Definition:

Childbirth is the period from the onset of regular uterine

contractions until expulsion of the placenta . .

–at the onset of labor the position of the fetus with respect to the birth canal is critical to the route of the

delivery .

–It is important to know the fetal position within the uterine cavity at

the onset of labor

Fetal lie : is the relation of the long axis of the fetus to that of the mother it

is either longitudinal 99% or transverse or oblique (due polyhyd ,p.p ,ulnine

anomali)

Fetal presentation is the portion of the fetal body that is either fore most within

the birth canal or closest proximity to it.

1(cephalic presentation.

•It is classified according to relation ship

between the head and the body of the fetus.

2 (face presentation

•Fetal neck sharply extended so that the

occiput and back come in contact

3(brown presentation

•Partially extended head .is the greatest diameter 13.5cm fronto bregmatic

4(Breech. presentation

eith.Frankcompletfootling.

Delivery usually by cls

Fetal postion

•Relation ship of an chosen portion of the fetal presenting pant to the Rt or Lt .side

of birth canal

Labor with.Occiput presentation.

•1)in the most of the cases the vertex inter the pelvis with the sagittal suture lying in

transverse pelvic diameter .

•(L.O.T. )40%

•(R.O.T. )20%

Cardinal movements in the mechanism of labor and

Delivery in left .occiput. anterior position

Descent

Flexion

Internal rotation

External rotation

Expulsion

Descent:

•This movement is the First requisite for the birth of New born .

•usually follow the engagement .

•

Descent occe due to

•1)pressure of the A.F

•2)Direct pressure to the breech by contraction.

•3)bearing down of maternal abd .muscles.

•4)extention of fetal body.

Flexion:

•When descending head meets resistance from cervix –walls of the pelvis or pelvic floor

•This results in the chin brought into more contact with the fetal thorax.

•-and the suboccipitobregmatic diameter . will be presentation

Internal Rotation

•This movement consists of turning of the head in such a manner that the occiput gradually moves toward the symphysis

pubis .anteriorly

Extension

•After internal Rotation the sharply flexed head reaches the vulva and undergoes

extension

External Rotation–The delivered head undergoes restitution .to

oblique position followed by complition of external

•rotation to transverse position .

Expulsion

•Immediately after external Rotation . the anterior shoulder appears under

symphysis and the perineum soon becames. Distended by post shoulder

2 (onset of labor.•The plysiological processes in human

pregnancy that result in initiation of labor remain poorly defined .

•uterotonin production .

•elevation of the uterotonin receptors in myometriam

Progesterone Estrogen

Reloxin Corticotrophin Releasing hormone (CRH)

Prostaglandins

oxytocin receptors .

Fetal ACTH

Characteristics of normal labor

• Latent phase•defined as the point at whitch the pt. has

regular contraction and cervical dilatation less than 5cm

• avaragble duration is 12hr

•

First stage of laborRegular uterine contraction lead

To cervical dilatation

Formation of distinct lower uterine and upper segments

Duration 4.9 hour

Second stage of labor

•This stage begins when cervical dilatation is complete and ende with

Fetal delivery.

•Duration: 50 min up to2hr in nullparus 20 min 1hr in multi para.

Third stage of labor

•From expulsion of the fetus till the Delivery of placenta it is 30 min