Perinatal infections

Definition

An infection caused by a bacteria or virus that can be passed from a mother to her baby during pregnancy or delivery is called a perinatal infection.

Description

Perinatal infections include bacterial or viral illnesses that can be passed from a mother to her baby either while the baby is still in the uterus, during the delivery process, or shortly after birth. Maternal infection can, in some cases, cause complications at birth. The mother may or may not experience active symptoms of the infection during the pregnancy. The most serious and most common perinatal infections, and the impact of these diseases on the mother and infant, are discussed below in alphabetical order. It is important to note that men can become infected and can transmit many of these infections to other women. The sexual partners of women who have these infections should also seek medical treatment.

Causes & symptoms

Chlamydia

Cytomegalovirus

Cytomegalovirus (CMV) is a very common virus in the herpes virus family. It is found in saliva, urine and other body fluids and can be spread through sexual contact or other more casual forms of physical contact like kissing. In adults, CMV may cause mild symptoms of swollen lymph glands, fever, and fatigue. Many people who carry the virus experience no symptoms at all. Infants can become infected with CMV while still in the uterus if the mother becomes infected or develops a recurrence of the infection during pregnancy. Most infants exposed to CMV before birth develop normally and do not show any symptoms. As many as 6,000 infants who were exposed to CMV before birth are born with serious complications each year. CMV interferes with normal fetal development and can cause mental retardation, blindness, deafness, or epilepsy in these infants.

Genital herpes

Genital herpes, which is usually caused by Herpes simplex virus type 2 (HSV-2), is a sexually transmitted disease that causes painful sores on the genitals. Women who have their first outbreak of genital herpes during pregnancy are at high risk of miscarriage or delivering a low birth weight baby. The infection can be passed to the infant at the time of delivery if the mother has an active sore. The most serious risk to the infant is the possibility of developing HSV-2 encephalitis, an inflammation of the brain, with symptoms of irritability and poor feeding.

Hepatitis B

Hepatitis B is a contagious virus that causes liver damage and is a leading cause of chronic liver disease and cirrhosis. Approximately 20,000 infants are born each year to mothers who test positive for the hepatitis B virus. These infants are at high risk for developing hepatitis B infection through exposure to their mothers blood during delivery.

Human immunodeficiency virus (HIV)

Human immunodeficiency virus (HIV) is a serious, contagious virus which causes acquired immunodeficiency syndrome (AIDS). About one-fourth of pregnant women with HIV pass the infection on to their newborn infants. An infant with HIV usually develops AIDS and dies before the age of two.

Human papillomavirus

Human papillomavirus (HPV) is a sexually transmitted disease that causes genital warts and can increase the risk of developing some cancers. HPV appears to be transferred from the mother to the infant during the birth process.

Rubella (German measles)

Rubella is a virus that causes German measles, an illness that includes rash, fever, and symptoms of an upper respiratory tract infection. Most people are exposed to rubella during childhood and develop antibodies to the virus so they will never get it again. Rubella infection during early pregnancy can pass through the placenta to the developing infant and cause serious birth defects including heart abnormalities, mental retardation, blindness, and deafness.

Streptococcus

Group B streptococcus (GBS) infection is the most common bacterial cause of infection and death in newborn infants. In women, GBS can cause vaginitis and urinary tract infections. Both infections can cause premature birth and the bacteria can be transferred to the infant in the uterus or during delivery. GBS causes pneumonia, meningitis, and other serious infections in infants.

Syphilis

Syphilis is a sexually transmitted bacterial infection that can be transferred from a mother to an infant through the placenta before birth. Up to 50% of infants born to mothers with syphilis will be premature, stillborn, or will die shortly after birth. Infected infants may have severe birth defects. Those infants who survive infancy may develop symptoms of syphilis up to two years later.

Diagnosis

Chlamydia

Chlamydial bacteria can be diagnosed by taking a cotton swab sample of the cervix and vagina during the third trimester of the pregnancy. Chlamydial cell cultures take three to seven days to grow but many laboratories are not equipped to run the tests necessary to confirm the diagnosis.

