourth degree laceration) by race/ethnicity among women considered to have a short perineal length. Further, subgroup analyses were performed comparing nulliparas to multiparas.
Results:
Among 344 study participants, there was no statistically significant difference in mean perineal length by race/ethnicity (White 4.0 ± 1.1 cm, African-American 3.7 ± 1.0 cm, Latina 4.1 ± 1.1 cm, Asian 3.8 ± 1.0 cm, and other/unknown 4.0 ± 0.9 cm). Considering parity, more multiparous Asian and African-American women had a short perineal length (20.7 and 23.5%, respectively, p = 0.05). Finally, the rate of severe perineal lacerations in our cohort was 2.6% overall, but was 8.2% among Asian women (p = 0.04).
Conclusions:
We did not find a relationship between short perineal length and risk of severe perineal laceration with vaginal delivery, or a difference in mean perineal length by maternal race/ethnicity. However, we did find that women of different racial/ethnic groups have varying rates of severe perineal laceration, with Asian women comprising the highest proportion.
