Endometrial lining of 0.3cm is relatively thin and is abnormal. Usually there are different periods of menstruation and the lining may be different at different times. When it is three days after menstruation, the endometrium is between 0.4-0.5cm. At the time of ovulation, the endometrium is around 0.8cm. Only a thickened endometrium can help conception. When menstruation is imminent, the endometrium will be above 0.9cm, or even around 1.1cm, and menstruation may occur. Endometrium 0.3cm which is relatively thin, it is recommended to have an examination including endocrine hormone examination to rule out any endocrine hormone abnormalities. If the endometrium is thin due to some surgical operation, adhesions may exist. Hysteroscopy is recommended and medication should be administered to help restore menstruation to normal.