A 31-year-old female G3P2 presented to the emergency department with vaginal spotting for one week and worsening lower abdominal cramping. She tested positive on a home pregnancy test one day prior to presentation. On the day of presentation, she passed a small blood clot and bled through one pad. She had not yet seen an OB for this pregnancy. Her last menstrual period was one month and three days prior. The current pregnancy is undesired. She denied fevers, chills, urinary symptoms, lightheadedness, palpitations, shortness of breath, nausea, or vomiting.
Vitals: BP 95/55; HR 75; Temp 98.4°F; Resp 16; SpO2 100% on room air
Abdomen: Soft; tender to palpation in the suprapubic region, no guarding or rebound tenderness
GU: Scant blood in the vaginal canal, no clots or tissue; os closed, no adnexal tenderness, no cervical motion tenderness
bHCG: 36,966
Rh Factor: Positive
Hgb: 9.2
Ectopic pregnancy needs to be ruled out. This patient has vaginal bleeding, a positive pregnancy test, and abdominal pain. She has not established care with an OB provider and has not had a confirmed intrauterine pregnancy. Specific ultrasound findings for an ectopic pregnancy include a gestational sac with a yolk sac outside of the uterus. Findings suggestive of an ectopic pregnancy include complex adnexal masses, free fluid with debris (suggestive of rupture), and an empty gestational sac within an adnexal mass.
Yes, this is a viable intrauterine pregnancy (IUP). Confirmation can be done with transabdominal ultrasound but in very early pregnancy may require a transvaginal ultrasound. Findings needed to confirm an IUP include a gestational sac containing a yolk sac within a thickened myometrium. The hyperechoic structure seen on transabdominal and transvaginal ultrasounds for this patient is an intra-uterine device (IUD) that is in place. The risk of pregnancy with an IUD in place is <1%; according to a database of 18 million hospital deliveries, the reports of retained IUD at birth was 12 per 100,000 births. For pregnancies with an IUD in place, the rate of ectopic pregnancy is higher. There is also a higher risk of maternal infection, miscarriage, preterm premature rupture of membranes, preterm birth, and intrauterine fetal demise. For desired pregnancies, if the strings are visible, the IUD is removed as soon as possible and a single dose of azithromycin is given due to increased risk of infection during pregnancy. There is limited evidence to guide management for desired pregnancies when strings are not visible. One option is hysteroscopic removal, although this increases the risk of pregnancy loss. More than 50% of pregnancies with in situ IUDs were found to end in spontaneous abortion.
Take-Home Points
- A definite IUP requires an intrauterine gestational sac with yolk sac and/or embryo (with or without cardiac activity).
- Pregnancy with an IUD is extremely rare and increases the risk of ectopic pregnancy, maternal infection, miscarriage, PPROM, preterm birth, and fetal demise.
- Management for desired pregnancies with IUDs in place when IUD strings are visible consists of early IUD removal with a single dose of prophylactic antibiotics.
- ACOG Practice Bulletin No. 121: Long-acting reversible contraception: Implants and intrauterine devices. Obstet Gynecol. 2011 Jul;118(1):184-196. doi: 10.1097/ AOG.0b013e318227f05e. PMID: 21691183.
- Ganer H, Levy A, Ohel I, Sheiner E. Pregnancy outcome in women with an intrauterine contraceptive device. Am J Obstet Gynecol. 2009 Oct;201(4):381.e1-5. doi: 10.1016/j.ajog.2009.06.031. Epub 2009 Aug 29. PMID: 19716537.
- Roline, C.E., Heegaard, W.G. & Anderson, K.S. Early pregnancy with an intrauterine device in place. Crit Ultrasound J 3, 91–92 (2011). https://doi.org/10.1007/s13089-011-0068-1
Natalie Campbell, MD
Mount Sinai Hospital
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