Early pregnancy

The above ultrasound images show a bicornuate uterus with a gestation sac in the right cornu (1). The empty left cornu (2) shows typical decidual changes of pregnancy. The 3rd image (bottom) is a sagittal section through each cornu.

2) Cornual pregnancy:

Sonography of the uterus shows a gestation sac of 6 weeks 4 days age, in the right cornu of the uterus. 3-D image of the uterus further confirms the findings. These ultrasound images are diagnostic of cornual pregnancy (a type of ectopic pregnancy). Ultrasound images courtesy of Dr. Latha Natrajan, Bangalore, India.

3) Another example of cornual or interstitial pregnancy:

These ultrasound and color Doppler images show a gestation sac of 15mm. in the right cornu of the uterus (interstitial region of the fallopian tube). This patient had undergone IVF with embryo transfer 1.5 months back. The transvaginal Color / Power Doppler images (below) show a ring of vessels around the sac with a yolk sac (image lower right) within the gestation sac. No embryo is visualized at this stage. Note the empty endometrial cavity which shows decidual change. This pregnancy needs to be terminated with urgent surgical intervention.

4) Sonography of ruptured ectopic (tubal) pregnancy with pelvic hemorrhage:

Sonography of the pelvis done on this female patient with pelvic pain and tenderness revealed: 1) enlarged (bulky) uterus with grossly thickened endometrium (decidual cast) of almost 15 mm. The uterus shows absence of any gestation sac. No pseudosac is seen. 2) Transvaginal scan of the pelvis shows a large collection of hemorrhagic fluid in the cul de sac 3) A right adnexal mass, presumably in the Right Fallopian tube is also seen. A left ovarian hemorrhagic cyst is also present.

These ultrasound images suggest a right tubal gestation with hematosalpinx with rupture of the Rt. Fallopian tube.

Ultrasound images courtesy of Dr. Gunjan Puri, Surat, India. The ultrasound machine used was the Toshiba Xario.

5) HETEROTOPIC GESTATION (also called Heterotopic pregnancy or simultaneous intrauterine and extrauterine pregnancy or coexistent intrauterine and extrauterine pregnancy):

This patient presented with signs of early pregnancy with left sided pelvic pain and tenderness. Sonography of the pelvis shows an intrauterine pregnancy with a 6 weeks size embryo in the uterine cavity. There is also a coexistent left adnexal mass with a yolk sac like structure measuring 3 mm. and a possible embryo in the sac (6 weeks size). The right and left ovaries are separately identified on transvaginal ultrasound. These ultrasound images suggest heterotopic gestation (intrauterine embryo and a gestation sac in left adnexal region). Ultrasound images courtesy of Dr. Gunjan Puri, Surat, India. He used a Toshiba Xario ultrasound system here.

6) Right ectopic pregnancy:

This patient had bleeding per vagina after testing positive for pregnancy. Ultrasound images show a sac like structure in the uterine cavity. However, the shape of the "gestation sac like structure" is elliptical with the tear drop shape suggesting something more ominous than the appearance of an anembryonic gestation. This appearance is typical of a pseudosac of ectopic pregnancy. Transvaginal ultrasound images of this case are shown below:

The images show a cystic mass (of 15 mm.) in the right adnexal region which is poorly vascular (this is unusual as the typical ring of fire sign of ectopic is not seen). In all probability, this is an ectopic pregnancy (right tubal gestation) which has not yet ruptured (there is little or no fluid or blood in the cul de sac). The pseudosac of ectopic gestation seen in the uterine cavity is different from the typical gestation sac in that it does not show the bright echogenic decidual reaction of a normal intrauterine gestation or even an anembryonic gestation. This patient underwent surgery for right ectopic gestation.

Scar Pregnancy (pregnancy in LSCS scar):

This patient presented with 5 weeks amenorrhoea and pelvic pain. She also has a history of previous caesarean section (LSCS). Ultrasound images of the uterus show a sac like structure in the lower segment of the uterus within the myometrium of the anterior wall of uterus. Color Doppler images of the uterus show increased flow (hyperemia) around the sac. Lab investigations also confirmed her pregnancy. These images suggest a LSCS scar pregnancy (caesarean scar pregnancy). Scar pregnancies are extremely rare (less than 1% of all pregnancies) and are believed to result from a canalization of the LSCS scar to the endometrial cavity. The potential for severe hemorrhage from such ectopic pregnancies is very high due to the potential for rupture of the myometrial tissue around the sac. These ultrasound images of LSCS scar pregnancy are courtesy of Dr. Nirmali Dutta, MD, Abu Dhabi, UAE.

