Clinical Review
UPDATE ON OBSTETRICS
The drive to do more and do it faster continues, leading to notable advances in prenatal diagnosis and fetal therapy, but is not sustainable over...
American College of Obstetricians and Gynecologists. Committee Opinion No. 608: Influenza vaccination during pregnancy. Obstet Gynecol. 2014;124(3):648–651.
We no longer consider pregnancy an immunosuppressed state but, rather, a more immune-modulated system. However, there is no question that the unique physiologic state of pregnancy places a woman and her fetus at increased risk for infection. This was devastatingly obvious during the H1N1 epidemic of 2009 and was reemphasized during a 2014 outbreak of Listeria monocytogenes. We are reminded again during the largest Ebola virus outbreak in history in West Africa, where women have been disproportionately affected.
No neonates have survived Ebola
Although Ebola infections in the United States have been very few, vigilance for people at risk of infection and preparedness to act in the case of infection are vitally important.
The Ebola virus is thought to be spread to humans through contact with infected fruit bats or primates. Human-to-human transmission occurs through direct contact with blood or body fluids (urine, feces, sweat, saliva, breast milk, vomit, semen) of an infected person or contaminated objects (needles, syringes). The incubation period is 2 to 21 days (average, 8–10 days).
Infected people become contagious only upon the appearance of fever and symptoms, which include headache, muscle pain, fatigue, weakness, diarrhea, abdominal pain, vomiting, bleeding, and bruising. The differential diagnosis includes malaria, typhoid, Lassa fever, meningococcal disease, influenza, and Marburg virus.
Treatment of Ebola is supportive care and isolation (standard, contact, and droplet precautions). Prevention is through infection-control precautions and isolation and testing of those exposed, with monitoring for 21 days.
Although pregnant women are not thought to be more susceptible to infection, they are at increased risk of severe illness and mortality, as well as spontaneous abortion and pregnancy-related hemorrhage. No neonates of women infected with Ebola have survived to date.
The CDC recommends that physicians screen patients who have traveled to West Africa and those with fevers and implement appropriate isolation and infection-control precautions. Many hospitals have developed Ebola task forces with this in mind.
Updated information is available at www.cdc.gov/vhf/ebola/index.html.
Pregnant women are highly susceptible to Listeriosis
A nationwide food recall in mid-2014 prompted significant media attention to L monocytogenes, particularly its effect on pregnant women, who have an incidence of Listerial infection 13 times higher than the general population. Although maternal illness is relatively mild, ranging from a complete lack of symptoms to febrile diarrhea, there is an increased risk to the fetus or neonate of loss, preterm labor, neonatal sepsis, meningitis, and death. The perinatal mortality rate is 29%.
The mainstay of prevention during pregnancy is improved food safety and handling, as well as counseling of pregnant women to avoid unpasteurized soft cheeses, raw milk, and unwashed fruits and vegetables, and to avoid or heat thoroughly lunch meats and hot dogs.
When a pregnant woman is exposed to Listeria, management depends on the clinical scenario, as outlined by ACOG:
- Asymptomatic pregnant women do not require testing, treatment, or fetal surveillance. Any development of symptoms within 2 months may justify further evaluation, however.
- Pregnant women with mild gastro-intestinal or flulike symptoms but no fever also can be managed expectantly. Blood cultures may be appropriate; if positive, antibiotic therapy should be initiated.
- A febrile pregnant woman should have blood cultures assessed and be started on antibiotics. The preferred regimen is intravenous ampicillin 6 g/day with or without gentamicin for 14 days. If delivery occurs, placental cultures may be assessed. Listeriosis also can be diagnosed by amniocentesis. Stool cultures are not recommended.
Influenza is largely preventable
It is important to remember that one of the most dangerous viruses for pregnant women can be prevented. However, only 38% to 52% of women who should have received the influenza vaccine around the time of pregnancy actually did so between 2009 and 2013, according to the ACOG Committee Opinion cited above. Pregnant and postpartum women are at increased risk of serious illness, prolonged hospitalization, and death from influenza infection.
The vaccine is safe and effective. Not only does it prevent maternal morbidity and mortality, but it reduces neonatal complications. Inactivated vaccine is recommended for all pregnant women at any gestational age during the flu season.
Because many women are hesitant to accept the vaccine, accurate education is essential to dispel misconceptions about it and its components. It has been shown that if an obstetric clinician recommends the vaccine and makes it available, pregnant patients are five to 50 times more likely to receive it. As obstetricians, we are compelled to make this a priority in our practice.
