A 33-year-old woman, gravida 2 para 1, at 32 weeks gestation is brought to the labor and delivery unit and precipitously delivers a male infant within 2 minutes of arrival. The infant appears small for gestational age. Apgar scores are 5 and 6 at 1 and 5 minutes, respectively. The mother did not receive prenatal care this pregnancy. On delivery, the placenta appears pale and enlarged. In addition, the umbilical cord is inflamed with multiple areas of abscess-like foci of necrosis surrounding the umbilical vessels. Which of the following is the most likely cause of these findings?

Question

A 33-year-old woman, gravida 2 para 1, at 32 weeks gestation is brought to the labor and delivery unit and precipitously delivers a male infant within 2 minutes of arrival.  The infant appears small for gestational age.  Apgar scores are 5 and 6 at 1 and 5 minutes, respectively.  The mother did not receive prenatal care this pregnancy.  On delivery, the placenta appears pale and enlarged.  In addition, the umbilical cord is inflamed with multiple areas of abscess-like foci of necrosis surrounding the umbilical vessels.  Which of the following is the most likely cause of these findings?

Quizplus · Accepted Answer

11ec160b_3a01_55b3_9249_cf72922287ec_MD0001_00 Patients with an atypical delivery (eg, preterm [<37 weeks gestation], small for gestational age) undergo placental evaluation to search for an underlying cause (eg, infection, placental insufficiency). In this patient, histopathology shows umbilical cord inflammation with abscess-like foci of necrosis surrounding the umbilical vessels. This constellation of findings (ie, umbilical cord necrosis, small for gestational age) suggests an infectious etiology, likely congenital infection. In this patient, the most likely cause is congenital syphilis, which occurs when Treponema pallidum spirochetes in the maternal circulation attach to and traverse the endothelial cells of the umbilical vein, thereby spreading to the placenta and fetus (transplacental transmission). In response, fetal inflammatory cells are recruited along the umbilical vessels, causing cord inflammation and perivascular necrosis (necrotizing funisitis). Because of placental compromise, fetal perfusion decreases and leads to chronic fetal hypoxia and growth restriction. Because congenital syphilis can also cause severe fetal anemia, the placenta may appear grossly pale and enlarged with hydropic villi. Newborns with suspected congenital syphilis require nontreponemal testing (eg, rapid reagin test, VDRL). Affected infants require penicillin therapy to prevent late manifestations (eg, saddle nose, notched [Hutchinson] teeth). Routine prenatal care usually prevents congenital syphilis by screening for and treating maternal syphilis. (Choice A) Group B Streptococcus colonizes the female genitourinary and gastrointestinal tracts and can ascend following rupture of membranes to cause intraamniotic infection. Although histopathology may reveal inflammation of the membranes (chorioamnionitis), cord necrosis and growth restriction are not typically present because chorioamnionitis is acute, in contrast to an insidious congenital syphilis infection. (Choice B) Partial hydatidiform moles, which typically result from fertilization of an ovum by 2 sperm, can cause enlarged, hydropic placental villi; the placenta typically has foci of trophoblastic proliferation. (Choice C) Placenta accreta spectrum occurs when placental villi implant on or invade into the uterine myometrium. Placental examination typically reveals missing (retained) placental tissue and adherent myometrial fibers. (Choice D) Rh(D) incompatibility, which occurs when maternal anti-D antibodies attack Rh(D)-positive fetal red blood cells, can lead to fetal anemia, growth restriction, and fetal and placental hydrops (eg, pale, enlarged placenta). However, it does not cause umbilical cord inflammation with abscess-like foci of necrosis. Educational objective: Patients with an atypical delivery (eg, preterm) require placental evaluation. Umbilical cord inflammation with abscess-like foci of necrosis suggests congenital syphilis (ie, spirochete infection with Treponema pallidum).

A 33-Year-Old Woman, Gravida 2 Para 1, at 32 Weeks