How big is pelvis suitable for natural labor?

summary

Pelvic measurement refers to the pelvic measurement of pregnant women using pelvic measuring device, which is an essential item of prenatal examination. The pelvis can support and protect the reproductive organs and other organs in the pelvis. At the same time, it is also the most important part of the birth canal. It is an important channel for the fetus to give birth. Its shape and size are related to whether it can give birth smoothly, and how large is the pelvis suitable for spontaneous delivery? Let's talk about it

How big is pelvis suitable for natural labor?

The transverse diameter of the pelvic outlet refers to the distance between the two ischial tubercles, with an average length of about 9cm. It is the meridian of the fetal presentation through the pelvic outlet, which is closely related to delivery. If the transverse diameter of pelvic outlet is shorter, and the sum of transverse diameter of pelvic outlet and posterior sagittal diameter is more than 15 cm, the normal size fetus can still be delivered through vagina.

Women with large pelvis are relatively easy to give birth, but it's not enough to just look at the size of pelvis. Delivery is a complex project, and the conditions of labor force, birth canal and fetus are also very important! During delivery, in addition to the strong contraction of the uterus, but also with the help of the abdominal muscle, diaphragm, levator ani muscle, in order to get the fetus out of the maternal body.

But for fat pregnant women with big buttocks, there are often a large number of "pig teammates" - fat! They will greatly weaken the contractile force of abdominal wall muscles and other muscle groups, resulting in insufficient productivity and increased difficulty of delivery. The birth canal includes the pelvis and the soft birth canal. No matter how wide the pelvis is, the inner opening of the pelvis is the only way for the fetus to pass during delivery.

matters needing attention

Not all women are suitable for natural labor. If the fetal position is abnormal and the pelvis is small, these can be detected by B-ultrasound in advance. Relative indications, such as late delivery, macrosomia, temporary abnormal change of fetal position, etc. For pregnant women with such obvious indications, doctors would recommend cesarean section.