Complications of Pregnancy

Spread

Transplacental spread (in utero)

Organisms present in the maternal bloodstream during infection may infect the placenta and cross to the fetal circulation. Many (such as cytomegalovirus [CMV], rubella, listeria or toxoplasma) are a much greater threat to the baby than to the mother, who is often unaware of even a primary infection.

Transplacental infection may occur throughout pregnancy, but the effects on the foetus vary with the stage and the nature of the infecting agent. Much organ development takes place in the first 8 weeks of embryonic life so organ damage is more likely at this stage of pregnancy.

Intrapartum Infection

There is considerable exposure to maternal blood, secretions and tissues during birth. Invasive inten/ention e.g. use of scalp electrodes, adds to the risk of transmission e.g. HIV, HSV.

Postpartum

There can be spread of infection from several sources:

• Hands or respiratory tract of contacts e.g. mother, other family, visitors, health care workers e.g. RSV, measles, enteroviruses
• Instruments e.g. HBV, HCV
• Breast milk may transmit infection e.g. CMV, HIV