Spontaneous abortion, also known as miscarriage, is the unplanned expulsion or extraction of an embryo or fetus before 20 weeks of gestation. Risk factors include advanced maternal age, previous spontaneous abortions, smoking, and certain medications. Most spontaneous abortions are due to fetal chromosomal or structural abnormalities. Clinically, women present with vaginal bleeding and pelvic pain. Diagnosis involves pelvic examination, ultrasound criteria for gestational sac size and fetal heart activity. Treatment options include expectant management, medical methods using misoprostol, or surgical evacuation. Prevention focuses on preconception counseling and screening, and treating underlying maternal conditions.

1. Spontaneous abortion

2. Definition
• Clinically recognised pregnancy loss before
20th week of gestation
• Expulsion or extraction of an embryo or fetus
weighing 1000gm or less
• 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

5. Maternal age
• Most important risk factor in healthy women
• 30yrs: 9-17%
• 35yrs: 20%
• 40yrs: 40%
• 45yrs: 80%

6. Previous spontaneous abortion
• Previous successful pregnancy: 5% risk
• 1 miscarriage: 20%
• 2 consecutive miscarriages:28%
• ≥3 consecutive miscarriages:43%

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)
• Extremes of maternal weight: prepregnancy
BMI<18.5 OR >25kg/m2
• Maternal fever:100°F(37.8°C)

9. Etiology
• Fetal
• Maternal
• unexplained

10. Etiology
• Foetal factors
– Chromosomal abnormalities(50% ),
• aneuplodies ,monosomy X,Triploidy
• Trisomy 16 : mc autosomal trisomy,lethal
• Abnormalities arise de novo
– Congenital anomalies
– Trauma: invasive prenatal diagnostic procedures

11. Aetiology :Maternal factors
– Maternal endocrinopathies: hypothyroidism,
insulin dependant diabetes
– Congenital or acquired uterine abnormalities:
interfere with implantation & growth
– Maternal diseases: acute maternal infection
(listeria, toxo, parvo B19,rubella,CMV)
– Radiation in therapeutic doses
– Hypercoagulable state(thrombophillias)

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:
– Amount of bleeding, dilated cervix
– P/V: uterine size
• 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
Crown rump length (CRL) is an ultrasound
measurement that is used during a pregnancy. The

18. Differential diagnosis
• Physiologic: placental sign
• Ectopic pregnancy
• Gestational trophoblastic disease
• Cervical/vaginal/uterine pathology
• Physical examination
• Transvaginal sonography(TVS)
• Serial quantitative ßhCG

19. 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)

20. Post diagnostic classification
• Based upon the location of POC (Products of
conception)
• Degree of cervical dilatation(pelvic exam)
• Pelvic ultrasound
• Categorization impacts clinical management
– Threatened
– Inevitable
– Incomplete/complete
– Missed

21. 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

22. Threatened abortion: m/m
• Expectant
• Progestin treatment: most promising, efficacy
not established
• Bed rest
• Avoid vigorous activity
• Avoid heavy lifting
• Avoid sexual intercourse

23. 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

24. Inevitable abortion
• Vaginal bleeding, typically accompanied by
crampy pelvic pain
• Dilated cervix( internal os)
• Products of conception felt or visualised
through the internal os

25. Incomplete abortion
• Vaginal bleeding and/or pain present
• Cervix is dilated
• Products of conception partially expelled out
• Uterine size less than period of amenorrhea

26. Complete abortion
• There is minimal bleeding.
• Pain stops.
• Uterus is hard and much smaller
• The cervix is closed

27. Missed abortion
• Non viable intrauterine pregnancy
• Cervical os is closed
• POC not expelled
• May notice that symptoms associated with
early pregnancy have abated

28. Septic abortion
• Tender and painful uterus.
• Offensive vaginal bleeding.
• High temperature.Rapid pulse. .Unstable blood pressure.
• Shock.
Treatment
• Isolation.
• Clinical bacteriological to identify the infectious organisms.
• Administration of antibiotics as doctor orders.
• Intake and output chart should be kept.
• The soiled pads should be properly collected and burned

30. Management
• Complete evacuation of uterine contents(POC)
• Surgical methods: suction evacuation/suction
curettage/dilation & evacuation
• Medical methods: Misoprostol,mifepristone
• Expectant
• All have similar efficacy

31. Surgical evacuation
• Performed under IV sedation & paracervical
block
• Prophylactic antibiotics
• Operating room/procedure room
• Potential complications
• Anaesthesia related,
• uterine perforation, cervical trauma,
• infection, intrauterine adhesions

32. 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

33. 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

34. Expectant m/m
• Stable vital signs
• No evidence of infection
• Offered after proper counseling
• If unsuccessful after 4 wks ,surgical evacuation
is needed

35. 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

36. Abortion : complications
• Hemorrhage
• Uterine perforation
• Retained products of conception
• Endometritis
• Septic abortion: abortion accompanying
intrauterine infection

38. 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

39. 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

40. 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

41. 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