Cervical ripening is the preparation of the cervix for labour and delivery. The Bishop score is the commonest used methodology to assess it. For more like this visit my page on YouTube https://www.youtube.com/@mudiagaakpoghene2243

1. CERVICAL RIPENING AND THE
BISHOP SCORE
BY
Dr Moses Akpoghene
Medical Officer
Obstetrics and Gynaecology department
Federal Medical centre Jalingo

2. OUTLINE
• Introduction
• The Uterine cervix
• Ripening of the cervix
• Pathophysiology of cervical ripening
• Evaluation of cervical ripening
• Bishop scoring system
• Initiation of cervical ripening
• Contra indication to cervical ripening
• Summary
• References

3. INTRODUCTION
• Induction of labor is common in obstetric practice.
According to literature, the rate varies from 9.5 to 33.7
percent of all pregnancies annually.
• In the absence of a ripe or favorable cervix, a
successful vaginal birth is less likely.
• Therefore, cervical ripening or preparedness for
induction should be assessed before a regimen is
selected.
• Assessment is accomplished by calculating a Bishop
score. When the Bishop score is less than 6, it is
recommended that a cervical ripening agent be used
before labor induction.

4. In pregnancy, the uterine cervix serves 2 major functions.
• First, it retains its physical integrity by remaining firm
during pregnancy as the uterus dramatically enlarges.
• This physical integrity is critical so that the developing
fetus can remain in the uterus until the appropriate
time for delivery.
UTERINE CERVIX

5. UTERINE CERVIX
• Second, in preparation for labor and delivery, the
cervix softens and becomes more distensible, a
process called cervical ripening.
• These chemical and physical changes are required
for cervical dilation, labor and delivery of a fetus.

6. UTERINE CERVIX
• The human cervix consists mainly of extracellular
connective tissue.
• The predominant molecules of this extracellular matrix are
type 1 and type 3 collagen, with a small amount of type 4
collagen at the basement membrane.

7. UTERINE CERVIX
• Intercalated among the collagen
molecules are glycosaminoglycans
and proteoglycans, predominantly
dermatan sulfate, hyaluronic acid,
and heparin sulfate. Fibronectin and
elastin also run among the collagen
fibers.
• The highest ratio of elastin to
collagen is at the internal os. Both
elastin and smooth muscle decrease
from the internal to the external os
of the cervix.

8. RIPENING OF
THE CERVIX
• Cervical ripening refers to the softening of the cervix that
typically begins prior to the onset of labor contractions and
is necessary for cervical dilation and the passage of the
fetus.
• Cervical ripening results from a series of complex
biochemical processes that ends with rearrangement and
realignment of the collagen molecules.

9. RIPENING OF THE CERVIX
• The cervix thins, softens, relaxes and dilates in response to
uterine contractions, allowing the cervix to easily pass over
the presenting fetal part during labor.

10. • Associated with cervical ripening is
an increase in the enzyme
cyclooxygenase-2, leading to a
local increase of prostaglandin E2
(PGE2) in the cervix.
• Prostaglandin F2-alpha is involved
in the process via its ability to
stimulate an increase in
glycosaminoglycans.
PHYSIOLOGY OF CERVICAL
RIPENING

11. • Prostaglandins lead to dilation of small vessels in the cervix, increase
in collagen degradation, increase in hyaluronic acid, increase in
chemotaxis for leukocytes, which causes increased collagen
degradation and increase in stimulation of interleukin (IL)–8 release.
• IL-8 can lead to neutrophil chemotaxis, which is associated with
collagenase activity and cervical ripening.
PHYSIOLOGY OF CERVICAL
RIPENING

12. PHYSIOLOGY OF
CERVICAL
RIPENING
• This increased hyaluronic acid content in the cervix
leads to an increase in water molecules that
intercalate among the collagen fibers causing
decreased collagen fiber alignment, decreased
collagen fiber strength and diminished tensile strength
of the extracellular cervical matrix.

13. • An associated change with the cervical ripening process is
an increase in cervical decorin (dermatan sulfate
proteoglycan 2), leading to collagen fiber separation. This
causes decrease in cervical firmness.
• All these occur with decrease in chondroitin sulfate and
together lead to softening of the cervix (ie, ripening).
PHYSIOLOGY OF
CERVICAL RIPENING

14. Contractions cause
reorientation on cervix
• Under the effect of myometrial
contractions, the cervix passively
dilates and is pulled over the
presenting fetal part.
• Evidence also indicates that the
elastin component of the cervix
behaves in a ratchetlike manner
so that dilation is maintained
following the contraction.

