A 39-year-old primigravid woman at 7 weeks gestation comes to the emergency department for vaginal bleeding. She has had dark brown vaginal spotting and mild uterine cramping for the past day. The patient has felt extreme fatigue and has had daily nausea and vomiting for the past week. Blood pressure is 112/68 mm Hg and pulse is 86/min. The abdomen is soft and without rebound or guarding. On pelvic examination, there is scant dark blood in the vagina, and the cervix is visually closed. Pelvic ultrasound is shown in the image below: Which of the following is the most likely diagnosis in this patient?

Question

A 39-year-old primigravid woman at 7 weeks gestation comes to the emergency department for vaginal bleeding.  She has had dark brown vaginal spotting and mild uterine cramping for the past day.  The patient has felt extreme fatigue and has had daily nausea and vomiting for the past week.  Blood pressure is 112/68 mm Hg and pulse is 86/min.  The abdomen is soft and without rebound or guarding.  On pelvic examination, there is scant dark blood in the vagina, and the cervix is visually closed.  Pelvic ultrasound is shown in the image below:  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

Explanation: 11ec25c8_da4d_c751_bc81_977ac50869f5_MD0003_00 Vaginal spotting and mild abdominal cramping are common during the first trimester and are usually benign in patients with a closed cervix and an intrauterine gestation on fetal ultrasound. This patient has 2 intrauterine gestations, or a twin pregnancy, on ultrasound. Risk factors for twin gestation include increasing maternal age, fertility-enhancing therapies (eg, ovulation induction), increased parity, and family history. Increased first-trimester nausea and vomiting can be early indicators of a twin pregnancy and are likely due to elevated hCG and progesterone levels. Twins are classified based on chorionicity (number of placentas) and amnionicity (number of amniotic sacs); this is best assessed during the first trimester. Monochorionic-monoamniotic twins (ie, 1 placenta and 1 amniotic sac) are diagnosed by a lack of a dividing intertwin membrane. Monochorionic-diamniotic twins (ie, 1 placenta and 2 amniotic sacs) are diagnosed by a T sign, which occurs when both amnion layers meet at the shared placenta at a 90-degree angle. Dichorionic-diamniotic gestations (ie, 2 placentas and 2 amniotic sacs) present as either 2 visually separate placentas or the appearance of a fused placenta identified by a thick, intertwin membrane and a placental projection where the intertwin membrane meets the placenta (ie, lambda sign). This patient has a dichorionic-diamniotic twin pregnancy with a lambda sign. Dichorionic-diamniotic twins are the most common twin gestation and have the fewest pregnancy complications of the twin gestation types. (Choice A) An anembryonic gestation, a pregnancy with no embryonic development, can present with vaginal spotting. Ultrasound typically reveals an empty gestational sac (ie, gestational sac ≥25 mm with no embryo or yolk sac). empty gestational sac (Choice B) A complete hydatidiform mole classically presents with a Swiss-cheese or snowstorm appearance on ultrasound rather than with 2 fetuses. (Choice C) An incomplete spontaneous abortion presents with vaginal bleeding and cervical dilation with visible products of conception at the cervix or vagina. This patient's cervix is closed. (Choice D) An ultrasound of a normal singleton gestation with fibroid would reveal a single embryo and a separate, well-circumscribed, hypoechoic mass with shadowing, which is not seen on this patient's ultrasound. Educational objective: Dichorionic-diamniotic twin pregnancies are identified on ultrasound with 2 intrauterine gestations, 2 placentas, and 2 amniotic sacs. References: Ultrasound surveillance in twin pregnancy: an update for practitioners. (http://www.ncbi.nlm.nih.gov/pubmed/30479634) Role of ultrasonography in the management of twin gestation. (http://www.ncbi.nlm.nih.gov/pubmed/29536536)

A 39-Year-Old Primigravid Woman at 7 Weeks Gestation Comes to the Emergency