Pregnancy & Childbirth
The effects of pregnancy and childbirth on the pelvis are finally getting some well-deserved attention, both in the scientific community and in popular culture. In turn, an educated expectant mother is better able to understand what happens to her body and is able to communicate her concerns to her health care provider.
Effects of pregnancy on the pelvic region
Although the pelvis appears to be a fairly rigid circle of bone, it is actually a group of four separate bones: the sacrum and coccyx at the back, and the Ilia (hipbones) on either side. During pregnancy, a hormone called relaxin is secreted to soften (and eventually open) the pelvic joints in preparation for childbirth. This change in the pelvic bones and joints may cause a feeling of instability and can contribute to back pain and a loss of balance.
The pelvic region also includes a web of muscles, nerves, and ligaments. During pregnancy, the muscles of the pelvic floor are stressed, especially in the later months, when the weight of pregnancy is at its heaviest. This added pressure may cause some women to leak urine. Pregnancy can also alter the strength and elasticity of the pelvic muscles and ligaments, damage nerves in the pelvic region, or, in rare cases, alter the position of organs. These issues can, in turn, affect pelvic health, setting the stage for issues such as urinary or fecal incontinence after the pregnancy is complete.
Effects of childbirth on the pelvic region
As the fetus descends through the birth canal, the dilation of the pelvic opening affects the vagina, bladder, and urethra, as well as the surrounding muscles, ligaments, and nerves. The intense pressure and stretching of the vaginal canal may cause nerve damage and/or muscle detachment and weakness. In some instances, the perineal tissue (between the vagina and the rectum) can tear. For a woman who has experienced a perineal injury with her first delivery, the risk of spontaneous tears increases with subsequent deliveries.
Other factors may increase the risk of pelvic floor injury, including:
- Prolonged second stage of labor
- Use of forceps or vacuum extraction delivery
- Larger than average babies (also referred to as fetal weight)
- Twins or higher-multiple pregnancies
- Advanced maternal age
- Episiotomy: This procedure, which involves cutting the perineal tissue, can also increase the risk of pelvic floor injury and should be discussed with your physician, health care provider, or midwife before delivery.
- Epidurals: This procedure, which involves the injection of anesthesia via a catheter placed into the outermost part of the spinal canal, can slow labor or numb the sensation of natural contractions, increasing the need for forceps, vacuum delivery, or even cesarean section.
The more severe the injury to the pelvic floor, the higher the likelihood that symptoms will persist beyond the normal post-partum recovery period.
Cesarean delivery vs. vaginal birth
One area of intense debate and research is the risk of vaginal delivery vs. cesarian section (C-section). Some studies cite a significant reduction in pelvic floor injury with childbirth by cesarean delivery, but most pelvic health professionals emphasize that the risks associated with surgery, both for the mother and the baby, may outweigh the benefits. These risks must be carefully evaluated before making a decision. The choice between vaginal or cesarean birth is highly personal and should be discussed with your physician, health care provider, or midwife well before childbirth.
Other Considerations for Childbirth
Some hospitals and birthing centers offer less-traditional options for labor and delivery. These options include:
- Water birth
- Non-continuous fetal monitoring
- Alternate birthing positions
- Pushing only according to natural urges
- Perineal massage and stretching to avoid episiotomy
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