Ctyomegalovirus

Past or recent infection with CMV can be identified by antibody tests and CMV can be grown from body fluids.

Genital herpes

The appearance of a genital sore is enough to suspect an outbreak of genital herpes. The sore can be cultured and tested to confirm that HSV-2 is present.

Hepatitis B

A blood test can be used to screen pregnant women for the hepatitis B surface antigen (HBsAg) in prenatal health programs.

Human immunodeficiency virus (HIV)

HIV can be detected using a blood test and is part of most prenatal screening programs.

Human papillomavirus

HPV causes the growth of warts in the genital area. The wart tissue can be removed with a scalpel and tested to determine what type of HPV virus caused the infection.

Rubella (German measles)

Pregnant women are usually tested for antibodies to rubella, which would indicate that they have been previously exposed to the virus and therefore would not develop infection during pregnancy if exposed.

Streptococcus

GBS can be detected by a vaginal or rectal swab culture, and sometimes from a urine culture. Blood tests can be used to confirm GBS infection in infants who exhibit symptoms.

Syphilis

Pregnant women are usually tested for syphilis as part of the prenatal screening.

Treatment

Chlamydia

Pregnant women can be treated during the third trimester with oral erythromycin, for 7-14 days depending on the dose used. Newborn infants can be treated with erythromycin liquid for 10-14 days at a dosage determined by their body weight.

Ctyomegalovirus

No drugs or vaccines are currently available for prevention or treatment of CMV.

Genital herpes

The antiviral drugs acyclovir or famciclovir can be administered to the mother during pregnancy. Little is known about the risks of these drugs to the fetus, however, the risk of birth defects does not seem to be any higher than for women who do not take these medications. Infants with suspected HSV-2 can be treated with acyclovir. Delivery of the infant by cesarean section is recommended if the mother has an active case of genital herpes.

Hepatitis B

Infants born to mothers who test positive to the HBsAg test should be treated with hepatitis B immune globulin at birth to give them immediate protection against developing hepatitis B. These infants, as well as all infants, should also receive a series of three hepatitis B vaccine injections as part of their routine immunizations.

Human immunodeficiency virus (HIV)

Pregnant women with HIV should be treated as early in the pregnancy as possible with zidovudine (AZT). Other newer drugs designed to treat HIV/AIDS may also be used during pregnancy with the knowledge that these drugs may have unknown effects on the infant. The risks and benefits of such treatments need to be discussed. Infants born with HIV should receive aggressive drug treatment to prevent development of AIDS.

Human papillomavirus

Genital warts are very difficult to treat and frequently reoccur even after treatment. They can be removed by cryotherapy (freezing), laser or electrocauterization (burning), or surgical excision (cutting) of the warts. Some medications (imiquimod 5% cream, podophyllin, trichloroacetic acid or topical 5-fluorouracil) can be applied to help dissolve genital warts. Cesarean delivery rather than vaginal delivery seems to reduce the risk of transmission of HPV from mothers to infants.

Rubella (German measles)

No treatment is available. Some health care providers may recommend giving the mother an injection of immune globulin (to boost the immune system to fight off the virus) if she is exposed to rubella early in the pregnancy. However, no evidence to support the use of these injections exists. Exposure to rubella early in pregnancy poses a high risk that the infant will have serious birth defects. Termination of the pregnancy may be considered. Women who have not been previously exposed to rubella will usually be vaccinated immediately after the first pregnancy to protect infants of future pregnancies.

Streptococcus

Pregnant women diagnosed with GBS late in the pregnancy should be treated with antibiotics injected intravenously to prevent premature labor. If transmission of GBS to the newborn infant is suspected or if the baby develops symptoms of infection, infants can be treated with antibiotics.

Syphilis

Antibiotic therapy, usually penicillin, given early in the pregnancy can be used to treat the infection and may prevent transmission to the infant.

