Congenital infections are transmitted from mother to child, either before birth across the placenta * , or perinatally—after the protective membranes rupture (waters break) or during labor and delivery when the infant is exposed to
The developing fetus and newborn are protected from most infections by antibodies * in the mother's blood. Most congenital infections result from either a serious untreated maternal infection or a common—usually mild—infection for which the mother lacks antibodies.
Congenital infections can be caused by viruses, bacteria, or parasites * . The mother may have few or no symptoms and be unaware that she is infected. The consequences for the fetus or newborn may be disastrous: miscarriage, preterm labor, fetal or neonatal * death, birth defects, or serious illness.
Worldwide, HIV is the most dangerous congenital infection. An HIV-infected mother can transmit the virus to her baby through the placenta during labor and delivery, or through her breast milk. Without intervention about 15 to 45 percent of HIV-positive mothers will pass the virus to their infant. About 15 percent of HIV-infected newborns develop serious symptoms or die of AIDS within the first year. Without treatment half of these children die by the age of two years.
Hepatitis * B and C viruses can be transmitted to the infant during birth. In rare cases, hepatitis B can be transmitted through the placenta and may increase the risk of premature birth (birth before 37 weeks gestation).
Genital herpes * is caused by type 2 herpes simplex virus (HSV-2) or, less frequently, by HSV-1, which is the virus that usually causes cold sores. A first episode of genital herpes during pregnancy can be passed to the fetus because the mother does not yet have protective antibodies. It can cause preterm birth. If a mother has active genital herpes during childbirth, the infant may be born with facial or genital herpes, which in some cases has serious effects on the neonate.
Chlamydial infection * , caused by the bacterium Chlamydia trachomatis (truh-KO-mah-tis), and gonorrhea * , caused by the bacterium Neisseria gonorrhoeae (nye-SEER-e-uh gah-no-REE-eye), can be transmitted to the infant during passage through the birth canal, causing conjunctivitis * . Chlamydial infection can also cause premature membrane rupture and labor.
During pregnancy, if a woman is infected with syphilis * , which is caused by the bacterium Treponema pallidum (trep-o-NEE-mah PAL-id-um), or was inadequately treated for a previous infection, the bacteria can be transmitted either prenatally or perinatally. Unless the woman is treated with antibiotics, almost half of all fetuses infected during gestation die before or shortly after birth.
Cytomegalovirus (CMV), a member of the herpesvirus family *
If a woman contracts chickenpox—caused by the varicella zoster (varuh-SEH-luh ZOS-ter) virus, another member of the herpesvirus family—during the first 20 weeks of pregnancy, there is a 2 percent risk that her newborn will have congenital varicella syndrome, which includes multiple birth defects. The greatest risk is if the mother contracts the virus just before delivery, when she has not yet produced antibodies to protect the newborn. In this case, the baby may develop severe or even fatal chickenpox.
If contracted early in pregnancy, rubella virus infection—German measles—can be passed to the fetus through the placenta. Rubella infection during the first 10 weeks of pregnancy may cause miscarriage, fetal death, or premature delivery. More than 50 percent of infected newborns have severe birth defects.
Parvovirus B19 causes fifth disease in children, an acute disease that causes rash on cheeks and extremities with fever and malaise. About one-third of infants whose mothers contract fifth disease during pregnancy show signs of infection at birth. Although it is not usually dangerous, fifth disease contracted early in pregnancy can cause miscarriage or severe fetal anemia that can lead to congestive heart failure and fetal death.
Although invasive group B streptococcal (GBS) infection usually has no symptoms, in pregnant women it can cause uterine infections called amnionitis (am-nee-o-NYE-tiss) or stillbirth. GBS bacteria can be passed from mother to child shortly before or during birth.
Toxoplasmosis is caused by the one-celled parasite Toxoplasma gondii, which is commonly found in cats. Most cats that have toxoplasmosis are only infectious through their droppings for a several week period during initial infection. Most people infected with toxoplasmosis have no symptoms and most pregnant women have antibodies that protect the fetus. Women who become infected for the first time shortly before or during pregnancy can pass it to their fetuses, causing congenital toxoplasmosis. If maternal infection occurs during the third trimester * , the fetal infection rate is highest. The most severe fetal complications occur with first-trimester infections.
