This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Which of the following can be used to delay preterm contractions of uterus with best neurological outcome for the fetus? 
Select and explain. 
A. Mgso4, B. Nifidipine, C. Ritodrine, D. Isoxprine
A: Mgso4
Answer: A: Mgso4 
Explanation: Ans. A.MgSo4Antenatal magnesium sulfate for both tocolysis and fetal neuroprotection in premature rupture of the membranes before 32 weeks' gestation. Other tocolytic drugs:Ritodrine, salbutamol and magnesium sulphate are tocolytic drugs used to terminate preterm labour and delivery.Other tocolytic drugs are isoxsuprine, indomethacin, calcium channel blockers, glyceryl trinitrate, atosiban and glyceryl trinitrate.