Lecture for maternity nursing

1. Feto-pelvic relationship
NURS 419
Dr. Howieda Fouly
Assistant professor of Maternity Nursing

2. OBJECTIVES
By the end of this lecture the student will be
able to
 Enlighten the factors affecting the birth
process
 Describe the components of fetal skull
 Differentiate between the types of maternal
pelvis
Feto-Pelvic relationship

3. Factors Affecting The Birth Process
 Four major factors interact during normal
childbirth are often called the 5 Ps:
 Passenger,
 Passageway,
 Powers,
 Position, & Psyche.
Feto-Pelvic relationship
Ch. 12th 241-247

4.  Philosophy (touch base)
 Partners (Support)
 Patience (birth time)
 Patient (Preparation & knowledge);
 Pain management
Additional factors (+ Ps)

5. Consists of the
 maternal pelvis and soft tissues.
 The bones and joints linking occurs near
term because of increased levels of the
hormone relaxin.
Passage

6.  Fetus, ( Fetal Skull),Membranes, & Placenta.
Powers
 Uterine Contractions
 Maternal Pushing Efforts
Position ( Maternal)
Psyche
 A woman’s psychological response to birth is
influenced by anxiety, culture, expectations, life
experiences, and support.
Passenger

7. Fetal Head
 The fetus enters the birth canal in the cephalic presentation
96% of the time.
 The fetal shoulders are also important because of their width,
usually can be moved to adapt to the diameter of the pelvis.
Passenger

8. Bones
2 frontal bones
2 parietal bones
1 occipital bone
These bones are not fused but are connected by sutures
Sutures
Fontanels
The wider spaces at the intersections of the
sutures
Fetal Skull
Bones, Sutures, Fontanels & landmarks

9. Fetal head
The sutures and fontanels
 Allow the bones to move slightly,
 changing the shape of the fetal head
 Molding adapt to the size and shape of the
pelvis by Provide important landmarks to
determine fetal position (relation of a fixed
reference point on the fetus to the quadrants of the
maternal pelvis) and head flexion during
vaginal examination.

10. Fontanels
 The anterior fontanel (bregma):
 shape formed by the intersection of
 4 sutures( 2 coronal,1 frontal, & 1 sagittal) which connect
the 4 bones: (2 frontal and 2 parietal bones).
 The posterior fontanel
 shape formed by the intersection of
 3 sutures ( 1 sagittal and 2 lambdoid), which connect the 3
bones ( 2 parietal and 1 occipital) bone.

11.  Anterior fontanelle ( bregma)
 Posterior fontanelle (lambda)
 Mentum – chin (M)
 Sinciput – brow
 Vertex – space between fontanels
 Occiput – occipital bone (O)
Landmarks of Fetal Skull

12. Fetal Head Diameters.
Anteroposterior diameter
varies with the degree of head flexion.
- Suboccipitobregmatic,(SOB) 9.5 cm ( well flexed).
- Occipital frontal (OF) 11 cm
 Supraoccipito-mental (Mento vertical) 13.5 cm: {Brow
presentation}.
 Sub-mento bregmatic 9.5 cm: {Attitude: complete
extension, Face presentation}.

13. Fetal skull diameters
Transverse Diameters
Anteroposterior diameter

14. Passage
Remember : maternal pelvis and soft tissues.
 The linea terminals( pelvic brim) divide
the bony pelvis into:
 False pelvis.
 True pelvis
 Inlet (upper pelvic opening)
 Mid-pelvis (cavity)
 Out let (lower pelvic opening)
Cahpter 12 pp 241-243

15. True pelvis structure
I-Inlet (brim):-is slightly
transverse , oval shape.
Boundaries: are
Promontory of the sacrum,
sacro-iliac joint,
iliopectineal imminence,
upper border of the pubis

16. Diameters of inlet
Antropsterior diameter of inlet (
(Obsteric diameter) 10.5cm
 middle of the sacral promontory to the
most prominent point symphysis pubis.
Oblique diameter 12.5cm
Transverse diameter of inlet
13-13.5 cm

17. True pelvic structure
II-The pelvic Cavity
Greatest pelvic dimensions)
 All Diameters of cavity
are equal in
antropsterior, oblique
and transverse (12 cm)

18. III.Outlet (least pelvic
dimensions)
• The obstetrical
outlet is the space
between the narrow
pelvic strait and the
anatomical outlet.
• 13-12-11

19. The Four Types of Pelvis
 1-Gynacoid
 2-Anthropoid
 3-Android
 4-Platypelloid

20. 1.Fetal Lie. The orientation of the long axis of the fetus to the
long axis of the woman
Variations in the Passenger
(Relationship between fetus & Pelvis)
Longitudinal Lie In > 99% of pregnancies
Transverse lie : long axis of the fetus is at a right angle to the woman’s long axis <1%
Oblique lie: some angle between the longitudinal lie and the transverse lie.

21.  Def. The relation of fetal body
parts to each other
 The normal fetal attitude is
flexion, of the head toward
the chest and the arms and
legs flexed over the thorax.
 The back is curved in a
convex “C” shape.
2. Fetal Attitude

22.  Three categories of Presentation:
 (1) cephalic (2) breech (3) shoulder
 The most common is cephalic presentation.
 Other presentations are associated with prolonged
labor and other problems.
3. Presentation.

23.  Variations of Cephalic Presentation
1. Vertex/ occiput presentation the most common type
“favorable” because the smallest suboccipitobregmatic
diameter is presenting.
Cephalic Presentation

24. 2. Military:The head is neither
flexed nor extended.
The longer occipitofrontal
diameter is presenting.
.
Variations of Cephalic Presentation ….cont
3. Brow: The fetal head is
partly extended.
unstable, usually converting
to a vertex if the head flexes
or to a face presentation if it
extends.
The longest
supraoccipitomental
diameter is presenting

25. 4. Face—
The head is extended, near to fetal
spine.
The submentobregmatic diameter is
presenting

26.  A breech presentation occurs when the fetal buttocks enter
the pelvis first, in about 3% to 4% of births.
Occurs due to
Fetal abnormality as hydrocephalus
Abnormalities of the maternal uterus and pelvis and with
placenta Previa
Breech Presentation

27. Full (complete)
The head,
knees, and hips
are flexed, the
buttocks are
presenting.
Frank breech
This is the most
common (fetal legs
are extended across
the abdomen toward
the shoulders).
Footling breech:
This occurs when
one or both feet
are presenting.
Variations of breech presentation

28. Shoulder Presentation
The shoulder presentation is a transverse lie and accounts for
only 0.3% of births.
Occurs: more often with preterm birth, high parity, prematurely
ruptured membranes, hydramnios, and placenta previa

29. 4 quadrants:
 Right (R) & Left (L) anterior Right & Left posterior.
R.S. between fetal presenting part & maternal pelvis
Occiput (O)
Mentum (M)
Sacrum (S)
Anterior (A)
Posterior (P)
Transverse (T)
Position
Fetal position describes the location of a fixed reference point
on the presenting part in relation to the four quadrants of the
maternal pelvis

30. e.g.Left occiput
anterior (LOA)
Occiput anterior (OA)