A 32-year-old woman, gravida 1 para 0, comes to the office for an initial prenatal visit after a positive home pregnancy test. The patient has had some nausea and breast tenderness but no abdominal cramping or vaginal bleeding. Her last menstrual period was 9 weeks ago; prior to conception she had regular, monthly menstrual cycles with 5 or 6 days of heavy bleeding. During the first 2 days of her menses, the patient had painful cramping, particularly after stopping her oral contraceptives last year. She has no chronic medical conditions, and her only medication is a daily prenatal vitamin. The patient does not use tobacco, alcohol, or illicit drugs. Bimanual pelvic examination shows a 15-week-size, mobile uterus with an irregular contour. Urine pregnancy test is positive. Which of the following is the most likely cause of this patient's uterine size-date discrepancy?

Question

A 32-year-old woman, gravida 1 para 0, comes to the office for an initial prenatal visit after a positive home pregnancy test.  The patient has had some nausea and breast tenderness but no abdominal cramping or vaginal bleeding.  Her last menstrual period was 9 weeks ago; prior to conception she had regular, monthly menstrual cycles with 5 or 6 days of heavy bleeding.  During the first 2 days of her menses, the patient had painful cramping, particularly after stopping her oral contraceptives last year.  She has no chronic medical conditions, and her only medication is a daily prenatal vitamin.  The patient does not use tobacco, alcohol, or illicit drugs.  Bimanual pelvic examination shows a 15-week-size, mobile uterus with an irregular contour.  Urine pregnancy test is positive.  Which of the following is the most likely cause of this patient's uterine size-date discrepancy?

Quizplus · Accepted Answer

Explanation: 11ec25c8_da91_fcbe_bc81_3d279b1e4113_MD0003_00 This pregnant patient has a uterine size-greater-than-date discrepancy: a 15 week-size uterus at 9 weeks gestation based on her last menstrual period (LMP). A size-greater-than-date discrepancy usually has an obstetric cause, such as incorrect dating (the most common cause), multiple gestation, polyhydramnios, or gestational trophoblastic disease (eg, hydatidiform mole). However, none of the above conditions would produce an irregular uterine contour in early pregnancy (Choices D, E, and G). An abnormal uterus is more likely. In this patient with an irregular uterine contour and history of heavy menses, the most likely cause is leiomyomata uteri (uterine fibroids). Leiomyomas are benign, uterine smooth muscle tumors and the most common pelvic tumor in women. Fibroids share some clinical features (eg, uterine enlargement, constipation) with pregnancy. Other signs and symptoms vary by fibroid size and location: Leiomyomas on the uterine surface (subserosal) and within the uterine wall (intramural) are most likely to cause an enlarged uterus, an irregular uterine contour, and bulk symptoms (eg, pelvic pressure, constipation). Submucosal fibroids (located beneath the endometrium) can cause prolonged and/or heavy menstrual bleeding with painful cramping (ie, dysmenorrhea) in nonpregnant patients. This patient likely has all 3 fibroid types. Although most fibroids do not adversely affect pregnancy, having large or multiple fibroids can increase the risk of obstetric complications (eg, spontaneous abortion, preterm labor, postpartum hemorrhage) and the rate of cesarean delivery. (Choice A) Patients with adenomyosis can have painful, heavy menstrual bleeding and an enlarged uterus. However, the uterine contour is normal because the proliferation of ectopic endometrial glands is contained within the uterine wall. adenomyosis (Choice B) An ectopic pregnancy is typically tubal or adnexal in location and therefore unlikely to cause an enlarged uterus or affect the uterine contour. A palpable adnexal mass may be present. ectopic pregnancy (Choice C) Endometriosis can cause dysmenorrhea; however, endometrial implants are typically adnexal (ie, endometrioma), peritoneal, or rectovaginal and therefore unlikely to cause an enlarged uterus with an irregular contour. Endometriosis Educational objective: In pregnancy, leiomyomata uteri (uterine fibroids) can cause a uterine size-greater-than-date discrepancy and an irregular uterine contour. References: The impact of fibroid characteristics on pregnancy outcome. (http://www.ncbi.nlm.nih.gov/pubmed/24705132)

A 32-Year-Old Woman, Gravida 1 Para 0, Comes to the Office