6 Bewildering Symptoms in Newborns That Parents Don’t Expect


Pediatrician Dr. Paul Smolen here. Parents are often bewildered by some of the bizarre physical symptoms their babies develop soon after birth. Stay tuned and I will break down some of these unexpected baby bodily changes in today’s installment of Portable Practical Pediatrics.

Photo compliments of Pixabay Images

Musical Intro

Science Drive of Pregnancy

Pregnancy and the first few months of life for a baby are a time of radical change with respect to their hormone balance as well as the germs that live on their skin. These changes cause some unexpected physical symptoms in many babies, possibly some that you have or are going to see in your children. Understanding the biology of what’s going on with your baby is essential to having insight into your baby’s changing physiology so let’s take a quick tour down Science Drive to better understand these changes, shall we?

–Radical Change Number One-Hormones Come and Go

First, let’s consider the changes that babies experience with regards to hormones. You remember learning about hormones in biology class- those circulating chemicals that turn on or off various tissue functions in your baby’s body. Think about a baby being exposed to the large amount of estrogen that is required to keep a pregnancy going all the way to term. This has a tremendous effect on a wide variety of an infant’s bodily systems. Think about it, as far as hormones, your baby has been pregnant along with their mothers. I know what you are thinking,  “If I have a boy, estrogen doesn’t effect boys right?” Yes it does as I am about to describe to you in a minute!  Just because your baby is a boy doesn’t mean that their cells don’t know what estrogen is and what to do when it is around as you about to see.

Shifting gears, now imagine the effects on your baby when suddenly all that estrogen disappears- at delivery.  Suddenly, your infant is no longer pregnant hormonally and you can begin to see the effects of the male hormone that babies have small amounts of- testosterone. And for those of you with daughter babies, yes, girls make a small amount of testosterone and it has effects on them as well. Their cells know what to do when turned on by testosterone just like the boys and estrogen. Shortly after birth, your baby’s little endocrine system is getting whiplash now with all this hormonal flux isn’t it!

Now let’s make the leap between hormone levels and what these hormones do an to an infant’s body. Here is a short summary of the effects of estrogen and testosterone on your baby’s body:

First let’s start with the effects of estrogen and other female hormones on your baby

  • Estrogen promotes breast growth- Pregnancy is the ultimate high estrogen state and just ask any pregnant mom about what happened to her breasts during her pregnancy!
  • Estrogen stimulates the lining of the uterus to grow thicker and become more vascular.
  • Estrogen stimulates vaginal cells to produce mucous, a thick mucous in response to estrogen stimulation.
  • And on the flip side, a sudden decrease in estrogen stimulates uterine bleeding- shedding of the uterine lining- a period
  • And a sudden fall in estrogen also allows other hormones that moms produce (namely prolactin) to stimulate milk production.

Ok, that’s the effects of estrogen or a sudden change in estrogen. How about the effects of testosterone

Remember, when mom’s estrogen levels precipitously fall, the effects of testosterone start to become more pronounced in your baby, temporarily in the few months after birth.

  • Testosterone promotes oil production in your baby’s skin in areas where they have a lot of oil glands- their face and scalp. Under certain conditions, this can even lead to acne, just like teenagers get, especially with all the new microbes that are living on their skin.
  • Testosterone in some people causes hair loss-Take a look at older men and you can usually see that effect known as male pattern balding.
  • Testosterone is essential to males having erections

All this hormonal chaos creates real physical changes you may have seen in your baby. More on that in the next section of this pedcast.

–Radical Change Number Two- Living on dry land. 

As if all this hormone craziness wasn’t enough, consider the fact that a baby has been in an aquatic sterile environment until the moment of birth. Think about being in water for 9 months and then suddenly becoming a land, air encased creature. That’s what happens to your baby just after birth, especially their skin and as you would expect, a baby’s skin undergoes massive changes. Shedding of the surface of their skin is suddenly different as are the billions of microbes inhabiting your babies skin. Talk about drastic changes! From ocean living to desert life in an instant.


Most Common Unexpected/Bewildering Symptoms Parents Notice

So how do these two changes, that of hormones and that of living environment, effect your baby? In bewildering ways it turns out that I hope you are now equipped to understand.

  • First bewildering symptom: Many little newborn girls have a thick vaginal discharge that many parents think is abnormal but now you understand that since the baby has been under the influence of very high estrogen levels, of course they may have a thick vaginal discharge.  Remember, thick vaginal discharge is on effect of high estrogen levels.
  • Second bewildering symptom: Many newborn girls experience vaginal bleeding shortly after birth. Recall what happens when estrogen levels suddenly fall in girls-that’s right, a sloughing of uterine lining cells along with some bleeding. A mini period. So if someone asks you when your daughter had her first period, an accurate answer might well be “At birth”.
  • Third bewildering symptom:  Many newborns, both male and female have swollen breasts and even produce milk for a while. These babies are actually lactating. This is true in both baby boys as well as baby girls. So if someone asks you if boys can lactate, the answer is “Most assuredly they can and already have!”.
  • Fourth bewildering symptom: Babies frequently develop something we associate with teenagers, acne. This usually pops up at about 2-6 weeks of age and can be very distressing to parents. Now remember that I told you before that acne is a testosterone effect in children of all ages and now that the effects of mom’s super high estrogen levels are gone, here comes acne- greasy infected skin with crops of pimples in oily places. It’s temporary though in most infants thank goodness.
  • Fifth bewildering symptom: Balding, you heard me right, good old hair loss. This is a little more complicated but experts think a combination of effects cause balding in babies. These reasons involve both radical change 1 (hormone changes) and radical change 2 (change of environment) that we discussed on Science Drive.  Some babies have genes that trigger testosterone to stunt hair follicle growth and cause hair loss, just like in old men; other babies, develop a condition where excess skin oil cakes together with shedding skin cells on the scalp, promoting a low grade fungal infection  and inflammation along with hair loss (this process is called seborrheic dermatitis); and finally, very young babies are known to lose their first hair called lanugo and replace it with vellous fine hair like bald men have ultimately coarse adult hairs. That whole process takes months to years to occur. In the mean time, babies have periods of baldness during these changes.
  • Sixth Bewildering Symptom: Many if not most little boys have penile erections, even when they are only months old. And now you know why- that rascally testosterone raising its head again. If you ever studied psychology you may remember that Sigmund Freud had a lot to say about this bewildering symptom in children.


All of these strange symptoms, vaginal discharge just after birth, vaginal bleeding in the first week of life, swollen milk engorged breasts early in life, acne and oily skin in babies 2-6 weeks of life, balding in the first two years of life, and intermittent penile erections are really normal in babies but often startle parents into thinking something is wrong with their baby. These symptoms are actually normal and common in many babies. But by all means, if you have concerns about ANY symptom your child has, make sure to discuss it with that wonderful person you call your child’s pediatrician. That’s why they are there and are ready to help!


If you value the information that you get from Portable Practical Pediatrics, consider taking a moment and sharing an episode with family and friends. And while you at it, a like, share, or review where you get podcasts would be very helpful.  This is Doc Smo, recording in studio 1E,  hoping that by giving some bewildering baby symptoms the limelight, I can help many parents gain needed insight. Until next time.


Many thanks to Dr. Monica Miller and Dr. Charlotte Rouchouze for their help in the production of this pedcast.