2. Pregnancy
Pregnancy is the development of one or more offspring, known as
an embryo or fetus, in a woman's uterus. It is the common name
for gestation in humans.
Embryo &
Fetus
An embryo is the developing offspring during the first 8 weeks
following conception.
Subsequently the term fetus is used until birth.
3. Fig.1- First trimester
(week 1-week 12)
Fig.2- Second trimester
(13- 28 week)
Fig.3-Third trimester
(week 29-week 40)
Stages of pregnancy
4. First trimester (week 1-week 12)
During the first trimester body undergoes many changes. Hormonal
changes affect almost every organ system in the body. These changes
can trigger symptoms even in the very first weeks of pregnancy.
period stopping is a clear sign of pregnancy.
Changes may include:
Extreme tiredness
Tender, swollen breasts.
Upset stomach
Mood swings
Constipation (trouble having bowel movements)
Need to pass urine more often
Headache
Heartburn
Weight gain or loss
5. Second trimester (week 13-week
28)There may noticed the symptoms like nausea and fatigue are
going away. But other new, more noticeable changes to the body
are now happening. Abdomen will expand as the baby continues
to grow.
Changes are:
Stretch marks on the abdomen, breasts, thighs, or buttocks
Darkening of the skin around the nipples
A line on the skin running from belly button to pubic hairline
Numb or tingling hands
6. Third trimester (week 29-week
40)Many women find breathing difficult and notice they have to go
to the bathroom even more often. This is because the baby is
getting bigger and it is putting more pressure on the organs.
Changes are:
Shortness of breath
Heartburn
Swelling of the ankles, fingers, and face.
Tender breasts
Trouble sleeping
The baby "dropping", or moving lower in your abdomen
Contractions
7. Pelvic Inlet
The line between the narrowest bony points formed by the Sacral
promontory and the inner pubic arch is termed obstetrical conjugate: It
should be 11.5 cm or more. This anteroposterior line at the inlet is 2 cm
less than the diagonal conjugate (distance from undersurface of pubic
arch to sacral promontory). The transverse diameter of the pelvic inlet
measures 13.5 cm.
8. Pelvic Outlet
The lower circumference of the lesser pelvic is very irregular; the space
enclosed by it is named the inferior aperture or pelvic outlet
It has the following boundaries:
Anteriorly: the pubic arch
Laterally: the ischial tuberosities
Posterolaterally: the inferior margin of the sacrotuberous ligament
Posteriorly: the tip of the coccyx
9. Pelvic types
Gynecoid:
Ideal shape, with round to slightly oval inlet best chances for normal vaginal
delivery. It has an almost round brim and will permit the passage of an average-
sized baby with the least amount of trauma to the mother and baby in normal
circumstances. The pelvic cavity is usually shallow, with straight side walls and
with the ischial spines not so prominent as to cause a problem as the baby moves
through.
Android
triangular inlet, and prominent ischial spines, more angulated pubic arch. It has a
heart-shaped brim and is quite narrow in front. The pelvic cavity and outlet is often
narrow, straight and long. The ischial spines are prominent. Women with this shape
pelvis may have babies that lie with their backs against their mothers’ backs and
may experience longer labours. It is important that these women take an active role
during their labour and need to squat and move around as much as possible
10. Anthropoid
The widest transverse diameter is less than the anteroposterior diameter. It
has an oval brim and a slightly narrow pelvic cavity. The outlet is large,
although some of the other diameters may be reduced. If the baby engages in
the pelvis in an anterior position, labour would be expected to be
straightforward in most cases.
Platypelloid
Flat inlet with shortened obstetrical diameter. It has a kidney-shaped brim and
the pelvic cavity is usually shallow and may be narrow in the anterior-
posterior (front to back) diameter. The outlet is usually roomy. During labour
the baby may have difficulty entering the pelvis, but once in, there should be
no further difficulty
11. Fetal
Relationship Engagement: The fetus is engaged if the widest leading part (typically
the widest circumference of the head) is negotiating the inlet.
Station: Relationship of the bony presenting part of the fetus to the
maternal ischial spines. If at the level of the spines it is at “0 (zero)”
station, if it passed it by 2cm it is at “+2” station.
Attitude: Relationship of fetal head to spine: flexed, neutral
(“military”), or extended attitudes are possible.
Position: Relationship of presenting part to maternal pelvis, i.e.
ROP=right occiput posterior, or LOA=left occiput anterior.
12. Cont…
Presentation: Relationship between the leading fetal part and the pelvic
inlet: cephalic, breech (complete, incomplete, frank or footling), face,
brow, mentum or shoulder presentation.
Lie: Relationship between the longitudinal axis of fetus and long axis of
the uterus: longitudinal, oblique, and transverse.
Caput or Caput succedaneum: Oedema typically formed by the tissue
overlying the fetal skull during the vaginal birthing process.
Cephalo-pelvic disproportion exists when the capacity of the pelvis is
inadequate to allow the fetus to negotiate the birth canal.
