ABORTION

INA S. IRABON, MD, FPOGS, FPSRM, FPSGE

OBSTETRICS AND GYNECOLOGY

REPRODUCTIVE ENDOCRINOLOGY AND INFERTILITY
To download lecture deck:
REFERENCE

Cunningham FG, Leveno KJ, Bloom SL, Spong CY, Dashe JS,
Hoffman BL, Casey BM, Sheffield JS (eds).William’s Obstetrics
24th edition; 2014; chapter 18 ABORTION
OUTLINE

š NOMENCLATURE
š FIRST-TRIMESTER SPONTANEOUS ABORTION
š CLINICAL CLASSIFICATION OF SPONTANEOUS ABORTION
š MANAGEMENT OF SPONTANEOUS ABORTION
š MIDTRIMESTER ABORTION
š CERVICAL INSUFFICIENCY
š INMIDTRIMESTER ABORTION
 DEFINITION OF ABORTION

š defined as the spontaneous or induced

termination of pregnancy before fetal viability.
š miscarriage and abortion are terms used
interchangeably in a medical context.
š Other terms: early pregnancy loss, wastage, or
failure.
š pregnancy termination before 20 weeks’
gestation or with a fetus born weighing < 500 g
(National Center for Health Statistics, the
Centers for Disease Control and Prevention, and
the World Health Organization)
 Other terms:

1. Spontaneous abortion—includes threatened, inevitable,

incomplete, complete, and missed abortion.
2. Septic abortion is used to further classify any of these that are
complicated further by infection.
3. Recurrent abortion—repetitive spontaneous abortions
4. Induced abortion—surgical or medical termination of a live fetus
that has not reached viability.
 FIRST-TRIMESTER SPONTANEOUS ABORTION:
Pathogenesis

š More than 80 percent of spontaneous abortions occur within the first 12 weeks
of gestation.
š Closely linked to fetal chrosomal anomalies
š Death is usually accompanied by hemorrhage into the decidua basalis,
followed by adjacent tissue necrosis that stimulates uterine contractions and
expulsion.
š the key to determining the cause of early miscarriage is to ascertain the cause
of fetal death.
 specific assays for minute concentrations of maternal serum most frequently identified chromosomal anomaly. Although
β-hCG and reported that two thirds of these early losses were most trisomies result from isolated nondisjunction, balanced
clinically silent. structural chromosomal rearrangements are found in one
partner in 2 to 4 percent of couples with recurrent miscar-
Fetal Factors Currently, there are factors known to influence clinically
apparent spontaneous abortion, however, it is unknown riages. Trisomies have been identified in abortuses for all
except chromosome number 1, and those with 13, 16, 18, 21,
if these same factors affect clinically silent miscarriages.
By way of example, the rate of clinical miscarriages is
almost doubled when either parent is older than 40 years
60 (55%)

Chromosomal anomalies (%)

(Gracia, 2005; Kleinhaus, 2006). But, it is not known
Approximately half of miscarriages are
if clinically silent miscarriages are similarly affected by 50
parental age.
anembryonic, that is, with no identifiable 40 (35%)
embryonic elements (blighted ovum)
■ Fetal Factors 30
The other 50 percent are embryonic
As shown miscarriages,
in Table 18-1, approximately half of miscarriages 20
which commonly display a developmental
are anembryonic, that is, with no identifiable embryonic ele-
abnormality of the zygote,
ments. Lessembryo,
accurately, the termfetus, ormayatbe used
blighted ovum 10 (5%)
(Silver, 2011). The other 50 percent are embryonicc miscarriages,
times, the placenta. which commonly display a developmental abnormality of the 0
First Second Third
zygote, embryo, fetus, or at times, the placenta. Of embryonic
Of embryonic miscarriage, half of these—25
miscarriage, half of these—25 percent of all abortuses—have
trimester trimester trimester

percent of all abortuses—have

chromosomal anomalies chromosomal
and thus are aneuploid abortions. The
FIGURE 18-1 Frequency of chromosomal anomalies in abortuses
and stillbirths during each trimester. Approximate percentages
anomalies and thus areremaining
aneuploid abortions.
cases are euploid abortions, that is, carrying a normal for each group are shown. (Data from Eiben, 1990; Fantel, 1980;
chromosomal complement. Warburton, 1980.)
 Fetal Factors

Autosomal trisomy is the most frequently identified chromosomal anomaly.