About 15 to 45 percent of pregnant women with untreated HIV transmit the virus to their fetuses or newborns. But in the United States, widespread HIV testing and antiretroviral (ARV) therapy (drugs used against any single-strand RNA viruses) have dramatically reduced the number of congenital HIV infections.
CMV is the most common viral infection affecting infants born in the United States, about one out of every 150 newborns. Some 50 to 80 percent of women of childbearing age have antibodies that protect against CMV. However, 1 to 4 percent of American mothers have their first or primary CMV infection during pregnancy and about one-third of these infections are transmitted to fetuses. Each year about 5,000 American children develop permanent disabilities due to congenital CMV infection.
Because most adults have chickenpox as children or are vaccinated against the disease, it is estimated that an American woman's risk of contracting varicella during pregnancy is less than 1 in 1,000. Likewise, in the past rubella was a major cause of birth defects; but routine vaccinations * have made prenatal * infection rare in the developed world.
About 50 percent of all women are infected with parvovirus as children or adolescents and have protective antibodies. Miscarriage due to parvovirus occurs in less than 5 percent of women who are infected during pregnancy.
GBS disease is the most frequent cause of life-threatening infection in newborns. Up to 20 percent of women carry GBS in their vaginas during the last trimester of pregnancy, with the potential of infecting the infant during birth. The use of antibiotics during delivery has decreased the rate of congenital GBS infections in the United States to 1,000 live births per year.
The Centers for Disease Control and Prevention (CDC) estimates that 25 to 45 percent of childbearing-age women carry the parasite that causes toxoplasmosis. In one-third of women infected for the first time during pregnancy, the parasite infects the placenta and enters the fetal circulation. Congenital infection occurs in 1 out of every 800 to 1,400 infants born to infected mothers.
Many HIV-infected infants do not have symptoms at birth. Children infected before birth generally develop symptoms of AIDS faster than adults. They may be sick from birth or fail to grow and develop at a normal rate.
Newborns with congenital hepatitis B may initially have no symptoms. Without vaccination about 90 percent eventually develop symptoms of chronic * hepatitis.
Congenital HSV infection may be limited to the skin or involve various organs. Widespread infection can result in permanent brain damage, intellectual disability * , or death. Initial symptoms of congenital herpes usually appear within four weeks of birth and may be mild:
More serious symptoms of congenital HSV infection include the following:
Congenital syphilis can cause premature birth and is a severe, disabling, and often life-threatening disease. If not treated early, it may cause facial deformity, blindness, deafness, neurological * conditions, and death.
A surviving newborn with untreated congenital syphilis may have no initial symptoms but may gain little weight and, during the first month of life, may develop the following:
Other early-stage symptoms of congenital syphilis include the following:
Most infants with congenital CMV have neither symptoms nor long-term problems. But a CMV infection in early pregnancy can cause birth defects and is a leading cause of congenital deafness. In later pregnancy, CMV infection may cause serious newborn illness.
About 10 to 15 percent of infants with congenital CMV infection have symptoms at birth that may include the following:
Over the first few years of life, 0.5 to 15 percent of CMV-infected infants develop growth, development, hearing, vision, or neurological problems.
A fetus infected with varicella zoster early in gestation may develop pocks that can cause limb deformities. Congenital varicella syndrome is characterized by the following:
Rubella infections contracted later in pregnancy do not cause congenital defects, although the newborn may become seriously ill and eventually develop diabetes * . Rubella infections early in pregnancy can result in congenital rubella syndrome (CRS), which is associated various birth defects, including the following:
Newborns with CRS also may have the following:
Although not usually dangerous, symptoms of congenital fifth disease include the following:
Maternal infection with GBS at conception or within the first two weeks of pregnancy may lead to hearing and vision loss and intellectual disability. GBS transmitted perinatally is the most common cause of sepsis * and meningitis in newborns and is a frequent cause of newborn pneumonia.
