Reproduction

This article is about human pregnancy and birth. For end result, see Babies. For Older children, see Children.

Reproduction is the means by which human babies are created.

Overview[edit]

There are three ways a human can reproduce, assuming children are enabled in the storyteller settings.

Natural reproduction, through pregnancy.
Assisted reproduction, through surrogacy.
Artificial reproduction, through growth vats.

Natural reproduction[edit]

Pawns in romantic relationships have a chance to get pregnant when they initiate lovin'. Note that pawns must share a two-person bed, bedroll, or sleeping spot at the same time to initate lovin'. The Sleeping Alone debuff only checks if 2 pawns are assigned the same bed; they don't need to sleep at the same time or ever engage in lovin' to avoid it.

Chance[edit]

The prospective parents' chance of successfully reproducing is primarily controlled by their Fertility stat. The player has three options to adjust pregnancy rates from Lovin' in any relationship. By opening the social tab, to the right of a Lover, Fiancee, or Spouse, you can see a button that lets you change the couple's approach for having kids.

	Normal (Default)	x1 pregnancy chance.
	Avoid pregnancy	x0.25 pregnancy chance.
	Try for baby	x4 pregnancy chance.

Therefore, the total chance of pregnancy in one relationship is likely:

Pregnancy chance per relationship = Mother's fertility x Father's fertility x Reproductive Approach x Times Lovin'

The actual chance that a pair of pawns will do Lovin' each night varies, but it requires them to share the same bed and sleep at the same time. For further information, including the factors that influence the lovin' chance, see Lovin'.

Pregnancy[edit]

Pregnancy lasts for 18 days, broken into three 6-day trimesters. The player will receive a notification when the pregnancy starts and when it progresses from one trimester to the next. The pregnant pawn will gain penalties to movement, manipulation, and hunger rate, increasing each trimester as seen in the chart below. Other than the statistical penalties, pregnant pawns have no restrictions on the activities they pursue.

If the mother is in poor health, such as Malnutrition, she might suffer a miscarriage.^[Details]

Stage	Effects
First trimester	Hunger rate offset: +10%
Second trimester	Moving: −10% Manipulation: −5% Hunger rate offset: +30%
Third trimester	Moving: −50% Manipulation: −10% Hunger rate offset: +50%

During the first trimester, a pawn will gain the New pregnancy moodlet, which can either be positive or negative direction: +3 I'm pregnant! It makes me happy., or −3 I'm pregnant and not very happy about it. When the pawn is not happy about their pregnancy, you can perform an operation to end their pregnancy This will result in a mood buff of +5 I'm relieved I'm not pregnant any more. Throughout their pregnancy, they will also occasionally gain mood buffs or debuffs due to hormone-induced mood swings, which includes the third trimester.^{[Detail needed]} Mood swings are visible in the Health tab as a condition affecting the brain. They vary in severity, direction, and duration, appearing as: "Pregnancy Mood (<duration>, <type>)" with the description This common side effect of pregnancy represents a rising and falling mood caused by unbalanced hormones. Accompanying this, the pawn will get a positive or negative moodlet labeled Pregnancy mood <type>. Mood swings are short-lived, with the longest duration seen so far being 10 hours.

Types of Mood swings:

−14 Pregnancy mood collapse mood
−8 Pregnancy mood down mood
4 Pregnancy mood up mood
8 Pregnancy mood high mood

Pregnant pawns may also receive the "morning sickness" condition, which lasts 4 to 8 in-game hours. Along with health effects, they will gain the −3 mood debuff Sick.

Morning sickness:

Consciousness: ×0.8
Moving: ×0.9
Manipulation: ×0.9
Vomiting MTB: 1.8 hours

Note that Pawns in the character selection menu can begin the game already pregnant.

Assisted reproduction[edit]

Science enables new methods for obtaining babies. After Fertility Procedures has been researched, you can extract ova from female pawns and fertilize them to form an embryo, for use in surrogate pregnancies or vat-grown babies.