(chromosomes 13, 16,18,21,22 are most common)
Monosomy X (45,X) is the single most frequent specific chromosomal
abnormality. (Turner syndrome)
Autosomal monosomy is rare and incompatible with life.
Triploidy is often associated with hydropic or molar placental degeneration
Tetraploid fetuses most often abort early in gestation, and they are rarely
liveborn.
Chromosomally normal fetuses abort later than those that are aneuploid (peaks
at approximately 13 weeks, incidence highest for maternal age > 35)
 Maternal Factors

1. Maternal age
2. Maternal infection: Chlamydia trachomatis see in 4% of abortuses
3. Medical disorders: Diabetes mellitus, thyroid disease, celiac disease,
anorexia/bulimia nervosa. IBD, SLE
4. Medications
5. Cancer: Cancer survivors who were previously treated with abdomi-
nopelvic radiotherapy, chemotherapy
6. nutrition: severe dietary deficiency and morbid obesity
 Maternal Factors

7. Surgical procedures: surgical procedures performed during early pregnancy do not

increase the risk for abortion, except if it involves early removal of the corpus luteum or the ovary
in which it resides.
š If performed before 10 weeks’ gestation, supplemental progesterone should be given.
š Between 8 and 10 weeks, a single 150-mg intramuscular injection of 17-hydroxyprogesterone
caproate is given at the time of surgery.
š If between 6 to 8 weeks, then two additional 150-mg 17-hydroxyprogesterone
caproate is given at the time of surgery.

Other progesterone regimens include: (1) oral micronized progesterone 200 or 300 mg orally once
daily, or (2) 8-percent progesterone vaginal gel (Crinone) given intravaginally as one
premeasured applicator daily plus micronized progesterone 100 or 200 mg orally once daily
continued until 10 weeks’ gestation.
 Maternal Factors

8. Social and behavioral factors: smoking, alcohol, excessive caffeine

consumption (approximately 5 cups of coffee per day—about 500 mg of
caffeine)
9. Occupational and environmental factors: environmental toxins such as
arsenic, lead, formaldehyde, benzene, and ethylene oxide; exposure to
antineoplastic drugs, sterilizing agents, and x-rays
10. Immunologic factors: APAS
11. Inherited thrombophilias
12. Uterine defects
 Clinical Classification of Spontaneous Abortion

1. Threatened Abortion: bloody vaginal discharge or bleeding appears through

a closed cervical os during the first 20 weeks; fetus is viable on ultrasound
2. Inevitable Abortion: gross rupture of the membranes along with cervical
dilatation
3. Incomplete Abortion: bleeding that follows partial or complete placental
separation and dilation of the cervical os
4. Complete abortion: history of heavy bleeding, cramping, and passage of
tissue or a fetus
 TABLE 18-6. Some Causes of Midtrimester Spontaneous
MIDTRIMESTER ABORTION Pregnancy Losses
Fetal anomalies
Chromosomal
Structural
Uterine defects
š end of the first trimester until the fetus Congenital
weighs ≥ 500 g or gestational age Leiomyomas
Incompetent cervix
reaches 20 weeks
Placental causes
š Risk factors for second-trimester abortion Abruption, previa
include race, ethnicity, prior poor Defective spiral artery transformation
Chorioamnionitis
obstetrical outcomes, and extremes of
Maternal disorders
maternal age Autoimmune
š Closely linked to recurrent miscarriages Infections
Metabolic

Data from Allanson, 2010; Dukhovny, 2009; Joo, 2009;

Romero, 2011; Saravelos, 2011; Stout, 2010.
Cervical Insufficiency

š Also known as incompetent cervix

š characterized classically by painless cervical dilatation in the second
trimester.
š It can be followed by prolapse and ballooning of membranes into
the vagina, and ultimately, expulsion of an immature fetus.
š Risk factors: previous cervical trauma such as dilatation and
curettage, conization, cauterization, or amputation
š transvaginal sonography documents cervical shortening < 25 mm
Cervical Insufficiency

