Normal Labor and Delivery Erick Caesarrani A., dr., SpOG, MKes

Definitions Labor – Uterine contractions that result in effacement and dilatation of the cervix. Braxton-Hicks – Uterine contractions NOT associated with cervical change. Shorter in duration Less intense Over lower abdomen and groin Resolve with ambulation Lightening – Descent of the fetal head into the pelvis

Definitions Preterm labor – Prior to 37 weeks Term – 37 to 42 weeks Post term – After 42 weeks Post dates – After 40 weeks

Normal Labor and Delivery In order to maximize the patient’s chance at a vaginal delivery it is important to understand the basics of labor and delivery: Stages of labor Mechanics of labor Cardinal movements of labor Delivery

Stages of Labor 1st Stage Interval between onset of labor and full cervical dilatation 2 phases: Latent – period between onset of labor and point at which a change in slope of rate of cervical dilatation is noted. Active – Greater rate of cervical dilatation and usually begins around 2-3cm

Stages of Labor 2nd stage 3rd stage Interval between full cervical dilatation and delivery Duration Nulliparous – 2 hours Multiparous – 1 hours 3rd stage Delivery of the placenta and membranes Duration – maximum of 30 minutes

Normal Labor and Delivery In order to maximize the patient’s chance at a vaginal delivery it is important to understand the basics of labor and delivery: Stages of labor Mechanics of labor Cardinal movements of labor Delivery

Mechanics of Labor (3P) The Powers Forces generated by uterine musculature Frequency, amplitude, and duration of ctx’s Observation, manual palpation, tocodynamometry, intrauterine pressure catheter (IUPC) Measured in Montevideo units Average strength of ctx’s (mmHG) x no. of ctx’s in 10 minutes Adequate 200-250 MVUs External monitoring - measure the change in shape of the abdominal wall as a fxn of uterine contractions, therefore qualitative rahter than quantitative. Allows accurate correlation of FHT pattern with uteirne activity, does not allow measurement of ctx intensity or basal intrauterine tone. IUPC - Most precise. Come at a cost—require membrane rupture, risk of uterine perforation, infection

Mechanics of Labor Passenger Fetal size Lie Abdominal palpation or Ultrasound Macrosomia (>4500g) associated w/ failure to progress Lie Longitudinal axis of fetus relative to longitudinal axis of uterus Longitudinal*, transverse or oblique Fetal size calculations subject to large degree of error Malpresentaiton – 5% of term labors

Mechanics of Labor Passenger (cont) Presentation Fetal part that directly overlies pelvic inlet Cephalic, breech, or shoulder Compound – presence of >1 fetal part overlying the pelvic inlet Funic – umbilical cord presenting at pelvic inlet Malpresentation – any presentation that is not cephalic with occiput leading Fetal size calculations subject to large degree of error Malpresentaiton – 5% of term labors

Mechanics of Labor Passenger (cont) Attitude Position Position of head with regard to fetal spine (ie: degree of flexion or extension) Flexion allows smallest diameter of fetal head to present at pelvic inlet Position Relationship of a nominated site of presenting part to denominating location on internal pelvis Example: cephalic presentation Position – cephalic presentation, nominated site is the occiput. Breech presentation, nominated site is the sacrum Malposition = any position NOT ROA, OA, or LOA

Mechanics of Labor

Mechanics of Labor Passenger (cont.) Station Multifetal Pregnancy Measure of descent of presenting part of the fetus through the birth canal. Multifetal Pregnancy Increase probability of abnormal lie and malpresentation in labor Station – ischial spines mark mid-point (0 station)

Mechanics of Labor Passenger (cont.) Leopold’s maneuvers #1 – Correct dextrorotation of the uterus with the back of one hand and delineate the fundus with the other to determine gestational age and/or appropriate size. #2 – Run hands down maternal abdomen on either side of fetus to determine fetal lie, identifying small parts and fetal spine #1 - Dextrorotated b/c of sigmoid colon position #3 -Breech is oftern larger, softer, less well defined

Mechanics of Labor Passenger (cont.) Leopold’s maneuvers #3 – Firmly grasp upper and lower poles of fetus by placing fingers at uterine fundus and above symphysis to determine presentation and fetal size. #4 – Move hands in bilaterally from anterior superior iliac crests to determine whether or not the presenting part of the fetus is engaged in maternal pelvis. Head regarded as unengaged if examiner’s hands are see to converge below fetal head. #1 - Dextrorotated b/c of sigmoid colon position #3 -Breech is oftern larger, softer, less well defined

