Normal andabnormallabor Doç. Dr. Oluş APİ
Labour (parturition) • It is the process where by painful , regular uterine activity (contraction) with progressive cervical effacement and dilatation accompanied by decent of the presenting part leads to expelled of the fetus from the uterus at or beyond 24 (or 28) completed weeks of pregnancy.
Term Labour PTL prolonged 24 W 42W 40W 28 W 37 W 1 LNMP Labour can occur at:
Normal labour: • Spontaneous expulsion, through the natural passages (birth canal) of a single, mature (37-42 completed weeks of pregnancy) • Alive fetus, presenting by vertex, within a reasonable time, without fetal or maternal complications.
Terms • Fetal lie the relationship of the long axis of the fetus to that of the mother. • If the two are parallel, then the fetus is said to be in a longitudinal lie (present in over 99 percent of labors at term). • If the two are at 90-degree angles to each other, the fetus is said to be in a transverse lie. • If the fetal and the maternal axes may cross at a 45-degree angle, forming an oblique lie, which is unstable and always becomes longitudinal or transverse during the course of labor.
Fetal presentation • The portion of the fetal body that is either foremost within the birth canal or in closest proximity to it • In longitudinal lies, the presenting part is either cephalic or breech presentations, respectively. • In transverse lie, the shoulder is the presenting part.
cephalic presentation breech presentation shoulder presentation
Types of Cephalic presentation Vertex or occiput presentation Sinciput presentation face presentation brow presentation
Types of breech presentation Frank type Complete type incomplete type or footling presentation
Fetal position • Refers to the relationship of an arbitrarily chosen portion of the fetal presenting part to the right or left side of the maternal birth canal. • The dertermining points in vertex, face, and breech presentations are fetal occiput, chin (mentum), and sacrum respectively. • The presenting part in right or left positions may be directed anteriorly (A), transversely (T), or posteriory (P). There are six varieties of each of the three presentations.
Fetal positions of breech presentation Fetal positions of cephalic presentation
Diagnosis of fetal presentation and position • Abdominal palpation (Leopold maneuver) • Vaginal examination • Auscultation • imaging studies: ultrasonography, computed tomography, or magnetic resonance imaging
Leopold maneuver • Leopold maneuver is established by Leopold in1848 • Preparations before examination • Instruct woman to empty her bladder first. • Place woman in dorsal recumbent position, supine with knees flexed to relax abdominal muscles. Place a small pillow under the head for comfort. • Drape properly to maintain privacy • Explain procedure to the patient. • Warms hands by rubbing together. (Cold hands can stimulate uterine contractions). • Use the palm for palpation not the fingers
First Maneuver: To determine fetal part lying in the fundus. To determine presentation. procedure: Using both hands, feel for the fetal part lying in the fundus. • Head is more firm, hard and round, and is more mobile and ballottable. • Breech feels as a large, nodular mass.
Second Maneuver: • To identify location of fetal back.To determine position. Procedure: One hand is used to steady the uterus on one side of the abdomen while the other hand moves slightly on a circular motion from top to the lower segment of the uterus to feel for the fetal back and small fetal parts.Use gentle but deep pressure. • Fetal back is smooth, hard, and resistant surfaceKnees and elbows of fetus feels with a number of small, irregular, mobile parts
Third Maneuver: • To determine engagement of presenting part. procedure: Using thumb and finger, grasp the lower portion of the abdomen above symphisis pubis, press in slightly and make gentle movements from side to side. • The presenting part is engaged if it is not movable. • It is not yet engaged if it is still movable
Fourth Maneuver: • To determine if the presentation has descended into the pelvis • To determine the position of the fetal presentation procedure: Facing foot part of the woman, using the tips of the first three fingers, exerts deep pressure in the direction of the axis of the pelvic inlet Use both hands.
Onset of labour :Not definitely known – however there are several theories, but none of them is completely proven. Mechanical theories: - uterine distension Hormonal theories: • Maternal : • progesterone withdrawal • oxytocin stimulation • prostaglandins • serotonin • fetal: • fetal cortisol • fetal membranes • Neuronal factors: • sympathetic- alpha receptor stimulation
Diagnosis • symptoms: • True labour pains – colicky pain in the abdomen and back are characterized by:
Show – blood stained mucous. • SROM • Signs: • palpable or recorded uterine contraction • effacement and dilation of the cervix • formation of forewater
STAGES OF LABOUR I-The First stage: stage of cervicaleffacement and dilatation Definition:the first stage of labour refers to the period from the onset of true uterine contractions to the fully dilation of the cervix, when the diameter of the cervical os measures 10cm.
Duration: • primigravida = 8-12 h • multigravida = 6-8 h Phases of the first stage: • Latent phase: started when the cervix dilatated slowly and reached to about 3cm. • in primigravida = 8h • in multigravida = 4h • - Active phase: rapid dilatation of the cervix to reach 10cm • in primigravda = 4h • in multigravida =2h
II-The Second stage of labour: stage of delivery of the fetus. Definition:the second stage of labour refers to the period from complete cervical dilatation to the birth of the fetus. Duration: • in primigravida =1 h • in multigravida = ½ h however the timing of the second stage is very different to determine and controversial and can be extended as much as there is progress in descent and no harm to the mother or fetus
The second stage of labour has two phases: • Passive phase – stage of descent of the presenting part and dilatation of the vagina – due to contraction and retraction of the uterine muscle. • Expulsive phase – stage of bearing down – due to contraction and retraction of the uterine muscle and voluntary efforts by diaphragm and abdominal muscles.
III-The Third stage of labour: • The stage of expulsion of the placenta and membranes. • Duration: up to 30 minutes, however the average length of the third stage of labour is 10 minutes.
Mechanism: the third stage is made of two phases: • The first phase: phase of placental separation occurs through the spongiosa layer of the decidua at the time of expulsion of the baby or very soon afterwards. The shearing force responsible for the separation is the contraction and retraction of the uterus, reducing the uterine volume and the area of the placental site, as the fetus is expelled.
The second phase: phase of placental expulsion – The separated placenta descends from the upper (active) segment into lower (passive) uterine segment, cervix, and vagina by two mechanisms: • -Schultze mechanism:(80%) • The placenta delivered as an inverted umbrella with it’s fetal surface presenting first followed by the membranes with retro-placental haematoma. • Mattews – Duncan mechanism: (20%) • The placenta delivered side way and it presents with it’s inferior surface first.