There are many reasons why redness disappears in late pregnancy, which may be related to complete miscarriage, preterm labor, placenta praevia, placental abruption, and so on.
1. Complete miscarriage: there are many factors that cause complete miscarriage, commonly due to maternal factors, embryonic factors, environmental factors, etc., resulting in redness and then disappear in late pregnancy, mainly manifested as vaginal bleeding and abdominal pain.
2. Preterm labor: it may be related to the increase of prostaglandin synthesis, infection, the increase of adrenocorticotropin-releasing hormone, uterine overstretching, etc. It starts with irregular contractions, accompanied by a little vaginal bleeding or bloody secretion, and develops gradually into contractions.
3. Placenta praevia: If the placenta of the mother is abnormal, the endometrium is diseased or damaged, or the trophoblast of the fertilized egg is delayed in development, the redness will appear and then disappear in the late stage of pregnancy, and the amount of bleeding is relatively small at the beginning, and will increase with the development of the uterus.
4. Placental abruption: when there is a sudden decrease in intrauterine pressure, vascular lesions and other factors, leading to the phenomenon of seeing red and then disappearing in late pregnancy, the main clinical manifestations of abdominal pain, vaginal bleeding, accompanied by uterine pressure and uterine tension increased.
There may be other reasons for the disappearance of redness in late pregnancy, so it is recommended to go to the hospital in time for examination under the guidance of the doctor, and according to the results of the examination, targeted treatment.