Although symptoms of congenital toxoplasmosis usually are very mild or absent, it can cause premature birth, low birthweight, or severe illness or death shortly after birth. Infection occurring early in fetal development can cause learning and motor * disabilities and other neurological symptoms. Other problems that may be present at birth or may not be apparent for months or years include the following:
Diagnosis of maternal, fetal, and congenital infections can be difficult. An obstetrician may diagnose a maternal infection based on a woman's symptoms and blood tests. Sometimes a fetal infection can be diagnosed using ultrasound * . In newborns, congenital infections may be diagnosed based on a physical exam, symptoms, and blood or urine tests. Ultrasound may be used to image the newborn's brain and an echocardiogram * may diagnose heart problems.
Infants born with serious infections are treated in a neonatal care unit with intravenous * (IV) drugs. Infants born to infected mothers may be treated with medications even if they show few or no signs of infection.
Most infants born to HIV-infected mothers test positive for maternal antibodies against HIV for 6 to 18 months after birth. Additional tests are performed to determine whether an infant is truly infected with HIV. Tests performed within 48 hours of birth detect only about 40 percent of HIV infections, so testing is repeated after one and six months. Treatment of congenital HIV infection with combination ARV drugs reduces child mortality by up to 67 percent.
Pneumonia caused by Pneumocystis carinii is often the first AIDS-related illness to appear in HIV-infected infants and is a major cause of death during the first year. The Centers for Disease Control and Prevention recommends that all babies born to HIV-infected mothers be treated with anti-pneumonia drugs beginning at four to six weeks and continuing until the infant is found to be HIV-negative.
Infants born to mothers infected with hepatitis B are given both the first dose of hepatitis B vaccine and hepatitis B immune globulin * within 12 hours of birth. The second and third doses of vaccine are given at one and six months of age.
Maternal HSV infection can be diagnosed by a culture * from an affected genital site, preferably on the first day of an outbreak, or a blood test. Newborns with congenital herpes are treated immediately with intravenous antiviral medications. Eye infections are treated with trifluridine drops. Although immediate medication may prevent or reduce the damage from HSV, one-half of infants born with severe HSV infections die and the other one-half may suffer brain damage.
Congenital chlamydial infection is treated with erythromycin eye ointment and oral * tablets. Conjunctivitis and pneumonia in newborns usually respond well to treatment with antibiotics.
An antibiotic ointment such as silver nitrate is placed under the eyelids of all newborns as preventive treatment for congenital gonorrhea. An infant born to a gonorrhea-infected mother is treated with intravenous antibiotics.
Congenital syphilis is identified during routine newborn blood testing and is treated with antibiotics. Syphilis in an older infant may be diagnosed by the following means:
Prenatal diagnosis of CMV may include blood tests for maternal antibodies and fetal ultrasound. Symptoms of congenital CMV, including retinitis, are treated with antiviral medications. With treatment most infants with congenital CMV survive, although almost all suffer from its effects.
Congenital chickenpox is treated immediately to prevent serious complications or death. There is no specific treatment for CRS; rather, infants are treated for specific conditions.
GBS can be diagnosed by culturing the bacteria from the blood, spinal fluid, skin, vagina, or rectum. Newborns infected with GBS are treated immediately with intravenous antibiotics. Although antibiotic treatment is very effective, about 5 percent of newborns with congenital GBS die.
Prenatal tests for toxoplasmosis include:
It has been suggested that all pregnant women and newborns be screened for toxoplasmosis.
Postnatal diagnosis of congenital toxoplasmosis may be based on the following:
Fetal toxoplasmosis may be treated by giving the mother pyrimethamine and sulfonamides during the later second and third trimesters of pregnancy. Newborns with symptoms of toxoplasmosis are treated with the following:
Although the consequences of congenital infections can be devastating, they are often relatively easy to prevent, because maternal treatment with antiviral medications or antibiotics reduces the risk to the fetus. The CDC recommends that on their first prenatal visit all pregnant women be screened for the following:
Sometimes pregnant women who are at high risk for hepatitis B infection are vaccinated. More than 95 percent of infants born to hepatitis B-infected mothers can be protected by administering the first dose of vaccine and immune globulin within 12 hours of birth.