Both methods require extracting an ovum from a fertile female pawn, be they colonist, prisoner, or slave, through a medical operation in the pawn's Health tab: "Extract ovum for IVF". The operation requires one of any type of medicine and a doctor, although it is a relatively easy surgery, with a 500% multiplier on success, and 0% chance of death on failure.

The ovum may then be fertilized by a fertile male colonist or slave (but not a prisoner or guest) to produce an embryo. As long as the male pawn's fertility is above 0% this will be successful. The resulting embryo can then be implanted in female pawns (may be prisoner, colonist, or slave) to initiate a pregnancy, placed in a growth vat, or sold.

Surrogacy[edit]

With the Fertility Procedures research, you can create embryos. They can then be implanted into a pawn for a chance for the pawn to become pregnant. The chance of success depends on the surrogate's own Fertility.

Even if they did not supply the ovum, the surrogate will be considered the birth mother. Otherwise, it will act as a regular pregnancy.^[Verify]. A pawn born this way will consider both their surrogate and genetic mother as the pawn's parents in terms of social opinions.

Growth vats[edit]

Birth[edit]

Your first warning for a pawn's upcoming childbirth comes during a pawn's pregnancy: the player will receive one notification when the mother hits the third trimester about "<Colonist>'s baby prep", which explains all the steps you can take to help the mother give birth successfully. Besides preparing a location and doctor for the birth, this notification reminds you to prepare a food source for the baby and build them a crib. Labor will happen roughly 6 days after, starting with a notification of "<Colonist> in labor!".

Once labor begins, the birthing procedure can be initiated by clicking on the mother, and selecting the "Begin birth" option. This allows the player to select participants and a Doctor, much like Ideology's rituals. The procedure will take place at a bed or sleeping spot, chosen automatically (preferring medical beds) if the mother is not already in bed. All of these choices have an effect on the birth's quality, which affects the chance that the mother and baby will come out of childbirth alive and healthy. You can view the exact factors and their influence in the Quality section below. The expected duration of this operation is variable, but will end once the baby has been born or mother has died.

Labor[edit]

The progress of labor can be tracked in the mother's health tab. Labor begins with contractions, different stages of dilation that change randomly over time, with all adding various amounts of pain and restrictions on movement for the mother. Many stages will incapacitate her, so even before the childbirth operation begins, it is important to bring her to a bed. When the childbirth operation has proceeded for a while, you will receive a small notification saying "<mother>'s labor has entered the final stage", and the labor will progress to the final "pushing" stage.

Stages of labor:

dilation, mild: pain +25%, moving x40%
dilation, intense: pain +50%, moving x20%
dilation, debilitating: pain +85%, moving x0%
pushing: pain +85%, moving x0%

Once the childbirth procedure has begun, any spectating loved ones may socialize with each other, but the doctor and mother will be focused on their tasks. Spectators and the doctors can leave if needed, by selecting a pawn and then pressing the "Leave child birth" option. Finally, you can cancel the birth operation by selecting any of the involved pawns and then selecting the "Cancel child birth" option, which allows you to restart childbirth later.

Quality[edit]

When starting the child birth procedure, a screen will show you the expected quality of the birth, determined by (descending order of influence):

Age of the mother: The mother has a natural +50% quality bonus between ages 20-30. Outside this range, the bonus drops. See the graph below.
Doctor's medical skill: Can range from +0-25%. Starting at 0% with skill level 1 and increasing by 1.25% every level, up to a maximum of 25% at skill level 20.
Room cleanliness: Cleanliness can range from 0-0.6, giving +0-10% in quality bonuses.
Other factors, gives up to 5% each:
- Loved one present: The presence of someone that the mother considers a friend or more gives +5% quality, with no stacking for multiple friends or a better friend. By default, the father will be selected to be present. If the doctor performing the operation is a friend, they will count towards this bonus too, and forcing father to participate in addition to doctor will give nothing.
- Indoors: If inside, the quality gains +5%.
- Bed health effects: Contributes up to 5% depending on the type of bed: sleeping spots and bedrolls give no bonus. Regular and royal beds give a +2% bonus while hospital beds give a +5% bonus.