http://radiology.rsna.org/content/245/2/385.full.pdf+html (free article and images)

LSCS scar Pregnancy- Case-2:

Gestation sac with embryo in Cesarean scar: Gestation sac in Lower segment Myometrium

Gestation sac in Cesarean section scar: Ultrasound image of scar pregnancy:

This is yet another case of Cesarean section scar pregnancy. The gestation sac with an embryo and yolk sac are seen in the lower segment. The location of the sac within the myometrium of the lower segment and with the scar tissue seen extending to the endometrial cavity are clear indicators that this is indeed a scar pregnancy. A cervical pregnancy is a close differential diagnosis; however, in cervical pregnancy the sac would lie within the endometrium and would be lower down within the cervix. The LSCS (lower segment cesarean section) scar is also visualized in these transvaginal ultrasound images ruling out a cervical pregnancy. Scar pregnancy is a type of ectopic pregnancy. Ultrasound images are courtesy of Dr. Nirmali Dutta, MD, UAE.

7) Anembryonic gestation:

Sonography of early pregnancy in this case shows bulky (enlarged) gravid uterus showing a gestation sac of 13mm. (5 weeks, 1 day). The images show absence of the embryo. These ultrasound images suggest anembryonic gestation (usually known as missed abortion or blighted ovum). It is advisable to repeat the sonography (after 1 week to 10 days ), in such cases to rule out delayed development of the embryo. Other differential diagnoses include: inevitable abortion, incomplete abortion etc. One of the other causes of anembryonic gestation includes early demise of the embryo, leaving an empty sac.

8) Embryonic demise:

These ultrasound images show an intrauterine gestation sac with subchorionic hematoma (see transvaginal scan image in lower row), with an abnormally large yolk sac (7mm. size). This pregnancy is of 10 weeks gestational age (going by the date of last menstrual period). However the poorly developed embryo measures 6 mm. in size (6 weeks 2 days) and shows no cardiac activity which was confirmed by Power Doppler imaging. These ultrasound findings suggest embryonic demise. (Note: By current criteria, an embryo of more than 5 mm. in size showing no cardiac activity on transvaginal sonography, is considered to be non-viable/ case of embryonic demise).

9) Subchorionic hematoma:

This 1st trimester patient complained of pain in the lower abdomen. Sonography of the gravid uterus shows an anechoic collection (blood--> see arrows) in the upper part of the gestation sac between the decidual tissue and the chorion. There is also evidence of separation of the margins of the early placenta (abruption). The embryo, in this case, showed cardiac activity. These ultrasound images are diagnostic of subchorionic hematoma. It is advisable to follow this case with repeat sonography after 1 week and closely monitor the hematoma.

10) Abnormalities of yolk sac:

Large yolk sac:

This ultrasound image of early 1st trimester pregnancy shows a large yolk sac within the gestation sac in the uterine cavity. Both abnormally large or small yolk sacs are associated with poor prognosis and usually end in embryonic demise. No embryo was visualized in this case. A yolk sac diameter of greater than 5.6 mm. before 10 weeks gestational age indicates bad prognosis. In this case the yolk sac measured 10.6 mm. (This sonographic image is courtesy of Dr. Durr e Sabih, Pakistan).

11) Double decidual sac sign:

These ultrasound images show the sagittal section of the uterus in a 4 week, 6 days old pregnancy. The double decidual sac sign is clearly present, showing a normal early intrauterine pregnancy. This sign helps differentiate a normal intrauterine pregnancy in its early stages from the pseudosac of ectopic pregnancy. The double decidual sign consists of the decidua parietalis surrounding the decidua capsularis with the gestation sac encased within the Decidua capsularis. The decidua capsularis is separated from the decidua parietalis by a small amount of fluid within the endometrial cavity. The decidua parietalis lines the uterine cavity whilst the decidua capsularis encases the gesation sac. The decidua capsularis and decidua parietalis join or attached at the decidua basalis. (FL= fluid in endometrial cavity; SAC= GESTATION SAC). The double decidual sac sign is so named because of the sonographic appearance of 2 concentric rings around the gestation sac; this is a normal finding in early pregnancy.