The Case of a Perpetual Pregnancy

Examining the Genetics of a Norn from MalkinMalkin recently shared an interesting genome of a Norn with a rather unique problem. Stuck pregnancies in Creatures 1 usually occur as the result of a genetic mutation. Naturally, I couldn’t stop myself from wanting to take a closer look! Special thanks to Malkin for sending over some additional files and giving me permission to use this little lady as a case study. My first order of business was to give her a name. And so she was dubbed Penny the Pregnant, or “Penny” for short. She comes from a line of Hippy Norns, who have their own unique genome. In this case, though, I only wanted to examine the reasons behind Penny’s stuck pregnancy. Jump on board for a not-so-awful look at the genetics side of Creatures!


Chemical reactions define rules for individual chemicals and chemical combinations. These genes can also state the rules for how chemicals are used up, and each reaction has a defined half-life to determine how often it occurs.

Original: 158 Ado F MutDupCut 1*Gonadotrophin + 2*Estrogen => 1*Gonadotrophin; half-life=40
Mutation: 158 Ado F MutDupCut 1*Glycotoxin + 2*Estrogen => 1*Gonadotrophin; half-life=40

This gene is used to suppress the production of estrogen during a Norn’s pregnancy. Gonadotrophin is produced at the beginning of a pregnancy so that estrogen falls significantly. This will keep a female from going through her usual cycle, thereby ensuring that she can only carry one egg at a time. There are a few other factors that go into this process, yet this is an important gene! For Penny, her estrogen will never decrease during her pregnancy unless she consistently has glycotoxin present in her system. It introduces an interesting scenario since this might result in her being able to become pregnant at any time, even when she is already incubating an egg. The even odder part of this mutation is that glycotoxin is much safer for Penny. Although it will still eat away at her glycogen, glycotoxin will bind with estrogen to produce gonadotrophin. Although this isn’t an ideal reaction, it means that the deathcap mushroom is a little less dangerous! As interesting as this gene is, it isn’t the actual cause of Penny’s stuck pregnancy…


Chemical emitters define specific conditions within a Creature in order to affect chemicals. Some examples include experiencing stress from excessive drives, becoming cold due to environmental conditions, and more.

Original: 157 Ado F MutDupCut Creature, Reproductive, I am pregnant, chem=Progesterone, thresh=0, samp=13, gain=4, features=Digital
Mutation: 157 Ado F MutDupCut Creature, Reproductive, I am pregnant, chem=74, thresh=0, samp=13, gain=4, features=Digital

In short, this gene states that progesterone will slowly increase when a female Norn is pregnant. Another gene indicates that an egg will be laid when progesterone reaches a certain threshold. The trouble with Penny? Her body produces chemical 74 in response to being pregnant, and the corresponding “lay egg” gene is still looking for progesterone. This is precisely why the Observation Kit doesn’t correctly recognize her pregnancy, and why she will never be able to lay an egg naturally. Just another example of how a minor change in one gene can lead to serious consequences.

Unusual Estrogen Levels with a Creatures Stuck PregnancyPenny’s estrogen cycle appears to continue on normally, yet her progesterone level remains at zero. The egg she is carrying inherited both of these genetic mutations. Such bad luck! Yet Penny herself seems to be doing just fine with the news that she’ll be eternally pregnant. The only major downside is the idea that she could have the potential to become pregnant again with the normal estrogen cycle. One stuck egg is more than enough, Penny!

Malkin also noted something about a mismatch between the reactions between Penny and her parents. As far as I can tell, this indicates that she has 96 chemical reactions, while her parents have 92 reactions each. She simply has a few copies of the Hippy Norn glycogen genes. This may make a small difference, but shouldn’t be nearly as obvious as her pregnancy gene mutations! Hopefully this has been a palatable case study that isn’t too long, yet still explains how stuck pregnancies can result from the smallest of genetic mutations. Good luck to you, Malkin, and I wish Penny all the best!

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