••• Chapter 12^ Obstetric Complications^113
❍ What percentage of childbearing age women show immunity to varicella zoster (chicken pox)?
95%.
❍ What life-threatening complications can affect a patient with adult onset varicella infection?
Encephalitis and pneumonia.
❍ What is the role of varicella zoster immunoglobulin (VZIG) and varicella vaccine in pregnancy?
VZIG is administered within 96 hours of significant exposure, and is 60% to 80% effective in preventing
infection. Varicella vaccine is an attenuated live virus, and should NOT be given during pregnancy. Acyclovir
can also be effective in preventing varicella when given prophylactically (800 mg po 5 × day for 5 to
7 days).
❍ What is the fetal effect of maternal parvovirus B-19 infection in pregnancy?
Most fetuses are unaffected. An increased risk of miscarriage is seen with early exposure, and rarely, a syndrome of
nonimmune hydrops can be seen. Parvo B-19 is thought to cause anemia by reducing supply rather than increasing
destruction of erythrocytes. Treatment is intrauterine blood transfusion.
❍ What is missing on microscopic examination of the placenta when placenta accreta, increta, and percreta?
Nitabuch layer, a line of separation between myometrium and invading trophoblasts.
❍ Name risk factors for placental abruption.
Smoking, trauma, cocaine, hypertension, preterm premature rupture of membranes, retroplacental fibroids,
multiple gestation, inherited thrombophilia, and possibly advanced age/parity, trauma, dysfibrinogenemia,
hydramnios, and intrauterine infections.
❍ The occurrence rate of placental abruption is?
1%.
❍ What is the recurrence rate of placental abruption?
15- to 20-fold higher.
❍ How accurate is U/S at detecting placental abruption?
50%.
❍ What complications can be anticipated in the use of a cell-saver autotransfusion for uterine or adnexal
surgery in the pregnant patient?
Potential amniotic fluid contamination (minimal after processing) and Rh incompatibility between maternal
and fetal blood.