Spontaneous abortion, also known as miscarriage, refers to the clinically recognized loss of a pregnancy before 20 weeks of gestation. The most common risk factors are advanced maternal age, previous spontaneous abortion, and maternal smoking. Symptoms typically include vaginal bleeding and pelvic pain. Diagnosis involves pelvic examination, ultrasound criteria for gestational sac size and fetal cardiac activity. Management depends on the classification as threatened, inevitable, incomplete, or complete abortion and may involve expectant monitoring, medical treatment with misoprostol, or surgical evacuation. Prevention focuses on preconception counseling and treatment of underlying maternal medical conditions.
2. Definition
• Clinically recognised pregnancy loss before
20th week of gestation
• Expulsion or extraction of an embryo or fetus
weighing 500gm or less(WHO)
• Synonymous with miscarriage
• Latin :aboriri: to miscarry
3. Incidence
• MC early pregnancy complication
• Frequency decreases with increasing
gestational age
• Incidence:8-20%(clinically recognised
pregnancies)
• Women who had a child: 5% incidence of
miscarriage
• 80% spontaneous abortion :< 12 wks
4. Risk factors
• Advanced maternal age
• Previous spontaneous abortion
• Medications & substances (smoking)
• Mechanisms responsible for abortion: not
apparent
• Death of fetus precedes spont. expulsion,
finding cause involves ascertaining the cause
of fetal death
5. Maternal age
• Most important risk factor in healthy women
• 30yrs:9-17%
• 35yrs:20%
• 40yrs:40%
• 45yrs: 80%
7. Medications or substances
• Heavy smoking(>10 cigarettes/day) :
vasoconstrictive & antimetabolic effects of
tobacco smoke
• Moderate to high alcohol consumption(>3
drinks/week)
• NSAIDS use(acetaminophen) :abnormal
implantation & pregnancy failure due to
antiprostaglandin effect
8. Other factors
• Low plasma folate levels(≤2.19ng/ml): no
specific evidence to support
• Extremes of maternal weight: prepregnancy
BMI<18.5 OR >25kg/m2
• Maternal fever:100°F(37.8°C), no evidence to
support
12. Clinical presentation
• Vaginal bleeding
– Scant brown spotting to heavy vaginal bleeding
– Amount /pattern does not predict outcome
– May be accompanied by passage of fetal tissue
• Pelvic pain
– Crampy /dull in character
– Constant/intermittent
• Incidental finding on pelvic ultrasound in
asymptomatic patient
13. Diagnostic evaluation
• History
– Period of amenorrhea ,LMP/USG
• Physical examination: Complete pelvic
examination:
– P/S,:source, amount of bleeding, dilated cervix,
POC visible at Os/in vagina
– P/V: uterine size(consistent with GA)
• Pelvic ultrasound
14. Pelvic ultrasound
• Most useful test in diagnostic evaluation of
women with suspected spontaneous abortion
• Foetal cardiac activity: most important (5.5-
6wks)
• Foetal heart rate
• Size & contour of G.sac
• Presence of yolk sac
• Best evaluated ,transvaginal approach(TVS)
15. Pelvic USG: criteria for spontaneous
abortion
• Gestational sac ≥ 25mm in mean diameter
that does not contain a yolk sac or embryo
• An embryo with CRL ≥7 mm with no cardiac
activity
If the GS or embryo is smaller than these dimensions:
repeat pelvic USG in 1-2 weeks
17. Lab evaluation
• Human chorionic gonadotropin: serial,
quantitative, useful in inconclusive USG
findings
• ABO ,Rh: need for 50/300µg anti D
• Haemoglobin/hematocrit
• Serum progesterone<5ng/ml(nonviable
pregnancy)
18. Post diagnostic classification
• Based upon the location of POC
• Degree of cervical dilatation(pelvic exam)
• Pelvic ultrasound
• Categorization impacts clinical management
– Threatened
– Inevitable
– Incomplete/complete
– Missed
19. Threatened abortion
• Vaginal bleeding has occurred
• The cervical os is closed
• Diagnostic criteria for spontaneous abortion
has not met
