HIV infection in pregnant women – a chronic progressive infectious disease caused by the pathogen from the group of retroviruses, and occurring before conception or gestational period. For a long period of time occurs latently.
When the primary reaction is manifested by hyperthermia, skin rash, lesions of the mucous membranes, a transient increase in lymph nodes, diarrhoea. In the subsequent occurs generalized lymphadenopathy, gradually losing weight, develop HIV-associated disorders. Is diagnosed by laboratory methods (ELISA, PCR, investigation of cellular immunity). For the treatment and prevention of vertical transmission antiretroviral therapy is applied.
HIV infection in pregnant women
HIV infection is a strong anthroponoses retransmissions with parenteral mechanism of infection from an infected person. Over the last 20 years the number of newly identified HIV-infected pregnant has increased almost 600 times and exceeded $ 120 per 100 thousand patients. Most women of childbearing age were infected sexually, the proportion of HIV-positive patients with drug dependence does not exceed 3%.
In accordance with the rules of asepsis, adequate antiseptic treatment of instruments for invasive procedures and effective serological monitoring were able to reduce the frequency of infection due to occupational injury, blood transfusions, due to the use of contaminated tools and donated materials. More than 15% of cases to accurately determine the source of the pathogen and mechanism of infection is not possible. The relevance of special support to HIV-infected pregnant women due to high risk of infection of the fetus in the absence of adequate deterrent treatment.
Causes of HIV infection in pregnant women
The causative agent is a retrovirus, the human immunodeficiency one of the two known types of HIV-1 (HIV-1) or HIV-2 (HIV-2), represented by multiple subtypes. Usually infection occurs before pregnancy, at least – at the time of or after the child’s conception, during gestation, delivery, postnatal period. The most common means of transmission of an infectious agent in pregnant is a natural (sexual) secret through the mucous membranes of an infected partner. Possible infection at intravenous introduction of narcotic drugs, in violation of the rules of asepsis and antisepsis during invasive manipulation, the performance of duties with the possibility of contact with blood of the carrier or the patient (health care workers, paramedics, beauticians).
In pregnancy, the role of some artificial parenteral ways of infection increases and they acquire a certain specificity:
- Transfusion-transmissible infection. If complications arise during pregnancy, childbirth and the postpartum period increases the probability of blood loss. The scheme of treatment of the most severe krovotecheniyah introduction donated blood and received from it products (plasma, erythrocyte mass). The transmission of HIV is possible with the use of tested for the virus material from infected donor in case of blood sampling during the so-called seronegative window of incubation, lasting from 1 week to 3-5 months from the moment of introduction of the virus into the body.
- Instrumental contamination. Pregnant patients more often than non-pregnant, prescribe invasive diagnostic and therapeutic procedures. To exclude fetal abnormalities used amnioscopy, amniocentesis, chorion biopsy, cordocentesis, placentocentesis. With the diagnostic purpose perform endoscopic examinations (laparoscopy), medical – suturing the cervix, and fetal fetoscopes drainage operations. Infection through contaminated instruments is possible in childbirth (when suturing of injuries) and for caesarean section.
- Transplant transmission of the virus. Possible options for couples planning pregnancy in severe forms of male infertility, are insemination with donor sperm or use for IVF. As in the case of blood transfusions, in such situations there is a risk of infection through use of infected material obtained in the seronegative period. Therefore, with the preventive purpose it is recommended to use sperm donors, who have successfully passed the HIV test six months after the delivery of the material
The spread of HIV in the body with the blood and macrophages, which initially introduced the pathogen. The virus has a high tropism for the target cells, in membranes which contain a specific protein receptor is CD4 – T-lymphocytes, dendritic cells, part of the monocytes and b-lymphocytes, resident microphages, eosinophils, bone marrow cells, nervous system, intestines, muscles, vascular endothelium, horizontalist of the placenta, possibly sperm. After replication, the new generation of the pathogen leaves the infected cell, destroying it.
The greatest cytotoxic effect of immunodeficiency viruses have on T4-lymphocytes type I, which leads to depletion of cell populations and disruption of immune homeostasis. Progressive decline of the immune system degrades the protective characteristics of the skin and mucous membranes, reduces the efficiency of the inflammatory response to the penetration of infectious agents. The result is in the final stages of the disease, patients develop opportunistic infections caused by viruses, bacteria, fungi, helminthes, protozoan flora, there are the typical AIDS tumors (non-Hodgkin’s lymphoma, Kaposi’s sarcoma), starts an autoimmune process, eventually leading to the death of the patient.
