What is the reason for occasional sharp, cramp-like pain in the lower back at 4 months pregnant?

Patient's question:

No

Doctor's answer:

It is recommended to undergo further color Doppler ultrasound examination in the gynecology department of the hospital to determine or rule out uterine contractions or threatened miscarriage. After that, appropriate symptomatic treatment can be administered. If it is confirmed, intramuscular injection of progesterone and oral intake of VE capsules for fetal preservation treatment can be performed, along with bed rest.