A hormone called estrogen plays an important role in a woman’s menstruation & pregnancy. It is responsible to thickening uterine lining each month. When the estrogen level is drop-down, the lining is released from the uterus and you get your period.
Endometrium goes through three phases during the typically 28-day menstrual cycle –
- Menstrual phase (days 1-5)
Typical thickness is 1-4mm
2. Proliferative phase (days 6-14)
Typical thickness is 5-7mm
3. Secretory phase (days 15-28)
Typical thickness is 7-14mm
Endometrium, the innermost layer of the uterus thus is an important factor during pregnancy. If it is less than 7mm, medical treatment is needed for a successful pregnancy.
In case of the thin uterine lining, conceiving is not a problem but continuation of the pregnancy is sometimes difficult. Fortunately, there are medicines available for increasing the endometrial thickening.
Some medical conditions like cancer, fibroids, and polyps can also cause the uterine walls to thicken.