The fifth month of pregnancy refers to 17 ~ 20 weeks of pregnancy. At this time, the fetus is 20~25 cm tall and weighs 250~300 grams. The whole body grows fine hairs (manes) and begins to grow long hairs, and the eyebrows and nails are neat. The size of the head is like an egg. The top-heavy body is divided into three parts, and the proportion of the body finally appears symmetrical. The skin gradually turns red, the subcutaneous fat begins to calm down, and the skin becomes opaque. The fetal heartbeat is very active, and the fetal hands and feet can move freely in amniotic fluid.

The first week of 5 months: the fetal size is about 14cm and the weight is about 200 grams;

The second week of 5 months: the fetal size is about 15cm, and the fetal weight is 200-250 grams;

The third week of 5 months: the fetal size is about 15- 16 cm and the weight is about 260 grams;

The fourth week of 5 months: the fetal size is about 18cm, and the fetal weight is 300-350 grams;

The last week of 5 months: the fetal size is about 19cm and the weight is about 350 grams.

During this period, the heartbeat of normal fetus is getting stronger and stronger, and the fetal heart rate is 120 ~ 160 times per minute. 18 weeks later, the fetal heart can be heard on the mother's abdominal wall with a stethoscope. At the same time, the fetus can also hear strong voices from outside; You can have prenatal education. At this stage, the normal fetus is about 18-27cm in length and 250-300g in weight. At this time, the fetus has the function of swallowing and urinating.