Human Immunodeficiency Virus (HIV) and Pregnancy

Human immunodeficiency virus (HIV) is an infection with a global prevalence and currently has no cure or vaccine. Women living with HIV who become pregnant or who acquire the virus during pregnancy are at risk of both maternal and perinatal morbidity and mortality mainly if the virus is poorly controlled. 

Furthermore, there is a risk of vertical transmission to the fetus during pregnancy, labour and post-delivery through breastfeeding.

More About Human Immunodeficiency Virus (HIV) 

The virus belongs to the family of retroviruses; there are two serotypes of the human immunodeficiency (HIV) virus:

 

1. HIV 1 

HIV-1 is the most common. About 95%of people living with HIV around the world have HIV-1. And it has 3 Major classes

• • M (Main)

The M group of viruses accounts for more than 90 % of HIV infections worldwide and has nine subtypes, called clades, designated by the letters A–D, F–H, J, and K, as well as many recombinant forms.

The most prevalent subtype in West Africa is Clade A, while Clade B is commoner in the Americas and Western Europe

• • N (New)
  • O (outlier)

2. HIV 2

HIV-2 is found more commonly in West Africa and is associated with a lower viral load, a slower rate of both CD4 cell decline and clinical progression to AIDS when compared with HIV-1.

HIV-2 is less likely to progress into AIDS because of its lower transmissibility. Thus, individuals infected by HIV-2 mostly remain non-progressors for a long period, while patients infected by HIV-1 progress faster and contract AIDS.

Impact of Human Immunodeficiency Virus on Pregnancy

Immune function is suppressed in HIV-infected women. There is a decrease in antibodies and complement levels in early pregnancy and a more significant decrease in immune response that does not involve antibodies.

Studies have shown that pregnancy may however not affect the progression of HIV. Infected pregnant women are more likely to develop early pregnancy complications such as 

1. Bacterial pneumonia.
2. Urinary tract infections.
3. Spontaneous abortion.
4. Higher rates of ectopic pregnancy and increased stillbirth rates.

These risks appear to be lower in asymptomatic HIV-positive pregnant women.

Monitoring HIV Infection in Pregnancy

The following monitors HIV progression in pregnancy:

1. Viral load (measures the Virus replication)

This is considered the gold standard for monitoring adherence and treatment success. Where the viral load is not effectively suppressed, an adherence intervention should precede a repeat viral load test. Viral load monitoring has a high likelihood to motivate adherence by engaging clients in the process of monitoring their results and understanding the meaning of their results. 

High viral load – more than 10,000 copies of the virus per ml signifies an actively reproducing virus and damage to the immune system is more likely but less than 20 copies (Undetectable) is always the goal of HIV treatment.

2. CD4 Count

They are the T-Helper cells. These cells directly kill infected host cells, activating other immune cells, producing cytokines and regulating the immune response.

HIV preferentially infects and destroys their levels thus reflecting the degree of immune competence. Once the CD 4 count falls below 200 x 10⁶/L, the patients are at risk of developing opportunist infections

Thus a CD4 count looks at the number of CD4 cells in a blood sample. Decreasing levels of CD4 cells signal damage to the immune system.

What Does Human Immunodeficiency Virus Do To The Defense System?

HIV infection begins with the binding of the virus particle (virion) to the host cell, followed by replication and integration into the host genome. This then causes progressive depletion of CD4 cells and this compromises the immunity of the host and creates the potential for opportunistic infections, tumours etc and if unchecked can result in full-blown AIDS.

Antenatal Care

The effects of HIV on pregnancy and the risk of Mother-to-Child-Transmission (MTCT) make screening for infections an essential part of antenatal care for all pregnant women. The World Health Organization recommends that in high-prevalence settings (>5% prevalence), provider-initiated testing and counselling (PITC) for HIV should be considered a standard component of the package of care in all antenatal care settings. 

The “opt-out” approach to HIV testing may be offered to all women as part of routine antenatal tests during the first antenatal visit. The women in this approach reserve the right to decline the test without any sanctions from the provider.

 Women who decline the test initially often accept to be tested later in pregnancy with more detailed counselling. HIV testing may also be offered late in pregnancy (about 36 weeks) or labour to women whose status is unknown or who had tested negative earlier in pregnancy but remain at risk of a new infection. 

HIV testing and counselling should be voluntary with the principles of consent, confidentiality, counselling, and ensuring that test results are linked with appropriate care, treatment and preventive services. HIV screening and counselling involve pre-test information, HIV testing, and post-test and follow-up counselling.