15. EVALUATION OF CERVICAL RIPENING
• A variety of techniques have been developed to quantify cervical
ripening in order to predict the timing of labor and delivery
• The most commonly used methodology to evaluate cervical
ripening is the Bishop score because it is simple and has the most
predictive value.
• Other methods that have been described in the literature,
generally for gauging the risk of preterm labor, include ultrasound
assessment of the cervix and detection of fetal fibronectin in
cervicovaginal secretions.

16. • In the 1964 article "Pelvic Scoring for Elective Induction,"
obstetrician Edward Bishop described his method to determine
whether a doctor should induce labor in a pregnant woman.
• In his earlier publication (1955), Bishop argued that elective
induction of labor is most appropriate for women who have
previously given birth, with a cervical dilation of at least three
centimeters, and fetuses that have descended low in the womb.

17. • Bishop spends the last part of "Pelvic Scoring for Elective Induction"
explaining his Bishop Score, the pelvic scoring system he devised to judge
whether or not a pregnant woman and her fetus are biologically ready to
enter into labor.
• The scoring system consists of five pelvic measurements, and the total of
all five scores determines whether or not a pregnant woman can be safely
induced.
• The first three measurements have scores ranging from zero to three,
while the last two measurements have scores ranging from zero to two. In
total, the highest score is thirteen, with higher scores indicating that the
woman can be safely induced.

18. DILATATION
• The first and most important element of the Bishop
score is dilatation.
• Dilatation is the distance the cervix is opened measured
in centimeters (cm)

19. EFFACEMENT
• The second measurement is of the effacement, or thinning, of
the cervix.
• It is reported as a percentage from zero percent (normal
length cervix of 3cm) to 100% or complete (paper thin cervix).
• Points are given from 0 to a maximum of 3 points for a cervix
effaced to 80 % or greater.

20. STATION
• The third measurement is
of the distance between
the fetus's head and the
woman's pelvis (station).
• Station is the position of
the baby's head relative
to the ischial spines.
• Points are given from 0 to
a maximum of 3 points
for a station of 1 + or 2+.

21. CONSISTENCY
The fourth measurement is of the consistency of the cervix. This is texture of
the cervix on examination.
• Firm : The cervix feels hard and rubbery .
• Medium: The cervix feels compressible but not soft
• Soft : The cervix feels mushy
In primigravid women, the cervix is typically tougher and resistant to stretching
and with subsequent vaginal deliveries, the cervix becomes less rigid and
allows for easier dilation at term.

22. POSITION
• The final measurement of the Bishop Score is of the
alignment between the cervix and the birth canal.
• The position of the cervix relative to the fetal head and
maternal pelvis

23. Bishop applied the Bishop Score to five hundred pregnant women who
later had natural, spontaneous births without being induced. He found
that the average duration of pregnancy, meaning the period of time
between the scoring examination and natural delivery of an infant, was
directly related to the Bishop Score.

24. INTERPRETING THE BISHOP SCORE

25. • The Bishop score has been modified severally since then. One of
such is the replacement of effacement with cervical length in cm,
with scores as follows: 0 for >4 cm, 1 for 3-4 cm, 2 for 1-2 cm, 3 for
<1 cm.
• Cervical length may be easier and more accurate to measure and
have less inter-examiner variability.

26. OTHER MODIFICATIONS
• Another modification for the Bishop's score is the
modifiers:
• One point is added to the total score for:
– 1. Existence of pre-eclampsia
– 2. Each previous vaginal delivery
• One point is subtracted from the total score for:
– 1. Postdate/post-term pregnancy
– 2. Nulliparity (no previous vaginal deliveries)
– 3. PPROM; preterm premature (prelabor) rupture of
membranes

27. INITIATION OF CERVICAL RIPENING
A variety of methods have been developed to
induce cervical ripening in the preparation of
the cervix for labor and delivery.
• Pharmacological methods: including
prostaglandins, low-dose oxytocin infusion,
Mifepristone, Relaxin.
• Non pharmacological methods: Balloon
catheter, membrane stripping, sexual
intercourse etc.

28. PHARMACOLOGIC CERVICAL
RIPENING
PROSTAGLANDINS
• Prostaglandins act on the cervix to enable ripening by a
number of different mechanisms.
• They alter the extracellular ground substance of the cervix,
and PGE2 increases the activity of collagenase in the
cervix.
• They cause an increase in elastase, glycosaminoglycan,
dermatan sulfate, and hyaluronic acid levels in the cervix.
• Finally, prostaglandins allow for an increase in intracellular
calcium levels, causing contraction of myometrial muscle.

