It has always been assumed that this was just an old wives’ tale, however recent research has revealed that there might actually be some truth to it after all.
Researchers from Radboud University Nijmegen in the Netherlands have discovered that women who have three children are likely to have fewer teeth than those with two children.
One theory is that elevated levels of hormones progesterone and oestrogen interfere with calcium absorption, leaving teeth vulnerable to decay and gum disease.
Pregnancy cravings may also play a role because they make women more likely to eat sugary or acidic treats.
In addition, morning sickness can damage teeth as stomach acids can soften tooth enamel.
Earlier this month Hollywood actress Kate Hudson, who is expecting a baby girl with boyfriend Danny Fujikawa, revealed on Instagram that her third pregnancy has been the most challenging due to the intense morning sickness she has experienced.
She wrote: “They say girls make you sicker and that, for me, has been the truth. It has been interesting so far.”
About 50 per cent of women will experience some mild gingivitis (gum disease) during pregnancy, causing the gums to become inflamed and bleed.
Left unchecked, bacteria can build up in the mouth and may enter the bloodstream, causing infection which can lead to periodontal disease.
This is a serious gum infection which destroys the fibres that attach the teeth to the gums and the bones that hold the teeth in the mouth.
Not only can this result in irreversible bone and tooth loss but research suggests it can also affect the baby. Several studies show a link between periodontal disease and premature, low birth weight babies.
This increased risk of gum problems is one of the reasons that NHS dental care is free during pregnancy and until one year after your due date.
To get it, you need to apply for a maternity exemption certificate, so ask your doctor, nurse or midwife for form FW8.
In the meantime, here’s a checklist of what you need to know about looking after your teeth during pregnancy.
1.Use a toothbrush with soft bristles as pregnancy hormones can cause the gums to swell and become sore.Using a sensitive toothpaste will also help to relieve any discomfort.
2.Take vitamin C and calcium supplements to help keep your teeth healthy and strong. The nutrients are really important for bone growth and development for both you and baby.
3.Be careful with cravings. Maintaining a healthy, balanced diet full of fresh greens and dairy products is best for dental health. Sugary foods can lead to tooth decay and other health problems.
4.A dry mouth can be common during pregnancy as hormonal changes can lead to a lack of saliva. Stay hydrated by drinking plenty of water and chew sugar-free gum to keep your mouth moist.
5.Avoid having X-rays as radiation can pass through body tissue and potentially harm the baby. In a dental emergency, always advise your dentist that you are pregnant as alternative treatment may be available.
6.If possible avoid taking any type of medication when you are pregnant. Many antibiotics and over-the-counter painkillers can affect the baby’s development, including discolouration of teeth.
7.Hold off using any teeth-whitening products which contain peroxide as the oxidation process could be harmful to the developing baby.
8 If you suffer from morning sickness, try to avoid cleaning your teeth straight after being sick as stomach acids can soften tooth enamel. Rinse your mouth out with fresh water and wait at least half an hour before brushing your teeth.
9 Avoid mouthwashes containing alcohol. Use cooled boiled water and sea salt instead.
10.It is best to discuss with your dentist whether any new or replacement fillings can be delayed until after your baby has been born. The Department of Health advises that amalgam fillings shouldn’t be removed during the pregnancy period.