First trimester of pregnancy

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Transcript First trimester of pregnancy



TRIMESTER PREGNANCY FAILURE Shortened to emphasize medical student curriculum requirements

Carlos M. Fernandez, M.D

Department of Obstetrics and Gynecology Advocate Illinois Masonic and Medical Center


Diagnosis of IUP

“Double decidual sign” at 4½ to 5 wks

Gestational sac + yolk sac at 5 wks (a definitive sign of IUP)

GS + yolk sac + embryo at 5½ to 6 wks

CRL >5 mm – fetal cardiac activity present Seeber BE and Barnhart KT. Obstet Gynecol 2006;107:339-413

First sign of IUP: double decidual sign

    Earliest finding is the “double decidual sign” (arrows) seen around 4½-5 wks gestation initially eccentric in location It excludes pseudogestational sac (free fluid or blood within endometrium)

  

Gestational Sac (confirmed by double decidual sign)

Grows 1 mm per day Usually seen by 4 ½ to 5 weeks of gestation Discriminatory ß-hCG with TVS: usually quoted 1000 2000 ß-hCG IU/L. Depends upon:  Skill of the sonographer and image magnification  Frequency (5-10mHz) and resolution of the transducer  Uterine abnormalities, fibroids  Multiple gestation

Gestational Sa


Discriminatory ß-hCG with

TVS 1000 - 2000 ß-hCG IU/L :

Discriminatory ß-hCG with

TAS : ≥ 6500 ß-hCG IU/L Bhatt & Dogra, Radiol Clin N Am 45 (2007) 549-560

The gestational sac diameter is used to calculate gestational age

Long axis Short axis

Second sign of IUP: Yolk Sac

      First structure visualized within the gestational sac Round , bright ring <6mm A definitive sign of IUP Involutes after 11 weeks Can be seen half a week before normal embryo is seen When enlarged (“hydropic”), solid or duplicated, it is a very poor prognosis sign

Third sign of IUP: GS + yolk sac + embryo

    GS + yolk sac + fetal pole at 5½ to 6 wks The fetal pole (arrow) is better seen on the zoomed in image GS grows 1mm/day Embryo grows 1mm/day

Fourth sign of IUP: GS + YS + embryo + cardiac activity

    Double decidual sign +yolk sac+ fetal pole +cardiac activity Cardiac activity confirms a live intrauterine pregnancy Cardiac activity is usually detected at 5 ½ to 6 weeks from last menstrual period CRL ≥5 mm – fetal cardiac activity present


Serum concentrations of ß-hCG in 443 normal pregnancies ß-hCG is first detected in maternal serum 6 to 9 days after conception . The levels rise in a logarithmic fashion, peaking 8 to 10 weeks after the last menstrual period, followed by a decline to a nadir at 18 weeks , with subsequent levels remaining constant until delivery Second International Standard ß-hCG Braunstein G D, et al. Am J Obstet Gynecol 1976 ; 126:678-81.

Serial ß-hCG

  

The doubling time for a normal IUP is 2 days


with a range of 1.4 to 2.1 days Doubling of ß-hCG is

less reliable after 10,000 mIU/ml ,

at this level pregnancy is better evaluated with U/S

15% of normal IUP

can demonstrate an

abnormal rise of ß-hCG Kadar N, et al. Obstet Gynecol 1981;52:162-6

ß-hCG up to 10000 mIU/ml

 The

minimal rise

in ß-hCG for a

viable pregnancy



in 48 hours  The

minimal decline

of a

spontaneous abortion



in 48 hours 

A rise or fall in serial ß-hCG values that is slower than this is suggestive of an ectopic pregnancy Seeber BE and Barnhart KT. Obstet Gynecol 2006;107:339-413

Hypothetical illustration of the rise, or fall, of serial hCG values in women with an EP 53% 21-35% Seeber BE and Barnhart KT. Obstet Gynecol 2006;107:339-413


Spontaneous abortion or miscarriage

 Spontaneous abortion is a fetal loss before week 20 of pregnancy 

Early loss is before menstrual week 12

Late loss refers to losses from weeks 12 to 20

80% of miscarriages occurring in the first trimester

Ferri: Ferri's Clinical Advisor 2012, 1st ed



   Miscarriage is the most common serious pregnancy complication affecting recognized pregnancies approximately 30% of biochemical pregnancies and 11–20% of clinically The diagnosis of miscarriage is made most commonly by trans-vaginal ultrasound (TVS) assessment After a diagnosis of miscarriage, last for up to 12 months half the women undergo significant psychological effects, which may Cecilia Bottomley, Tom Bourne. Diagnosing miscarriage. Best Practice & Research Clinical Obstetrics & Gynecology 2009; 23:463-77


 The crucial role of chromosomal imbalance in abnormal early human development is well established  Approximately 50–60% of first-trimester spontaneous abortions have karyotype abnormalities Igor N Lebedev, Nadezhda V Ostroverkhova, Tatyana V Nikitina, Natalia N Sukhanova and Sergey A Nazarenko. Features of chromosomal abnormalities in spontaneous abortion cell culture failures detected by interphase FISH analysis. European Journal of Human Genetics 2004; 12:513–20


 The most frequent type of chromosomal abnormalities detected are: 1.

