Normal labour: - University of Babylon



Normal labour:

Parturition:

Means birth of the baby, toward the end of the pregnancy the uterus increase its excitability due to hormonal and mechanical factors.

Then strong uterine contraction develop ending by expulsion of the fetus.

1- hormonal factors: in the mother increase estrogen to progesterone ratio, and increased secretion of the oxytocin by the posterior pituitary.

in the fetus increased oxytocin, incr. cortisol, incr. prostaglandin from the fetal membranes.

2- mechanical factors: stretching of the smooth muscle lead to incr. contractility, so contractions can be induced by fetal movements and over distended uterus in twin pregnancy.

Labor contractions continue to occur by a +ve feedback mechanism when the uterine cervix is stretched by the fetal head this will lead to contractions of the uterine body and increase the oxytocin secretion by the post. Pit.

Definitions from the references: (homework)

Attitude, caput saccedaneum, effacement of the cervix, Engagement, Position, presenting part, Partogram, Show, Station, Term, Vertex, synclitism.

Definition of labour:

Labor is defined as the onset of a sequence of painful regular uterine contractions that results in progressive effacement and dilatation of the cervix with descent of the presenting part and voluntary bearing-down efforts leading to the expulsion of the products of conception through the vagina.

There are some terms and definitions read them in (obstetrics by ten teachers): attitude, caput saccedaneum, effacement of the cervix, engagement, position, presenting part, partogram, show, station, term, vertex, synclitism.

Physiologic Preparation for Labor:

Prior to the onset of true labor, several preparatory physiologic changes commonly occur. The settling of the fetal head into the brim of the pelvis, known as lightening, usually occurs 2 or more weeks before labor in first pregnancies. In women who have had a previous delivery, lightening often does not occur until early labor. Clinically, the mother may notice a flattening of the upper abdomen and increased pressure in the pelvis. This descent of the fetus is often accompanied by a decrease in discomfort associated with crowding of the abdominal organs under the diaphragm (eg, heartburn, shortness of breath), and an increase in pelvic discomfort and frequency of urination.

[pic]

During the last 4–8 weeks of pregnancy irregular, generally painless uterine contractions occur with slowly increasing frequency. These contractions, known as Braxton Hicks contractions, may occur more frequently, sometimes every 10–20 minutes, and with greater intensity during the last weeks of pregnancy. When these contractions occur early in the third trimester, they must be distinguished from true preterm labor. Later, they are a common cause of "false labor," which is distinguished by the lack of cervical change in response to the contractions.

During the course of several days to several weeks before the onset of true labor, the cervix begins to soften, efface, and dilate. In many cases, when labor starts, the cervix is already dilated 1–3 cm in diameter. This is usually more pronounced in the multiparous patient, the cervix being relatively more firm and closed in nulliparous women. With cervical effacement, the mucus plug within the cervical canal may be released. When this occurs, the onset of labor is sometimes marked by the passage of a small amount of blood-tinged mucus from the vagina known as bloody show.

symptoms of labour:

1- colicky abdominal pain and backache

2- increased vaginal discharge which may be bloody stained

discharge or watery (show).

➢ (Show: it means the passage of a small amount of blood-tinged mucus from the vagina).

3- in advanced stage of labour (late 1st and 2nd stage) there is increased pain and felling of bearing down

4- increased frequency of micturition, and urge for bowel evacuation when the baby’s head press on the bladder and rectum

Signs:

1- frequent uterine contractions by abdominal palpation (tightening of the uterus)

2- progressive cervical dilatation and descent of the presenting part by vaginal examination

Stages of labour

Normal labor is a continuous process that has been divided into three stages for purposes of study, with the first stage further subdivided into two phases, the latent phase and the active phase. The first stage of labor is the interval between the onset of labor and full cervical dilatation.

The duration of the first stage of labor in primipara patients is noted to range from 6–18 hours, while in multiparous patients the range is reported to be 2–10 hours. The lower limit of normal for the rate of cervical dilatation during the active phase is 1.2 cm per hour in first pregnancies and 1.5 cm per hour in subsequent pregnancies.

The second stage is the interval between full cervical dilatation and delivery of the fetus.

The duration of the second stage in the primipara is 30 minutes to 3 hours, and is 5–30 minutes for multiparas.