29. PHARMACOLOGIC CERVICAL
RIPENING
PROSTAGLANDINS
Risks associated with the use of prostaglandins
include
• Uterine hyperstimulation
• Maternal side effects such as nausea, vomiting,
diarrhea, and fever.
• Currently, two prostaglandin analogs are
available for the purpose of cervical ripening,
dinoprostone gel (Prepidil) and dinoprostone
inserts (Cervidil).

30. PROSTAGLANDINS
• Cochrane reviewers examined 52 well-designed
studies using prostaglandins for cervical ripening
or labor induction. They compared with placebo.
• Results showed that the use of vaginal
prostaglandins increased the likelihood that a
vaginal delivery would occur within 24 hours.
With comparable caesarean section rates.
• The only drawback appears to be an increased
rate of uterine hyperstimulation and
accompanying FHR changes.
PHARMACOLOGIC CERVICAL
RIPENING

31. PHARMACOLOGIC CERVICAL
RIPENING
MISOPROSTOL
• Misoprostol (Cytotec) is a synthetic PGE1
analog that has been found to be a safe and
inexpensive agent for cervical ripening,
although it is not labeled by NAFDAC for that
purpose.
• Clinical trials indicate that the optimal dose
and dosing interval is 25 mcg intravaginally
every four to six hours.

32. PHARMACOLOGIC CERVICAL
RIPENING
MISOPROSTOL
• Higher doses or shorter dosing intervals are
associated with a higher incidence of side
effects, especially hyperstimulation syndrome
(tachysystole and hypersystole)
• Finally, uterine rupture in women with previous
cesarean section is also a possible complication,
limiting its use to women who do not have a
uterine scar.

33. PHARMACOLOGIC CERVICAL
RIPENING
MISOPROSTOL
• The Cochrane reviewers concluded that use of
misoprostol resulted in an overall lower
incidence of cesarean section.
• In addition, there appears to be a higher
incidence of vaginal delivery within 24 hours of
application and a reduced need for oxytocin
augmentation.
• The risks of hyperstimulation and uterine rupture
are also present here.

34. MIFEPRISTONE
• Mifepristone is an antiprogesterone agent. Progesterone
inhibits contractions of the uterus, while mifepristone
counteracts this action.
• A RCT has shown that women treated with mifepristone are
more likely to have a favorable cervix and likely to deliver
within 48 to 96 hours and less likely to undergo cesarean
section (compared to placebos).
• However, little information is available about fetal outcomes
and maternal side effects; thus, there is insufficient
information to support the use of mifepristone for cervical
ripening
PHARMACOLOGIC CERVICAL
RIPENING

35. Low dose oxytocin
• In this method, a low-dose oxytocin infusion is
performed, with an increase in dose from 1 to 4
mU/min.
• Ferguson et al showed this method to be
comparable to intravaginal misoprostol for cervical
priming.
• Because of the ease of turning off the oxytocin
infusion, they suggested that this method may have
a preferential role in high-risk patients whose
fetuses are at increased risk for intolerance of labor.
PHARMACOLOGIC CERVICAL
RIPENING

36. RELAXIN
• The hormone relaxin is thought to promote
cervical ripening.
• Cochrane reviewers evaluated results of four
studies involving 267 women and concluded
that there is insufficient support for the use of
relaxin.
• Thus further trials are needed.
PHARMACOLOGIC CERVICAL
RIPENING

37. Stripping of the Membranes
Stripping of the membranes causes an increase in the
activity of phospholipase A2 and prostaglandin F2 (PGF2)
as well as causing mechanical dilation of the cervix, which
releases prostaglandins.
The membranes are stripped by inserting the examining
finger through the internal cervical os and moving it in a
circular direction to detach the inferior pole of the
membranes from the lower uterine segment.
NON PHARMACOLOGIC CERVICAL
RIPENING

38. Stripping of the Membranes
• Literature showed that stripping of the membranes
alone does not seem to produce clinically important
benefits, but when used as an adjunct appears to be
associated with a lower mean dose of oxytocin needed
and an increased rate of normal vaginal deliveries.
NON PHARMACOLOGIC CERVICAL
RIPENING

39. Balloon dilators
• Balloon devices provide mechanical pressure
directly on the cervix as the balloon is filled. A
Foley catheter (26 Fr) or specifically designed
balloon devices can be used.
NON PHARMACOLOGIC CERVICAL
RIPENING

40. • The catheter is placed in the uterus, and the
balloon is filled.
• Direct pressure is then applied to the lower
segment of the uterus and the cervix.
• This direct pressure causes stress in the lower
uterine segment and probably the local
production of prostaglandins.
• In some studies, the catheter is combined with a
saline solution as an extra-amniotic infusion.
NON PHARMACOLOGIC CERVICAL
RIPENING

