Oral retinoids are a type of medicine used to treat severe acne. They’re sold under the brand name Roaccutane, among others.

While oral retinoids are very effective, they can have harmful effects if taken during pregnancy. These medicines can cause miscarriages and major congenital abnormalities (harm to unborn babies) including in the brain, heart and face. At least 30% of children exposed to oral retinoids in pregnancy have severe congenital abnormalities.

Neurodevelopmental problems (in learning, reading, social skills, memory and attention) are also common.

Because of these risks, the Australasian College of Dermatologists advises oral retinoids should not be prescribed a month before or during pregnancy under any circumstances. Dermatologists are instructed to make sure a woman isn’t pregnant before starting this treatment, and discuss the risks with women of childbearing age.

But despite this, and warnings on the medicines’ packaging, pregnancies exposed to oral retinoids continue to be reported in Australia and around the world.

In a study published this month, we wanted to find out what proportion of Australian women of reproductive age were taking oral retinoids, and how many of these women were using contraception.

Our results suggest a high proportion of women are not using effective contraception while on these drugs, indicating Australia needs a strategy to reduce the risk oral retinoids pose to unborn babies.

Contraception options

Using birth control to avoid pregnancy during oral retinoid treatment is essential for women who are sexually active. Some contraception methods, however, are more reliable than others.

Long-acting-reversible contraceptives include intrauterine devices (IUDs) inserted into the womb (such as Mirena, Kyleena, or copper devices) and implants under the skin (such as Implanon). These “set and forget” methods are more than 99% effective.

The effectiveness of oral contraceptive pills among “perfect” users (following the directions, with no missed or late pills) is similarly more than 99%. But in typical users, this can fall as low as 91%.

Condoms, when used as the sole method of contraception, have higher failure rates. Their effectiveness can be as low as 82% in typical users.

Oral retinoid use over time

For our study, we analysed medicine dispensing data among women aged 15–44 from Australia’s Pharmaceutical Benefit Scheme (PBS) between 2013 and 2021.

We found the dispensing rate for oral retinoids doubled from one in every 71 women in 2013, to one in every 36 in 2021. The increase occurred across all ages but was most notable in young women.

Most women were not dispensed contraception at the same time they were using the oral retinoids. To be sure we weren’t missing any contraception that was supplied before the oral retinoids, we looked back in the data. For example, for an IUD that lasts five years, we looked back five years before the oral retinoid prescription.

Our analysis showed only one in four women provided oral retinoids were dispensed contraception simultaneously. This was even lower for 15- to 19-year-olds, where only about one in eight women who filled a prescription for oral retinoids were dispensed contraception.

A recent study found 43% of Australian year 10 and 69% of year 12 students are sexually active, so we can’t assume this younger age group largely had no need for contraception.

One limitation of our study is that it may underestimate contraception coverage, because not all contraceptive options are listed on the PBS. Those options not listed include male and female sterilisation, contraceptive rings, condoms, copper IUDs, and certain oral contraceptive pills.

But even if we presume some of the women in our study were using forms of contraception not listed on the PBS, we’re still left with a significant portion without evidence of contraception.

What are the solutions?

Other countries such as the United States and countries in Europe have pregnancy prevention programs for women taking oral retinoids. These programs include contraception requirements, risk acknowledgement forms and regular pregnancy tests. Despite these programs, unintended pregnancies among women using oral retinoids still occur in these countries.

But Australia has no official strategy for preventing pregnancies exposed to oral retinoids. Currently oral retinoids are prescribed by dermatologists, and most contraception is prescribed by GPs. Women therefore need to see two different doctors, which adds costs and burden.

Rather than a single fix, there are likely to be multiple solutions to this problem. Some dermatologists may not feel confident discussing sex or contraception with patients, so educating dermatologists about contraception is important. Education for women is equally important.

A clinical pathway is needed for reproductive-aged women to obtain both oral retinoids and effective contraception. Options may include GPs prescribing both medications, or dermatologists only prescribing oral retinoids when there’s a contraception plan already in place.

Some women may initially not be sexually active, but change their sexual behaviour while taking oral retinoids, so constant reminders and education are likely to be required.

Further, contraception access needs to be improved in Australia. Teenagers and young women in particular face barriers to accessing contraception, including costs, stigma and lack of knowledge.