Prevention of mother-to-fetus HSV transmission includes the following:
An examination or HSV test can indicate whether a pregnant woman has active genital herpes near the time of delivery. Outbreaks just prior to delivery may be prevented by treatment with antiviral drugs. Women with active herpes lesions are likely to deliver the fetus by cesarean section to reduce the risk of transmission.
Screening pregnant women for gonorrhea is important because women often do not know that they are infected, and antibiotic treatment can prevent congenital infection. Because women often are infected with both gonorrhea and chlamydia, a combination of antibiotics is used to treat the infections simultaneously. Likewise, adequate antibiotic treatment of a syphilis-infected pregnant woman protects the fetus from congenital disease.
Pregnant women should be tested for GBS between the 35th and 37th weeks of pregnancy to determine whether the bacteria are likely to be present during delivery. Pregnant women with GBS in their urine are treated with penicillin. Intravenous antibiotics may be administered from the moment following membrane rupture through labor and delivery. Antibiotic treatment reduces the risk of congenital GBS infection from 1 in 200 to 1 in 4,000.
Treatment with spiramycin for toxoplasmosis occurring within the first or early second trimester of pregnancy can prevent transmission to the fetus. It is important that pregnant women take measures to avoid Toxoplasma infection by taking the following measures:
See also AIDS and HIV Infection • Chickenpox (Varicella) • Chlamydial Infections • Cytomegalovirus (CMV) Infection • Fifth Disease • German Measles (Rubella) • Gonorrhea • Hepatitis • Herpes Simplex Virus Infections • Sexually Transmitted Infections (STIs): Overview • Shingles (Herpes Zoster) • Streptococcal Infections • Syphilis • Toxoplasmosis • Zika Virus Infection
Dyer, O. “Zika Virus Spreads Across Americas as Concerns Mount Over Birth Defects.” British Medical Journal 351 (December 23, 2015).
Kumar, Bid, and Alfirevic, Zarko, eds. Fetal Medicine. Cambridge, UK: Cambridge University Press, 2016.
Lowdermilk, Deitra, et al., eds. Maternity & Women's Health Care, 11th edition. St. Louis, MO: Elsevier, 2016.
Emory University School of Medicine, Department of Pediatrics. “Congenital Infections.” http://www.pediatrics.emory.edu/divisions/neonatology/dpc/conginf.html (accessed March 6, 2016).
Mayo Clinic. “Cytomegalovirus (CMV) Infection.” http://www.mayoclinic.org/diseases-conditions/cmv/basics/symptoms/con-20029514 (accessed March 6, 2016).
American Congress of Obstetricians and Gynecologists. 409 12th Street SW, Washington, DC 20024. Telephone: 202-638-5577. Toll-free: 800-673-8444. Website: http://www.acog.org (accessed March 6, 2016).
Centers for Disease Control and Prevention. 1600 Clifton Rd., Atlanta, GA 30329-4027. Toll-free: 800-232-4636. Website: http://www.cdc.gov (accessed March 6, 2016).
March of Dimes. 1275 Mamaroneck Ave., White Plains, NY 10605. Telephone: 914-997-4488. Website: www.marchofdimes.org (accessed March 6, 2016).
* placenta (pluh-SEN-ta) is an organ that provides nutrients and oxygen to a developing baby; it is located within the womb during pregnancy.
* antibodies (AN-tih-bah-deez) are protein molecules produced by the body's immune system to help fight specific infections caused by microorganisms, such as bacteria and viruses.
* parasites (PAIR-uh-sites) are organisms such as a protozoan (one-celled animals), worm, or insect that must live on or inside a human or other organism to survive. An animal or plant harboring a parasite is called its host. A parasite lives at the expense of the host and may cause illness.
* neonatal (ne-o-NAY-tal) means pertaining to the first four weeks after birth.
