13 Critical Things You Should Never Do In Your First Trimester

There aren’t many hard and fast rules about what not to do during your pregnancy, beyond abstaining from alcohol and drugs, of course. For the most part, you can continue with most of your prepregnancy life.

But because the health and safety of your growing baby is essential, here’s a list of 13 things to avoid while pregnant.

Certain foods


Toxoplasmosis is a common infection that occurs in most birds and mammals, including humans, and can cause serious problems in pregnancy. The parasite called Toxoplasma gondii (T. gondii) can be found in cat faeces or soil — or cat litter that is contaminated with infected cat faeces.

The risk of getting toxoplasmosis when you’re pregnant is very low. But if do you get toxoplasmosis in the early stages of pregnancy, the risk of miscarriage is increased and it can cause blindness and brain damage in an unborn baby.

Signs of toxoplasmosis include mild flu-like symptoms, such as high temperature, sore throat and aching muscles. However, in most cases, toxoplasmosis doesn’t cause any symptoms.

Pregnant women are not routinely screened for toxoplasmosis. It’s therefore important that you know how to prevent infection.

Cleaning products

Check the labels of cleaning products to make sure there are no safety warnings for pregnant women. If you use cleaning products, glues, paint or any other household chemicals, follow the safety directions on the label. Make sure the room is well ventilated when you are cleaning — open windows and doors.

Some moth balls and toilet deodorant cakes contain a substance called naphthalene. Exposure to very large amounts of naphthalene can damage blood cells, leading to a condition called haemolytic anaemia. Symptoms that may occur after exposure to large quantities of naphthalene include fatigue, loss of appetite, nausea, vomiting and diarrhoea. Newborn babies are particularly at risk if they are exposed to naphthalene.


It’s great to be active and stay fit while you’re pregnant, but check with your midwife or doctor first to make sure there are no health problems that prevent you from exercising. If there are no problems, try to do 30 minutes of moderate exercise, like walking or swimming, on most days of the week.

Regular exercise can:

  • help you stay at a healthy weight
  • help you relax
  • help make you stronger and fitter — good for coping with pregnancy, labour and being a parent
  • help decrease discomforts like back pain and varicose veins that affect some pregnant women

Fake tan

The active ingredient in fake tan is dihydroxyacetone (DHA), a non-toxic substance that reacts with cells in the outermost layer of the skin and produces a brown pigment (colour) called melanoidin. The DHA does not go beyond the outer layer of skin and therefore is not absorbed into the body. It is fine to use fake tan creams and lotions while you are pregnant.

It is not a good idea to have a spray tan while you are pregnant because you might inhale some spray, and it is not know whether this is dangerous for the baby. Also, fake tans can sometimes cause an allergic reaction. Pregnancy changes your hormone levels and can make the skin more sensitive than normal. If you do use fake tan, always test the product on a small area of skin first to see if you have a reaction.

Although some fake tans contain sun protection, the SPF (sun protection factor) is usually very low. Increased skin sensitivity when pregnant can mean you’re more likely to burn, so use a high protection cream (minimum SPF 30) and stay out of the sun as much as possible.

No one should use tanning pills or tanning injections. Tanning pills contain high amounts of betacarotene and/or a chemical called canthaxanthin that have been linked with dangerous side effects, including damage to the eyes and the liver. Injections containing Melanotan, which increases melanin in the skin, are not approved by the Therapeutic Goods Administration (TGA) for tanning, and it is classified as a prescription-only medicine.


There are some foods you should avoid when you’re pregnant because they might make you ill or harm your baby. Learn more about the foods you should avoid, or that you need to take extra care with when you’re pregnant here.


There is no safe level of alcohol during pregnancy. Whether you are planning a pregnancy, already pregnant or breastfeeding, not drinking is the safest option as alcohol can harm your unborn baby.

Hair dye

Most research, although limited, shows that it’s safe to colour your hair while pregnant. Some studies have found that very high doses of the chemicals in hair dyes may cause harm. However, these doses are massive compared to the very low amount of chemicals when you dye your hair.

Many women decide to wait to dye their hair until after the first 12 weeks of pregnancy, when the risk of chemical substances harming the baby is much lower. If you are colouring your hair yourself, or you work in a hair salon, you can reduce the risk further by making sure that you:

  • wear gloves
  • leave the dye on for the minimum time
  • work in a well-ventilated room

Highlighting your hair, by putting the dye only onto strands of hair, also reduces any risk. The chemicals used are only absorbed by your hair, and not by your scalp or bloodstream.

Semi-permanent pure vegetable dyes, such as henna, are a safe alternative.

Pregnancy can affect your hair’s normal condition. For example, your hair may react differently to colouring or perming and become more or less absorbent, frizzy or unpredictable.