Interventions to Reduce Mother-to-Child Transmission (MTCT) of Human Immunodeficiency Virus (HIV)

1. Maternal Intervention

• • Anti-retroviral treatment (ART) for all HIV-positive women.

In women not already taking treatment but requiring treatment, deferring commencement until the second trimester, after the period of organogenesis and when symptoms of morning sickness are likely to have settled may be considered.

Those taking agents known to cause fetal abnormalities like Efavirenz should have their regimen altered.

It is recommended that combinations of a minimum of three drugs from at least two different classes of anti-retroviral should be used for treatment. These drugs are expected to act at different points of the HIV life cycle. 

Typically, a backbone of 2 Nucleotide Reverse Transcriptase Inhibitors (NRTIs) combined with an Integrase inhibitor; a Non-Nucleotide Reverse Transcriptase Inhibitors (NNRTI) or a Protease inhibitor, PI is used. 

Single or dual drug therapy for HIV infection is not recommended for treatment because of the increased risk of the development of drug resistance. 

• • Co-trimoxazole prophylaxis 
  • TB screening, prophylaxis and treatment 
  • Mode of Delivery

Studies have shown that the majority of transmissions occur at the time of delivery. Increasing the duration of rupture of the membrane leads to a higher rate of transmission. Rupture of more than 4 hours confers double the risk of transmission to the child. Also, higher viral loads lead to increased transmission.

Caesarean-section (C/S) delivery is associated with a substantial reduction in the risk of transmission with both high and low viral load counts but Patients and clinicians are questioning the rationale for elective C/section in women with the undetectable virus.

• • Continued infant feeding counselling and support

Breast-feeding doubles the risk of transmission 

• • Nutritional counselling and support 
  • Sexual and reproductive health services including family planning 

It is important to discuss postnatal follow-up. Advice on suitable contraceptives. It’s been found that most HIV drugs are Enzyme inducing and therefore may reduce the efficacy of oral contraceptive pills. Most women chose the intrauterine contraceptive device (IUCD) for effective contraception and also for a reduction in pill burden.

• • Cervical cancer screening psychosocial support.
  • Partner counseling and testing 
  • Pre-Exposure Prophylaxis (PrEP) for serodiscordant couples 

2. Interventions For The Exposed Baby

• • Antiretroviral prophylaxis 

Here Niverapine Syrup is given. This is for high-risk babies viz:

1. Born to HIV-positive women who have been on treatment for less than 4 weeks at the time of delivery.
2. Born to women with established HIV infection with viral

load> 1000 copies/mL in the four weeks before delivery.

3. Born to women with incident HIV infection during pregnancy (this includes women diagnosed in labour) or during breastfeeding.
4. Identified for the first time during the postpartum period, with or without a negative HIV test prenatally. 

• • Routine immunization and growth monitoring and support.
  • Co-trimoxazole prophylaxis starting at 6 weeks
  • HIV diagnostic testing using 

1. 1. 1. At Birth

Dried blood spots (DBS) for DNA- Polymerase chain reaction (PCR) or Nucleic acid tests NAT) is used at birth (when available), 6 to 8 weeks of age and 6 weeks after breastfeeding has ended. 

1. 1. 2. HIV antibody tests can be used for HIV screening for children older than 9 months where the virologic test is not available. 

HIV antibody test is the recommended diagnostic testing for children older than 18 months. 

HIV antibody tests should primarily be used for screening infants and children less than 18 months of age, to establish exposure status where the mother has not herself been tested for HIV or is willing to be tested.

• Ongoing infant feeding counselling and support Screening and management of tuberculosis. 
• Prevention and treatment of malaria.
• Nutritional care and support.
• Antiretroviral therapy for all HIV infected.
• Psychosocial care and support 

Conclusion

A woman diagnosed with HIV during pregnancy not only has to consider her health and that of her unborn child and also the possibility of her existing Children and partner being infected.

There is no curative treatment for HIV and there is no guarantee against maternal-to-child transmission. 

In the absence of intervention, the rate of transmission of HIV from a mother living with HIV to her child during pregnancy, labour, delivery or breastfeeding ranges from 15% to 45%.

Since the global shift to, and accelerated rollout of, highly effective, simplified interventions based on lifelong maternal antiretroviral therapy (ART) for women living with HIV, virtual elimination of mother-to-child transmission (MTCT) – also known as “vertical transmission” – is feasible.