Prognosis

Chlamydia

Without treatment, the most serious consequences of chlamydial infection are related to complications of premature delivery. Treatment of the mother with antibiotics during the third trimester can prevent premature delivery and the transfer of the infection to the baby. Infants treated with antibiotics for eye infection or pneumonia generally recover.

Ctyomegalovirus

The chance for recovery after exposure to CMV is very good for both the mother and the infant. Exposure to CMV can be very serious and even life threatening for mothers and infants whose immune systems are compromised, for example those receiving chemotherapy or who have AIDS/HIV infections. Those infants who develop birth defects after CMV exposure may have serious and life long complications.

Genital herpes

Once a woman or infant is infected, outbreaks of genital herpes sores can reoccur at any time during their lifetimes.

Hepatitis B

Infants treated at birth with the immune globulin and the series of vaccinations will be protected from development of hepatitis B infection. Infants infected with hepatitis B develop a chronic, mild form of hepatitis and are at increased risk for developing liver disease.

Human immunodeficiency virus (HIV)

Treatment with AZT during pregnancy significantly reduces the chance that the infant will be infected with HIV from the mother.

Human papillomavirus

Once infected with HPV, there is a life-long risk of developing warts and an increased risk of some cancers.

Rubella (German measles)

Infants exposed to rubella virus in the uterus are at high risk for severe birth defects including heart defects, blindness, and deafness.

Streptococcus

Infection of the urinary tract or genital tract of pregnant women can cause premature birth. Infants infected with GBS can develop serious and life threatening infections.

Syphilis

Premature birth, birth defects, or the development of serious syphilis symptoms is likely to occur in untreated pregnant women.

Prevention

Use of a barrier method of contraceptive (condom) can prevent transmission of some of the infections. Intravenous drug use and sexual intercourse with infected partners increases the risks of exposure to most of these infections. Pregnant women can be tested for many of the bacterial or viral infections described; however, effective treatment may not be available to protect the infant.

Key Terms

Cesarean section

A surgical procedure in which an incision is made in a woman's abdomen to deliver the infant from the uterus.

Ectopic pregnancy

A condition that ends in miscarriage, in which the fertilized ovum attaches somewhere other than in the uterus (for example in the fallopian tube or abdomen).

Encephalitis

Inflammation or swelling of the brain.

Perinatal

The period of time around the time of pregnancy and delivery.

Pneumonia

An infection and inflammation of the lungs which usually causes shortness of breath, cough, fever, and chest pain.

Further Reading

For Your Information

Books

• Toth, Peter P., and A. Jothivijayarani. "Obstetrics: Group B Streptococcal Infection" In University of Iowa Family Practice Handbook. 3rd ed. The Virtual Hospital Website: http://www.vh.org/Providers/ClinRef/FPHandbook/Chapter08/28-8.html.

  Periodicals

• "Program to Prevent Perinatal Hepatitis B Virus Transmission in a Health Maintenance Organization: Northern California, 1990-1995." Morbidity & Mortality Weekly Report 46(1997): 378-380.
• Schuchat, Anne. "Prevention of Perinatal Group B Streptococcal Disease: A Public Health Perspective." Morbidity & Mortality Weekly Report 45(1996).
• "Update: Perinatally Acquired HIV/AIDS: United States, 1997." Morbidity & Mortality Weekly Report 46(1997): 1086-1092.

  Other

• Larkin, Julie A., et al. "Recognizing and Treating Syphilis in Pregnancy." Medscape Women's Health 3(1998). http://www.medscape.com.
• McGregor, James A., and Janice I. French. "Preterm Birth: The Role of Infection and Inflammation." Medscape Women's Health 2(1997). http://www.medscape.com.
• Toney, John F., and Julie Larkin. "Contemporary Strategies for Detecting Chlamydial Infection in Women." Medscape Women's Health 1(1996). http://www.medscape.com.
• Woolley, Paul. "Genital Herpes: Treatment Guidelines." Medscape Women's Health 2(1997). http://www.medscape.com.

Gale Encyclopedia of Medicine. Gale Research, 1999.