The patient came to the emergency department at Bintang Amin Hospital with G1P0A0, 33 weeks pregnant with tight abdominal pain since 1 week ago. The patient said she felt nauseous and that the patient was pregnant with twins. Blood mucus (-), water-water (-). First menstruation at the age of 12 years, menstruation lasts 4-5 days, patient changes sanitary napkins 3 times a day. On physical examination, vital signs were found including blood pressure 110/60 mmHg, pulse 126 x/minute, respiratory rate 20 x/minute, temperature 36.5 °C, oxygen saturation 99%. On external examination DJJ: A. 155x/minute, B: 157x/minute, TFU: 40cm, HIS: 2x10'20'', internal examination of vaginal tocher no opening. On hematological investigations, a decrease in hemoglobin was found to be 11.4 g/dl, a decrease in hematocrit of 34%, a decrease in MCV of 74 fl and MCH of 25 pg. On ultrasound examination, A: BPD: 8.42 cm, HC: 27.90 cm, AC: 29.33 cm, FL: 6.69cm, EFW1: 2288g, B: BPD: 7.22 cm, HC: 27.52 cm, AC: 29.60 cm, FL: 4.73 cm, EFW2: 1598 g. The diagnosis in this case is primigravida with twin-to-twin transfusion syndrome. The treatment received by the patient was IVFD RL 20 tpm + protein drip 1 amp/8 hours, dexamethasone 2x2amp, cefazolin 2x1gr/iv, pronalges supp 2 extra. The prognosis in this patient is dubia. Keywords: Gemelli; Pregnant; TTTS. Pasien datang ke UGD Rumah Sakit Bintang Amin dengan G1P0A0 hamil 33 minggu dengan keluahan perut terasa kencang sejak 1 minggu yang lalu. Pasien mengatakan terasa mual dan pasien hamil kembar. Lendir darah (-), air-air (-). Haid pertama pada umur 12 tahun, haid selama 4-5 hari, pasien ganti pembalut sebanyak 3x sehari. Pada pemeriksaan fisik didapatkan tanda-tanda vital diantaranya tekanan darah 110/60 mmHg, denyut nadi 126 x/menit, laju pernapasan 20x/menit, suhu 36,5 °C, saturasi oksigen 99%. Pada Pemeriksaan luar DJJ: A. 155x/menit, B: 157x/menit, TFU: 40cm, HIS: 2x10’20’’, pemeriksaan dalam vaginal tocher belum ada pembukaan. Pada pemeriksaan penunjang hematologi didapatkan penurunan hemoglobin dengan 11,4 g/dl, penurunan hematokrit 34 %, penurunan MCV 74 fl dan MCH 25 pg. Pada pemeriksaan USG didapatkan A: BPD: 8.42 cm, HC: 27.90 cm, AC: 29.33 cm, FL: 6.69cm, EFW1: 2288g, B: BPD: 7.22 cm, HC: 27.52 cm, AC: 29.60 cm, FL: 4.73 cm, EFW2: 1598 g. Diagnosis pada kasus ini yaitu primigravida dengan twin to twin transfusion syndrome. Tatalaksana yang didapat oleh pasien yaitu IVFD RL 20 tpm + proterin drip 1 amp/8jam, dexametason 2x2amp, cefazolin 2x1gr/iv, pronalges supp 2 extra. Prognosis pada pasien ini yaitu dubia. Kata Kunci: Gemelli; Hamil; TTTS.