Video Transcript : Daphne Metland: Okay, Emily, we're going to talk about the pelvis and how it's changing during pregnancy. At 30 weeks of pregnancy, you are probably noticing a lot of changes in your body, and you've got a lovely little bump. Emily: Thank you! Daphne: We're going to look at the pelvis and how it changes during pregnancy to accommodate your growing baby. So I've got a pelvis here, and you'll be glad to know this it's a plastic one, it's not real. But it's quite useful just to see that the pelvis is very much like a basin, a basin without a bottom, because the bottom bit is the muscle, the sling of muscles underneath. But this basin shape is useful because that's where your baby sits as it's growing, and it keeps the baby safe within this bony cage. And the smallest bit of the pelvis is the brim, this piece here and usually the baby goes down through that brim at about 36 weeks. And that's a good sign, because if the baby's gone through that smallest bit, you're pretty sure it will be able to get out. So for a first-time mother, when that baby engages and moves down, it's a really good sign that the baby's getting ready for labor. But before that, you may have noticed that you're getting quite a lot of back pain and pain at the front of the pelvis in pregnancy. It's worth just working out why. If you feel these big bones here at the top of your pelvis with your hands, those are the big wide bones that make the top of the pelvis. And then if you walk your fingers round the back you'll get to the sacroiliac joint here, the spine, and then this big wedge-shaped joint. Then if you come back up here, and walk your hands down the front of your pelvis, you'll get to the pubic bone at the front. And it's these two joints that tend to cause pain and discomfort in pregnancy, and that's because they're held in place by sliding ligaments, and your body secretes a hormone to soften them. This is one of the joints that's held in place with sliding ligaments, and my plastic pelvis has got screws that allow my joint to move, but your body will be secreting hormones that soften those ligaments and allow this whole joint to move. And it has the same effect around the front, on this joint, the pubic joint at the front and that can move out. Is that where you've been feeling pain? Emily: Yes! Daphne: And that's because this joint is moving and opening up. If you look through the pelvis, you can see it's a circle, and that's where the baby's head comes through. Women have nice circular pelvises to make space for the baby. And the other thing to notice is this tailbone at the end here. In men that's fixed in an upright position, so there's not very much room to get a baby through. In women that can flatten right out, and it really gives a lot more space, so as the baby comes through, the bone flattens out of the way, and then the baby comes up, rotates around the pubic bone, and gets born. Emily: Okay! Copyright © Babycenter All Rights Reserved.

• published: 25 Feb 2015
• views: 36593