Birth quality is determined at the moment of the baby's birth; allowing the doctor or loved ones to leave, or having the room grow dirty, has an effect on birth quality.

Additional quality from Mother's age
	14 yrs: +0% 15 yrs: +30% 20 yrs: +50% 30 yrs: +50% 40 yrs: +30% 65 yrs: +0% Note: Bonus is linearly interpolated between these points

Outcomes[edit]

Depending on the quality, the baby can be born healthy or sickly, or they may die during birth, also known as being stillborn. At lower qualities, there is also a chance that the mother can die during childbirth. The quality needs to be >90% for the best possible outcomes. Since the probability of a bad outcome increases drastically below 20% birth quality, it's strongly recommended to provide at least the bare necessities, such as a bed indoors, as even a few percent above 0% in birth quality will contribute massively to the outcome.

Birth Outcome Chance	Mother Death Chance

You will receive a notification when the birth is complete, and the baby will appear on an adjacent tile. If the baby was born alive, a pawn with the Childcare work enabled can be instructed to either move the baby to a safe space, or to deliver it to the mother for breastfeeding. The baby will be born hungry, with a mood penalty of −6.^{[Thought Template]}

If your baby was healthy, the notification is "Healthy child birth", and it gives you 24 hours to choose a name for the baby. You can also name stillborn babies via the stillborn notification.^{[Notification title?]}

These are only time where you can completely customize the baby's first and last names, and you additionally can add an optional nickname. The game will suggest the mother and father's last names on this screen, and provide random suggestions for the other names. Until then, the baby's name is temporary, and called "Baby <Mother's last name>". The baby will also receive the Childhood title "Newborn", and belong to the mother's faction. The baby's parents will receive a 15-day mood boost that "<Baby> was born healthy" +8.

If the baby is born sick, they are affected by a form of infant illness, which can start at a variable intensity. If left untreated before 10 days is up, the baby dies, but if it lives through 10 days after birth, the illness will no longer affect the baby. You will also get the chance to name your baby.

If the baby is stillborn, then the mother and father will experience a negative moodlet. If a surrogate mother is used, the biological mother will receive the moodlet.

If the mother survived childbirth, she will remain in bed, incapacitated by exhaustion (Postpartum exhaustion) for 16 hours. She'll no longer feel any pain from childbirth, but won't be able to move. However, if another pawn delivers her baby to her, she can begin breastfeeding.

Lactation[edit]

The condition of being able to breastfeed a baby. The breasts are actively producing and storing milk. The lactating state begins when a mother gives birth, and continues indefinitely as long as she breastfeeds a baby at least once every 10 days. People who are lactating will have a harder time becoming pregnant.
— Description

Upon a successful natural childbirth, the birthing mother will begin lactating. A lactating pawn can breastfeed babies, even if not their own. Lactation lasts indefinitely, but stops after 10 days of not breastfeeding a baby or if the pawn is malnourished with a MTB of 4 hours so roughly stopping at 40% malnutrition. If a lactating pawn is sent on a pawn lending quest, the 10-day timer will tick down unless they are sent along with a baby or babies that they can feed.

While lactating, the pawn gains a milk fullness stat, which starts at 100%. When it is above 24.8%, a pawn can breastfeed any baby, reducing milk accordingly. Mother's Food Consumption is increased by +1 nutrition per day, for a total of 2.6 nutrition per day, regardless of milk fullness. For reference, 1 simple meal is 0.9 nutrition. Half of the increased hunger scales with milk regeneration rate, which decreases as the pawn gets hungry. The other half of the increased hunger scales with metabolic efficiency, which can result with even more nutrition per day being consumed by such a pawn.