* hepatitis (heh-puh-TIE-tis) is an inflammation of the liver. Hepatitis can be caused by viruses, bacteria, and a number of other noninfectious medical conditions.
* chlamydial infection (kla-MIHdee- ul) can occur in various forms in which the bacteria can invade the urinary and genital systems of the body, as well as the eyes and lungs. One of its most common forms is a sexually transmitted infection (STI), usually passed from one person to another through unprotected sexual intercourse.
* herpes (HER-peez) is a viral infection that can produce painful, recurring skin blisters around the mouth or the genitals, and sometimes symptoms of infection elsewhere in the body.
* gonorrhea (gah-nuh-REE-uh) is a sexually transmitted infection (STI) spread through all forms of sexual intercourse. The bacteria can also be passed from an infected mother to her baby during childbirth. Gonorrhea can affect the genitals, urethra, rectum, eyes, throat, joints, and other tissues of the body.
* conjunctivitis (kon-jung-tih-VY-tis), often called pink eye, is an inflammation of the thin membrane that lines the inside of the eyelids and covers the surface of the eyeball. Conjunctivitis can be caused by viruses, bacteria, allergies, chemical irritation, and other conditions or diseases that cause inflammation.
* syphilis (SIH-fih-lis) is a sexually transmitted infection that, if untreated, can lead to serious lifelong problems throughout the body, including blindness and paralysis.
* herpesvirus family (her-peez-VYrus) is a group of viruses that can store themselves permanently in the body. The family includes varicella zoster virus, Epstein-Barr virus, and herpes simplex virus.
* trimester (tri-MES-ter) is any of three periods of approximately three months each into which a human pregnancy is divided.
* vaccinations (vak-sih-NAYshunz), also called immunizations, are the giving of doses of vaccines, which are preparations of killed or weakened germs, or a part of a germ or product it produces, to prevent or lessen the severity of the disease that can result if a person is exposed to the germ itself.
* prenatal (pre-NAY-tal) means existing or occurring before birth, with reference to the fetus.
* chronic (KRAH-nik) lasting a long time or recurring frequently.
* nasal (NA-zal) of or relating to the nose.
* rectum is the final portion of the large intestine, connecting the colon to the outside opening of the anus.
* vagina (vah-JY-nah) is the canal, or passageway, in a woman that leads from the uterus to the outside of the body.
* feces (FEE-seez) is the excreted waste from the gastrointestinal tract.
* cataracts (KAH-tuh-rakts) are areas of cloudiness of the lens of the eye that can interfere with vision.
* liver is a large organ located beneath the ribs on the right side of the body. The liver performs numerous digestive and chemical functions essential for health.
* encephalitis (en-seh-fuh-LYE-tis) is an inflammation of the brain, usually caused by a viral infection.
* pneumonia (nu-MO-nyah) is inflammation of the lungs.
* meningitis (meh-nin-JY-tis) is an inflammation of the meninges, the membranes that surround the brain and the spinal cord. Meningitis is most often caused by infection with a virus or a bacterium.
* neurological (nur-a-LAH-je-kal) refers to the nervous system, which includes the brain, spinal cord, and the nerves that control the senses, movement, and organ functions throughout the body.
* lymph nodes (LIMF) are small, bean-shaped masses of tissue containing immune system cells that fight harmful microorganisms. Lymph nodes may swell during infections.
* spleen is an organ in the upper left part of the abdomen that stores and filters blood. As part of the immune system, the spleen also plays a role in fighting infection.
* failure to thrive is a condition in which an infant fails to gain weight and grow at the expected rate.
* lesions (LEE-zhuns) is a general term referring to a sore or a damaged or irregular area of tissue.
* anus (A-nus) is the opening at the end of the digestive system, through which waste leaves the body.
* hernias (HER-nee-ah) are protrusions of organs through connective tissue or cavity walls.
* jaundice (JON-dis) is a yellowing of the skin, and sometimes the whites of the eyes, caused by a buildup in the body of bilirubin, a chemical produced in and released by the liver. An increase in bilirubin may indicate disease of the liver or certain blood disorders.
