First trimester complications Flashcards
when should the gestation sac be present
1800 mIU/ml TA
1000 mIU/mL TV
gestational sac diameter
l+ W+ H /3 = #
CRL
Most accurate (+/- .5 wks) (3 days)
used b/t 6- 12 wks
longest length excluding legswhat does crown-rump length plus 6 equal
gestational weeks
normal Gestational Sac
A normal GS grows 1.1mm/day from 5 to 8 weeks
what is the GS meaurement
Reliable indicator of gestational age prior to identification of CRL
when is the GS used to determine GA
Used to determine GA up to 6 weeks then MSD is primarily used to correlate GS size to CRL
Crown rump length
Embryo grows at a rate of 1 mm/day in the 1st trimester
Curled position
GA from 5.5 weeks +
Measurement from the top of head to the lower edge of torso
reflects embryonic growth
Highly accurate - Error of +/- 3 to 5 days
CRL used until 12 to 13 weeks
when should embryo be seen
TA = 25mm MSD EV = 16mm MSD
what percent of clinically recognized pregnancies are spontaneously miscarried
15%`
; loss rate may be even higher for early, clinically unrecognized pregnancies.
most common presentation for complications
Most common presentation for complications is vaginal spotting or frank bleeding, occurring in nearly 25% of patients during early stage of pregnancy.
implantation bleed
Appears post implantation (21days LMP)
Visible at 6-10 weeks
Sonographically may appear as a sonolucent space outside the gestational sac
Patient may be asymptomatic or present with painless spotting
subchorionic hemorrhage
Most common occurrence of bleeding in first trimester is from subchorionic hemorrhage.
Low-pressure bleeds result from process of implantation of fertilized ovum into endometrial cavity and myometrial wall.
Hemorrhage found between myometrium and margins of gestational sac; may or may not be associated with placenta
clinical findings of subchorionic hemorrhage
bleeding, spotting or uterine cramping; if hemorrhage becomes large enough, can lead to spontaneous abortion
findings can distinguish subchorionic hemorrhage from what
abruption placentae
subchorionic hemorrhage appearance
Crescent-shaped sonolucent fluid collection between the gestational sac and the uterine wall
if subchorionic hemorrhage is symptomatic (bleeding) increased chance of
miscarriage,
preeclampsia,
placental abnormalities,
preterm delivery
Size date discrepancy
Unsure LMP (incorrect dates) Presence of Fibroids Scarring Obesity Multiple gestation Molar pregnancy Pregnancy failure
diagnosis of a true GS may be made only in the presence of
yolk sac or embryo
without findings of intrauterine pregnancy, an intrauterine fluid collection could represent
pseudogestational sac associated with ectopic pregnancy
embryonic heart rates
5 - 6 weeks - 100 BPM
6+ weeks - 120 to 160 BPM
findings diagnostic of pregnancy failure
CRL of >7mm and no heartbeat
Mean sac diameter of >25mm and no embryo
Absence of embryo with heartbeat of >2wk after a scan that showed gestational sac without a yolk sac
``
Absence of embryo with heartbeat >11 days after a scan that showed a gestational sac with a yolk sac
Abortion
Spontaneous or induced termination of an early pregnancy and expulsion of fetal and placental tissues.
Anembryonic pregnancy (Blighted ovum)
Pregnancy that has failed prior to the development of an identifiable embryo or in which embryonic tissue has been resorbed after early embryo demise
