1、正常分娩(英文)Definitions：Labor is the process by which contractions of the gravid uterus expel the fetus and the other products of conception after 28 weeks from the last menstrual period.Term Delivery：A term delivery occurs between 37 and 42 weeks from the last menstrual period.Premature labor：Preterm l
2、abor is that occurring before 37 weeks of gestational age.Postdate pregnancy：Postdate pregnancy occurs after 42 weeks.Not sure:1、Cervix ripend and lower uterine segment development theory；2、；3、；4、；5、Immunologic theory；The etiology of laborMaturation of fetus and change of uterus function is necessar
3、y.The progress and final outcome of labor are influenced by 4 factors.(1)the powers(2)the passage(3)the passenger(4)the psycheFour Determinate Factors of LaborThe expulsive forces(The powers)The power that expulse the fetus and the other products of conception is called the expulsive forces,which in
4、clude uterine contraction intra-abdominal pressure levator ani muscles contractions.Uterine contractions Have three unique characteristics:Rhythm:。Symmetry and polarity RetractionPeriods of relaxation between contractions are essential to the welfare of the fetus.RhythmIncrease in frequency and dura
5、tion宫缩宫缩间歇期间歇期宫缩宫缩极极期期进行退行Characteristic of normal uterine actionSymmetry and Polarity The intensity of the upper segment of the uterus is the most strong Retraction:The myometrium of the upper uterine segment does not relax to its original length after contractions;rather,it becomes relative fixed
6、at a shorter length.The intra-abdominal pressureCreated by contraction of the abdominal muscles simultaneously with forced respiratory efforts with glottis closed.It is a necessary auxiliary to uterine contractions in second stage of labor。After the placenta has separated,its spontaneous expulsion i
7、s aided by the mother increasing intra-abdominal pressure。腹肌子宫收缩力膈肌肛提肌 Form a V-shaped sling that tends to rotate the occipital anteriorly(internal rotation)。Help the fetus extension and delivery。Help the expulsion of the placenta。levator ani muscles contractionsPassage The passage of the fetus deli
8、very,including:the bony pelvis and soft tissues of pelvis骶骶 骨骨Os sacrum髂髂 骨骨 os ilium 耻骨联合耻骨联合Symphysis publis骶骶 尾尾 关关 节节Sacro-iliac jiont尾尾 骨骨Os coccyx坐骨结节坐骨结节Os ischiumThe bony pelvis(the true pelvis)Pelvic inlet plane Pelvic midplane Pelvic outlet planeThree pelvic plane:Pelvic inlet plane Have t
9、hree diameters:(1)Anteroposterior diameter or The true conjugate:average 11cm.(2)Transverse diameter:average 13cm.(3)Inclined diameter:average 12.75cmThe true conjugateThe transverse diameterThe inclined diameterThree anteroposterior diameters of the pelvic inletThe smallest plane of the pelvis,part
10、icular importance in obstructed labor.Anteroposterior diameter of mid pelvis：average 11.5cm.Transverse diameter of mid pelvis：alse be called interspinous diameter,average 10cm.Pelvic midplaneAnteroposterior diameter of Anteroposterior diameter of mid pelvismid pelvisTransverse diameter Transverse di
11、ameter of mid pelvisof mid pelvisTransverse diameter of the midpelvisFour diameters:Anteroposterior:diameter of outlet：11.5cm。Transverse outlet：the distance between the inner edges of the ischial tuberosities。9cm Anterior sagittal diameter：6cm。Posterior sagittal diameter：8.5cm。Pelvic outlet plane41、
12、T Transverse outlet2、Anterior sagittal diameter3、Posterior sagittal diameter4、Anteroposterior diameter of outlet Pelvic axis and inclination of pelvicPelvic axis：The axis of the pelvis refers to the curve of the birth canal as described by a line drawn through the center of each of the four planesIn
13、clination of pelvic:The angle of the pelvic inlet plane with ground level when women stand.always 60 degree。Pelvic axis Inclination of pelvic The soft part of the birth canal Formation of lower uterine segment、cervix、vagina、soft tissue in the floor of pelvis.The lower uterine segment Developed from
14、the isthmus of the uterus of nonpregnant women.Physiologic retraction ring:The actively contracting upper segment becomes thicker as labor advances,the lower uterine segment is relatively thin compared with the upper segment,between them a physiologic retraction ring appear.Changes of cervixEffaceme
15、nt of cervixdilatation of cervixThe upper segment contracts,retracts,and expels the fetus;in response to the force of the contractions of the upper segment,the ripened lower uterine segment and cervix dilate and thereby form a greatly expanded、thinned-out muscular and fibromuscular tube through whic
16、h the fetus can be extruded.分娩过程中宫颈的变化分娩过程中宫颈的变化primigravidamultiparaEffacement of cervixdilatation of cervixA crook canal formed by the vagina、tissue of pelvic floor and perineum as the fetal descending.FPassengerSize of the fetus head Very important for delivery。The vault is composed of 2 frontal
17、bones,2 parietal bones,and one occipital bone.They are slightly separated from one another at the margins of abutment and by wider spaces,the anterior and posterior fontanelles.Four diameter of fetus head：Biparietal diameter：The greatest transverse diameter of the head,which extends from one parieta
18、l bone to other.Average 9.3cm.Occipito-frontal diameter：Which follows a line extending from a point just above the root of the nose prominent portion of the occipital bone.Average 11.3cm.Suboccipito-bregmatic diameter.Which follows a line drawn from the middle of the large fontanel to the undersurfa