Mechanics of Labor Passage Bony pelvis + soft tissues X-ray pelvimetry now rarely used, having been replaced by a trial of labor 4 types of the female bony pelvis Bony pelvis = sacrum, ilium, ischium, and pubis Soft Tissue = 1st stage of labor  cervix 2nd stage of labor  pelvic floor muscles Gynecoid – preferred; oval shaped, far-space ischial spines Anthropoid – exaggerated oval shape to the inelt with alrgest diameter being A-P. More often associated w/ occiput deliveries. Android – male pattern, heart-shaped, prominent sacral promonitory and ischial spines. Increased risk of CPD. Platypelloid – Broad, flat, exaggerated oval-shaped inlet

Mechanics of Labor Passage Bony pelvis = sacrum, ilium, ischium, and pubis Soft Tissue = 1st stage of labor  cervix 2nd stage of labor  pelvic floor muscles Gynecoid – preferred; oval shaped, far-space ischial spines Anthropoid – exaggerated oval shape to the inelt with alrgest diameter being A-P. More often associated w/ occiput deliveries. Android – male pattern, heart-shaped, prominent sacral promonitory and ischial spines. Increased risk of CPD. Platypelloid – Broad, flat, exaggerated oval-shaped inlet

Normal Labor and Delivery In order to maximize the patient’s chance at a vaginal delivery it is important to understand the basics of labor and delivery: Stages of labor Mechanics of labor Cardinal movements of labor Delivery

Cardinal Movements of Labor Engagement Passage of widest diameter of presenting part to level below the plane of the pelvic inlet 0 station Occurs earlier in nulliparous women (36 wks) Descent Downward passage of presenting part through the pelvis. Flexion Occurs passively as the head descends due to the shape of the bony pelvis and resistance of pelvic floor soft tissues Allows smallest diameter of fetal head to pass through the pelvis.

Cardinal Movements of Labor Internal Rotation Rotation of presenting part from original position (transverse) to anteroposterior position Extension Occurs once fetus has descended to the level of the introitus Base of occiput in contact with inferior margin of symphysis pubis

Cardinal Movements of Labor External Rotation Return of fetal head to correct anatomic position in relation to the fetal torso Expulsion Delivery of rest of fetus Anterior shoulder delivered first with rotation under the symphysis pubis

Normal Labor and Delivery In order to maximize the patient’s chance at a vaginal delivery it is important to understand the basics of labor and delivery: Stages of labor Mechanics of labor Cardinal movements of labor Delivery

How to effectively deliver a baby Prepare for the delivery taking into account parity, progression of labor, presentation of fetus, complications of labor When head crowns and delivery is eminent, protect the perineum + downward pressure to keep head flexed Ritgen’s maneuver my help if delay in delivery of the fetal head Sterile towel used to palpate fetal chin through the rectum to apply upward pressure to facilitate extension of fetal head After delivery of head Allow for external rotation (restitution). Reduce nuchal cord Suction fetal mouth and nares After clearing fetal airway Place a hand on each parietal eminence to apply downward traction to deliver anterior shoulder Followed by upward traction to deliver posterior shoulder With traction, avoid perineal injury and brachial plexus

How to effectively deliver a baby After complete delivery of infant Cradle in a single arm below the perineum to allow maximal blood transfer to infant Delivery of the placenta 3 classic signs of placental separation: Lengthening of the umbilical cord Gush of blood from vagina Change in shape of the uterine fundus to a more globular appearance

How to effectively deliver a baby Delivery of the placenta Active management of 3rd stage has been shown to reduce total blood loss Brandt-Andrews Maneuver: abdominal hand secures the uterine fundus to prevent uterine inversion while the other hand exerts sustained downward traction on umbilical cord Crede maneuver – cord is fixed with lower hand while the uterine fundus is secured and sustained upward traction is applied using abdominal hand

How to effectively deliver a baby Inspect the placenta Abnormalities of lobulation Site of insertion of umbilical cord into the placenta Marginal insertion –inserts into edge of placenta Membranous insertion – vessels course through the membranes prior to attaching to placental disk Length (50-60cm) 2 arteries and 1 vein Single umbilical artery associated with 20% risk of other structural anomalies.

