Diagnostic ultrasound ( PDFDrive )

1074 PART IV Obstetric and Fetal Sonography
A
B
FIG. 30.32 Interstitial Ectopic Pregnancy. (A) Sagittal TAS demonstrates an unremarkable endometrial stripe. (B) Transverse TAS shows a
gestational sac containing an embryo (black arrow) eccentrically positioned within the uterus, separate from the endometrial stripe (white arrow).
The pregnancy was terminated with direct injection of methotrexate within the gestational sac, avoiding uterine surgery.
A
B
FIG. 30.33 Cervical Ectopic Pregnancy. (A) TAS sagittal view of the uterus shows a pseudogestational sac in the endometrium. A second
luid collection is seen in the cervix secondary to the gestational sac. (B) Sagittal TVS of the cervix shows a gestational sac containing an embryo.
for less than 1% of all ectopic pregnancies, and can be confused
with abortion in progress. Ultrasound can help to distinguish
an intracervical ectopic pregnancy by documenting an embryo
with a heartbeat or color Doppler–documented peritrophoblastic
low. Remember that an aborting gestational sac may present in
the lower uterine segment and cervix on its way out of the uterus.
Sonographically in an aborting gestation, the sac will be oblong,
the embryo (if present) will not have a heartbeat, and there will
be no trophoblastic vascularity because it has detached from the
uterine wall. Clinically, both situations are associated with vaginal
bleeding, but the abortion will more likely produce crampy pain
as well. Occasionally an abortion in progress will still show low
when being scanned, but follow-up imaging will show lack of
low. herefore before any interventional procedure for a cervical
ectopic is performed, we always check to see if cardiac activity
is still present.
Cesarean scar implantation appears to be increasing, with
more cases appearing in the literature. 121 he patient may
present with painless vaginal bleeding and a history of one or
more cesarean sections. An early sonogram will show a sac
implanted in the lower uterine segment, with local thinning of
the myometrium (Fig. 30.34, Video 30.8). here is usually
prominent vascularity at the implantation site. Catastrophic
hemorrhage may result, with the need for complete hysterectomy.
Treatment of a scar implantation is oten protracted. A
dilation and curettage procedure is seldom advised because the
thin lower segment may be perforated. Medical therapy is more
common, with methotrexate taken systemically and oten
injected locally as well. Presence of a live embryo may require
careful injection of potassium chloride into the embryo to stop
cardiac activity.
Abdominal pregnancies are also rare. hese pregnancies
oten result from uterine rupture from an interstitial ectopic
pregnancy (Fig. 30.35) but may also more rarely occur from
direct implantation. When diagnosed in the irst trimester,
these pregnancies are typically treated in a similar way to tubal
ectopic pregnancies. When diagnosed in the third trimester,
abdominal pregnancies may result in a viable neonate.