Lecture 2: Labour & its problems

Dr.Nassrin Malik Aubead

Objectives

-Describe the principles of labour.

-Describe in outline the most common lie , fetal presentations and positions.

-Describe the principles of inducing labour

-Describe how the physiological state of the fetus may be monitored during

labour

-Describe, in principle, how delivery may be facilitated by intervention.

-Describe the processes which normally limit maternal blood loss after birth.

-Describe the causes of post partum haemorrhage

Progress of labour is depend on three variables (3 P):-

1-The powers, i.e.the efficiency of uterine contractions.

2-The passages,i.e, the uterus, cervix, and the bony pelvis.

3-The passenger, i.e.,the fetus( with particular respect to the size ,

presentation, and position ).

Pelvic outlet

The Passenger

• The size and presentation of the fetus is critical in labour. The

orientation of the head of the fetus when entering the pelvis (in a cephalic

delivery) is variable and as such the head diameter of the fetus varies in

different positions.

0

Attitude

13.5

Presentation : refers to the part of the fetus that is lowermost within the

maternal pelvis like normal presentation (vertex)

Malpresentation (Abnormal presentations ) :any presentation other than the

vertex and therefore includes brow , face, breech ,shoulder, compound

presentations and cord presentation.

Position: Refers to the relation ship between the dominator of the fetal presenting part relative to the maternal pelvis land marks.

Dominator

also known as extended breech) presentation with

extension of the legs

breech presentation with flexion of the legs

What are the incidence & risk factors for breech presentation?

The majority of persistent breech presentations recognized antenatally

are delivered by Caesarean section to avoid fetal risks. However there is

still a place for the vaginal delivery of a breech presentation(e.g

maternal choice and the failure to detect breech presentation until very

late in labour).

Why vaginal beech delivery is risky?

Assessment of Progress of labour

PARTOGRAM is a graphical information about the progress of labour in which the

salient information about the fetal wellbeing, maternal well-being and the

progress of labour are recorded into a chart.

Partogram helps to identify at an early stage those women whose labour is slow.

Failure to progress in labour may be due to:

• Inadequate Power

– Insufficient uterine contraction

• Inadequate Passage

– Abnormal bony pelvis

– Rigid perineum

• Abnormalities of the Passenger

– Fetus too big

– Abnormal fetal presentation (malpresentation) e.g breech, brow, face.

– Abnormal fetal position (malposition) e.g occiput posterior.

Indications

MATERNAL

• Preeclampsia, eclampsia

•PROM, Chorioamnionitis.

•Prolonged pregnancy(usually

offered after 41 completed weeks) -

•Unexplained antepartum

haemorrhage.

•Medical conditions: Intrahepatic

cholestasis of pregnancy.

•Deteriorating maternal illness: DM,

Heart ds, Renal ds,Chr. HT etc.

•Social’ reasons.

FETAL

• IUFD

• Fetal anomaly

incompatible with life

• Severe IUGR

• Rh-isoimmunisation

•Twin pregnancy continuing beyond 38

weeks.

• Macrosomia

The principles of inducing labour

METHODS OF INDUCTION

Breast/nipple stimulation

Sexual intercourse

Membrane stripping

Amniotomy or ARM

Acupuncture/acupressure

Balloon catheters

Lamineria tents

Synthetic osmotic dilators

" Herbs, evening primrose oil

" Homeopathic prep

" Enemas

" Castor oil

" Oxytocin

" Prostaglandins –

PGE2,Misoprostol

" Relaxin

" Nitric oxide donors

" mifepristone

CHEMICAL NONHORMONAL NATURAL

MECHANICAL HORMONAL

Monitoring the physiological state of the fetus during labour:

During labour fetal heart rate can be assessed using either:

External monitoring by:

- A Pinard stethoscope .

- A handheld Doppler ultrasound.

- Continuous external electronic fetal

monitoring (EFM) using CTG.

or

Internal monitoring by :

Fetal Scalp Electrode

Interventions that facilitate delivery by :

Cesarean Section

• Subrapubic Incision

• Linea alba and anterior layers of the rectus sheaths are transected and resected superiorly,

• Rectus muscles are retracted laterally or divided through their tendinous parts

allowing reattachment without muscle fiber injury.

Immediately after delivery, the fundus of the uterus

begins to contract. This is to deliver the placenta which

can take up to 30 minutes In a normal and healthy

response it should feel firm and not boggy. It begins to

involute with contractions of the smooth muscle of the

uterus .

The interlacing arrangement of muscle bundles has been

referred to as the "living ligatures" or "physiologic

sutures" of the uterus as the lead to closure of the

endometrial blood vessels after labour.

Postpartum haemrrhage

• Primary PPH – blood loss of 500ml or more within 24hours of

delivery.

• Secondary PPH – significant blood loss between 24 hours and 6

weeks after birth.

Why do we care?

Obstetric haemorrhage – more than 1000ml Very rapidly lead to maternal death.

Major obstetric haemorrhage is defined as blood loss ≥2,500 ml, or requiring a blood transfusion ≥5 units red cells or treatment for coagulopathy

Causes of secondary PPH:

-Uterine infection – (known as endometritis).

- Infection of the vaginal or cervical tears.

-Retained placental fragments or tissue

-Abnormal involution of the placental site (inadequate closure and sloughing of

the spiral arteries at the placental attachment site).

-Uterine fibroid, endometrial polyp.

-Undiagnosed cervical carcinoma.

-Blood diseases.

-Trophoblastic disease (very rare).

Puerperial Pyrexia

- A clinical sign that merits careful investigation.

- A temperature of 38 C° more on any 2 occasion in the first 10 days after delivery

excluding the first 24 hr.

CAUSES:

1. Urinary tract infection

2. Genital tract infection

3. Breast infection (mastitis, abscess)

4. Deep vein thrombosis or pulmonary embolism

5. Respiratory infection

6. Other non-obstetrics causes

7. Surgical wounds e.g. C.S