š surgically with cerclage, which reinforces a weak cervix by a purse-

string suture.
š Contraindications to cerclage usually include bleeding, uterine
contractions, or ruptured membranes.
š prophylactic cerclage before dilatation is preferable, but a rescue/
“emergency” cerclage can be performed after the cervix is found
to be dilated, effaced.
š timing of surgery: elective cerclage is usually done between 12 and
14 weeks’ gestation.
 362 Early Pregnancy Complications

Cervical Insufficiency

SECTION 6
šCerclage Procedures
1. McDonald (1963)
FIGURE 18-5 McDonald cerclage A
procedure for incompetent cervix.
A. Start of the cerclage procedure B
with a No. 2 monofilament suture
being placed in the body of the
cervix very near the level of the
internal os. B. Continuation of suture
placement in the body of the cervix
so as to encircle the os. C. Encircle-
ment completed. D. The suture is
tightened around the cervical canal
sufficiently to reduce the diameter of
the canal to 5 to 10 mm, and then
the suture is tied. The effect of the
suture placement on the cervical
canal is apparent. A second suture
placed somewhat higher may be of
C
value if the first is not in close prox-
imity to the internal os. D
 C
value if the first is not in close prox-
imity to the internal os. D

Cervical Insufficiency

š Cerclage Procedures
2. Shirodkar (1955)
A
FIGURE 18-6 Modified Shirodkar cerclage for
incompetent cervix. A. A transverse incision
is made in the mucosa overlying the anterior B
cervix, and the bladder is pushed cephalad.
B. A 5-mm Mersilene tape on a swaged-on
or Mayo needle is passed anteriorly to poste-
riorly. C. The tape is then directed posteriorly
to anteriorly on the other side of the cervix.
Allis clamps are placed so as to bunch the
cervical tissue. This diminishes the distance
that the needle must travel submucosally and
aids tape placement. D. The tape is snugly
tied anteriorly, after ensuring that all slack
has been taken up. The cervical mucosa is
then closed with continuous stitches of chro- C
mic suture to bury the anterior knot. D
Cervical Insufficiency

š Cerclage Procedures
3. Transabdominal cerclage: suture placed at the uterine isthmus AND
can be used if there are severe cervical anatomical defects or if there
have been prior transvaginal cerclage failure
CERCLAGE COMPLICATIONS:
š membrane rupture, preterm labor, hemorrhage, infection, or combinations
thereof.
š Membrane rupture during suture placement or within the first 48 hours
following surgery is an indication for cerclage removal because of the
likelihood of serious fetal or maternal infection
ortion train- In the absence of serious maternal medical disorders, abortion
assailed. The procedures do not require hospitalization. With outpatient

Management: How to evacuate the

gists (2009a)
on Council
1996 that
abortion, capabilities for cardiopulmonary resuscitation and for
immediate transfer to a hospital must be available.
First-trimester abortions can be performed either medically or

products of conception?
must include
Kenneth J.
ed in 1999
surgically by several methods that are listed in Table 18-7. Results

o work with
on and fam-
been started TABLE 18-7. Some Techniques Used for First-Trimester TABLE 18-8. Comparisons of Some Advantages and
2013). These Abortiona
Drawbacks to Medical versus Surgical
dence-based, Abortion
Surgical
ion methods
Dilatation and curettage Factor Medical Surgical
Vacuum aspiration
dents techni- Invasive Usually no Yes
Menstrual aspiration
omplete and Pain More Less
ion for fetal Medical Vaginal bleeding Prolonged, Light,
g medical or Prostaglandins E2, F2α, E1, and analogues
unpredictable predictable
0) rightfully Vaginal insertion
Incomplete abortion More common Uncommon
ning should Parenteral injection
Failure rate 2–5% 1%
Oral ingestion
Severe bleeding 0.1% 0.1%
ncy training Sublingual
Infection rate Low Low
l fellowships Antiprogesterones—RU-486 (mifepristone) and epostane
Methotrexate—intramuscular and oral Anesthesia Usually none Yes
ograms that, Time involved Multiple visits, Usually one
bstetrics and Various combinations of the above
follow-up visit, no
ry. Training a exam follow-up
All procedures are aided by pretreatment using
ith all meth-
hygroscopic cervical dilators. exam
have a high success rate—95 percent with medical and 99 per- first-trimester abortion. Half were given two 200-µg tablets
cent with surgical techniques. Further comparison of medical orally 3 hours preprocedure, and the other group was given pla-

