In the 4th month of pregnancy, if there is a slight redness, it should be taken seriously, mostly due to pre-eclampsia, placental hypoplasia, cervical lesions, etc., and should be treated after timely medical consultation to identify the causes. 1. Pre-eclampsia: If, in addition to a slight redness, there is also a slight abdominal pain, in the premise of confirmed intrauterine pregnancy, it is mostly considered pre-eclampsia, which may be triggered by violent mood swings, sports or excessive exertion during pregnancy. It may be triggered by violent mood swings, sports or excessive exertion during pregnancy. Pregnant women can take appropriate bed rest and go to the hospital accompanied by family members for fetal heartbeat and ultrasound examination to make a clear diagnosis, and can take fetal preservation treatment under the guidance of doctors, such as the application of progesterone, while paying attention to bed rest; 2. Placenta hypogonadism: due to the low position of the placenta and its proximity to the inner cervical opening, it is easy to cause bleeding from the lower edge of the placenta. When the fetus grows, the position of the placenta may move up with the rise of the uterine body, but usually pay attention not to do strenuous exercise, especially to avoid rapid squatting, and prohibit sexual life; 3, cervical lesions: such as pregnant women combined with cervical inflammation, cervical polyps and other diseases, can cause slight redness in more than 4 months of pregnancy, pregnant women need to go to the hospital for gynecological examination, such as vaginal examination, to clarify the cause and then treat the symptoms, if there is inflammation, the If there is any inflammation, anti-inflammatory treatment is needed. In the fourth month of pregnancy, the early pregnancy reaction will gradually disappear. Pregnant women need to eat reasonably, match meat and vegetables, maintain good living habits, rest more, avoid straining, keep a happy mood and adjust their mentality.