41. • Several RCTs compared the use of a balloon device with
administration of an extra-amniotic saline infusion,
laminaria, or prostaglandin E2 (PGE2).
• Results from these trials indicate that each of these
methods is effective for cervical ripening and each has
comparable cesarean-section delivery rates in women
with an unfavorable cervix.
• A meta-analysis involving 27 studies and 3532 patients
found that no difference between Foley balloon and PGE2
use in cesarean delivery rate. Further subgroup analysis
suggested that Foley balloon in combination with oxytocin
and EASI may indeed have a higher vaginal delivery rate
and lower rate of tachysystole.
NON PHARMACOLOGIC CERVICAL
RIPENING

42. The risks associated with balloon dilators as
other mechanical methods include
• Infection (endometritis and neonatal sepsis),
• Bleeding,
• Membrane rupture, and
• Placental disruption.
NON PHARMACOLOGIC CERVICAL
RIPENING

43. HYGROSCOPIC DILATORS
• Hygroscopic dilators absorb endocervical and local
tissue fluids, causing the device to expand within
the endocervix and providing controlled
mechanical pressure.
• The products available include natural osmotic
dilators (e.g., Laminaria japonicum) and synthetic
osmotic dilators (e.g., Lamicel).
• The main advantages of using hygroscopic dilators
include outpatient placement and no need for
FHR-monitoring.
NON PHARMACOLOGIC CERVICAL
RIPENING

44. SEXUAL INTERCOURSE
• Sexual intercourse is commonly recommended for promoting
labor initiation. Sexual relations usually involve
– Stimulation of the breasts and nipples, which can promote the
release of oxytocin.
– With penetration, the lower uterine segment is stimulated. This
stimulation results in a local release of prostaglandins.
– Female orgasms have been shown to include uterine
contractions, and
– Human semen contains prostaglandins, which are responsible for
cervical ripening.
• Only one study of 28 women resulted in minimally useful
data, so the role of sexual intercourse as a method of
promoting labor initiation remains uncertain
NON PHARMACOLOGIC CERVICAL
RIPENING

45. Others that have been suggested but not
supported in literature include
• Castor oil, hot baths and enemas
• Acupuncture and transcutaneous nerve
stimulation
• Herbal remedies such as Raspberry leaves and
Primrose oil.
NON PHARMACOLOGIC CERVICAL
RIPENING

46. Contraindications to cervical ripening
Contraindications to cervical ripening include, but are not limited to,
the following:
• Active herpes
• Fetal malpresentation
• Nonreassuring fetal surveillance
• Regular contractions
• Unexplained vaginal bleeding
• Placenta previa
• Vasa previa
• Prior uterine myomectomy involving the endometrial cavity or
classical cesarean delivery
• A relative contraindication to cervical ripening is ruptured
membranes.

47. In Summary
• Induction of cervical ripening is critical to successful
induction of labor in a pregnant patient whose cervix has
not gone through the ripening process.
• Cervical ripening allows the uterine contractions to
effectively dilate the cervix.
• The Bishop score is the is simple and has the most
predictive value thus it’s the most commonly used
methodology.
• There are pharmacological and non pharmacological
methods of inducing cervical ripening with varying
success rates but most popular are Prostaglandins,
Misoprostol and Balloon dilators.

48. REFERENCES
• Abboud, Carolina J., "“Pelvic Scoring for Elective Induction” (1964), by Edward
Bishop". Embryo Project Encyclopedia (2017-02-23). ISSN: 1940-5030
http://embryo.asu.edu/handle/10776/11426.
• American College of Obstetricians and Gynecologists (1999) Induction of labor.
Practice bulletin no. 10. Washington, D.C.: ACOG.
• Bishop EH (1964) Pelvic scoring for elective induction.Obstet Gynecol.;24:266-
8.
• Dutta DC (2001) Text Book of Obstetrics. 6ed. New Central Book Agency.
• Goldberg AB, Greenberg MB, Darney PD (2001) Misoprostol and pregnancy. N
Engl J Med;344:38-47.
• Goldman JB, Wigton TR (1999) A randomized comparison of extra-amniotic
saline infusion and intracervical dinoprostone gel for cervical ripening. Obstet
Gynecol;93:271-4.
• Cervical ripening. Available at
https://emedicine.medscape.com/article/263311-overview
• Norwitz E, Robinson J, Repke J. (2002)Labor and delivery. In: Gabbe SG, Niebyl
JR, Simpson JL, eds. Obstetrics: normal and problem pregnancies. 4th ed. New
York: Churchill Livingstone:353-94.
• Tenore JL. (2003) Methods for Cervical Ripening and Induction of Labor.
American Family Physician. 67 (10):