COURSE CLINICAL OF LABOR
3 Stages of Labor. Labor begin with contraction, dilation, and progressive descent of fetus. Stage I includes the Latent and Active Phase. Cardinal movements of labor are engagement, flexion, descent, internal rotation, extension, & external rotation. Latent Phase Beginning of labor to abrupt change in slope of labor curve, usually at 4 cm cervical Dilation. Nulliparity 20h upper limit (UL), parity 14h UL. Cervical exam to assess dilation, effacement, station, cervical position, and consitency of cervix; a Bishop score of >8 is favorable for SVD or induced labor. Prolonged Latent Phase: Differential Diagnosis: not really in labor (Braxton Hicks ctx), or in labor but with inadequate contraction and/or dilation. Tx: MgSO4 to abolish Braxton Hicks ctx. Or to augment labor with oxytocin or amniotomy if membrane have not ruptured. Active Phase (AP) Ends with complete cervical dilation, at ~10 cm. Minimal cervical dilation rate at 1cm/h for nulliparous women and 1.5 cm/h for parous women. Median rate is usually 23 cm/h. Protracted AP: Definition: slow rate of cervical dilation, usually associated with slow descent and weak ctx or ctx at slower frequency. Diff. Diagnosis: nl variant of labor progression, no tx required. Arrested AP: Definition: no further progress of cervical for dilation 2h. Diff. Diagnosis: -CPD (cephalo-pelvic disproportion), if 2h of adequate ctx w/o further dilation. Adequate ctx is every 2min, 80-90 mHg pressure, lasting 60-90 sec, or MVU >200 per 10min. MVU = Montevideo unit as recorded fr. IUPC (intrauterine pressure catheter). Tx for CPD is Csection. -inactive ctx: Tx is augmentation of ctx with oxytocin. Stage II Ends with delivery of fetus. Nulliparity 2h UL and 3h with epidural. Parity 1h UL and 2h with epidural. Prolonged Stage II: -normal variant, simply slow progress, with slow but still progressive descent of skull, then no tx needed. -no descent of skull after 2-3h, use vacuum or forcep. -in multiparous women, it is rare for stage II to be longer than 30 min. unless there is fetal macrosomia, persistent occip...