This randomized controlled trial, compares perioperative and postoperative pain score by using visual analog scale in pregnant women undergoing amniocentesis. The experimental group will be given oral paracetamol premedication whereas the controlled group will be given oral placebo premedication.

Perioperative and postoperative amniocentesis are often painful which cause concerns to those who has to undergo amniocentesis. Anxiety is one of the factor that may prolong operative time, resulting in an increase risk of complication from the procedure. Furthermore, pregnant women, in order to relief the pain, might require others drugs, which has both maternal and fetal side effect. So In conclusion, this study aims to compare efficacy of oral paracetamol premedication and oral placebo premedication by using visual analog scale to evaluate pain.

Inclusion Criteria:

• Singleton pregnant women undergo amniocentesis for the first time at Rajavithi Hospital in 2016-2017

Exclusion Criteria:

• Pregnant women with psychiatric disorder
• Contraindicated to paracetamol
• Pregnant women undergoing amniocentesis due to fetal anomaly
• Take oral paracetamol or other analgesics within 24-48 hrs before operation
• Deny to participate the research