The cervix, or opening to the uterus, serves as something of a lockbox in a pregnancy. When the fetus anchors itself in the womb, the cervix slams shut to secure the developing baby and keep out germs. But sometimes, in cases of cervical incompetence, the cervix fails to close properly. As the baby grows, it puts increasing pressure on the opening, possibly spurring premature labor and delivery.
Doctors typically manage cervical incompetence by putting a stitch in the cervix, known as a cerclage, to help keep the baby going through 37 to 38 weeks. In many cases, bed-rest is also advised.
Uterine fibroids and malformations of the uterus can also limit a baby's development. For example, a bicornuate uterus has two hornlike chambers instead of the usual oval shape. If the baby establishes in one of these smaller chambers, it has limited room to grow. In these cases, miscarriage or preterm delivery is often common, according to The American Academy of Family Physians (AAFP).
Did You Know?
Management of preterm labor and preterm birth account for health care expenditures of over $3 billion per year, according to the AAFP (Familydoctor.org).