The third stage of labor is the period between the delivery of the fetus and the delivery of the placenta. the duration of the third stage is 0–30 minutes for all pregnancies.

Separation of the placenta generally occurs within 2–10 minutes of the end of the second stage, but it may take 30 minutes or more to spontaneously separate. Signs of placental separation are: (a) a fresh show of blood from vagina, (b) the umbilical cord lengthens outside the vagina, (c) the fundus of the uterus rises up, and (d) the uterus becomes firm and globular.

management of labou:

1- Admission assessment:

When a pregnant woman started labour or when she has spontaneous rupture of membranes at term she should be admitted and full assessment of her condition is accomplished.

To start with: FULL HISTORY ON ADMISSION about the

The frequency, strength and duration of her contractions and when they began

Is there any history of watery vaginal discharge or bleeding, and ask about the colour and amount of the amniotic fluid lost if there is SROM.

Details of her past obstetrical history, mode of deliveries, any history of delivering big baby? C/S

LMP, GA , ask her about her ANC (it is better if she is bringing her ANC card with her, her blood group and Rh), any problem during the current pregnancy (medical or obstetrical) like PIH, APH or reduction in the fetal activity or IUGR.

Ask her about the recent activity of her fetus.

Then we PROCEED FOR EXAMINATION of the woman

General examination, her vital signs: BP, temp., PR,

Then abdominal examination: for any previous scars,

Leopold's maneuvers are a series of four abdominal palpations of the gravid uterus that can be used to ascertain fetal lie, presentation, and estimated weight.

[pic]

The fundus is palpated to ascertain the presence or absence of a fetal pole (longitudinal or transverse lie) and the nature of the fetal pole (cephalic or breech).

The lateral walls of the uterus are examined using one hand to palpate and the other to fix the fetus. In longitudinal lies, the lateral uterus is usually occupied by the fetal spine (long, firm, and linear) and small parts or extremities.

The nature and station of the presenting part is determined by palpating above the symphysis pubis.

If the presentation is vertex, the cephalic prominence is palpated to determine the position of the fetal head. If the head is well flexed, neither chin nor occiput will be prominent.

also assess the engagement which is an important sign for good progress of labor, unengaged head should raise the suspicion of malposition or deflexed head or may be any abnormality in the pelvis that prevent the descent of the presenting part like a uterine fibroid, ovarian mass or placenta previa.

In case of deeply engaged head then the head can not be felt by abdominal examination (rule of five fifths) and it is called to be in zero station while if you can feel the whole of the head suprapubically it is called to be floating head which is a bad sign, if only two fifths of the fetal head can be palpated abdominally so the head is engaged .

Assessment of the uterine contractions is performed by direct abdominal palpation for at least ten minutes to count the number of contractions, strength and frequency during these ten minutes.

Also FHR should be checked at the start by a pinard stethoscope or sonicaid to prove viability and exclude fetal compromise.

Vaginal examination after taking her consent, we have to explain the purpose and technique of the procedure for the patient:

Then the index and middle fingers are passed to the top of vagina and cervix gently to assess the dilatation of the cervix digitally in centimeters (if the cervix is not palpable this means 10 cm dilatation), effacement by % of the cervical canal length which is normally 3 cm at 36 weeks of gestation (if I find it 1.5 cm I can say that it is 50% effaced).

[pic]

(Effacement)

If the cervix is 3 cm dilated or more the position of the presenting part can be assessed, the position is defined by the relation of the land mark or the denominator of the presenting part to the maternal pelvis as in vertex presentation the occiput must be determined if it is (RT or LT) occipito-transverse, or if it is in oblique position like the( RT or LT) occipito-anterior, or the (RT or LT) occipito- posterior when the occiput related to the RT sacroiliac joint or the LT one respectively.

[pic] (positions)

The occiput can be identified by vaginal examination if the patient has ruptured membranes, by identifying the posterior fontanel(triangular), failure to find the posterior fontanel may be due to deflexed head or due to caput which is the edema of the presenting part which obscure the landmarks during examination.

If there is ruptured membranes the color and amount of the coming fluid should be assessed if large amount of clear fluid or scanty with blood or meconeum staining which is a warning sign of fetal distress.

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