Ultrasound of the female pelvis Chapter 32 Early Pregnancy Failure and Ectopic Pregnancy Holdorf Ultrasound of the female pelvis

Contents Early Pregnancy Failure Complete Abortion Incomplete Abortion Missed Abortion Threatened abortion Inevitable Abortion Anembryonic Pregnancy

Ectopic Pregnancy Locations Sonographic Pitfalls Doppler Criteria Other Diagnostic Features

Is this Gyn or OB? Cross-over Actually Abnormal First Trimester

Early Pregnancy failure Abortion is the termination of a pregnancy prior to 20 weeks of gestation. Spontaneous abortion (SAB) usually occurs 1-3 weeks after embryonic or fetal demise. Approximately 12% of all pregnancies end in spontaneous abortion. with 75% occurring before the 16th week. While the cause of SAB frequently cannot be determined in an individual patient, etiologies include: endocrine factors, failure of the corpus luteum, maternal mullerian defects, interruption of embryonic development and specific chromosomal causes.

Pathologically, SAB begins with hemorrhage into the decidua basalis Pathologically, SAB begins with hemorrhage into the decidua basalis. Inflammation and necrosis occur around the region of implantation with subsequent detachment of the conceptus. Uterine contractions and expulsion of intrauterine contents occur through a dilated cervix. There are several classifications of early pregnancy failure:

Complete abortion Evacuation of all products of conception. Clinical Signs Rapid decline of hCG levels Vaginal bleeding with presence of tissue/clots Cramping Cessation of pain and brisk bleeding after conceptus has been passed Disappearance of symptoms of pregnancy

Sonographic findings Empty uterus with “clean” endometrial stripe Moderate to bright endometrial echoes Presence of Trophoblastic Doppler waveforms surrounding the endometrium normally persist for up to 3 days post SAB.

Empty uterus after a complete spontaneous AB

Incomplete Abortion Partial evacuation of products of conception. Diagnosed early after the clinical event. Clinical signs Slow fall or plateau of hCG levels Moderate cramping Persistent, heavy bleeding

Sonographic Findings Presence of complex collection of echoes within endometrial cavity (may be due to air bubbles or retained products of conception). Persistence of Trophoblastic vascularized tissue near the endometrial cavity for up to 5 days post event.

Incomplete Spontaneous Abortion

Missed Abortion The presence of an embryo within the uterus, without evidence of cardiac activity. May be retained for months following the embryonic demise. Occurs more commonly in the second trimester.

Clinical signs hCG levels less than expected for dates loss of symptoms of pregnancy decrease in uterine size brownish vaginal discharge without frank bleeding

Sonographic findings presence of a gestational sac with or without a fetal component absence of fetal cardiac activity or limb motion acoustic shadowing arising from the endometrium indicating the presence of air bubbles or calcified fetal parts fetal size less than expected for dates Uterus smaller than expected for dates.

Missed Abortion

Threatened abortion A condition in which the future of the pregnancy may be in jeopardy but the pregnancy continues.

Clinical signs Closed cervix Slight bleeding or cramping Diagnosis Not able to diagnose sonographically

Threatened Abortion

Inevitable Abortion SAB is imminent when any of two or more of the following clinical signs is noted: Moderate effacement of the cervix (obliteration of the uterine cervix by shortening and softening during labor so that only the external orifice remains) Cervical dilatation > 3cm Rupture of membranes Bleeding for more than 7 days Persistent cramping

Sonographic findings Gestational sac identified in the cervix (distinguished from a cervical ectopic using Doppler) or lower uterine segment Cervical dilatation Sonolucent crescent surrounding the gestational sac

Inevitable abortion

Anembryonic Pregnancy The presence of a gestational sac in the uterus in which an embryo has failed to develop or died at a stage too early to be visualized. Formerly known as a “blighted ovum.”

Clinical signs Uterus small for dates Variable hCG levels. Rise normally then plateau or fall Vaginal spotting Closed cervix

Sonographic findings No identifiable embryo in a GS of 25mm or larger Absence of do8uble sac sign “empty amnion (visible by 7 weeks LMP)

Anembryonic pregnancy

Ectopic Pregnancy

Ectopic pregnancy is the implantation of the conceptus outside of the endometrial cavity. It is also know as an extra-uterine pregnancy. The most common site of an ectopic implantation is the ampullary portion of the fallopian tube (90%).

The incidence of ectopic gestations has increased over the past ten years as a result of an increase in the occurrence of PID, tubal reconstructive surgeries and assisted-fertility programs. Risk of recurrence is 12-18%.

LOCATIONS of ECTOPIC IMPLANTATION

Adnexal ectopic Pregnancies may occur in any portion of the fallopian tube or ovary. Sites in the tube include the isthmic, ampullary, fimbrial, or interstitial portions; 90% of ectopics occur in the ampullary tube. Ovarian implantations (which are very rare) include tubo-ovarian or abdomino-ovarian. Uterine ectopic pregnancies exist when the conceptus implants on any site within the uterus but outside the endometrial cavity. Implantation sites can be within the cornua, in a uterine sacculation or scar, or cervically.

uterine sacculation or scar Uterine sacculation is rare complication affecting the pregnant uterus, and is difficult to diagnose. Sacculation consists of a transitory pouch or sac-like structure caused by inverted uterine polarity.