Management: How to evacuate the

and surgical methods is shown in Table 18-8. Medical therapy cebo. Marginal benefits ascribed to misoprostol included easier
has more drawbacks in that it is more time consuming; it has an cervical dilatation and a lower composite complication rate.
unpredictable outcome—extending for days up to a few weeks; Another effective cervical-ripening agent is the progesterone
and bleeding is usually heavier and unpredictable (Niinimäki, antagonist mifepristonee (Mifeprex). With this, 200 to 600  µg

products of conception?
2009; Robson, 2009). Likely for these reasons, only 10 percent is given orally. Other options include formulations of prosta-
of abortions in the United States are managed using medical glandins E2 and F2a, which have unpleasant side effects and are
methods (Templeton, 2011). usually reserved as second-line drugs (Kapp, 2010).

■ Cervical Preparation ■ Surgical Abortion

There are several methods that will soften and slowly dilate Surgical pregnancy termination includes a transvaginal approach
Cervical preparation to dilate the cervix
the cervix to minimize trauma from mechanical dilatation
(Newmann, 2014). A Cochrane review confirmed that hygro-
through an appropriately dilated cervix or, rarely, laparotomy
with either hysterotomy or hysterectomy. With transvaginal
366 Early Pregnancy Complications
LAMINARIA
Va
tag
vac
(G

SECTION 6
ges
firs
inc
inf
rep
un
cen
inc
A B C
du
FIGURE 18-7 Insertion of laminaria before dilatation and curettage. A. Laminaria immediately after being appropriately placed with 36
its upper end just through the internal os. B. Several hours later the laminaria is now swollen, and the cervix is dilated and softened.
C. Laminaria inserted too far through the internal os; the laminaria may rupture the membranes.
A 22

Te
Management: How to
Abortion

evacuate
the products of conception? FIGURE 18-9 Dilatation of cervix with a Hegar dilator. Note that
the fourth and fifth fingers rest against the perineum and but-
tocks, lateral to the vagina. This maneuver is an important safety FIGURE 18-10 A suction curette has been placed through the
measure because if the cervix relaxes abruptly, these fingers pre- cervix into the uterus. The figure shows the rotary motion used to
vent a sudden and uncontrolled thrust of the dilator, a common aspirate the contents. (From Word, 2012, with permission.)
cause of uterine perforation.
and evacuation of fetal parts. With complete removal of the
fetus, a large-bore vacuum curette is used to remove the pla-
Complications. The incidence of uterine perforation with centa and remaining tissue. This is better accomplished using
Dilatation and Curettage (D&C) elective abortion is variable, and determinants include clinician
skill and uterine position. Perforation is more common with a
intraoperative sonographic imaging.

retroverted uterus and is usually recognized when the instru- Dilatation and Extraction (D&X)
š dilating the cervix and then evacuating
ment passes without resistance deep into the pelvis. Observation
FIGURE 18-9
is usually sufficient if the uterine perforation Dilatation
is small,
This is similar to dilatation and evacuation except that a suc-
of cervix with a Hegar dilator. Note that
as when tion cannula is used to evacuate the intracranial contents after
the fourth and fifth fingers rest against the perineum and but-
produced by a uterine sound or narrow dilator. Although per-
the pregnancy by mechanically tocks, lateral to the vagina. This maneuver is an important safety FIGURE 18-10 A suction curette has been placed through the
forations through old cesarean incisionmeasure
or myomectomy
because if the scars
cervix relaxes abruptly, these fingers pre- cervix into the uterus. The figure shows the rotary motion used to
are potentially possible, Chen and colleagues (2008) reported no
vent a sudden and uncontrolled thrust of the dilator, a common aspirate the contents. (From Word, 2012, with permission.)

