More Than Skin Deep

The generational trickle-down effect of EDCs from mother to child.

Inside This Issue

• How EDCs affect not just conception, but pregnancy, baby biology and even grandkids

• Why these hormone-disrupting chemicals cross the placenta and show up in breast milk

• The overlooked science of skin absorption, layering and low-dose accumulation

• A practical audit to clean up your bathroom cabinet, plus what ingredients to look out for

• A gentle reminder that reducing the dose lightens the load, for your body, your baby and the planet

Last time, we looked at how personal care products could affect your reproductive health and ability to conceive.

Here it is if you missed it:

The Lingering Effects of EDCs

As we covered in the last issue, endocrine disruptors impair ovulation and sperm development, with wider ripple effects across reproductive health. They’ve been linked to menstrual irregularities, PCOS, endometriosis, uterine fibroids, testicular disorders, low testosterone and hormone-related cancers including breast, testicular and ovarian.

But after conception, these chemicals don’t stop outside the cells of the rapidly dividing zygote: the fertilised egg.

They can also alter the course of a pregnancy, with research consistently linking EDC exposure to higher risks of miscarriage, preterm birth, low birth weight, small-for-gestational-age infants, placental dysfunction and gestational diabetes.

EDCs are lipophilic, meaning they’re fat lovers, and like to store themselves in fatty tissues. Why? Because our bodies haven’t evolved to figure out how these Johnny-come-latelies should be cleared.

They’re intrepid travellers too, crossing the placenta and entering the developing fetus via the umbilical cord.

Not only do we have evidence that these chemicals are found in meconium (baby’s first poo), but also in breast milk.

Think about that: breast milk is biologically designed to nourish and protect. But that same richness - its fat content - can also serve as a vehicle for toxin transfer. As such, it’s an inadvertent detox. A pump-and-dump, where the mother’s toxic load goes down while the baby’s goes up.

Evolution never saw this coming. Not because evolution got it wrong, but because it never anticipated the chemical soup in which modern life exposes us to.

And all the more reason to consider a preconception detox, because breast milk is gold, and we want to keep it that way.

EDCs Don’t Just Pass Through. They Rewire the Developing Fetus

Once EDCs cross the placenta, they don’t simply pass through. They interact with a developing system that is exquisitely sensitive. Even low doses can alter biology and architecture in ways that influence lifelong health.

Potential outcomes associated with prenatal EDC exposure include:

• Altered brain development, particularly in stress reactivity, emotional regulation and attention (including increased risk of ADHD and other neurodevelopmental differences)

• Shifts in how metabolism, immunity and hormones are calibrated, often with effects that only emerge later in life

• Changes to the timing of puberty, either earlier or later than expected

Some effects are sex-specific.

Prenatal EDC exposure has been associated with:

In females:

• Irregular or disrupted menstrual cycles

• Increased risk of polycystic ovary syndrome (PCOS) and endometriosis

• Shorter anogenital distance, which has been linked to higher endometriosis risk in adulthood

In males:

• Reduced sperm count and motility in adulthood

• Smaller penis size (unfortunately labelled ‘micropenis’), higher rates of hypospadias (where the opening of the penis is in the wrong place), and undescended testes at birth

• Shorter anogenital distance, associated with reduced fertility potential and impaired testosterone signalling

The critical point:

These chemicals don’t just pass through: they reprogram.

A Word About Grandkids

In animal studies, the ripple doesn’t stop with the parent or their child - it reaches the third generation. That means the grandkids, who were never directly exposed, still show the effects.

What have they found in these grand-offspring? Changes in sperm and egg function, disrupted puberty timing, reproductive tract abnormalities and even altered stress and metabolic responses, none of which came from direct exposure.

Are rats humans? No. But we’re not about to test the safety of EDCs by rubbing them on a group of women trying to conceive, following them through pregnancy, and tracking their children’s reproductive health. That would be unethical - and a hard study to recruit for!

So instead, we find ourselves in a kind of global, unintentional trial. Eight billion of us, and for those who can afford it, layered in lotions, serums and fragrance, part of an experiment we didn’t exactly opt into.

