Case 70: HIV in pregnancy

CASE 70: HIV IN PREGNANCY

History

A 36-year-old Nigerian woman who has lived in the UK for 8 years attends the antenatal

clinic. She had a daughter by spontaneous vaginal delivery at term 12 years ago and a termination of pregnancy 9 years ago. She and her partner have now been trying to conceive for

4 years.

Her last menstrual period was 11 weeks ago. There is no significant gynaecological history

and last smear test was normal 2 years ago.

The woman saw the midwife for a routine antenatal booking appointment a week ago and no

relevant past medical history was reported. All routine booking blood tests were accepted.

INVESTIGATIONS

Normal range for

pregnancy

Haemoglobin 11.9 g/dL 11–14 g/dL

Mean cell volume 77 fL 74.4–95.6 fL

White count 4.1×109/L 6–16×109/L

Platelets 129×109/L 150–400×109/L

Blood group: AB positive

Hepatitis B surface antigen: negative

Syphilis: negative

HIV1/2: positive

Rubella: immune

CD4: 175/mm3

Viral load: 10,000 copies/mL

Questions

• What is the diagnosis?

• What is the next stage in management?

• What are the important points in the management of the pregnancy in view of

the diagnosis?100 Cases in Obstetrics and Gynaecology

192

ANSWER 70

The diagnosis is human immunodeficiency virus (HIV) infection. HIV screening in pregnancy is recommended for all women in the UK and the latest reported incidence was

approximately 0.4 per cent in inner London and less than 0.1 per cent for the rest of the UK.

It is particularly prevalent in women from Africa (2.5 percent compared with <0.5 per cent in

UK-born women). The vast majority of paediatric HIV cases in the UK result from motherto-child transmission. The low CD4 count suggests that this woman needs to commence

treatment, but there are no AIDS-defining illnesses in the history.

Immediate management

The woman needs to be informed of the diagnosis and a second different diagnostic test

performed to confirm the diagnosis. Most women choose to continue with their pregnancies,

but she may still wish to consider the option of termination, as she is only 11 weeks’ gestation.

She needs urgent referral to the genitourinary medicine specialist for further examination

and investigation for any HIV complications. She will need to start Pneumocystis carinii prophylaxis in view of the low CD4 count. All women with HIV need antiretroviral treatment

during pregnancy. In this woman’s case she should commence on highly active antiretroviral

therapy (HAART) in view of her high viral load. Psychological counselling in relation to the

diagnosis, the implications for her, her partner and her offspring (the fetus and her 12-yearold daughter) is very important.

Management of the pregnancy

Pregnancy does not adversely affect the HIV disease process. The important consideration is

therefore the prevention of transmission from mother to child. Untreated, approximately 25

per cent of infants of mothers with HIV will become infected. With appropriate measures,

this is reduced to less than 5 per cent:

• All HIV-infected women:

• Avoidance of breast-feeding

• Oral zidovudine to the neonate for 6 weeks postnatally

• Women with viral load >50 HIV RNA copies/mL at 36 weeks’ gestation:

• Intravenous zidovudine to the mother prior to delivery (ideally for 4 h)

• Elective caesarean section

Thus women with undetectable viral load at term may aim for a vaginal delivery (in the

absence of obstetric complications) as this has been shown to have no effect on the chance of

infant infection in such cases.

Confidentiality is of paramount importance for women diagnosed antenatally with HIV, and

coding systems in the hand-held obstetric notes can be helpful in alerting other medical staff

to the diagnosis.

KEY POINTS

• The incidence of HIV in pregnancy is increasing.

• To decrease vertical transmission all HIV positive women should avoid breastfeeding and the neonate should be given 6 weeks oral zidovudine.

• Elective caesarean section and predelivery intravenous zidovudine are indicated

in women with viral load > 50 HIV RNA copies/mL.