Vertical Transmission of Infections: Types, Complications, and Prevention

Introduction:

Pathogenic bacteria and viruses can rupture the placental barrier in utero during pregnancy or can be transmitted vertically during childbirth or at the time of breastfeeding. This is known as the vertical transmission of diseases. Some of the pathogenic microbial organisms that can be vertically transmitted include HIV (human immunodeficiency virus), herpes virus, cytomegaloviruses, Toxoplasma gondii, Treponema species, and rubella have been found to spread from mother to her embryo or baby via these various routes.

Vertical transmission of pathogenic infections can affect the health of both the mother and her embryo or the newborn baby in the long run. Infants infected prenatally (before the birth of the child) or during the perinatal (immediately after the birth of the child within a few hours) period may suffer from developmental anomalies, delayed motor and sensory responses, cognitive disabilities, hearing impairment, or loss of vision, and other neurological disorders. Also, mothers who spread the infection from their bodies to their offspring usually suffer from psychological stress and social stigma. They are also at a higher risk of acquiring frequent infections and developing serious complications in future pregnancies.

It is important to identify the infection present in the mother at an early stage and treat it accordingly to prevent the vertical transmission of the disease. Along with this, proper interventions should be done during childbirth and during postpartum care of the baby and mother. Postpartum care may include drug therapy (antibiotic or antiviral), planned cesarean surgery, and preventing the child from breastfeeding in certain situations.

What Is Vertical Transmission of Infections?

Vertical transmission of infections refers to the generational transmission of a pathogenic agent from a pregnant woman to her fetus, offspring, or baby through breast milk, placenta, or genital tract at the time of delivery. This vertical mode of transmission can occur during pregnancy (in utero). It may result in several outcomes depending on the type of pathogen involved and the severity of the microbial infection. A plethora of microbial pathogens, including bacteria, viruses, and parasites, can be involved.

Some of the vertically transmitted infections include HIV, measles, hepatitis, toxoplasmosis, herpes simplex viral infection, and syphilis. Sometimes, the mother remains asymptomatic despite the presence of an infection, but the infection, if transmitted to the newborn baby, can have serious implications. It can severely affect the health of the baby, sometimes leading to death.

What Are the Types of Vertical Transmission of Infections?

• Transplacental Transmission of Pathogens: The pathogen crosses the placental barrier and infects the embryonic fetus directly in this form of vertical transmission,

• Perinatal Transmission of Infections: This type of transmission occurs during the delivery of the child, where the infant may come in close proximity to the infected fluids of the mother.

• Breast Milk Vertical Transmission: HIV infection can be vertically transmitted through the mother’s breast milk to the child.

• Intrauterine Transmission: This occurs when the infected microbial pathogen contaminates the fetus before delivery, mainly via the amniotic fluid.

• Hereditary Transmission: In this type, the infection may be vertically transmitted through the generations in a family, as in the case of genetic diseases.

Which Infections Can Be Transmitted Vertically?

The most commonly encountered infections that can be transmitted vertically include:

• AID (Acquired Immunodeficiency Syndrome): AIDS is a fatal infection caused by HIV. This chronic condition can be passed down from the mother to the newborn baby throughout pregnancy, during childbirth, and while breastfeeding the baby.

• Syphilis: Syphilis is a contagious disease caused by the bacterium Treponema pallidum. This infection can spread to a baby either in utero or during delivery while coming in contact with the maternal fluids.

• Rubella: Also known as German measles, it is a type of viral infection. It can lead to severe developmental anomalies during childbirth and even death in some babies if the mother contracts the deadly virus during her pregnancy.

• Cytomegalovirus: Cytomegalovirus can infect the newborn baby and pose serious health hazards if it is vertically transmitted during in utero.

• Hepatitis B and C Viral Infection: Hepatitis B and C cause liver inflammation, sometimes causing liver damage. It can affect the baby if it is transmitted from mother to fetus during the course of pregnancy.

• Herpes Virus Infection: Herpes is a viral infection caused by the herpes simplex virus. It can also be transmitted from the mother to the child during pregnancy or during the perinatal period.

• Zika Infection: Zika virus has been identified recently as a vertically transmissible viral infection. It can pose serious health hazards in a newborn baby or fetus, including microcephaly if transmitted during pregnancy.

• Certain Bacterial Infections: Bacteria like Streptococci, Neisseria gonorrhoeae, and Chlamydia trachomatis can cause serious health complications in newborn babies if they are vertically passed down from the mother to her fetus.

• COVID-19 Vertical Transmission: COVID-19 vertical transmission can occur in a few cases. Pregnant ladies who are contaminated with COVID-19 during the third trimester of their pregnancy are at an increased risk of vertical transmissibility. Common clinical manifestations of COVID-19 in infants include acute respiratory distress syndrome, fever with chills, and feeding problems.

What Are the Complications of Vertical Transmission of Infections?

• Respiratory distress can cause rapid breathing and coughing.

• The skin rash in infants.

• Jaundice.

• Liver and spleen enlargement.

• Seizures.

• Increased pressure in the brain causes brain swelling (hydrocephalus).

• Babies born with low weight.

• Heart defects.

• Hearing and vision problems.

• Cognitive disabilities.

• Liver damage.

• Mortality in severe cases.

How to Prevent Vertical Transmission of Infections?

• Practice safe sex by using condoms during sex. It is especially important for pregnant women to prevent the vertical transmission of infection to the fetus.

• Pregnant women should be vaccinated against all possible infections.

• Avoid physical contact with an infected individual.

• Prenatal screening for all possible infectious diseases should be done to prevent vertical transmissibility.

• Provide proper antiviral or antibiotic therapy to the affected individual in case of recurrent infections.

Conclusion:

Vertical transmission of infection is caused by the passing down of infection from the mother to her embryonic fetus in utero or immediately after birth. It is important to prevent the vertical transmission of such viral and bacterial infections. There is an utmost need to protect infants from vertical transmission to safeguard their health. The COVID-19 pandemic has increased the demand for rapid research to prevent the spread of infection. More research is required to identify the mechanism of vertical transmission of infections.