Clin Obgyn 1990;33:432; Obgyn Cl N Am 1999;26:419; Am Fam Phys 2002;66:823

Cause: Multiple causes, but usually motor vehicle accidents; uterine rupture may be spontaneous in those with normal labor; as a result of previous uterine surgery such as myomectomy (Hum Reprod 1995;10:1475) or previous C-section (Am J Obgyn 1991;165:996)—high risk if previous classical C-section; from cocaine abuse (Am J Obgyn 1995;173:243); those with Asherman syndrome (Obgyn 1986;67:864); uterine anomalies; prior invasive molar surgery; h/o placenta accreta; abnormal fetal presentation; or fetal anomaly.

Epidem: Most maternal traumas are found to be minor, and fetal health is directly related to maternal well-being. Even those with minor maternal trauma, though, may have a problem with significant fetal injury or death. Three-point restraints—low-lying seatbelt with shoulder harness—convey the most protection to mother and fetus if they were to suffer a motor vehicle accident.

Pathophys: Although uterine rupture can occur with abdominal trauma, it happens < 1% of the time and it is more common to get retroperitoneal hemorrhage, splenic lacerations, liver lacerations or kidney lacerations from abdominal trauma in the gravid patient. Placental abruption may also be a factor in approximately 4% of minor traumas and up to 50% of major traumas.

Sx: Uterine rupture presents with a diffusely tender abdomen.

Si: Shock, unable to determine uterine fundus or fetal lie.

Crs: Timely diagnosis of a surgical abdomen is paramount.

Cmplc: Maternal hemorrhage causing shock or fetal distress or death.

Lab: CBC with diff; PT/PTT; medical blood type for consideration of Rhogam; Kleihauer-Betke of limited usefulness despite theoretic considerations in low-risk women (Am J Obgyn 2004;190:1461); consider type and cross; consider DIC profile if significant maternal/fetal transfusion suspected.

Cause: Implantation of embryo other than in uterus.

Epidem: Approximately 2% of all pregnancies with increasing incidence; 95% are tubal, but also can be ovarian, cervical, intra-abdominal (0.5%). Post-tubal ligation rate is 1:1,000 over 10 yr, it is 30:1,000, if electrocoagulation tubal performed. Increased in urban populations due to PID, previous pelvic surgery such as previous ectopic, IUD, and other reasons (Ann EM 1999;33:283); those in rural populations tend to have no risk factors (Fam Med 1996;28:111).

Pathophys: Scarred tubes have a slow transfer rate and the blastocyst implants wherever it is on d 6; of note, efficacy of oral contraceptives not affected by antibiotic use, except for rifampin—reports in past show equivocal findings secondary to bias (J Am Acad Dermatol 2002;46:917).

Sx: Nearly all in first trimester; report of missed period, although withdrawal bleeding may mask this. Abdominal/pelvic discomfort similar to menstrual pains, referred pain to shoulder may be a sign of diaphragmatic irritation from intraperitoneal bleeding.

Si: Nonspecific (Ann EM 1999;33:283), palpable pain or cervical motion tenderness may not be present; check for open cervical os which may be attained by bimanual exam or speculum exam if uncertain (EMJ 2004;21:461); hypotension may be present.

Crs: Without surgery, death in 2:1000 of the population.

Cmplc: Shock, surgical sterility.

Diff Dx: PID, spontaneous abortion (threatened), which has an increased risk in first trimester with caffeine use (Nejm 2000;343:1839), septic abortion, appendicitis, ruptured ovarian corpus luteum or follicle cyst, endometriosis cyst.

Lab: CBC with diff; serum β-HCG, with level < 1,000 mIU/ml with 4-fold higher risk (Ann EM 1996;28:10); type and screen (consider type and cross if in shock); progesterone levels not wholly reliable, but should be < 20-25 nanograms/ml in ectopic (Am J Obgyn 1989;160:1425);
subunit of β-HCG, the core fragment, may be predictive of ectopic if < 100 µg/L in the urine—data dredging (J Clin Endocrinol Metab 1994;78:497). Urine pregnancy test positive when serum level > 50 U, thus 90+% pos at first missed period. Serum CK not helpful (Brit J Obgyn 1995;6:233). Serum amylase is not helpful (Am J Emerg Med 1988:327).

X-ray: US with transvaginal is the gold standard in radiology (Fertil Steril 1998:62) and combined with serum β-HCG shows a sensitivity of 100% and specificity of 99.9% for ectopic pregnancy diagnosis (Obgyn 1994;84:1010)—intrauterine pregnancy (IUP) with an ectopic twin is rare phenomenon. US by US trained ER physicians with 90% sensitivity and 88% specificity for right diagnosis (Ann EM 1997;29:338), but the discriminatory zone was a serum β-HCG of 2000 mIU/ml, whereas other sonographers with discriminatory zone of 1000 mIU/ml or less (J Emerg Med 1998;16:699). Look for thin endometrial stripe (Fertil Steril 1996;66:474); is best when serum β-HCG < 1000 (Acad Emerg Med 1999;6:602), and even indeterminate scans should be subclassified as low, intermediate or high-risk (Acad Emerg Med 1998;5:313).

Cause: Trauma, chronic pulmonary or cardiac conditions, pulmonary embolus, substance abuse [eg, toluene (Obgyn 1991;77:504)] or other etiologies that may cause maternal death.

Epidem: Rare, but increases with increasing maternal age (Obgyn 1983;61:210) and previously higher frequency in adolescents (Clin Obgyn 1978;21:1191).