Monday, July 20, 2009

Pregnancy, Breastfeeding and Swine Flu A/H1N1

Last modified date:
29 May 2009

Breastfeeding and swine flu

Women who are breastfeeding should continue while receiving antiviral treatment or prophylaxis as they are not contraindicated in breastfeeding.

In particular mothers should feed on demand. Where possible additional formula should not be used so that the infant receives as much of the maternal antibodies as possible.

If a mother is ill, she should continue breastfeeding and increase feeding frequency. If she becomes too ill to feed then expressing milk may still be possible.

It the baby becomes too ill to breastfeed then expressed milk should be used.

The risk for swine influenza transmission through breast milk is unknown. However, reports of viraemia with seasonal influenza infection are rare.

Antiviral treatment

Antiviral drugs are not a cure, but can aid recovery if taken within 48 hours of symptoms developing. There are two possibilities: Oseltamivir (Tamiflu) and Zanamivir (Relenza)

Oseltamivir and its active metabolite, oseltamivir carboxylate, are excreted into human breast milk in very small amounts. Limited data suggest that clinical sequelae from maternal treatment would not be expected in a breastfed infant.

There are no data on zanamivir use during lactation but based on limited bioavailability the systemic exposure of a breast fed infant from maternal treatment is expected to be insignificant.

The overall consensus is that treatment with either drug is not a reason to discontinue, or put limitations on, breast feeding full-term or pre-term infants. Due to the very small amounts transferred into breast milk, and the limited oral bioavailability of either drug, the benefits of breast feeding are considered to outweigh any, albeit unidentified, risks.

Data on oseltamivir are limited. The recommendation for zanamivir is based on pharmacokinetic principles only.

Reducing the risk of transmission from mother to baby

As with general precautions, mothers should take steps to reduce the risk to their infant by washing their hands frequently with soap and hot water or a sanitiser gel and by using clean tissues to cover their mouth and nose when coughing or sneezing. Tissues should be binned after use.

Mothers and infants should stay as close together as possible and encouraged to have early and frequent skin-to-skin contact with their infants.

Babies hands should be washed if they have been in their mouth.

Limit sharing of toys and other items that have been in infants' mouths. Wash thoroughly with soap and water any items that have been in infants' mouths.

Keep dummies (including the dummy ring/handle) and other items out of adults' or other infants' mouths prior to giving to the infant.

The available scientific evidence shows that the basic face masks do not protect people from becoming infected and that the best way of reducing the risk of transmission is by hand washing and using and disposing of tissues.

General treatments of symptoms for breastfeeding women include drinking plenty of fluids and relief of symptoms with paracetamol or ibuprofen to control any fever.

Paracetamol is well tolerated and is licensed for women during pregnancy and for small children. It is also widely used for neonates, particularly in hospital and specialist care, although not specifically licensed for this group.

Over-the-counter influenza treatments containing decongestants and/or sedatives in addition to paracetamol and are not recommended. They are only marginally effective and there is also a risk that safe paracetamol dosage could be exceeded if over-the-counter remedies are used while paracetamol is also being taken. Instead nasal decongestant sprays, steam inhalations and a simple cough linctus can be used alongside paracetamol.

There are also suitable antibiotics, should these become necessary for the treatment of complications, such as bacterial respiratory infections.

Pregnancy and swine flu

As with many drugs, oseltamivir and zanamivir have not been specifically tested in pregnancy and breastfeeding and therefore are not licensed for this use. For both products (ie oseltamivir and zanamivir), use in pregnant and lactating women is only recommended based on the individual risk benefit assessment of the treating physician. Zanamivir results in significantly less systemic exposure than oseltamivir and therefore also significantly less potential exposure to the foetus. And therefore Relenza is the recommended antiviral for pregnant women.

Pregnant women should use paracetamol to control fever. Pregnant women should not take non-steroidal anti-inflammatory drugs for the treatment of flu symptoms, because they may interfere with the baby’s pulmonary blood flow.