Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2009 Jun;113(6):1272-1278.
doi: 10.1097/AOG.0b013e3181a5ef23.

The effect of childbirth on hiatal dimensions

Ka Lai Shek  1 , Hans P Dietz
Affiliations

The effect of childbirth on hiatal dimensions

Ka Lai Shek et al. Obstet Gynecol. 2009 Jun.

Abstract

Objective: To estimate changes in levator hiatal dimensions after childbirth in women with and without ultrasonographically visible morphological abnormalities of the levator ani and to correlate those changes with delivery mode.

Methods: A total of 296 nulliparous women were recruited. They were examined with four-dimensional translabial ultrasonography at 36-38 weeks of gestation and at 3-4 months postpartum. Peripartal changes in levator hiatal dimensions were correlated with delivery data.

Results: Mean postpartum follow-up was 5.3 months (median 4.1, interquartile range 3.7 to 5.1). Of 212 women who returned for follow-up, 101 had had normal vaginal deliveries (48%), 31 vacuum/forceps (15%), and 80 cesarean deliveries (38%). After cesarean delivery, there was a decrease in the mean hiatal area on Valsalva maneuver of 8.5% (P=.005). Vaginal delivery without avulsion was associated with an increase of 6% (P=.035). In women with avulsion injury, hiatal area increased by 28% (P=.002). Mean postpartum hiatal area on Valsalva was 25.46 cm after vaginal delivery with avulsion, 22.61 cm without avulsion, and 19.13 cm in the cesarean delivery group. After avulsion, hiatal area on contraction also increased significantly (P<.001).

Conclusion: Vaginal childbirth results in enlargement of the levator hiatus, especially after an avulsion. However, even without macroscopic levator trauma, there may be increased distensibility of the hiatus, which may be another mechanism leading to enlargement of the hiatus and pelvic organ prolapse.

Level of evidence: II.

PubMed Disclaimer

References

    1. Mant J, Painter R, Vessey M. Epidemiology of genital prolapse: observations from the Oxford Family Planning Association Study. Br J Obstet Gynaecol 1997;104:579–85.
    1. Hendrix SL, Clark A, Nygaard I, Aragaki A, Barnabei V, McTiernan A. Pelvic organ prolapse in the Women’s Health Initiative: gravity and gravidity. Am J Obstet Gynecol 2002;186:1160–6.
    1. Swift S, Woodman P, O’Boyle A, Kahn M, Valley M, Bland D, et al. Pelvic Organ Support Study (POSST): the distribution, clinical definition, and epidemiologic condition of pelvic organ support defects. Am J Obstet Gynecol 2005;192:795–806.
    1. DeLancey JO, Kearney R, Chou Q, Speights S, Binno S. The appearance of levator ani muscle abnormalities in magnetic resonance images after vaginal delivery. Obstet Gynecol 2003;101:46–53.
    1. Dietz HP, Simpson JM. Levator trauma is associated with pelvic organ prolapse. BJOG 2008;115:979–84.

Publication types

LinkOut - more resources