It’s always a good idea to do a strand test first, using the hair dye or treatment that you intend to use. Speak to your hairdresser for advice.

Hair treatments during breastfeeding

Information about hair treatments while breastfeeding is limited. However, it’s very unlikely that a significant amount of the chemicals used in hair dyes will be passed on through your breast milk. This is because very little enters your bloodstream. Many women have used hair treatments while breastfeeding, with no known negative results.


The risk of fumes from modern household paints harming your baby is low, but it’s impossible to know exactly how small the risk is. This is because it’s very difficult to measure the substances and chemicals your body absorbs during activities such as painting.

There has been very little research into the effects of paint fumes on unborn babies. The few studies that have been done show that the risk is extremely low.

Renovating houses can increase your exposure to lead. If your house was built before 1971 (when lead-based paint was still available), get advice before doing anything that disturbs the paint. Disturbing lead-based paint can spread lead dust into the air and around the house. It’s important that pregnant women and children aren’t around during renovations that disturb lead-based paint.

Any small risk to your baby is greatest during your first trimester when your baby’s organs start to develop. Any harmful fumes or chemicals at this stage could affect your baby more severely. As a precaution it’s best to avoid painting and decorating until at least the 14th week of your pregnancy.

Sauna or jacuzzi

There is little research on using saunas, jacuzzis and similar heated leisure facilities during pregnancy. However, it’s advisable to avoid them because of the risks of overheating, dehydration and fainting.

You’re likely to feel warmer during pregnancy. This is due to hormonal changes and an increase in blood supply to the skin. These hormonal changes can also often make pregnant women feel faint.

If you overheat, more blood flows close to your skin, to help cool your body by sweating. This means less blood flows to your internal organs such as your brain. If this happens, your brain may not get enough blood and, therefore, oxygen. This can make you feel faint.

When you use a sauna, jacuzzi, hot tub, steam bath or steam room, your body cannot lose heat effectively by sweating. Your body’s core temperature therefore rises. It’s possible that a significant rise in your core temperature may affect your unborn baby’s development, particularly in the first 12 weeks of the pregnancy.

Take care when you get out of a hot bath or stand up quickly, as these can also make you feel faint.


Sunbeds (solariums) give out ultraviolet (UV) rays, the same type of harmful radiation found in sunlight. Using a sunbed increases your risk of developing skin cancer including malignant melanoma, the most serious form of skin cancer. It is illegal to operate a commercial solarium in Australia.

There is no clear evidence about the effect of UV rays from sunbeds on an unborn baby. Some studies have suggested there may be a link between increased UV rays and a folic acid deficiency. This is because UV rays can break down folic acid.

Pregnant women often find that their skin is more sensitive than usual. If you use a sunbed when you are pregnant, your skin may therefore be more likely to burn.


If possible, you should avoid having an x-ray while you’re pregnant. Your healthcare professional will assess whether your treatment can wait until you’ve had your baby. They will assess whether the benefits of treatment outweigh the low risk of having an x-ray. They may also consider using another imaging method instead, such as an ultrasound scan.

The risk from x-ray radiation is related to the stage of pregnancy at which the exposure occurs and the dosage amount that reaches the baby. There is slight risk of birth defects and physical and mental development problems.

However, repeated exposure to radiation can damage the body’s cells, which can increase the risk of cancer developing. This is why the dose of radiation used in an x-ray is always as low as possible. X-rays during pregnancy carry a very small risk of exposing the unborn baby to radiation, which could cause cancer to develop during his or her childhood.

Dental x-rays

Make sure your dentist knows that you’re pregnant. If you need a dental x-ray, your dentist will usually wait until you’ve had the baby, even though most dental x-rays don’t affect the abdomen or pelvic area.

Other radiology tests

It is vital you tell your doctor or specialist if you are or may be pregnant because some procedures can affect the fetus. Your doctor or specialist will refer you for an appropriate radiology procedure if it is safe to do so. You must also inform the hospital or radiology practice when you make the appointment and the medical staff performing the procedure if you are or may be pregnant.

Breastfeeding and x-rays

In general, you do not need to interrupt breastfeeding to have radiological tests such as an x-ray, MRI, CT, angiogram, ultrasound or mammogram. These examinations do not affect breastfeeding.

But it is important that you tell your doctor or specialist if you are breastfeeding. Some procedures can involve a radioactive substance being injected into your vein that will take a few days to flush out of your body through your urine. While it is in your body, a very small amount of radioactive substance can be passed on to your child through the breast milk. Your doctor or specialist and their staff will give you instructions, such as to express and throw away breast milk for a short time after having the scan, so that your child is not exposed to the radioactive substance unnecessarily.

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