Autosomal trisomies ─ 52 % 2.



Monosomy X ─ 19 % Polyploidies ─ 22 % Other ─ 7 % Hsu, LYF. Prenatal diagnosis of chromosomal abnormalities through amniocentesis. In: Genetic Disorders and the Fetus, 4th ed, Milunsky, A (Ed), The Johns Hopkins University Press, Baltimore 1998. p.179


Clinical classification of spontaneous abortion

Laifer-Narin SL. Ultrasound for Obstetrics Emergencies. Ultrasound Clin . 2011; 6: 177-193

Type Definition

Threatened abortion Vaginal bleeding during the first 20 weeks of pregnancy and no evidence of cervical dilation <50% of threatened abortions will progress to loss of pregnancy

Missed abortion

Intrauterine demise of the conceptus without either vaginal bleeding or expulsion of the products of conception Incomplete abortion Vaginal bleeding with dilation of the cervix and partial expulsion of the conceptus

Complete abortion

Inevitable abortion Vaginal bleeding with expulsion of all of the products of conception Abortion in progress in which the bleeding is profuse with cervical dilation but a maintained intrauterine pregnancy

Differential Diagnosis of Threatened Abortion







Undetermined or physiologic (implantation related) Ectopic pregnancy Sub-chorionic bleed, found in ~20% of threatened Ab Gestational trophoblastic disease Impending spontaneous miscarriage Cervix, vaginal or uterine pathology

This section is too in-depth for most medical students; use it only for the most interested students!


How to define miscarriage using ultrasound-comparing and contrasting national guidelines

Royal College of Obstetricians and Gynaecologists. The Management of Early Pregnancy Loss. Green Top Guideline No. 25. October 2006

 Miscarriage:  Miscarriage is defined at first scan when gestational sac with MSD greater than 20 mm an no embryonic contents or CRL > 6 mm with no heart beat  Or subsequently if sac remain empty after at least one week or still no cardiac activity 1 week after initial

How to define miscarriage using ultrasound-comparing and contrasting national guidelines

The Institute of Obstetricians and Gynaecologists Royal College of Physicians of Ireland Transvaginal Ultrasound Embryo > 7 mm No cardiac activity Miscarriage Gestational sac > 20 mm No embryo or yolk sac Miscarriage

What is the evidence to support the cut-offs used to diagnose miscarriage?

Conclusions First systematic review of ultrasound diagnosis of miscarriage

Studies are 15–20 years old, small numbers of miscarriage, reference standards were poor (method of miscarriage confirmation)

Various cut-off values used (4–6mm for CRL, 13–25mm for MSD), making pooling of data impossible

Best (most specific) criteria appeared to be MSD > 25mm with a missing embryo or MSD > 20mm with a missing yolk sac

These criteria had a 95% CI of 0.96–1.00, therefore diagnoses of early fetal demise may be wrong. up to 4 out of 100 A single incorrect diagnosis of miscarriage is one too many Jeve Y et al ., UOG 2011 Nov

Abdallah Y , et al . Limitations of current definitions of miscarriage using mean gestational sac diameter and crown–rump length measurements: a multicenter observational study . Ultrasound Obstet Gynecol 2011; 38: 497–502

    Prospective multicenter study 1060 patients of IPUV


Current definitions used to diagnose miscarriage by ultrasound are potentially unsafe In order to minimize the risk of a false-positive diagnosis of miscarriage the following cut-off could be introduced 

Empty gestational sac or sac with a yolk sac but no embryo seen with MSD >25 mm

Embryo with an absent heartbeat and CRL > 7 mm

Summary Summary

 Data from these studies show that current definitions used to diagnose miscarriage are potentially unsafe  Significant interobserver variability may be associated with a misdiagnosis of miscarriage  Current national guidelines should be reviewed to avoid inadvertent termination of wanted pregnancy  Large prospective studies with agreed reference standards are urgently required


Risk Factors for Ectopic Pregnancy

 Prior ectopic  Previous tubal surgery  History of tubal ligation  Intra-uterine contraceptive device  History of infertility  History of PID  History of chlamydia or gonorrhea  Smoking



Retained Products of Conception (RPOC)

Oscar Sadan, Abraham Golan, Ofer Girtler, Samuel Lurie, Abraham Debby, Ron Sagiv, Shmuel Evron, Marek Glezerman. Role of Sonography in the Diagnosis of Retained Products of Conception. JUM 2004 23:371-4     RPOC are well-known and troublesome complications after spontaneous or induced abortion and parturition Patients usually have abdominal pain, bleeding, fever, and an open cervical external os The diagnosis is based on the sonographic appearance of intrauterine echogenic material Retained products of conception are generally treated by D&C to empty the uterine cavity. This exposes the uterus to additional potential trauma, with immediate risks such as bleeding, perforation, and infection and late sequelae such as intrauterine adhesions

Retained products of conception. Intrauterine heterogeneous, mixed echogenic mass with marked internal vascularity in a patient who recently underwent spontaneous abortion

Transvaginal sagittal sonogram of a uterus immediately after repeated D&C. A thin hyperechoic echo is shown, characteristic of an empty uterus.