• Managed expectantly: until symptoms resolve
or progresses
20. Threatened abortion: m/m
• Expectant
• Progestin treatment: most promising, efficacy
not established
• Bed rest: randomised trials have refuted the
role
• Avoid vigorous activity
• Avoid heavy lifting
• Avoid sexual intercourse
21. Threatened abortion :m/m
• Counsel about risk of miscarriage
• Return to hospital in case of additional vaginal
bleeding, pelvic cramping or passage of tissue from
vagina
• Repeat pelvic USG until a viable pregnancy is
confirmed or excluded
• Viable pregnancy, resolved symptoms: prenatal care
• If symptoms continue: monitor for progression to
inevitable, incomplete, or complete abortion
22. Inevitable abortion
• Vaginal bleeding, typically accompanied by
crampy pelvic pain
• Dilated cervix( internal os)
• Products of conception felt or visualised
through the internal os
23. Incomplete abortion
• Vaginal bleeding and/or pain present
• Cervix is dilated
• Products of conception partially expelled out
• Uterine size less than period of amenorrhea
24. Missed abortion
• Non viable intrauterine pregnancy
• Cervical os is closed
• POC not expelled
• May notice that symptoms associated with
early pregnancy have abated
25.
26. Management
• Complete evacuation of uterine contents(POC)
• Surgical methods: suction evacuation/suction
curettage/dilation & evacuation
• Medical methods: Misoprostol,mifepristone
• Expectant
• All have similar efficacy
28. Medical methods
• Misoprostol: drug of choice
• Efficacy depends on dose & route of
administration
• 400mcg vaginally every 4 hours for 4 doses
• Expulsion rate : 50-70%
• Low cost, low incidence of side effects, stable
at room temperature, readily available, timing
of use can be controlled by patient
29. Misoprostol
• WHO consensus report on misoprostol
regimen
– Missed abortion: 800mcg vaginally,or 600 mcg
sublingually
– Incomplete abortion: 600mcg orally
• Expulsion rate: 70-90%
30. Choosing the method
• Surgical evacuation : heavy bleeding,
intrauterine sepsis, medical co morbidities,
misoprostol is contraindicated
– Shorter time to completion of treatment
– Lowers risk of unplanned admissions
– Lower need for subsequent treatment
31. Expectant m/m
• Stable vital signs
• No evidence of infection
• Offered after proper counseling
• If unsuccessful after 4 wks ,surgical evacuation
is needed
32. Complete abortion
• POC expelled completely from uterus &
cervix
• Cervical os is closed
• Uterus small in size (GA)
• Resolved or minimal vaginal bleeding & pain
• Aim of t/t: ensure that bleeding is not
excessive & all POC have expelled
• Theoretically does not need treatment
35. Summary
• Clinically recognised pregnany losses <20 wks
gestation
• Most common complication of early
pregnancy
• Advanced maternal age, previous
spontaneous abortion, maternal smoking: risk
factors
• Mostly due to fetal structural/chromosomal
abnormalities
36. Summary
• Present with menstrual delay, vaginal
bleeding& pelvic pain
• D/D: uterine or other genital tract bleeding in
viable pregnancy, ectopic,& GTD
• Pelvic examination & pelvic ultrasound: key
elements for diagnosis
• Spontaneous abortion diagnosed based on
USG criteria
• Categorised as threatened/incomplete/missed
37. Summary
• Preconceptual & prenatal counseling & care
regarding modifiable aetiologies ,risk factors
are most imp intervention
• Normal menstrual cycle resumes in 4-6 weeks
• hCG returns to normal 2-4wks
38. Prevention of spont.abortion
• Preconception & prenatal counseling
• Routine screening & optimal disease
control(diabetes, thyroid, thrombophilia)
• Correction of uterine structural
anomalies(septum, submucosal myoma,
intrauterine adhesions) prior to pregnancy
• Avoiding exposure to teratogen or infections
• Modifiable risk factors
