Gestational sac >10mm without visible yolk sac
Gestational sac >18mm without fetal pole
Collapsed gestational sac
Pseudogestational sac
Endometrial breakdown during ectopic pregnancy
May be erroneously interpreted as true gestational sac in ectopic pregnancy
Irregularly shaped
Located in endometrial cavity, instead of eccentrically within endometrium
No yolk sac present
May not have double decidual sac sign
Absence of fetal heart beat in embryo with CRL >5mm
FHR <90 bpm
Molar pregnancy
Many small, irregular cystic structures in endometrium
"Snowstorm appearance"
Endometrial breakdown during ectopic pregnancy
May be erroneously interpreted as true gestational sac in ectopic pregnancy
Irregularly shaped
Located in endometrial cavity, instead of eccentrically within endometrium
No yolk sac present
May not have double decidual sac sign
Many small, irregular cystic structures in endometrium
"Snowstorm appearance"
Implantation of blastocyst outside of endometrium
Occur in fallopian tubes, cervix, ovaries, peritoneal cavity, or scar of prior uterine surgery
Most definitive sonographic sign is gestational sac with yolk sac, embryo, or fetal heart beat outside of the endometrium
Tubal pregnancy
"Tubal ring" sign: echogenic thick-walled anechoic sac visualized between uterus and ovary (separate from ovary when pressure applied to fallopian tube with probe)
Interstitial Pregnancy
Implantation of gestational sac in muscular wall of uterus at proximal regional of fallopian tubes
"Interstitial line" sign: hyperechoic line from endometrial stripe to cornual region adjacent to interstitial gestational sac
Cervical Pregnancy
Implantation of gestational sac below internal cervical os
Can cause life-threatening hemorrhage
Must distinguish between cervical ectopic and spontaneous abortion at level of cervix
"Tubal ring" sign: echogenic thick-walled anechoic sac visualized between uterus and ovary (separate from ovary when pressure applied to fallopian tube with probe)
Implantation of gestational sac in muscular wall of uterus at proximal regional of fallopian tubes
"Interstitial line" sign: hyperechoic line from endometrial stripe to cornual region adjacent to interstitial gestational sac
Implantation of gestational sac below internal cervical os
Can cause life-threatening hemorrhage
Must distinguish between cervical ectopic and spontaneous abortion at level of cervix
Bimodal age distribution: young women (15-30yo) and post-menopausal women
Typically occur in enlarged ovaries (>5cm)
Benign mature cystic teratomas
Hemorrhagic/large ovarian cysts
Cystic neoplasms
Cystadenomas
Polycystic ovarian syndrome
Sonographic signs associated with torsion
Enlarged ovary from edema, engorgement, hemorrhage
Midline ovary
Free<unk>  fluid
Underlying ovarian lesions
Peripherally displaced follicular cysts
Doppler findings:
Decreased/absent venous or arterial flow
Absent/reversed diastolic flow
Can have normal flow (from dual supply from uterine and ovarian arteries)
Benign mature cystic teratomas
Hemorrhagic/large ovarian cysts
Cystic neoplasms
Cystadenomas
Polycystic ovarian syndrome
Enlarged ovary from edema, engorgement, hemorrhage
Midline ovary
Free<unk>  fluid
Underlying ovarian lesions
Peripherally displaced follicular cysts
Doppler findings:
Decreased/absent venous or arterial flow
Absent/reversed diastolic flow
Can have normal flow (from dual supply from uterine and ovarian arteries)
Decreased/absent venous or arterial flow
Absent/reversed diastolic flow
Can have normal flow (from dual supply from uterine and ovarian arteries)
Pelvic ultrasound 
Bladder ultrasound
Ultrasound 
Musculoskeletal ultrasound
FAST exam
Emergency contraception
Renal ultrasound
Urine analysis