Spontaneous abortion Dr.Renu Singh

Definition Clinically recognised pregnancy loss before 20 th week of gestation Expulsion or extraction of an embryo or fetus weighing 500gm or less(WHO) Synonymous with miscarriage Latin :aboriri: to miscarry

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

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

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

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

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

Other factors Low plasma folate levels(≤2.19ng/ml): no specific evidence to support Extremes of maternal weight: prepregnancy BMI 25kg/m 2 Maternal fever:100°F(37.8°C), no evidence to support

Etiology Fetal Maternal unexplained

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

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) : inconclusive – Radiation in therapeutic doses – Hypercoagulable state(thrombophillias) : RPL

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

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

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)

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

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

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)

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

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

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

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

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

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

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

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

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

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

Misoprostol WHO consensus report on misoprostol regimen – Missed abortion: 800mcg vaginally,or 600 mcg sublingually – Incomplete abortion: 600mcg orally Expulsion rate: 70-90%

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

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

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

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

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

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

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

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