Domestic virologists used in the systematization of stages of HIV infection, suggested by V. Pokrovsky. It is based on the criteria of seropositivity, the severity of symptoms, presence of complications.
The proposed classification shows the gradual development of infection from the moment of infection to the final clinical outcome:
- Incubation stage. HIV is present in the human body, it is active replication, however, antibodies are not detected, signs of acute infectious process do not exist. Duration seronegative incubation is usually 3 to 12 weeks, the patient is contagious.
- Early HIV infection. Primary the body’s inflammatory response to the spread of the pathogen lasts from 5 to 44 days (half of the patients 1-2 weeks). In 10-50% of cases the infection immediately takes the form of asymptomatic carriage that is considered to be more prognostically favourable sign.
- Stage of subclinical manifestations. The viral replication and destruction of CD4 cells lead to a gradual build-up of immunodeficiency. The characteristic manifestation is generalized lymphadenopathy. The latent period in HIV infection lasts from 2 to 20 years or more (average 6-7 years).
- The secondary pathology. Exhaustion of protective forces manifest secondary (opportunistic) infections, cancer. The most common AIDS-defining diseases are tuberculosis, cytomegalovirus and Candida infections, Pneumocystis pneumonia, toxoplasmosis, Kaposi’s sarcoma.
- The terminal stage. Against the background of severe immunodeficiency marked cachexia, there is no effect from the applied therapy, for secondary diseases becomes irreversible. The duration of the final stage of HIV before the death of the patient is usually not more than a few months.
Practicing obstetricians and gynaecologists are more likely to provide specialized services for pregnant women, being in incubation period at the early stage of HIV infection or its subclinical stage, at least – with the appearance of secondary disorders. Understanding the characteristics of the disease at each stage allows to choose the optimal scheme of pregnancy and the most appropriate method of delivery.
The symptoms of HIV infection in pregnant women
Because during pregnancy the majority of patients determined of I-III stages of the disease, pathological clinical signs are missing or look not specific. During the first three months after infection from 50-90% of the infected is observed early acute immune reaction, which is manifested by weakness, slight fever, urticarial, petechial, papular rashes, inflammation of the mucous membranes of the nasopharynx, vagina. Some pregnant women have enlarged lymph nodes, develops diarrhea. With significant immunosuppression may cause transient, mild candidiasis, herpes infection, other intercurrent diseases.
If the HIV infection occurred before pregnancy, and the infection has evolved to the stage of latent subclinical manifestations, the only sign of infection is persistent generalized lymphadenopathy. A pregnant woman is detected with at least two lymph nodes with a diameter of 1.0 cm, located in two or more groups not related to each other. When the feeling of the lymph nodes are elastic, painless, not connected with surrounding tissues, the skin over them are unchanged. The number of nodes is stored for 3 months or more. The secondary symptoms of the pathology associated with HIV infection, pregnant women are identified rarely.
The most serious consequence of pregnancy in HIV-infected women, perinatal (vertical) infection of the fetus. Without adequate therapy, limiting the likelihood of infecting the child reaches 30-60%. In 25-30% of cases of human immunodeficiency hits from mother to child through the placenta, in 70-75% – during delivery while passing through an infected birth canal, 5 to 20% through breast milk. HIV infection in 80% of perinatal infected children develops rapidly and the symptoms of AIDS occur within 5 years. The most characteristic signs of the disease are malnutrition, persistent diarrhea, lymphadenopathy, hepatosplenomegaly, and developmental delay.
Intrauterine infection often leads to damage to the nervous system, with diffuse encephalopathy, microcephaly, atrophy of the cerebellum, the deposition of intracranial calcifications. The likelihood of perinatal infection increases with the acute manifestations of HIV infection with high viremia, a significant deficiency of T-helper cells, extragenital diseases of the mother (diabetes, cardiopathology, kidney diseases), the pregnant presence of sexually transmitted infections, chorioamnionitis. According to specialists in the field of obstetrics and gynecology, in patients infected with HIV, more likely, the threat of interruption of pregnancy, spontaneous abortions, premature birth, increased perinatal mortality.
Given the potential danger of HIV status of the patient for the unborn child and the medical personnel who test for HIV is included in the list of recommended routine examinations during pregnancy. The main tasks of the diagnostic phase are the identification of possible infection and determination of the stage of the disease, its clinical course and prognosis.
For diagnosis the most informative laboratory methods:
- Enzyme-linked immunosorbent assay. Used as a screening. Allows to identify in blood serum of pregnant antibodies to human immunodeficiency virus. In the seronegative period is negative. Considered the method of preliminary diagnosis requires confirmation of the specificity of the results.
