Use of insecticides in pregnancy

Date: January 2018, Version 1

What are insecticides?

Insecticides are chemicals that kill insect pests. They may be used around the home, for example to eradicate wasps, ants, or fleas, as treatments applied to the body, for example to eradicate lice or scabies, and on companion animals to treat fleas, ticks, and lice. They are used in agriculture and in the garden to kill insects that damage crops and plants. Outside the UK they are used in the environment to kill insects such as mosquitos that spread disease. Commonly used types of insecticide include carbamates, organophosphates, pyrethrins/pyrethroids, and neonicotinoids.

There are separate bump leaflets on treatment of head lice and scabies in pregnancy

Is it safe to use an insecticide in pregnancy?

Although there are numerous published studies on the possible effects of insecticide exposure in pregnant women and in fathers around the time of conception, there are many problems with the way that this information has been collected and analysed, which mean that the results are difficult to interpret and may not be reliable.

For example:

• In many of the studies, exposure to an insecticide is assumed (due to the mother’s or father’s job or place of residence) rather than confirmed
• Many people are exposed to several insecticides at the same time which means that the effects of any single insecticide are difficult to determine
• Additionally, women with exposure to high levels of insecticides may have a higher chance of other lifestyle factors (such as smoking and poverty) that can independently increase the risk of poor pregnancy outcomes

The effects of insecticide exposure during pregnancy and in men around the time of conception are therefore difficult to determine.

When deciding whether or not to use an insecticide during pregnancy it is important to weigh up how necessary this is to your health/wellbeing against the possible risks to you or your baby, some of which will depend on how many weeks pregnant you are. If you use an insecticide (whether or not you are pregnant) you should follow the manufacturer’s instructions for use, especially regarding quantities, level of ventilation required for indoor use, and use of personal protective equipment such as gloves or a face mask.

Women exposed to insecticides at work should follow local health and safety protocols to minimise exposure and should arrange for their employer to carry out a risk assessment.

What if I have already used an insecticide during pregnancy?

If use of the insecticide did not cause any symptoms of toxicity you do not need to take any action. If you experienced any unusual symptoms/toxicity after exposure to an insecticide in pregnancy you should report this to your doctor who may decide to contact UKTIS for further advice.

Will my baby need extra monitoring during pregnancy?

As part of their routine antenatal care most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects and to check the baby’s growth.

There is no good evidence that using an insecticide as directed during pregnancy causes any problems that would require extra monitoring of your baby. However, women who have experienced toxic symptoms and/or been exposed to very high levels of an insecticide during pregnancy may receive additional monitoring to ensure that the baby is growing and developing as expecting.

Are there any risks to my baby if the father has used an insecticide?

Studies that have investigated possible links between exposure of the father to insecticides around the time of conception and birth defects in the baby/other poor pregnancy outcomes have produced mixed findings, with some finding possible links and others finding no links. However, the results of these studies may not be reliable. In general, medicines and other substances used by men around the time of conception are considered unlikely to adversely affect a pregnancy.

Who can I talk to if I have questions?

If you have any questions regarding the information in this leaflet please discuss them with your healthcare provider. They can access more detailed medical and scientific information from www.uktis.org

How can I help to improve drug safety information for pregnant women in the future?

Our online reporting system (MyBump Portal) allows women who are currently pregnant to create a secure record of their pregnancy, collected through a series of questionnaires. You will be asked to enter information about your health, whether or not you take any medicines, your pregnancy outcome and your child's development. You can update your details at any time during pregnancy or afterwards. This information will help us better understand how medicines affect the health of pregnant women and their babies. Please visit the MyBump Portal to register.

General information
Sadly, miscarriage and birth defects can occur in any pregnancy.

Miscarriage occurs in about 1 in every 5 pregnancies, and 1 in every 40 babies are born with a birth defect. This is called the ‘background risk’ and happens whether medication is taken or not.

Most medicines cross the placenta and reach the baby. For many medications this is not a problem. However, some medicines can affect a baby’s growth and development.

If you take regular medication and are planning to conceive, you should discuss whether your medicine is safe to continue with your doctor/health care team before becoming pregnant. If you have an unplanned pregnancy while taking a medicine, you should tell your doctor as soon as possible.

If a new medicine is suggested for you during pregnancy, please make sure that the person prescribing it knows that you are pregnant. If you have any concerns about a medicine, you can check with your doctor, midwife or pharmacist.

Our Bumps information leaflets provide information about the effects of medicines in pregnancy so that you can decide, together with your healthcare provider, what is best for you and your baby.