The uterus size is measured to determine if the baby is growing normally at each stage of the pregnancy and it is compatible with the weeks of gestation or not.
During pregnancy, there are progressive changes occur not only confined to the genital organs but also to all the systems of the body.
All women want to know their baby’s growth whether it is compatible with the weeks of gestation or not. You can check the height of the uterus to know the growth of your baby.
The uterus which is in the non-pregnant stage measures about 7.5 cm in length, will measure 35 cm at term.
The purpose of measuring the height of the mother’s uterus is to determine if the baby is growing normally at each stage of the pregnancy. Uterus size or fundal height can be measured by a measuring tape. It is the distance between the top of the uterus (fundus) and the pubic bone (symphysis pubis).
Uterus Size in First Trimester
The uterus remains a pelvic organ until 12 weeks of pregnancy, it is just felt per abdomen as a bulge above the pubis. You can feel your pubic bulge or uterus size by touching your abdomen.
The uterus enlarges to the size of a hen’s egg at the 6th week, the size of a cricket ball at the 8th week and the size of a fetal head by the 12th week.
Uterus Size in Second Trimester
During the second trimester, the uterus enlarges progressively. The height of the uterus is midway between the symphysis pubis and umbilicus (belly button) at 16th week; at the level of the umbilicus at 24th week and between the umbilicus and ensiform cartilage at the 28th week.
It is expected that after 24 weeks of pregnancy, the fundal height for a normally growing baby will match the number of weeks of pregnancy (+2 or -2 cm). For example, if you’re 28 weeks pregnant then your fundal height will be about 28 cm.
Uterus Size in Third Trimester
During 3rd trimester, the distance between the umbilicus and ensiform cartilage (xiphisternum) is divided into 3 equal parts. The fundal height at 32 weeks is below the rib cage; at 36 weeks at the level of ensiform cartilage. It comes down to 32 weeks level at 40 weeks because of the engagement (dropping down of head into the pelvis) of the presenting part.
To determine whether the height of the uterus corresponds to 32 weeks or 40 weeks, engagement of the head should be tested. If the head is floating, it is of 32 weeks pregnancy and if the head is engaged, it is of 40 weeks of pregnancy.
Following the birth of the baby, the uterus gradually reverts back to the pre-pregnant state. It usually takes 6 weeks for the complete process.
In the above post, we have discussed the uterus size during pregnancy. Uterus size or the fundal height is the distance between the top of the uterus and symphysis pubis. During the first trimester, the uterus remains the pelvic organ. In the second trimester, the height is between the umbilicus and ensiform cartilage; in the third trimester, it lies below the rib cage. It is usually expected that after 24 weeks of pregnancy, the fundal height for a normally growing baby will match the number of weeks of pregnancy.