- Immune blotting. The method is a variation of ELISA, allows to determine serum antibodies to certain antigenic components of the pathogen, distributed according to molecular weight by electrophoresis. It is a positive result of immunoblot is a reliable sign of the presence of HIV infection in pregnant.
- PCR diagnostics. Polymerase chain reaction is considered to be a method for early detection of the pathogen at the time of infection from 11-15 days. With its help, in the serum of the patient determined by the viral particles. The reliability of the method is 80%. Its advantage is the possibility of quantitative control of copies of HIV RNA in the blood.
- A study of major subpopulations of lymphocytes. On the likely development of immunosuppression evidenced by the decrease in CD4 lymphocytes (T helper), 500/ál or less. Immunoregulatory index, showing the ratio of T-helpers and T-suppressors (CD8-lymphocytes), is less than 1.8.
When applying for birth previously unexplored pregnant from marginalized contingents it is possible to conduct a rapid analysis of HIV using a highly sensitive immunochromatographic test systems. For routine instrumental examination of the infected patients preferred non-invasive methods of diagnosis (transabdominal ultrasound, Doppler uteroplacental blood flow, cardiotocography). Differential diagnosis at the early stage of the reaction is carried out with SARS, infectious mononucleosis, diphtheria, measles, and other acute infections. Upon detection of a generalized lymphadenopathy is necessary to exclude hyperthyroidism, brucellosis, viral hepatitis, syphilis, tularemia, amyloidosis, red lupus, rheumatoid arthritis, lymphoma, other systemic diseases and cancer. According to the testimony of the patient consult an infectious disease specialist, dermatologist, oncologist, endocrinologist, rheumatologist, hematologist.
Treatment of HIV infection in pregnant women
The main tasks of pregnancy when infected with human immunodeficiency virus are suppression of infection, correction of clinical manifestations, prevention of infection of the child. Depending on the severity of symptoms and stage of disease assigned massive polytropic therapy antiretroviral drugs – nucleoside and non-nucleoside reverse transcriptase inhibitors, protease inhibitors, integrase inhibitors.
Recommended treatment regimens differ at different stages of gestation:
- When planning a pregnancy. Avoid embryotoxic effect, women with HIV positive status should stop receiving special preparations before the onset of the fertile ovulatory cycle. In this case, it is possible to fully exclude teratogenic effects on early stages of embryogenesis.
- Up to 13 weeks of pregnancy. Antiretroviral drugs used in the presence of secondary diseases, viral load exceeding 100 thousand copies RNA/ml, reducing the concentration of T-helper cells less than 100/µl. In other cases, pharmacotherapy is recommended to stop to eliminate the negative effects on the fetus.
- With 13 on 28 week. In the diagnosis of HIV infection in the second trimester or the treatment of an infected patient at this period in the emergency order appointed active antiretroviral therapy combination of three drugs – two nucleoside reverse transcriptase inhibitors and one drug from the other groups.
- From 28 weeks until delivery. Ongoing antiretroviral treatment is the prophylaxis of transmission of the virus from women to their infants. The most popular scheme, which from the beginning of 28 weeks pregnant is constantly taking zidovudine, and before the birth of single – nevirapine. In some cases, use of reserve schemes.
The preferred method of delivery in pregnant women with diagnosed HIV infection are natural childbirth. If their conduct is necessary to exclude any manipulation that violates the integrity of tissues, amniotomy, episiotomy, forceps, use vacuum extraction. Due to a significant increase in the risk of infection of the child prohibits the use of drugs that cause and reinforce tribal activities. Cesarean section is performed after 38 weeks of gestational period in the unknown indicators of viral load, its level is more than 1 000 copies/ml, no antenatal antiretroviral therapy and the impossibility of introducing Retrovir in childbirth. In the postpartum period, the patient continues taking recommended antiviral drugs. Because breastfeeding is prohibited, lactation suppressed with medication.
Prognosis and prevention
Adequate prevention of transmission of HIV from pregnant woman to the fetus can reduce the level of perinatal infection in up to 8% or less. In economically developed countries this figure does not exceed 1-2%. Primary prevention of HIV infection involves the use of barrier contraceptives, sexual life with a regular trusted partner, the rejection of injecting drugs, using sterile instruments while performing invasive procedures, careful control of donor materials. To prevent infection of the fetus important to the timely staging of HIV-infected pregnant registered in female consultation, the rejection of invasive prenatal diagnosis, the choice of the optimal antiretroviral regimens and mode of delivery, the ban of breast-feeding.