<prompt> ACOG defines arrest of the first stage of labour as completed latent phase with uterine contractions of strength 200MVUs without cervical changes for___1 hour2 hours3 hours4 hours  <response>: Ans. b 2 hours Ref Williams Obstetrics 22ndCh, 22; p. 540 The latent phase has been completed, with the cervix dilated 4 cm or more. A uterine contraction pattern of 200 Montevideo units0 or more in a 10-minute period has been present for 2 hours without cervical change. Arrest of dilatation was defined as 2 hours with no cervical change, and arrest of descent as 1 hr without fetal descent. Friedman and Sachtleben 1963 defined a prolonged latent phase as being greater than 20 hours in the nullipara and 14 hours in the multipara.Criteria for Diagnosis of Abnormal Labor Due to Arrest or Protraction DisordersLabor PatternNulliparaMultiparaProtraction disorderDilatation 1.2 cmhr 1.5 cmhrDescent 1.0 cmhr 2.0 cmhrArrest disorderNo dilatation 2 hr2 hrNo descent 1 hr 1 hrAbnormal Labor Patterns, Diagnostic Criteria, and Methods of TreatmentDiagnostic CriteriaLabor PatternNulliparasMultiparasPreferredExceptional TreatmentProlongation DisorderProlonged latent phase 20 hr 14 hrBed restOxytocin or cesarean delivery for urgent problemsProtraction Disorders 1 Protracted active-phase dilatation 1.2 cmhr 1.5 cmhrExpectant and supportCesarean delivery for CPD2. Protracted descent 1.0 cmhr 2 cmhr Arrest Disorders 1. Prolonged deceleration phase3 hr 1 hrOxytocin without CPDRest if exhausted2. Secondary arrest of dilatation 3. Arrest of descent2 hr2 hrCesarean delivery with CPDCesarean delivery4. Failure of descent 1 hr, with no descent in deceleration phase or second stage1 hr 