# The Risk of Using Cosmetics and Cosmetic Procedures During Pregnancy
## 4 The Risks of Cosmetics and Cosmetic Procedures
### Risks of Ingredients of Cosmetics
The prenatal exposure to these chemicals is associated with poor birth outcomes. A recent study reported the association between prenatal exposure to parabens and birth outcomes with positive relationships between maternal exposure to methyl parabens and birth weight [52]. Parabens are used to inhibit microbial growth and extend the shelf life of products, but they have been associated with dermatitis and allergies. Many cosmetics also contain synthetic fragrances, which may include up to 600 different ingredients. The exact components are often not disclosed, only labeled as \"Perfume\" or \"Fragrance\", leading to potential issues such as rashes, itching, cough, asthma, and vomiting, with some fragrances having a narcotic effect [53; 54]. * Formaldehyde: This is a toxic substance and is forbidden by the Cosmetics Regulation (EC) and is classified as a carcinogen (category 1B) and a skin sensitizer (Category 1). Some preservatives are allowed in cosmetic products fulfil their function since they are formaldehyde-releases, preserving the final cosmetic product. Substances such as DMDM hydantoin, imidazolidinyl urea, and diazolidinyl urea, commonly used in cosmetic products, are known to release formaldehyde to fulfil a preserving function in the finished product. Formaldehyde is prohibited in cosmetic products and cannot be intentionally added, but formaldehyde-releasing substances are permitted; they are listed on Annex V of the Cosmetics Regulation (EC), No. 1223/2009, and have to be used within the restrictions given. According to the previous regulation, these products must be labelled with the warning 'contains formaldehyde' when the amount of released formaldehyde was more than 0.05% in the final product in order to communicate the presence of the substance and avoid allergic reactions to sensitized customers [55]. * Aluminum (AI): AI is a known neurotoxin, and studies show that exposure can lead to neurological disorders. Aluminum is an element found in many items, including cosmetics and hygiene products like antiperspirants. The body usually excretes aluminum, but if levels exceed the body's capacity, it can stay in tissues and organs. Studies indicate that Al is toxic in all developmental stages and may produce irreversible health effects even at low levels. Since Al is known to cross the placental barrier, pregnant women should be advised about this risk and should also be informed about avoiding the post-natal exposure of their children to Al. Recent findings show the need for further research on aluminum exposure and its associated interactions in vulnerable populations, e.g., pregnant women [56]. * Toluene: Toluene is a solvent found in nail polishes and may be labeled Methylbenzene Toluol or Antisal 1a. Solvents increase the risk of miscarriage, stillbirth, preterm birth, low birth weight, and congenital disabilities. Those at greatest risk of exposure are those who work with solvents, such as cosmetologists, dry cleaners, artists, and printers [57]. * Oxybenzene: Oxybenzene is a recognized endocrine-disrupting chemical (EDC) and is used as an ultraviolet (UV) absorber (70% of sunscreen products). Many studies have identified this chemical in the urine and blood of women in pregnancy and fetal and umbilical cord blood. A recent study demonstrated that women with medium to high levels of oxybenzene in their urine were associated with giving birth to neonates with Hirschsprung's disease (HSCR) [58]. Oxybenzene is fat-soluble, meaning it enters into fat cells and can stay there for weeks, making it difficult for expecting women to know what their exposure level is. This is dangerous for both women in pregnancy and for women who are trying to conceive. Those who live in a sunny location and use sunscreen with oxybenzene daily all year round may have a higher risk factor than someone who uses it less frequently (e.g., on vacation).