Hunger Level	Malnourished	Ravenously hungry	Hungry	Full
Milk Regeneration	0%	25%	50%	100%
Extra Nutrition Per Day (0 metabolic efficiency)	0.5	0.63	0.75	1.0
Extra Nutrition Per Day (-5 metabolic efficiency)	1.13	1.25	1.38	1.63
Extra Nutrition Per Day (+5 metabolic efficiency)	0.25	0.38	0.5	0.75

Lactation also multiplies Fertility by ×5%, meaning the mother is very unlikely to get pregnant by any natural means.

Heredity[edit]

Inbreeding[edit]

If a child is born from an incestuous relationship, there's a risk of them becoming inbred. The likelihood of this is modelled proportionally to the pawns' coefficient of relationship, though it is largely simplified.

As a general rule, the risk is 80% for first-degree, 40% for second-degree, and 10% for third-degree relatives; however some exceptions apply, an example being 20% for cousins. Many fourth-degree relationships and beyond are simply referred to as "Kin". Kin relationships pose no risk for inbreeding, despite being considered incestuous. If two pawns are related in more ways than one, such as being both parent/child (80%) and grandparent/grandchild (40%), the highest number always takes priority when calculating inbreeding. Pawns being inbred will not directly increase this number, but since inbred is a gene it will follow the same rules of gene inheritance as all other genes.

It's possible to check for the inbred gene after conception by using the "Inspect baby genes..." button on the pregnant pawn or the embryo. The outcome of a pregnancy isn't affected by inbreeding, but should the baby be born, the game will display an additional line in the birth results: The baby shows signs of genetic abnormalities due to inbreeding.

Inbred	Complexity: +1 Metabolic efficiency: −2 Forced Trait: Slow learner Fertility: ×50% Immunity gain speed: ×85%

The risk of inbreeding goes as follows, higher numbers taking priority over lower ones:

Relation	Inbreeding risk	Coefficient of relationship
Parent/Sibling/Child	80%	50%
Grandparent/Aunt/Uncle/Niece/Nephew/Halfsibling/Grandchild	40%	25%
Halfniece/Halfnephew	40%	12.5%
Cousin	20%	12.5%
G. grandparent/Grandaunt/Granduncle/Grandniece/Grandnephew/G. grandchild	10%	12.5%
Half grandniece/Half grandnephew/Cousin once removed	10%	6.25%
Second cousin	10%	3.125%
Birth parent^[1]/Kin	0%	N/A

↑ Although birth parents are considered on the same level as biological parents, they aren't genetically related to the child they birth, and thus run no risk of inbreeding despite the game's warnings that they do.

Fertility[edit]

Contraceptives[edit]

There are many ways to manually change the likelihood of natural pregnancy. The simplest way in the game to prevent pregnancy is to not give pawns a double bed to themselves. However, it deprives them of the mood bonuses of Lovin' in the first place. By changing a couple's Reproductive Approach "Avoid pregnancy" in the social tab, pregnancy rate will be reduced by −75%, but still gives Lovin' at the same rate. Lactation, from having given birth before, gives a ×5% multiplier to Fertility.

A more stable way to prevent pregnancy is available from the Fertility Procedures research. This gives access to multiple operations, reversible or permanent, to prevent and stop pregnancies. These surgeries are considered sterilization and are not applicable to pawns who are already sterilized, including sterilization on operation failure (see below). Though, they can be performed on pawns who are infertile by other means (age, Sterile gene).

Neither of the IUD, Vasectomy and Tubal Ligation will be "healed" by luciferium, bioregeneration cycle and by applying healing or resurrection mech serum.

IUD[edit]

This is a method of preventing pregnancies that lasts indefinitely but is reversible. You can stop a female pawn from becoming pregnant with the "Implant IUD" medical operation, which is available at age 16+, has a base 100% success chance and no chance of pawn death upon failure. The operation requires 1 Medicine of any type and will anesthetize the pawn. The IUD lasts indefinitely and can be seen in the pawn's Health tab, but you can later remove it through the "Remove IUD" medical operation for 1 Medicine of Industrial quality (Glitterworld medicine cannot be used, this must be a bug). Women may embark with IUDs already implanted. If either of these operations is botched, the patient will become permanently sterile.^[Bug?]