Delivered Daily, Just Not in Tablet Form

Personal care is just one source of endocrine-disrupting chemicals. These compounds are also found in:

• Food packaging and plastic containers

• Household cleaners and flame retardants

• Pesticides sprayed on food

• Dust, tap water and indoor air

Whether via skin, air, water or food packaging, these chemicals still get into our bodies, just not as pills. If they were pills, many endocrine-disrupting chemicals (EDCs) would never have made it past regulatory approval.

But because they’re considered ‘indirect’ exposures: airborne, trace-level or leached from materials, they’ve slipped through the cracks of chemical regulation. Often, there's a scientific disconnect between presence and effect.

Biology doesn’t make that distinction. A molecule that mimics estrogen is still received as estrogen, no matter how it entered the body.

How Did These Chemicals Get a Free Pass?

Many of these chemicals were grandfathered into use decades ago, long before modern safety testing standards. And unlike pharmaceuticals, which require pre-market evidence, industrial chemicals, including those used in personal care products, don’t need to be proven safe before being widely used.

Yes, skincare products are dermatologically tested, but not for endocrine disruption, and rarely for cumulative or long-term effects after absorption.

Instead of proving safety upfront, regulators tend to act only when enough harm has already been documented. And even then, the bar is high.

Europe has banned over 1,700 ingredients from cosmetics. The US? About 11.
Australia? Somewhere in between, and good luck finding transparent stats.

Do the French, Americans and Australians have different biology? Different science?Or just different systems of accountability?

Watch the Layering: Cumulative Exposure, Compounded Risk

But is there real harm in dabbing on a little moisturiser?

Even small doses of EDCs, applied daily through moisturiser, deodorant, or foundation, can accumulate over time. Especially if you’re layering multiple products or adding heat (think hair dryers, saunas or sun).

And if these chemicals can’t ethically be studied on the general population, let alone pregnant women, their cumulative, synergistic effects certainly aren’t being studied either.

Less In, Less Passed On

You don’t need to (and can’t) eliminate everything. Just reduce the dose. These choices add up, not just in your body, but in the world around you.

Many of these chemicals end up in soil, water and wildlife, disrupting their reproduction too. So every swap you make lightens the load for your hormones, your future child and the planet they’ll inherit.

If you're ready to start somewhere, start with your skin. A few small swaps go a long way, especially when you're using them every day.

Bathroom Cabinet Clean-Out Is the New Pantry Clean-Out

• Pick a scanner app and audit your bathroom shelf. Try Yuka, Think Dirty or EWG’s Healthy Living

• Start with the products that get the most skin time: moisturisers, deodorants, sunscreens

• Then look at what lingers: leave-in treatments, masks, serums

• Finally, check the ones that rinse off: cleansers, soaps, scrubs

And if you’re curious about other everyday exposures beyond the bathroom, I’ll be writing more in a future issue on how to bring nature in and escort toxins out.

What to Watch For on the Label

You don’t need to memorise every chemical. Just start recognising the names that come up most often:

Parabens
Mimic estrogen. Disrupt cycles and sperm quality. Look for methyl-, propyl- and butyl-paraben.

Phthalates
Interfere with testosterone and ovarian signalling. Often hidden under “fragrance.”

Triclosan
Antibacterial. Disrupts thyroid function and the skin microbiome. Found in soaps and acne products.

Benzophenones
UV filters like oxybenzone. Cross the placenta. Estrogenic. Found in many sunscreens.

Siloxanes
Used for that ‘silky’ feel. Accumulate in fat. Potential endocrine disruptors.

Formaldehydes
Slow-releasing preservatives in hair, nail and cleansing products.

BHA / BHT
Synthetic antioxidants. Weakly estrogenic. May impact thyroid metabolism.

Till next time…

Warmly, Sonja

If this sparked something for you, tap 🧡 and hit Restack to pass it on.
Thanks for helping thoughtful fertility conversations travel further. 🤍

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This post is for educational purposes only and is not medical advice. Always consult a qualified practitioner before making decisions about your health.