In the general perception of mother-to-child transmission (MTCT) there are often fault zones where mother-to-child transmission occurs only during childbirth. However, mother-to-child transmission is a more complex process that involves multiple stages of pregnancy.
Mother-to-child transmission, also known as vertical transmission, does present a high risk of transmission during childbirth. When the foetus passes through the womb, it is likely to be exposed to endocrines containing pathogens in the mother’s womb, e.g., mothers living with AIDS, where there may be HIV in the production tract, and where the foetus is likely to inhale or be exposed during childbirth, thereby contracting the virus. Similarly, for mothers suffering from syphilis, the syphilis spiral in the delivery tract may attack the skin, mucous membranes, etc. of the foetus during childbirth, leading to syphilis infection in the newborn. The rates of mother-to-child transmission during childbirth vary according to the type of disease, but in general this stage is one of the key points of mother-to-child transmission.
However, mother-to-child transmission is by no means limited to the moment of birth. During pregnancy, especially in the late stages of pregnancy, as the placenta age and penetration increase, some viruses can enter the foetus through the placenta barrier. Like the hepatitis B virus, the hepatitis B virus in a pregnant woman may cross the placenta during pregnancy, infecting the fetus’ liver cells, making the foetus a carrier of hepatitis B virus before birth. If the rubella virus is infected with a pregnant woman and is not dealt with in a timely manner in the early stages of pregnancy, the virus can be infected by placenta, which can cause congenital rubella syndrome in the foetus, leading to serious heart malformations, hearing impairments and eye defects.
In addition, before delivery, if the foetal membranes are broken early, the water of the sheep is released and if the water is contaminated by pathogens, the foetus is exposed to the infected environment, increasing the risk of infection. Moreover, some viruses may be in a latent state in pregnant women and are activated during pregnancy by certain factors, such as the megacell virus, which can enter the placenta through blood circulation, thereby affecting the development of the foetus or causing infection.
It is worth noting that the risk of mother-to-child transmission may also exist in the post-natal breastfeeding chain. For example, the human immunodeficiency virus (HIV) can be found in breast milk, and if the mother is infected with HIV and no effective mother-to-child cut-off measures are in place, infants may be infected with HIV by ingestion of breast milk containing the virus during the breastfeeding process. Similarly, the Hepatitis B virus can be transmitted to infants through milk, and although the widespread application of the Hepatitis B vaccine and the Hepatitis B immunoglobin significantly reduces the risk of such transmission, it cannot be ignored.
Understanding the multiple ways and complexities of mother-to-child transmission is essential to prevent mother-to-child transmission. Periodic check-ups during pregnancy are essential for pregnant women at risk of infectious diseases. During pregnancy screening, it is possible to detect, in a timely manner, whether or not pregnant women are infected with certain infectious diseases and to take appropriate measures to stop them. For example, pregnant women with hepatitis B have access to antiretroviral treatment during pregnancy, reducing the internal load of the virus and reducing the risk of mother-to-child transmission; and pregnant women with AIDS have access to anti-retroviral treatment under the guidance of a doctor, as well as to suitable methods of delivery and feeding, such as uterine and artificial feeding, in order to minimize the incidence of mother-to-child transmission. In cases of vaccine-preventable infections such as rubella virus, female vaccination against rubella before pregnancy is effective in avoiding foetal injuries due to pregnancy infection.
Mother-to-child transmission does not occur only at the time of delivery, but extends throughout pregnancy, childbirth and the post-natal period. We should move away from this one-sided perception and increase awareness of the comprehensive nature of mother-to-child transmission in order to better take preventive measures, guarantee mother-to-child health, reduce the incidence of congenital infections and create a safer environment for the birth and growth of new lives.
