The endometrium is only 5mm pregnant probability will have the manifestation of preterm abortion, should promptly consult a specialist doctor for relevant examination, there has been a preterm abortion should be timely for the preservation of the fetus treatment. Normal female pregnancy endometrial thickness of 10mm ~ 12mm between, if the endometrial thickness of only 5mm, it is more likely to occur in the phenomenon of preterm miscarriage, due to the endometrial at this time is relatively thin, so as to give the gestational sac of the nutrients less, so that the phenomenon of miscarriage. If the thickness of the lining is only 5mm, you should consult a specialist in time for some relevant examinations, such as progesterone test, HCG (human chorionic gonadotropin) test, ultrasound, etc. If the results are normal, you should pay attention to the results of the examination. If the test results are normal, you should take rest, avoid exertion and observe more. If the test results show that there is already preterm labor, you should carry on the treatment of birth preservation, usually often applying progesterone injection or oral birth preservation tablets and other medications to promote the growth of the uterine lining. If the test result shows that there is preterm labor, you should be treated with fertility preservation, usually with progesterone injections or oral medication such as Protonix tablets. If the endometrium is only 5mm thick, it is important to consult a specialist to rule out any risky situations, so as not to delay the condition, and to follow the doctor’s instructions.