Nicorandil (potassium channel activator) is claimed to be as effective as Nifedipine (calcium channel blocker) for tocolysis in preterm labour

aim of the study: To assess the efficacy of Nicorandil compared with Nifedipine as a tocolytic agent in delaying labour for 48 hours following their administration

Preterm labour refers to a delivery that occurs between 20 weeks and before completing 37 weeks of gestation. It may or may not be preceded by preterm labor Preterm labor (PTL) is one of the leading causes of perinatal morbidity and mortality. It is one of the major public health problems, especially with reference to mortality, disability and health care expenses

The diagnosis of preterm labor based upon clinical criteria of regular painful uterine contractions occurs between 20 weeks and before 37 weeks gestation accompanied by cervical change (dilation and/or effacement). Vaginal bleeding and/or ruptured membranes in this setting increase diagnostic certainty , using the following specific criteria:

Uterine contractions (≥4 every 20 minutes or ≥8 in 60 minutes) Plus one of the following:-

• Cervical dilation equal or more than 3 cm
• Cervical length less than 20 mm on transvaginal ultrasound
• Cervical length between 20 to less than 30 mm on transvaginal ultrasound and positive fetal fibronectin test . (This criterion will not be relied upon in this study because it is costly and widely not available in most laboratories)

Since uterine contractions are the most frequently recognized sign of preterm labor, inhibition of uterine contractions with tocolytic agents to prolong pregnancy and reduce neonatal complications has been and continues to be the focus of treatment of preterm labor

• Nifedipine, a calcium channel blocker, could be used as a first line tocolytic agent

Owing to this side effects of Nifedipine, another novel drug (Nicorandil) is studied and according to literature Nicorandil is as effective as Nifedipine for tocolysis in preterm labour

is an anti-angina medication that has the dual properties of a nitrate and ATP-sensitive K+ channel activator. Nicorandil has proved to be safe as anti angina treatement in pergnency

Inclusion Criteria:

• BMI between (20 - 30 kg /m²).
• pregnant female with single viable fetus who presented to the outpatient clinic or Emergency room with the criteria of diagnosis of preterm labor between 28 and before completing 34 weeks pregnancy

Exclusion Criteria:

• - Any condition in which continuation of pregnancy will jeopardize maternal or fetal welfare.

• Cervix dilatation greater than 4 cm.

• Polyhydramnios [amniotic fluid index (AFI) greater than 24 cm or deep vertical pocket more than 8 cm.]

• Oligohydramnios (AFI less than 5 cm).

• Suspected intrauterine infection if Maternal fever is present as a constant feature plus one or more of the following:-

  • Maternal leucocytosis (more than 15,000)
  • purulent vaginal discharge
  • Fetal tachycardia more than 180 bpm.

• Growth restriction.

• Major antepartum hemorrhage

• Major maternal medical disorders such as diabetes, hypertension, systemic lupus,liver and kidney dysfunction .

• Multiple gestation pregnancy.

• Signs of fetal non reassuring CTG

• Signs of fetal abnormal CTG

• Lethal fetal anomaly incompatible with life.

• Premature Rupture of membrane.

  --Contraindication for the use of Nifedipine and/or Nicorandil such as drug allergy, cardiac disease, liver disease and kidney disease

• previous caesarean section

in about 3 months

all cases in both groups will not know which drug they receive