Episiotomy Indications : Shoulder dystocia Breech delivery Forceps or Vacuum extractor deliveries Occiput Posterior Positions Instances in which failure to perform an episiotomy will result in perineal rupture. Type of Episiotomy Characteristic Midline Mediolateral Surgical repair Easy More difficult Faulty healing Rare More common Postoperative pain Minimal Common Anatomical results Excellent Occasionally faulty Blood loss Less More Dyspareunia Occasional Extensions Uncommon

Dystocia Abnormalities of the maternal pelvis Contracted Inlet Dystocia literally means difficult labor, characterized by abnormally slow labor progress. Abnormalities of the expulsive forces Active Phase Disorder Second Stage Disorder Chorioamnionitis Ruptured Membrane w/o Labor Precipitous Labor Abnormalities of the maternal pelvis Contracted Inlet Contracted Midpelvic Contracted Outlet Pelvic Fracture Abnormalities of soft tissues of the reproductive tract that form an obstacle to fetal descent

Dystocia Complication Uterine Rupture Fistula Formation Abnormalities of presentation, position, or development of the fetus Face Presentation Brow Presentation Transverse Lie Compound Presentation Persistent Occiput Posterior Position Persistent Occiput Transverse Position Hydrocephalus Fetal Abdominal Distension Shoulder Dystocia Complication Uterine Rupture Fistula Formation Pelvic Floor Injury Post Partum Lower Extremity Nerve Injury Perinatal Complication

Incompetent Cervix Discrete obstetrical entity characterized by painless cervical dilatation in the second trimester. It can be followed by prolapse and ballooning of membranes into the vagina, and ultimately, expulsion of an immature fetus. Unless effectively treated, this sequence may repeat in future pregnancies. Transvaginal sonography to identify cervical incompetence. Etiology Previous trauma to the cervix such as dilatation and curettage Conization Cauterization Trachelectomy Exposure to DES in utero Evaluation and Treatment Decrease physical activity and abstain from intercourse. Cervical examinations each week or every 2 weeks to assess effacement and dilatation. Cerclage

Assisted Vaginal Delivery Indications for performing an assisted vaginal  delivery Maternal: ineffective contractions ineffective pushing maternal exhaustion. Fetal: suspected fetal compromise in the second stage of labour fetal malposition [OT, OP]. Prophylactic shortening of the second stage: maternal intracranial pathology hypertensive problems cardiac disease class III or IV. Contraindications for performing an instrumental delivery Fetal position undetermined Fetal head still above the ischial spines Malpositions brow or mento-posterior Known fetal malformations, e.g. neck teratomas Suspected fetal macrosomia in mother with diabetes Previous shoulder dystocia and current fetal size thought to be similar to previous pregnancy.

Forcep VS Vacuum Specific contraindications for the use of a vacuum extraction: fetal position undetermined fetal head still above the ischial spines malpresentations such as face or breech inability to achieve a proper application of cup prematurity <34 weeks of gestation suspected fetal bleeding problems assisted delivery under general anaesthesia any contraindication to maternal pushing. Specific situations where forceps delivery is preferred: where excessive caput is present over the vertex prematurity (gestation less than 34 weeks) face presentation after-coming head of a breech. maternal conditions that preclude pushing e.g. maternal cardiac disease suspected coagulopathy in the fetus.

Assisted Vaginal Delivery Complication Laceration and Episiotomy Urinary and Fecal Incontinence Scalp lacerations and bruising Subgaleal hematomas, Cephalohematomas Intracranial hemorrhage Neonatal jaundice Subconjunctival hemorrhage Clavicular fracture Shoulder dystocia Injury of sixth and seventh cranial nerves Erb palsy Retinal hemorrhage Fetal death Recomendation The classification of vacuum deliveries should be the same as that used for forceps deliveries (including station). The same indications and contraindications used for forceps deliveries should be applied to vacuum-assisted deliveries. The vacuum should not be applied to an unengaged vertex, that is, above 0 station. The individual performing or supervising the procedure should be an experienced operator. The operator should be willing to abandon the procedure if it does not proceed easily or if the cup dislodges more than three times

Cesarean Section Primary Indication Dystocia Nonreassuring fetal heart rate Abnormal presentation Unsuccessful trial of forceps or vacuum Placenta Previa Repeated Indication No VBAC attempt Failed VBAC Unsuccessful trial of forceps or vacuum

Terima Kasih