On the outside of the body, the perineum is the area of sensitive skin located between the genitals and the anus. Inside the body, the perineum is a diamond-shaped structure containing fibers, membranes, nerves, and muscles that aid in bladder and bowel control, as well as sexual intercourse.
Due to the pressure exuded on the perineum during vaginal childbirth, tearing is common for many women during labor, particularly first-time mothers.
To prevent or minimize perineal tears during childbirth, it helps to understand the anatomy of the perineum as well as how to care for it before and after delivery.
What Is the Function of the Perineum?
As mentioned above, the perineum is the area of skin located at the bottom of the pelvis between the vagina and anus. This delicate patch of skin is an erogenous zone in both females and males, largely contributing to sexual arousal and pleasure.
Within the body, the perineum acts as the foundation of the pelvic cavity, essentially supporting the pelvic floor muscles whose role is to hold the pelvic organs in place. The perineum also stabilizes the multiple muscles, membranes, and nerves that enable peeing, pooping, intercourse, and childbirth.
Anatomy of the Perineum Explained
Although only visible on the outside of the body as a small part of skin between the genitals and the anus, the perineum is larger and much more intricate on the inside of the body. Beginning at the pubic symphysis, which is the joint at the front of the pelvis, the perineum reaches back to the coccyx and from the left to right sitz bones within the pelvis.
For better understanding, the inner perineum is often described as a diamond-shaped structure that can be separated into two triangles by imagining a line from the left sitz bone to the right.
The Urogenital Triangle
The upper triangle, known as the urogenital triangle contains the genitals, the urethra, and the muscles that enable the hold and flow of urine.
The Anal Triangle
The lower triangle, known as the anal triangle, contains the pudendal nerve, the anal opening, muscles that control the opening and closing of the anus, and two ischioanal fossae. The fossae are fat-filled spaces on either side of the anal canal containing that enable it to expand and contract during and after defecation.
The Perineal Body
A collection of fibromuscular tissue known as the perineal body is found where the anal triangle and urogenital triangle meet. This tissue offers significant support to the pelvic floor muscles and is susceptible to strain during childbirth.
The Perineum and Childbirth
The most common symptom linked to the perineum is pain due to a perineal tear during vaginal childbirth. This is particularly common for first-time mothers and during the delivery of large babies.
Perineal tears typically occur during the last stage of labor when the vagina and perineum are stretched to their limit as the baby’s head and shoulders are pushed through the vaginal opening.
Most perineal tears are minor and heal on their own within 2-3 weeks. However, severe tears, which can damage the anal sphincter and pelvic floor muscles typically require sutures and a longer recovery of 6-8 weeks.
In the past, an episiotomy was often performed to prevent severe tearing of the perineum during vaginal childbirth. This involved making a small incision in the perineum to make more space for the baby to pass through the vaginal opening.
Recent research has shown, however, that rather than prevent severe perineal tearing, an episiotomy can increase the risk of future incontinence, pelvic organ prolapse, pain during sex, and pelvic pain.
For these reasons, obstetricians and midwives prefer to allow the perineum to naturally tear during vaginal childbirth and only perform an episiotomy if the baby or mother is in distress.
Can Perineal Tears During Childbirth Be Prevented?
Massaging the perineum from week 36 of pregnancy will better prepare the area for overstretching during childbirth and reduce the probability and/or severity of perineal tearing. Massaging the area for five minutes 3-4 times per week is recommended either with the hands or with a pelvic massage wand.
Other Conditions That Affect the Perineum
When perineal symptoms occur outside of childbirth they can be caused by pelvic injuries while bike riding or horseback riding, as well as sexual abuse or sexual trauma. The following are other common causes of perineal pain and discomfort:
- Pain when urinating, defecating, or having sex can signal an underlying issue with the pelvic floor muscles, perineum, or the associated pelvic organs
- Perineal itching or soreness that makes sitting uncomfortable could be caused by nerve damage or an allergic reaction to soaps, detergents, or skincare products.
- Perineal pain that worsens during bowel movements or is accompanied by swollen veins protruding from the anus is typically due to hemorrhoids
- Lumps, swelling, or redness on perineal skin could signal an infection or an abscess that has developed after surgery (or childbirth)
- Perineal pain that slowly develops over a few weeks or months can be caused by a trapped pudendal nerve
Should you notice any of these symptoms, schedule an appointment with your healthcare provider for a correct diagnosis and treatment.
Conclusion
The perineum, located between the vagina and the anus, is a sensitive part of the body that plays an anatomical role in urination, defecation, intercourse, sexual pleasure, and childbirth. Although pelvic traumas, injuries, sexual abuse, and hemorrhoids can cause perineal discomfort, perineal tearing during childbirth is the most common cause of perineal pain.
When recovering from perineal tearing during childbirth, long-term complications like incontinence, painful sex, and pelvic organ prolapse can be avoided through the regular and appropriate use of pelvic massage wands and vaginal dilators.
If you’re seeking to reduce the risk of perineal tearing during childbirth or avoid long-term complications afterward, speak with your obstetrician or a pelvic physical therapist about using these pelvic tools.
References
Teach Me Anatomy – The Perineum - https://teachmeanatomy.info/pelvis/areas/perineum/
Royal College of Obstetricians & Gynaecologists - Perineal tears during childbirth - https://www.rcog.org.uk/for-the-public/perineal-tears-and-episiotomies-in-childbirth/perineal-tears-during-childbirth/
Female Health Awareness - Understanding the Impact of a Vaginal Delivery on the Pelvic Floor - https://femalehealthawareness.org/en/understanding-the-impact-of-a-vaginal-delivery-on-the-pelvic-floor/
National Library of Medicine - Anatomy, Abdomen and Pelvis: Ischioanal Fossa - https://www.ncbi.nlm.nih.gov/books/NBK535387/
Obstetrics & Gynecology Online Library - Effectiveness of antenatal perineal massage in reducing perineal trauma and post-partum morbidities - https://obgyn.onlinelibrary.wiley.com/doi/abs/10.1111/jog.13640
Alberta Health - Perineal Abscess - https://myhealth.alberta.ca/Health/aftercareinformation/pages/conditions.aspx?hwid=abq6103