Dragon reproduction

A healthy dragoness can create a new life, a role which was part of the reason of their traditional veneration.

Statistics
The average number of children for any dragon couple throughout their livetimes is very much dependent on social status. The lower and middle classes are known for having large families, and six hatchlings per pair is the average. The higher classes, both monarchs of old and millionaires of today, have only a 1 to 3 eggs per mother. That is an old habit from the time when a dragon with a large hoard would not want to split it up amonst too many offspring, lest they lose the status their parents worked so hard to obtain.

Heat
The estrous cycle, known informally as the heat cycle, refers to the recurring physiological changes induced by reproductive hormones in the dragon species. Its start signifies sexual maturity, and it generally lasts until after the peak of the dragoness's maturity.

The estrus is the period when a dragoness is in heat. It can last from anywhere between 7 and 29 days, and is exemplified by a number of symptoms:
 * The dragoness feels a sense of sexual passion that can often be overwhelming, especially for the younger dragonesses. Older ones are known to channel this energy in platonic activities.
 * The dragoness begins releasing pheromones, that induce the interest of any nearby males that do not see her as family. They will not be driven to mate with them; instead, the pheromones affect them on a subconscious level; encouraging them to seek out the dragoness in heat and spend time with her, in the hopes of forming a connection of some sort.
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Contraceptives
Contraceptives for dragons are generally quite hard to come by. This is primarily a result of dragons being able to detect the pheromones of a prospective mate, and thus tell when a hatchling is likely to ensue from a mating. As a result, far less research has been done into methods of providing birth control to dragonkind than has been done for humankind, but a few types of birth control do exist; primarily barrier contraceptives such as condoms, as most hormonal contraceptives have a high chance of failure in dragonesses.

Aphrodisiacs
Conversely, there are several substances that can trigger anything from a short burst of passion to a full-blown heat. They can be used to help latebloomers kickstart their estrous cycle, though that practise is generally adviced against except in extraordinary circumstances, due to the emotional pressure this places on the young dragoness.

One of the oldest known dragon-specific aphrodisiacs, used when there is desire for more pleasure without the chance of offspring, is the substance known as Robanacea. It is traditionally made by growing Crystals inside a cauldron filled with a variety of herbs, the exact proportions being a well-kept secret. The crystals are traditionally stored in water-filled containers, as they evaporate on contact with nitrogen. It comes in two main types: one induces simple lust for as long as one is inhaling it (used from small dispensers in brothels, and keeping the air saturated with the scentless gas). The second kind is much more powerful, and meant as a medicine, to aid the young dragonesses that are late with their first heat, inducing both lust and fertility.

Amongst other influential figures, the Guardians have always discouraged the use of the substance, and advice safer but less potent alternatives, such as tackweed or ambergris (both known ingredients of Robanacea). In modern times however, the production is in the hands of a strictly-regulated Avalar-endorsed private factory, of which a descendant of the original inventor, Roba Hagizussa, is the majority shareholder.

Caution is advised when dealing with the substance. Possible effects of overdose include but are not limited to: confusion, dizziness, insomnia, hyperventilation, fever, fertility (when not intended), vomiting, quivering, convulsions, memory loss, loss of dexterity, loss of ability to speak, migraine, bleeding out of the ears, haemoptysis, abdominal pains, cramps, tachycardia (potentially leading to heart failure), and singultus.

Chronology
If mating happens during the heat, conception is basically guaranteed, and the pregnancy begins. In total, the phase of life from conception to hatching is eighteen months long, plus or minus a month depending on a variety of circumstances. It is divided into four "phases" in both popular and medical conversation.

Yolk phase
The first phase is the yolk phase, which generally lasts for nine months after conception. While a series of membranes develop around the fertilised ovum in order to protect the embryo, a sphere made up of vitamins, minerals, proteins, cholesterol and fat begins forming in the oviduct. This eventually becomes the albumen and yolk of the egg; the latter of which is used to sustain the embryo and aid its growth. As a result, the expecting dragoness will gradually increase her own food intake during this time, and often subconsciously seek out specific foods that will aid the development of her hatchling. In addition to this, it’s common for an expecting dragoness to experience a form of “morning sickness”, caused by their bodies forcibly ejecting ingested substances that could prove harmful to the embryo. A significant increase in the mother's weight becomes evident towards the end of this phase, and continues over into the next phase, as the embryo reaches its full size.

Shell phase
The second phase is the shell phase, which begins when a hard layer of calcium carbonate crystals stabilised by a protein matrix begins to form around the egg sac. During this time, the expecting dragoness gains an intense craving for bones, in order to ingest enough calcium for her body to create a shell around the egg. Prior to the creation of the Lacconcoctio spell in 494 AD - giving dragonkind the ability to safely ingest lactose - this process could take more than a month in to complete in heavily populated areas, but with the gradual increase in popularity of dairy products, and the onset of food supplements in the modern age, it’s possible for the process to be completed in a fortnight or less.

Carrying phase
Once the shell is fully formed, the egg is complete, and the embryo within receives no further sustenance from the mother; instead relying purely on the yolk. Despite this, in most cases the egg tends to remain within the mother’s oviduct for at least three months, although it is ready to be laid at any time. This is believed to be a remnant of an evolutionary tactic that allowed a dragoness ample time to find a safe nesting ground before laying her clutch, and as a result, dragonesses who are suffering from high levels of stress tend to clutch at much later dates than relaxed dragonesses. Inversely, it has been observed that dragonesses who experience a sudden period of stress - or even a physical assault - tend to clutch earlier than normal. The exact reasons for this are debated, but one prominent, if controversial theory suggests that this is the dragoness’ body attempting to quickly jettison extra weight - thus allowing the dragoness to flee to safety - by birthing the egg early.

Egg phase
The final phase is the egg phase, which consists of the stage between clutching and hatching. After the expecting dragoness clutches, the embryo inside the egg continues to grow until it has finished all the nutrients within, after which point it hatches. This phase generally takes six months, although it can vary significantly depending on when the egg was clutched.

Multiple birth
Twins are relatively common for dragons, compared to humans. Multiple birth may be either with two hatchlings in the same egg, or several smaller ones.

Triplets are still relatively common, but more of a stress on the mother. Quadruplets and higher are almost as rare as for humans.

When a monozygotic twin does not split apart early enough in the development, they may remain partially attached to one another, resulting in a Siamese twin. Multi-headed dragons are the most known version, because they tend to live longer than other variations.

Culture
A number of draconic cultural rituals revolve around the pregnancy (also referred to as "eggnancy").
 * Some cultures preserve the remains of the eggshells they were born in, as a good luck token. A few of them advice the mothers to consume their own eggshells upon their own first pregnancy, though this is discouraged by modern medical science.
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