Uterine sacculation is a rare complication of pregnancy that occurs in about 1 in 3000 pregnancies . It is defined as a sac-like structure that develops from an abnormal rotation of the uterine fundus. Without diagnosis and treatment, this can cause spontaneous miscarriage, intrauterine fetal death, uterine rupture, preterm delivery, placenta accreta, retained placenta and postpartum hemorrhage. However, this condition is hard to diagnosis.

Why does a c-section scar prevent you from having a vaginal birth with your next birth? In more than 99% of cases, c-section scars heal well and create strong tissues that knit the uterine tissue back together. It's almost always strong enough to withstand the stretching of another pregnancy and pressure of contractions. In very rare cases however, the scar can tear. This is more common (but still rare) with vertical incisions than horizontal ones (which is one of the reasons vertical incisions aren't done very often). If that scar tears, (called uterine rupture), it causes massive bleeding (hemorrhage) and is a life threatening emergency for both mother and baby.

Caesarean scar ectopic pregnancy Caesarean scar ectopic pregnancy (CSEP) is a rare type of ectopic pregnancy that becomes implanted in a C-section scar. It is often considered the rarest type of ectopic pregnancy Poor healing can result in a focal thinning of the scar, which may be susceptible to implantation of the gestational sac at this point rather than in the endometrial cavity

Caesarean scar pregnancy

Cervical Cervical ectopic pregnancies are a rare occurrence (1:16,000). Risk factors include previous uterine curettage. Cervical ectopics carry high morbidity and mortality rates, and attempts to evacuate the conceptus can cause massive hemorrhage. Total hysterectomy may be required if Methotrexate treatment fails.

Methotrexate Methotrexate stops cells from dividing. It can be used, other than surgery, to treat ectopic pregnancy. Administered by injection, and usually just 1 dose is needed. After injection: mild to moderate cramps or pain in the abdomen vaginal bleeding Blood test 2 to 3 times a week, for 2 to 3 weeks. This is to tell if the methotrexate worked to stop the pregnancy.

Side effects of methotrexate nausea and/or vomiting (for 24 hours) decreased appetite sores in the mouth headache redness, swelling, or pain at the injection site trouble sleeping diarrhea hair loss (rare)

Abdominal Abdominal pregnancy is rare: a conceptus may leave the pelvis and implant in the peritoneum. Sonographic findings in Abdominal Ectopic Pregnancy: Absence of myometrium surrounding the pregnancy Poor visualization of the placenta Presence of an empty uterus separate from the developed fetus Oligohydramnios Unusual fetal presentation

Can abdominal pregnancies be brought to term/viability? Yes and no. It is generally recommended to perform a laparotomy when the diagnosis of an abdominal pregnancy is made. However, if the baby is alive and medical support systems are in place, careful watching could be considered to bring the baby to viability. Women with an abdominal pregnancy will not go into labor.

Adnexal ectopic

Cervical ectopic

Abdominal ectopic

Heterotopic Heterotopic pregnancies are concurrent intra and extra uterine pregnancies. They can occur in the general population, but are more common in the fertility patient, who has undergone zygote or gamete transfer; in this population it has been estimated that heterotopic pregnancy risk is 1:2000-4000.

Heterotopic Pregnancy

Clinical findings for all ectopic pregnancies No specific findings are diagnostic for ectopic pregnancy. Common signs that should cause suspicion include:

Positive pregnancy test Abnormal rate of rise of serum hCG levels as expected for dates. Palpation of an adnexal mass (in the presence of a positive serum hCG is highly suspicious) Pelvic pain or bleeding within 1-8 weeks following the first missed menstrual period Leukocytosis or slight fever Pain referred to the shoulder caused by intra- peritoneal hemorrhage (right-shoulder pain caused by inflammation of the diaphragm).

Sonographic findings of an ectopic pregnancy IDENTIFICAITON OF AN EXTRA UTERINE GESTATIONAL SAC WITH A YOLK SAC IS THE GOLD STARDARD FOR MAKING A DIAGNOSIS OF AN ECTOPIC PREGNANCY. Empty uterus – an intrauterine GS should be identified with EV sonographically when the serum hCG levels reach 800-1000 mlU/ml (2IRP). Presence of an adnexal mass Free fluid in the cul-de-sac, adnexae, pericolic gutters or Morrison’s pouch. Presence of an endometrial decidual reaction.

Ruptured ectopic ultrasound findings

Sonographic pitfalls Presence of fluid in the endometrial cavity: known as a pseudogestational sac. Absence of the double sac sing eliminates this pitfall. Misidentification of a corpus luteum cyst as an adnexal ectopic (this commonly happens when depending on the RING OF FIRE criteria).

DOPPLER Criteria Using color Doppler, a RING OF FIRE surrounding the GS represents metabolically active Trophoblastic flow. A high velocity, low resistance spectral waveform indicates typical Trophoblastic flow patterns, but this too may be mimicked by flow at the margins of a corpus luteum cyst. Absence of Doppler signal cannot be used to exclude ectopic pregnancy.

Pseudogestational Sac

“RING OF FIRE”

Other diagnostic procedures While Sonography has become the primary diagnostic modality in examining patients for ectopic pregnancies, it can fail. When sonographic findings are inconclusive, other examination techniques can be used: Culdocentesis: may reveal free blood in the cul- de-sac Laparoscopy allows for the direct visualization and analysis of adnexal and intra-abdominal masses Exploratory laparotomy is used less frequently but allows for a definitive diagnosis.  

Culdocentesis

Laparoscopy