The pregnant body is truly amazing when you sit back and look at how much give and take it goes through during those nine months. At the beginning of your pregnancy, your uterus is about the size of your fist. It begins to enlarge at 8-12 weeks. Your doctor or midwife will begin to measure your uterus at your three month prenatal appointment and will continue measuring its growth at every appointment after that one.
The measurement your doctor or midwife is recording is the height of the fundus. The top of the uterus is called the fundus. The fundus is measured in relation to your pubic bone. Doctors and midwives use this measurement to make sure that your baby's growth is on target for your estimated due date. The height of the fundus also will tell a doctor or midwife if your baby is growing at a normal or adequate rate.
About one in five expectant mothers have what is referred to as a tilted or retroverted uterus in which the fundus is tilted towards the back instead of the front. In most pregnancies the uterus will right itself by the end of the first trimester. In rare cases when it doesn't, and where it becomes lodged in the pelvis putting pressure on the bladder, a catheter may need to be inserted to drain the mother's urine and then the uterus is gently pushed back into the proper position.
Why can uterus change its height?
During pregnancy, a uterus is a place for fertilized eggs to nest and grow. Therefore, the uterus also develops to accommodate the development of the fetus.
The length of the uterus during pregnancy can be changed without causing difficulties to other organs due to the elasticity of the abdominal wall muscles that are stretching.
Besides, other organs also adapt well to the new position when the uterus pushes out. Thanks to this feature, the fetus can grow and develop in the womb.
Landmarks of fundal height
From the week 12-14, the uterus will reach your pubic symphysis. The uterus then has a spherical shape.
When you have a 20 to a 22-week-old fetus, The height of Fundus during pregnancy varies and has reached the belly button.
Then in week 36-40, By this time, the uterus has reached the height of the sternum and navel.
Some conditions affect the height of Fundus
You might catch sight of some shorter or longer measured circumstances of the uterus. This due to the following conditions.
- Fetus descent into the pelvis, seen typically two to four weeks before delivery
- Error in estimated date of pregnancy based on the first day of the last menstrual period
- A fetus is healthy but physically small
- Non-longitudinal lie
- Small for gestational age or Intrauterine Growth Restriction
- Twins, or other types of multiple births
- Error in estimated date of conception
- The fetus is healthy but physically large
- Gestational diabetes causing a giant baby