1671682284934_PHYSIOLOGY OF FIRST STAGE OF LABOUR.pptx

Psychological changes of labour

1. PHYSIOLOGY OF FIRST STAGE OF LABOUR PRESENTED BY L MACKIE

2. SPECIFIC OBJECTIVES By the end of the lesson students should be able to: Define terms of labour Explain signs of labour Differentiate between true and false labour Discuss physiological changes that occur during first stage of labour

3. LABOUR This is a process by which the fetus is delivered with maternal effort from the uterus through the birth canal after 28 weeks gestation

4. NORMAL LABOUR This is the spontaneous expulsion of a live full term infant, vertex presentation within 24 hours and complete delivery of placenta and membranes without injury or complications to both mother and baby

5. FIRST STAGE OFN LABOUR Begins with regular painful uterine contractions dilatation of the cervix and ends when the cervix is fully dilated. DURATION A primigravida takes 12-14hrs and not more than 16hrs A multi gravida takes 7-9hrs and not more than 9hrs

6. 1.LIGHTENING This is the relaxation of the pelvic ligaments making the uterus to move down into the pelvis together with the presenting part. PREMONITORY SIGNS OF LABOUR

7. RUPTURE OF MEMBRANES Occurs because there is no support of the membranes after the dilating cervix with the increase of intrauterine pressure due to frequent uterine contractions. This leads to sudden rupture of membrane

8. SIGNS OF LABOUR Regular painful contractions Backache and lower abdominal pains Show Rupture of membranes {sometimes} Taking up and dilatation of the cervix

9. TRUE LABOUR Contractions are regular, painful, increase in frequency and intensity. Contractions dilate the cervix, help in effacement and promote descent of the presenting part.

10. FALSE LABOUR Contractions do not increase in intensity and duration Abdominal pains are relieved by sedation and ambulation No dilatation, effacement of the cervix and descent of the presenting part

11. PHYSIOLOGICAL CHANGES IN FIRST STAGE OF LABOUR 1.UTERINE ACTION : CONTRACTION It is temporary shortening of uterine muscle . The upper and lower segment both have smooth muscles which give the uterus an ability to contract The upper uterine segment is thicker while the lower segment is thinnner .

12. FUNDAL DOMINANCE Contractions are stronger and maintained for a longer period at the fundus than the lower segment . This is because the muscles are thicker

13. 2. RETRACTION This a permanent shortening of muscle fibres where the muscle does not become completely relaxed . This shortens the whole uterus and increased pressure helps to force contents out . There is pulling upward on the lower segment causing taking up of the cervix and dilatation of the cervical

14. 3.RELAXATION The resting tone of the muscle between contractions . Relaxation allows the flow of blood to the uterus , placenta and prevent fatigue of the muscles.

15. 4.POLARITY (uterine coordination) At the end of the pregnancy the uterus is divided into upper segment and lower segment. The upper segment gets shorter and thicker while the lower segment stretches and dilates .( Polality )

16. RETRACTION RING A ridge which forms at the lower border of the thick upper segment where it meets the thin lower segment . In normal labour the lower segment do not become distended because the fetus is gradually being expelled through the dilating os . Normally it is not palpable if seen, there is a problem

17. TAKING UP THE CERVIX Shortening of the cervix takes place at the end the pregnancy. When labour begins the cervix shortens and become part of the lower segment SHOW: This is the thick mucus plug which was in the cervical canal during pregnancy

18. FORMATION OF FORE WATERS As the lower uterine segment stretches and cervix dilates, the chorion becomes detached from the lower segment, there is no support The well flexed head fits well into the cervix and the loosed part of the amniotic sac bulges into the dilating cervix . The fluid in front of the head is called fore waters and the remainder behind the head is called hind waters.

19. RUPTURE OF MEMBRANES This occurs due to increased pressure in the fore waters as the fetus descend . When the pressure cannot be contained the membranes rupture