19、ce of the occipital bone just where it joins the neck.Average 9.5cmOccipito-mental diameter：From the chin to the most prominent portion of the occiput.Average 13.3cmSuboccipito-bregmaticoccipito-frontalOccipito-mental diameterFetal SkullVault.Face.Base.Position of the fetus Fetal position of a parti
20、cular presentation refers to the relationship of an arbitrary reference point on the fetus to a specific point in the right or left side of the maternal pelvis.Psychologic Factors A high level of anxiety during pregnancy has been associated with decreased uterine activity and with longer and dysfunc
21、tional labor。Diagnosis of laborThreatened laborFalse labor:Contractions occur at irregular intervals.;Intervals remain long;Intensity remains unchanged;Discomfort is chiefly in lower abdomen;Cervix does not dilate;Discomfort is usually relieved by sedation.Lightenting The settling of the fetal head
22、into the brim of the pelvis.Bloody Show In laborOnset of labor is spontaneous uterine contraction with progressive dilation of the cervix uterine contraction interval 30 intensity is middle or heavyMechanism of labor Mechanism of normal labor in occiput presentation include these cardinal movements
23、of labor:engagement descentflexioninternal rotationextensionexternal rotation,and expulsion.Engagement The mechanism by which the biparietal diameter,the greatest transverse diameter of the fetal head in occiput presentations,passes through the pelvic inlet is defined engagement.Descent Descent cont
24、inues progressively until the fetus is delivered;the other movements are superimposed on it.FlexionIn flexion,the chin is brought into more intimate contact with the fetal thorax,and the appreciably shorter suboccipitobregmatic diameter(9.5cm)is substituted for the longer occipitofrontal diameter(11
25、.3cm).Internal rotation Internal rotation is a turning of the fetus occiput gradually moves from its original position anteriorly toward the symphysis pubis about 45 degrees.Its always finished in the end of the first stage of labor.ExtentionExtention brings the base of occiput into direct contact w
26、ith the inferior margin of the symphysis pubis.Restitution:The fetus head rotates to the position it occupied at engagement after it deliveried,following this the shoulders descend in a path similar to that traced by the head.External rotation：The anterior shoulder rotates internally about 45 degree
27、s to come under the pubic arch for delivery.The head continutly rotates left about 45 degrees to its position at birth.Flowing these maneuvers,the body,legs,and feet are deliveried.Mechanism of LaborTotal Stage of Labor and Treatment The total stage of labor begins with the regular uterine contracti
28、ons and ends when delivery of the placenta complete.Normal labor is a continuous process which has been divided into three stages for purposes of study.First stage of labornThe first stage begins with the onset of labor and ends when Second stage of labor Third stage of laborFrom the birth of the in
29、fant to delivery of the placenta 515min,Total stage of labor：24hFirst stage of labor（cervical dilation stage）Second stage of labor（fetus expulsive stage）Third stage of labor（placenta expulsive stage）515min 30minClinical course and treatment in first stage1,Contraction and dilation of cervixChart of
30、labor stage；Acceleration phase:cervical dilation from 3cm to 4cm.1.5h；Maximum acceleration phase:cervical dilation from 4cm to 9cm，2h;Deceleration phase:cervical dilation from 9cm to 10cm，30min。The decent of the fetal head is measured to assess the progress of labor The level of the presenting fetal
31、 part in the birth canal is described in relationship to the ischial spines,which are halfway between the pelvic inlet and the pelvic outlet.Management:Blood pressure、cervical dilation、fetus descending、uterine contraction；When the membranes ruptured,please check the fetal heat rate,fluid colour and
32、amount at onceFetal heart rate 120160bpm latent stage 12h fetal heat rate active stage 15-30 minute Need for subsequent vaginal examinations to identify the status of the cervix and the station and position of presenting part will vary considerably.Management of second stage of laborManifestation Ut
33、erine contraction may last 1.5 minutes and recur at times after a resting phase of no more than a minute.The woman typically begins to bear down The perineum begins to bulge and the overlying skin becomes tense and glistening.Head visible on vulva gapping Crowning of headBetween uterine contractions
34、 the presenting part tends to recede slightly,but“crowing”occurs when the head is visible at the vaginal introitus and not receding in between contractions.Management of the second stageFetal heart rate:should be auscultated at least every 510min.Maternal expulsive efforts.Preparation for deliveryMa
35、nagement of third stage of labor.Clinical course After delivery of the infant,the height of the uterine fundus and its consistency are ascertained.Uterine contraction reappear after stopping for few minutes.Placental separationSigns of placental separation：a.the uterus becomes globular and firmer.b.
36、The umbilical cord lengthened outside the vagina c.A fresh show of blood from vaginad.the uterus fundus rises up.Pay attention to:Examine the placenta to ensure complete removal.Examine the soft part of the birth canal.Prevention of excessive postpartum bleeding.Uterine contraction、bladder distension此课件下载可自行编辑修改，仅供参考！此课件下载可自行编辑修改，仅供参考！感谢您的支持，我们努力做得更好！谢谢感谢您的支持，我们努力做得更好！谢谢
