The early symptoms of pregnancy with twins are similar to those of a singleton, as follows: 1) menopause, if the menstruation is delayed for more than 10 days in a normal mature woman, pregnancy should be considered; 2) early pregnancy reaction, nausea, vomiting, drowsiness, aversion to oil, twins have more early pregnancy reaction; 3) breast swelling and pain, areola deepening; ultrasound can confirm the diagnosis of intrauterine pregnancy and the number of intrauterine pregnancies, usually it takes 6-12 weeks for the detection of twins. The early detection of twin pregnancies is usually due to one egg and two fetuses. Monochorionic twins are found a little later.