Maternal infections are any infections occurring in a pregnant individual, caused by viruses, bacteria, parasites, or fungi. While some are mild, others pose significant health risks to both the pregnant person and the developing fetus or newborn. Due to physiological changes and a suppressed immune system, pregnant individuals can be more susceptible to certain infections.
Impact on Mother and Baby
Maternal infections can lead to complications for the pregnant individual, including increased illness severity, organ involvement, and a higher risk of preterm labor. Untreated urinary tract infections, for instance, can progress to kidney infections, potentially causing preterm labor. Intra-amniotic infections (chorioamnionitis) can trigger uterine contractions, contributing to preterm delivery. Some infections also increase the risk of postpartum complications like hemorrhage or uterine infection.
The impact on the developing fetus or newborn can range from mild to severe, including congenital infections, developmental issues, prematurity, low birth weight, and stillbirth. Vertical transmission, where the infection passes from mother to child, can occur during pregnancy through the placenta, during labor and delivery through the birth canal, or after birth through breastfeeding. Congenital infections can cause specific organ damage, developmental delays, hearing loss, vision problems, and in severe cases, life-threatening conditions like sepsis or meningitis. The severity of fetal complications often depends on the type of pathogen, the timing of the infection during pregnancy, and the extent of the inflammatory response.
Common Infections During Pregnancy
Group B Streptococcus (GBS) is a common bacterium found in the vagina or rectum of about 25% of pregnant women, often without symptoms. While generally harmless to the mother, GBS can be transmitted to the baby during vaginal delivery, potentially causing serious illnesses like sepsis, pneumonia, or meningitis in newborns. Screening for GBS is typically performed between 35 and 37 weeks of gestation.
Urinary Tract Infections (UTIs) are bacterial infections that frequently occur in pregnant individuals due to hormonal changes and pressure from the growing uterus on the bladder. If untreated, UTIs can lead to more severe kidney infections (pyelonephritis), which may increase the risk of preterm labor and low birth weight. Symptoms can include painful or frequent urination, cloudy urine, or lower back pain.
Rubella, also known as German measles, is a viral infection that typically causes mild flu-like symptoms and a rash in adults. If contracted during pregnancy, especially in the first trimester, it can cause severe birth defects in the baby, a condition known as congenital rubella syndrome (CRS). These defects can include deafness, cataracts, heart problems, intellectual disabilities, and low birth weight.
Cytomegalovirus (CMV) is a common herpes virus that most adults have been infected with by age 40, often without knowing. If a pregnant person acquires a new CMV infection during pregnancy, there is a risk of passing it to the baby, leading to congenital CMV. Congenital CMV can result in hearing loss, developmental delays, vision problems, and issues with the spleen or liver in the newborn.
Toxoplasmosis is a parasitic infection acquired from eating undercooked meat or contact with contaminated cat feces. If a pregnant individual gets toxoplasmosis, the parasite can cross the placenta and infect the fetus. This can lead to serious complications for the baby, including eye infections, brain damage, hydrocephalus (fluid on the brain), or microcephaly (unusually small head).
Parvovirus B19, also known as Fifth Disease, is a common viral infection that usually causes a mild rash in children. While often not serious for pregnant individuals, if infected, the virus can spread to the developing baby. Infection, particularly in the first half of pregnancy, can lead to severe anemia in the fetus and, in rare cases, miscarriage or stillbirth.
Sexually transmitted infections (STIs) such as Chlamydia, Gonorrhea, Syphilis, and HIV can also affect pregnancy. Chlamydia and Gonorrhea can increase the risk of preterm birth, eye infections, or pneumonia in infants. Syphilis can lead to stillbirth, premature birth, or congenital syphilis, causing severe health problems for the baby. HIV, while treatable with medications to reduce transmission, can still be passed from mother to baby during pregnancy, birth, or through breastfeeding if untreated.
Influenza (flu) and COVID-19 are respiratory viral infections that can pose increased risks during pregnancy. Pregnant individuals are more susceptible to severe illness from these viruses due to changes in their immune system. Complications can include pneumonia, hospitalization, and an increased risk of miscarriage, preterm birth, or stillbirth.
Prevention and Management
Preventing maternal infections involves a combination of proactive measures and routine healthcare practices. Vaccination plays a significant role in reducing the risk of certain infections during pregnancy. Healthcare providers generally recommend the influenza vaccine for all pregnant individuals during flu season and the Tdap vaccine (tetanus, diphtheria, and pertussis) during the third trimester. The Tdap vaccine helps to pass protective antibodies to the newborn, offering protection against whooping cough in early infancy.
Good hygiene practices are also important for prevention. This includes frequent handwashing with soap and water, especially after using the bathroom, before eating, and after coughing or sneezing. Avoiding close contact with sick individuals and refraining from sharing personal items can further reduce exposure to pathogens. Food safety is another key aspect, which involves cooking meat thoroughly to recommended internal temperatures, avoiding unpasteurized dairy products, and washing fruits and vegetables. Pregnant individuals are advised to avoid handling cat litter to prevent toxoplasmosis.
Early diagnosis and monitoring are achieved through regular prenatal check-ups and screening tests. Healthcare providers often screen for infections like Group B Streptococcus, Syphilis, HIV, and Hepatitis B and C during initial prenatal visits. Additional screenings may occur later in pregnancy or if risk factors are identified. These tests measure antigen or antibody levels or involve specialized genetic tests to determine infection status or immunity.
Treatment approaches for maternal infections vary depending on the specific pathogen. Bacterial infections are typically managed with antibiotics, which are chosen based on their safety profile during pregnancy. Viral infections may involve antiviral medications, such as acyclovir for herpes simplex virus or oseltamivir for influenza. For some viral infections like Cytomegalovirus, specific treatments during pregnancy are limited, and management focuses on monitoring the fetus for complications. Treatment plans are individualized and determined by healthcare professionals, considering the type of infection, gestational age, and potential risks and benefits for both the pregnant individual and the baby.