Headache, low blood pressure, local anesthetic toxicity and other bad effects may occur because painless injection is also an invasive operation, which is risky. 1. Headache: some women may have cerebrospinal fluid leakage after dural puncture, which may cause lower cranial pressure, resulting in headache after puncture. 2. Hypotension: some mothers may have impaired venous return or peripheral vasodilatation after painless puncture, resulting in decreased placental perfusion, fetal hypoxemia and acidemia. 3. Local anesthetic poisoning: individual mothers may be due to the local anesthetic mistakenly injected into the blood vessels or due to the local anesthetic dosage, the local blood vessels through the absorption of the rapid reaction caused by poisoning. The painless will also appear nausea and vomiting, dizziness, drowsiness, skin itching, urinary retention, nerve damage, prolongation of labor and other complications, may cause harm to the fetus and pregnant women, it is recommended that mothers according to their own situation in the doctor’s advice, discretionary choice of painless.