Nifedipine is mainly used in obstetrics in two aspects: 1. Blood pressure lowering, when the blood pressure rises in pregnancy, such as ≥160/110mmHg, it should be lowered in time. Nifedipine, as one of the preferred antihypertensive drugs in pregnancy, is relatively safe for mother and child, mainly by inhibiting calcium inward flow, diastolic vascular smooth muscle, and dilating small peripheral arteries, lowering the peripheral resistance, thus making the blood pressure drop. 2, Fetal preservation, when there are signs of preterm labor, such as abdominal paroxysmal pains, vaginal bleeding, and cervical insufficiency, in order to strive for the application of dexamethasone to promote the maturation of the fetal lungs in 48 hours, can be applied to inhibit fetal lung maturation, and can be used to prevent premature delivery, e.g., ≥ 160/110 mmHg. Nifedipine can be used to inhibit contractions, because nifedipine is a calcium channel antagonist, which can inhibit extracellular calcium ion in-flow to reduce intracellular calcium ion concentration, thus inhibiting contractions and playing a role in preserving the fetus.