* retinitis (reh-tin-EYE-tis) is an inflammation of the retina, the nerve-rich membrane at the back of the eye on which visual images form.
* microcephaly (my-kro-SEH-fahlee) is the condition of having an abnormally small head, which typically results from having an under-developed or malformed brain.
* diabetes (dye-uh-BEE-teez) is a condition in which the body's pancreas does not produce enough insulin or the body cannot use the insulin it makes effectively, resulting in increased levels of sugar in the blood. This can lead to increased urination, dehydration, weight loss, weakness, and a number of other symptoms and complications related to chemical imbalances within the body.
* bone marrow is the soft tissue inside bones where blood cells are made.
* joint is the structure where two or more bones come together, allowing flexibility and motion of the skeleton.
* sepsis is a potentially serious spreading of infection, usually bacterial, through the blood-stream and body.
* motor relates to body movement.
* macrocephaly (ma-kro-SEH-fahlee) means having an abnormally large head.
* hydrocephaly (hi-dro-SEHfah- lee) means having an abnormally large amount of cerebrospinal fluid in the brain, resulting in an enlarged skull and brain atrophy.
* seizures (SEE-zhurs) are sudden bursts of disorganized electrical activity that interrupt the normal functioning of the brain, often leading to uncontrolled movements in the body and sometimes a temporary change in consciousness.
* echocardiogram (eh-ko-KARdee- uh-gram) is a diagnostic test that uses sound waves to produce images of the heart's chambers and valves and blood flow through the heart.
* ultrasound also called a sonogram, is a diagnostic test in which sound waves passing through the body create images on a computer screen.
* intravenous (in-tra-VEE-nus) or IV, means within or through a vein. For example, medications, fluid, or other substances can be given through a needle or soft tube inserted through the skin's surface directly into a vein.
* immune globulin (ih-MYOON GLAH-byoo-lin), also called gamma globulin, is the protein material that contains antibodies.
* culture (KUL-chur) is a test in which a sample of fluid or tissue from the body is placed in a dish containing material that supports the growth of certain organisms. Typically, within days the organisms will grow and can be identified.
* oral means by mouth or referring to the mouth.
* central nervous system (SEN-trul NER-vus SIS-tem) is the part of the nervous system that includes the brain and spinal cord.
* ophthalmologic (off-thal-MOLLo-jik) means related to the function, structure, and diseases of the eye.
* heart failure is a medical term used to describe a condition in which a damaged heart cannot pump enough blood to meet the oxygen and nutrient demands of the body. People with heart failure may find it hard to exercise due to the insufficient blood flow, but many people live a long time with heart failure.
* blood transfusion is the process of giving blood (or certain cells or chemicals found in the blood) to a person who needs it due to illness or blood loss.
* cerebrospinal fluid (seh-ree-bro- SPY-nuhl) is the fluid that surrounds the brain and spinal cord.
* neurologic exam refers to systematic tests of how well various parts of the nervous system are functioning.
* CT scans, computed tomography (to-MOG-ra-fee) scans, or CAT (computerized axial tomography) scans, use computers to view structures inside the body.
* corticosteroids (kor-tih-ko-STIRoyds) are chemical substances made by the adrenal glands that have several functions in the body, including maintaining blood pressure during stress and controlling inflammation. They can also be given to people as medication to treat certain illnesses.
* cesarean section (si-ZAR-ee-an SEK-shun) is the surgical incision of the walls of the abdomen and uterus to deliver offspring in cases where the mother cannot deliver through the vagina.
* formula is a prepared, nutritious drink or a dry drink mix designed specifically for infants.
* microorganism is a tiny organism that can be seen only by using a microscope. Types of microorganisms include fungi, bacteria, and viruses.
* unpasteurized (un-pas-CHURized) refers to foods that have not undergone the process of pasteurization (pas-chu-rih-ZAYshun), in which food is heated to a certain temperature over a period of time to kill organisms and help make the food safer to consume.