scraping out the contents—sharp

perforations through such scars in 78 women
cal or surgical abortion.
cause ofundergoing medi-
uterine perforation.
and evacuation of fetal parts. With complete removal of the

curettage, by suctioning out the

If some instruments—especially suction and sharp
fetus, a large-bore vacuum curette is used to remove the pla-
curettes—pass through a uterine defect and into the peritoneal
Complications. The incidence of uterine perforation with centa and remaining tissue. This is better accomplished using
cavity, considerable intraabdominal damage can ensue (Keegan,
contents—suction curettage, or both.
elective abortion is variable, and determinants include clinician intraoperative sonographic imaging.
1982). In these women, laparotomy or laparoscopy to exam-
skill and uterine position. Perforation is more common with a
ine the abdominal contents is often the safest course of action. Dilatation and Extraction (D&X)
retroverted uterus and is usually recognized when the instru-
Bowel injury can cause severe peritonitis and sepsis (Kambiss,
ment passes without resistance deep into the pelvis. Observation This is similar to dilatation and evacuation except that a suc-
2000). A rare complication of curettage with more advanced
is usually sufficient if the uterine perforation is small, as when tion cannula is used to evacuate the intracranial contents after
pregnancies is sudden, severe consumptive coagulopathy.
produced by a uterine sound or narrow dilator. Although per-
If prophylactic antimicrobials are given, pelvic sepsis is
forations through old cesarean incision or myomectomy scars
decreased by 40 to 90 percent and depends on whether the pro-
are potentially possible, Chen and colleagues (2008) reported no
cedure is surgical or medical. Most infections that do develop
perforations through such scars in 78 women undergoing medi-
respond readily to appropriate antimicrobial treatment (Chap.
cal or surgical abortion.
37, p. 685). Rarely, infections such as bacterial endocarditis will
If some instruments—especially suction and sharp
develop, but they can be fatal (Jeppson, 2008). Uncommon
curettes—pass through a uterine defect and into the peritoneal
long-term complications of curettage include cervical insuffi-
cavity, considerable intraabdominal damage can ensue (Keegan,
ciency or uterine synechiae.
1982). In these women, laparotomy or laparoscopy to exam-
1 week if fetal cardiac activity is present or in 4 weeks if there
is no heart motion. If abortion has not occurred by the second TABLE 18-10. Some Techniques Used for
visit, it is usually completed by suction curettage. Midtrimester Abortiona

Midtrimester
Complications abortion Surgical
Dilatation and curettage (D&C)
In a 2-year review of more than 233,000 medical abortions
Dilatation and evacuation (D&E)
performed at Planned Parenthood affiliates, there were 1530
Dilatation and extraction (D&X)
(0.65 percent) significant adverse events. Most of these were
Laparotomy
ongoing pregnancy (Cleland, 2013). Bleeding and cramp-
Hysterotomy
ing with medical termination can be significantly worse than
Hysterectomy
menstrual cramps. Thus adequate analgesia, usually including
a narcotic, is provided. The American College of Obstetricians Medical
How to evacuate products
and Gynecologists (2011c) recommends that if there is enough Intravenous oxytocin
Intraamnionic hyperosmotic fluid
of conception?
blood to soak two or more pads per hour for at least 2 hours,
the woman is instructed to contact her provider to determine 20-percent saline
whether she needs to be seen. 30-percent urea
Unnecessary surgical intervention in women undergoing Prostaglandins E2, F2α, E1
medical abortion can be avoided if properly indicated follow-up Intraamnionic injection
sonographic results are interpreted appropriately. Specifically, Extraovular injection
if no gestational sac is seen and there is no heavy bleeding, Vaginal insertion
then intervention is unnecessary. This is true even when, as is Parenteral injection
common, the uterus contains sonographically evident debris. Oral ingestion
Another study reported that a multilayered sonographic pat- a
All procedures are aided by pretreatment using
tern indicated a successful abortion (Tzeng, 2013). Clark
hygroscopic cervical dilators.
and coworkers (2010) provided data that routine postabortal
Abortion

CONTRACEPTION FOLLOWING MISCARRIAGE OR ABORTION

š unless another pregnancy is desired right away, effective
contraception can be initiated very soon after abortion.
š an intrauterine device can be inserted after the procedure is
completed
š any of the various forms of hormonal contraception can be
initiated at this time
š For women who desire another pregnancy, sooner may be
preferable to later.
Thank you!
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