13. Pelvic
Floor The pelvic floor or pelvic diaphragm is composed of muscle
fibers of the levator ani, the coccygeus, and
associated connective tissue which span the area underneath
the pelvis.
The pelvic floor consists of three muscle layers:
Superficial perineal layer: innervated by the pudendal nerve
Bulbocavernosus
Ischiocavernosus
Superficial transverse perineal
External anal sphincter (EAS)
14. Pelvic Floor Cont..
Deep urogenital diaphragm layer: innervated by pudendal
nerve
Compressor urethera
Uretrovaginal sphincter
Deep transverse perineal
Pelvic diaphragm: innervated by sacral nerve roots S3-S5
Levator ani: pubococcygeus (pubovaginalis,
puborectalis), iliococcygeus
Coccygeus/ischiococcygeus
Piriformis
Obturator internus
15. Functions of the pelvic floor
It is important in providing support for pelvic viscera e.g.
the bladder, intestines the uterus(in females)
It maintenance of continence as part of the urinary and anal
sphincters.
It facilitates birth by resisting the descent of the presenting part,
causing the fetus to rotate forwards to navigate through the pelvic
girdle.
It helps maintain optimal intra-abdominal pressure.
16. Clinical significance
In women, the levator muscles or their supplying nerves can be
damaged in pregnancy or childbirth. In female high-level athletes,
perineal trauma is rare and is associated with certain sports.
Damage to the pelvic floor not only contributes to urinary
incontinence but can lead to pelvic organ prolapse. Pelvic organ
prolapse occurs in women when pelvic organs (e.g. the vagina,
bladder, rectum, or uterus) protrude into or outside of the vagina. The
causes of pelvic organ prolapse are not unlike those that also
contribute to urinary incontinence. These include inappropriate
(asymmetrical, excessive, insufficient) muscle tone and asymmetries
caused by trauma to the pelvis. Age, pregnancy, family history, and
hormonal status all contribute to the development of pelvic organ
prolapse.
Disorders of the posterior pelvic floor include rectal prolapse perineal
hernia , and a number of functional disorders including anismus.
Constipation due to any of these disorders is called "functional
constipation" and is identifiable by clinical diagnostic criteria.
17. At four weeks:
Baby's brain and spinal cord
have begun to form.
The heart begins to form.
Arm and leg buds appear.
Your baby is now an embryo
and one-twenty-fifth inch long.
Changes of the
baby
18. At eight weeks:
All major organs and external body
structures have begun to form.
Baby's heart beats with a regular
rhythm.
The arms and legs grow longer, and
fingers and toes have begun to form.
The sex organs begin to form.
The eyes have moved forward on the
face and eyelids have formed.
The umbilical cord is clearly visible.
At the end of eight weeks, baby is a
fetus and looks more like a human.
Your baby is nearly 1 inch long and
weighs less than one-eighth ounce.
19. At 12 weeks:
The nerves and muscles begin to work
together.
The external sex organs show if the
baby is a boy or girl.
Eyelids close to protect the developing
eyes. They will not open again until the
28th week.
Head growth has slowed, and baby is
much longer. Now, at about 3 inches
long, and weight is about 1 pound
20. At 16 weeks:
Muscle tissue and bone continue to
form, creating a more complete
skeleton.
Skin begins to form.
Develops in the baby's intestinal
tract. This will be the baby's first
bowel movement.
sucking reflex initiated.
The baby's length is about 4 to 5
inches and weighs almost 3 ounces.
21. At 24 weeks:
Bone marrow begins to make blood
cells.
Taste buds form on the baby's tongue.
Footprints and fingerprints have
formed.
Real hair begins to grow on the baby's
head.
The lungs are formed, but do not work.
The hand and startle reflex develop.
Your baby sleeps and wakes regularly.
The baby stores fat and has gained
quite a bit of weight.
Now at about 12 inches long, your
baby weighs about 1½ pounds.
22. At 32 weeks:
The baby's bones are fully formed, but
still soft.
The baby's kicks and jabs are forceful.
The eyes can open and close and sense
changes in light.
Baby's body begins to store vital
minerals, such as iron and calcium.
The baby's length is about 17-18 inch
and weight is about 4 pounds
23. At 36 weeks:
The protective waxy coating called
vernix gets thicker.
Body fat increases. Your baby is getting
bigger and bigger and has less space to
move around. Movements are less
forceful, but you will feel stretches and
wiggles.
Your baby is about 16 to 19 inches long
and weighs about 6 to 6½ pounds.
24. Weeks 37-40:
By the end of 37 weeks, your baby is
considered full term. Your baby's
organs are ready to function on their
own.
As you near your due date, your baby
may turn into a head-down position for
birth. Most babies "present" head
down.
At birth, your baby may weigh
somewhere between 6 pounds 2 ounces
and 9 pounds 2 ounces and be 19 to 21
inches long.
Most full-term babies fall within these
ranges. But healthy babies come in
many different sizes.