Incomplete abortion
Spontaneous abortion in which some products of conception remain in the uterus
Inevitable abortion
Failed early pregnancy that is in the process of being expelled from the uterus
Miscarriage
Spontaneous failure and expulsion of an early pregnancy
Missed abortion
Early failed pregnancy that remains in the uterus
gestational trophoblastic disease
Abnormal trophoblastic proliferation
Abnormal chromosome number
46 XX or 46 XY
69 XXX, 69 XXY, 69 XYY…..
Ectopic pregnancy
Implantation of a fertilized ovum in any area outside of the endometrial cavity
Associated risk factors if ectopic pregnancy
Rise in incidence of pelvic infections Use of intrauterine contraceptive devices (IUCDs) Fallopian tube surgeries Infertility treatments History of ectopic pregnancy
clinical presentation of ectopic pregnancy (most common)`
Vaginal bleeding
Pain
Palpable adnexal mass
other clinical presentations of ectopic pregnancy
non amenorrhea hypotension shoulder pain rebound tenderness guarding hypovolemic shock
ectopic b-HCG levels
Lower than normal value
Nonvisulaization of pregnancy at discriminatory level
1500 – 2500 mIU/mL
sites of ectopic pregnancy
fallopian tube -95% ampulla (70%) isthmus (12%) fimbria (11%) Intramyometrial (Interstitial) – 2-4% nual, Cervical, Intramural, Ovarian, Abdominal – 1%
most important finding when scanning for ectopic pregnancy is to determine
If normal intrauterine gestation (reducing probability of ectopic pregnancy)
If uterine cavity empty and adnexal mass present
As many as 20% of patients with ectopic pregnancy demonstrate intrauterine saclike structure known as pseudogestational sac.
Pseudogestational sac
Normal appearance
Thickened endometrium to 8 mm
Pseudosac vs normal Double decidual sac sign (DDSS)
Sonographic findings of ectopic pregnancy
Identification of extrauterine sac within adnexa one of most frequent findings of ectopic pregnancy
Extrauterine gestational sacs often demonstrate thickened echogenic ring, separate from ovary, which represents trophoblastic tissue or chorionic villi and possibility that embryo or yolk sac will be seen.
Color dopplere ectopic pregancy
Ring of fire sign
Due to increased flow surrounding the ectopic
Spectral Doppler shows low flow
Corpus luteal flow has similar characteristics
what is the most life-threatening ectopic gestation
Interstitial pregnancy, or cornual pregnancy
Location of this ectopic pregnancy is in segment of fallopian tube that enters uterus.
Cervical ectopic pregnancy
Hourglass shaped sac in cervix
Pending abortion vs. ectopic
Sliding sac sign (sliding of the gestational sac within the cervix when the transducer is gently pressed against the cervix)
Ovarian ectopic pregnancy
Normal tube
Gestational sac on ovary
Ovary and gestational sac connected by the ovarian ligament
Placental tissue mixed with ovarian cortex
Abdominal ectopic pregnancy
Fetus outside of the uterus
Failure to image uterine wall between fetus and urinary bladder
Close proximity to maternal anterior abdominal wall
Localization of placenta outside of the uterus
Heterotopic pregnancy
Ectopic coexisting with intrauterine (IUP) pregnancy
Incidence
1:30,000 natural pregnancies
1-3% with ovulation induction
IUP may go to term when ectopic has been resolved
Acute rupture
Formation of a complex mass Large adnexal mass Free fluid Hematosalpinx Hemoperitoneum Morison’s pouch Pelvic cul-de-sacs
Alternate modalities ectopic pregnancy
Defines ectopic
Maturity of present blood
Gold standard
treatment ectopic pregnancy
Expectant Spontaneous regression Tubal abortion Methotrexate (MTX) Surgery
fetal aneuploidy
Chromosomally abnormal
risk of fetal aneuploidy determined by
Maternal Serum biochemistry levels
Nuchal lucency measurements
Ductus venosus Doppler
when is NT measurement taken
45-84mm
what does NT meaurement do
Single most powerful marker available to differentiate euploid pregnancies from Down syndrome
Nuchal lucency meaurements
“avalue of less than ~2.2-2.8 mm in thickness is not associated with increased risk,however it is maternal age dependent and needs to be matched to exact gestational age and(CRL)”
Anembryonic pregnancy (Blighted ovum)
Gestational sac in which embryo fails to develop at an early stage that it is unseeable by ultrasound
what occurs in blighted ovum
trophoblast tissue continues to grow, gestational sac continues to grow, BHCG levels continue to increase (but not at expected rates)
what is the findings associated with blighted ovum
Large, empty gestational sac with no yolk sac, amnion or embryo