Many doctors and women are doing the right thing. But every woman should have an effective contraception plan in place well before starting oral retinoids. Only if this happens can we reduce unintended pregnancies among women taking these medicines, and thereby reduce the risk of harm to unborn babies.

Dr Laura Gerhardy from NSW Health contributed to this article.

Antonia Shand, Research Fellow, Obstetrician, University of Sydney and Natasha Nassar, Professor of Paediatric and Perinatal Epidemiology and Chair in Translational Childhood Medicine, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Head hair comes in many colours, shapes and sizes, and hairstyles are often an expression of personal style or cultural identity.

Many different genes determine our hair texture, thickness and colour. But some people’s hair changes around the time of puberty, pregnancy or after chemotherapy.

So, what can cause hair to become curlier, thicker, thinner or grey?

Curly or straight? How hair follicle shape plays a role

Hair is made of keratin, a strong and insoluble protein. Each hair strand grows from its own hair follicle that extends deep into the skin.

Curly hair forms due to asymmetry of both the hair follicle and the keratin in the hair.

Follicles that produce curly hair are asymmetrical and curved and lie at an angle to the surface of the skin. This kinks the hair as it first grows.

The asymmetry of the hair follicle also causes the keratin to bunch up on one side of the hair strand. This pulls parts of the hair strand closer together into a curl, which maintains the curl as the hair continues to grow.

Follicles that are symmetrical, round and perpendicular to the skin surface produce straight hair.

Life changes, hair changes

Our hair undergoes repeated cycles throughout life, with different stages of growth and loss.

Each hair follicle contains stem cells, which multiply and grow into a hair strand.

Head hairs spend most of their time in the growth phase, which can last for several years. This is why head hair can grow so long.

Let’s look at the life of a single hair strand. After the growth phase is a transitional phase of about two weeks, where the hair strand stops growing. This is followed by a resting phase where the hair remains in the follicle for a few months before it naturally falls out.

The hair follicle remains in the skin and the stems cells grow a new hair to repeat the cycle.

Each hair on the scalp is replaced every three to five years.

Hormone changes during and after pregnancy alter the usual hair cycle

Many women notice their hair is thicker during pregnancy.

During pregnancy, high levels of oestrogen, progesterone and prolactin prolong the resting phase of the hair cycle. This means the hair stays in the hair follicle for longer, with less hair loss.

A drop in hormones a few months after delivery causes increased hair loss. This is due to all the hairs that remained in the resting phase during pregnancy falling out in a fairly synchronised way.

Hair can change around puberty, pregnancy or after chemotherapy

This is related to the genetics of hair shape, which is an example of incomplete dominance.

Incomplete dominance is when there is a middle version of a trait. For hair, we have curly hair and straight hair genes. But when someone has one curly hair gene and one straight hair gene, they can have wavy hair.

Hormonal changes that occur around puberty and pregnancy can affect the function of genes. This can cause the curly hair gene of someone with wavy hair to become more active. This can change their hair from wavy to curly.

Researchers have identified that activating specific genes can change hair in pigs from straight to curly.

Chemotherapy has very visible effects on hair. Chemotherapy kills rapidly dividing cells, including hair follicles, which causes hair loss. Chemotherapy can also have genetic effects that influence hair follicle shape. This can cause hair to regrow with a different shape for the first few cycles of hair regrowth.

Hormonal changes as we age also affect our hair

Throughout life, thyroid hormones are essential for production of keratin. Low levels of thyroid hormones can cause dry and brittle hair.

Oestrogen and androgens also regulate hair growth and loss, particularly as we age.

Balding in males is due to higher levels of androgens. In particular, high dihydrotestosterone (sometimes shortened to DHT), which is produced in the body from testosterone, has a role in male pattern baldness.

Some women experience female pattern hair loss. This is caused by a combination of genetic factors plus lower levels of oestrogen and higher androgens after menopause. The hair follicles become smaller and smaller until they no longer produce hairs.

Reduced function of the cells that produce melanin (the pigment that gives our hair colour) is what causes greying.

Theresa Larkin, Associate professor of Medical Sciences, University of Wollongong

This article is republished from The Conversation under a Creative Commons license. Read the original article.