We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Conditions

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What is Mermaid Syndrome?

Tricia Christensen
By
Updated: Mar 03, 2024

Mermaid syndrome is also called sirenomelia and it is an extremely rare set of birth defects, which can vary in expression. The condition gets its name from one of the defects present, which is a fusing of the legs. The unseparated nature of the legs has been compared to a mermaid in appearance, hence the name.

If mermaid syndrome only had leg fusion, it might not be so very serious, but instead, children born with this congenital disorder have a wide variety of problems with other parts of the body. Genitals may be misshapen or absent, the bladder can be missing, spinal abnormalities may be present, and the kidneys may be seriously affected. Not that many years ago, the condition would have been considered always fatal within a few hours to days after a child is born, but there have been some successful surgeries that may ultimately alter outlook on treatment for this disease.

Several now “famous” patients have undergone treatments since the early 2000s. Shiloh Pepin, born in 1999, has received kidney transplants, restructuring of her urinary tract and other interventions. Milagros Cerron, born in 2004, had a successful surgery to separate her legs, and she is able to walk. Both girls face a lifetime of medical care. Shiloh received her second kidney transplant in 2007, but the fact that both girls did not die at birth or before it, is encouraging.

The defects associated with mermaid syndrome occur about once in 100,000 births. However, with a birth rate of over four million children a year in the United States, that would suggest about 40 children a year are born with this condition, in the US alone. These statistics must be sobering, if there are only a handful of children who have thus far managed to survive. Part of the issue may be medical prejudice toward not treating kids with mermaid syndrome, and strong recommendations from doctors that they be allowed to die, but proven treatment might alter this mindset in time.

Another reason survival can be so poor in mermaid syndrome is that severity of birth defects and types of defects may vary. With less severe forms, it’s possible that children will be able to survive to treatment. Greatly severe defects may mean the condition simply isn’t survivable for some of the children born with it. Some children do not even live to birth, and so part of assessing and treating mermaid syndrome in the future may be determining the types and severity of defects that exist.

The Health Board is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Tricia Christensen
By Tricia Christensen
With a Literature degree from Sonoma State University and years of experience as a The Health Board contributor, Tricia Christensen is based in Northern California and brings a wealth of knowledge and passion to her writing. Her wide-ranging interests include reading, writing, medicine, art, film, history, politics, ethics, and religion, all of which she incorporates into her informative articles. Tricia is currently working on her first novel.
Discussion Comments
By anon292355 — On Sep 19, 2012

I am a mother who had a newborn at 38 weeks along, who was born with this disease. It lived 15 minutes. The year was 1980. I was a healthy 18 year old female with no medical conditions.

I read the message about the doctor's sister, which makes me wonder if I may have been exposed to toxins. I worked in a nursing home as a house keeper at the time. So I was exposed to a lot of chemicals.

I should also add my husband is a Vietnam vet and he was exposed to Agent Orange. I am wondering if this might have been a factor. This child would have been his first born, but not my first born.

I am doing a report on the subject for a course at college. It still seems there is little known about this disease. With the technology we have today, there should be more medical information about it.

My baby's upper half was pretty much normal looking, but I never saw the deformities. I was told its legs appear fused. We buried the baby a few days later, and the funeral director told us that it was missing a lot of internal organs.

By anon257459 — On Mar 27, 2012

I am a mother who had a baby who passed away for mermaid syndrome. The reason she formed the way she did is I had identical twins so when they split they didn't split right. I found out I was pregnant at 2 weeks and never drank. I took every prenatal precaution. She lived for two hours after birth. I carried her for 36 weeks, and she lived for her identical sister who is almost 1.

By bear78 — On Feb 01, 2012

I saw mermaid syndrome patient Shiloh Pepin on TV before she passed away in 2009. She was such a strong and positive girl! She was ten at the time and I believe she's the longest-living person who had mermaid syndrome.

I think she was such a great example and inspiration to others with the syndrome, as well as parents and doctors. She proved that anything is possible.

When she was born, doctors had expected her to live for only several days at the most. But she proved them wrong and lived for a whole ten years. The most amazing part was how positive and happy she was during her TV interview! She certainly didn't let the condition bring her down!

By candyquilt — On Jan 31, 2012

@burcidi-- Wow! I had no idea that the first weeks of pregnancy was so important in terms of developing birth defects.

Do you think that mermaid syndrome can be prevented if mothers take extra caution during this time and stay away from all the possible culprits even before they become pregnant?

And I'm sure that it's possible to diagnose the syndrome pretty early on in the pregnancy with the use of a fetal ultrasound, right? So the pregnancy could be terminated early since the rate of survival for people with mermaid syndrome seems low. I'm sure that this would be a very difficult and painful decision to take for any mother though.

This article has definitely opened my eyes up about the possible complications during pregnancy and what the results may be. I have diabetes so this will be something I will need to consider and be careful about before getting pregnant.

By burcidi — On Jan 30, 2012

My brother is a doctor and he came over for dinner to my house last week. He was talking about an infant that was born with the mermaid syndrome and passed away ten minutes after birth.

I had never heard about this fetal syndrome before so he told me a little about the causes. I don't remember all the technical words he used. But from what I understand, the syndrome is caused by an injury to the embryo during the 3rd week of pregnancy.

This is apparently the time when the embryo starts forming the skeleton, reproductive organs and other tissues. He said that the injury could be caused by lots of different things like the mother having an infection, taking medications or being exposed to toxins, using alcohol and tobacco and chronic diseases like diabetes and hypothyroid.

He also showed me a picture of a newborn with the syndrome on the net and it was quite unbelievable. The infant had a single leg and two misshaped feet at the end. A genital organ could not be seen at all and the skeleton was clearly formed abnormally. The part of the infant which looked closest to normal was the head but the neck looked much thicker than usual.

Tricia Christensen
Tricia Christensen
With a Literature degree from Sonoma State University and years of experience as a The Health Board contributor, Tricia...
Learn more
Share
https://www.thehealthboard.com/what-is-mermaid-syndrome.htm
The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.

The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.