Implanted IUDs also stop pregnancies in the first trimester, an alternative to the Terminate Pregnancy operation.

Vasectomy[edit]

This is another method of preventing pregnancies that lasts indefinitely but is reversible. You can stop a male pawn from impregnating others with the "Perform vasectomy" medical operation, which is available at age 13+ and also has a base 100% success chance with no chance of pawn death upon failure. The vasectomy lasts indefinitely, with the operation requiring 1 Medicine of any type. You can later undo it through the "Reverse vasectomy" medical operation for 1 Medicine of Industrial quality (Glitterworld medicine cannot be used, this must be a bug). Men may embark with the operation already performed.^[Verify] If either of these operations is botched, the patient will become permanently sterile.^[Bug?]

Tubal ligation[edit]

This permanently stops a female pawn from being able to reproduce. "Perform tubal ligation" is a medical operation available at age 13+ and requiring 1 Medicine of any type. The surgery success chance is 100% and there is no chance of pawn death upon failure. The operation is irreversible.

Termination[edit]

If the pawn has already become pregnant past the first trimester, the only option left is to terminate the pregnancy. This can be achieved through the medical operation "Terminate pregnancy" requiring 2 Medicine of herbal quality or better and 1,500 ticks (25 secs) of work, after which the pawn will no longer be pregnant. There is a 2% of death if this operation fails, but a ×2 success chance factor. Note that the maximum success chance still applies, resulting in a 0.04% chance of death with max surgery success.

This operation can upset the affected pawn. Depending on the trimester of the pregnancy, a moodlet of −5 for the first, −10 for the second, and −20 for the third will occur, lasting for 10 days. If a pawn was not happy about the pregnancy, they will gain a +5 moodlet instead. If performed on another faction's pawn, it is considered a violation and will result in loss of goodwill.

This is the only fertility procedure that does not require the Fertility Procedures research.

Analysis[edit]

Growth vats are the "best" way to create your own children, with it being faster, having no risk to the mother, and able to be done with low Fertility. However, the nutrition cost is non-negligible, and researching growth vats requires Microelectronics. The vats themselves cost some steel, components, and research to make.

If both pawns are reasonably young, fertile, and sleeping at the same time, then pregnancy will be quite common; it is easy to get pawns pregnant, if you wanted them to.

If pregenancy is unwanted and Fertility Procedures has not been researched yet, the best way is to have two pawns sleep in different beds but in the same bedroom, avoiding Sleeping Alone but forgoing the boost from lovin'.

Version history[edit]

Biotech DLC Release - Introduced. Humans have a gestation cycle defined without Biotech, but they can not get pregnant.
1.4.3527 - Fix regression: Food consumption absurd during lactation.
1.4.3541 - Fix: Overactive temperature warning for baby moving.
1.4.3555 - Lactating no longer prevents pregnancy or ovum extraction, but now inflicts a ×5% multiplier to Fertility. Update the lactating hediff's description to mention that it reduces fertility. Pawns away on a PawnLend quest won't have their lactating condition expire if there are any babies with them that can feed. Terminate pregnancy operation increased to 2 medicine (from 1), work slightly reduced. Update the wording of the stillbirth letter to be a bit clearer about the choice of naming the baby, and allow the player to decide not to name the baby. Fathers now get a negative thought if their child is stillborn. If a baby is stillborn from a surrogate mother, the gene-mother gets a negative thought.
1.4.3557 - Colonists born in the colony no longer stay stuck in labor forever if the Ideology DLC was not active when they became a child.

Biotech (DLC)

Families: Relationships (Reproduction • Children)
Life stages (Babies • Children • Adults)
Furniture (Crib • Baby sleeping spot • Growth vat • Toy box • Baby decoration • School desk • Blackboard)
Mechanoids: Laborers (Agrihand • Cleansweeper • Constructoid • Fabricor • Lifter • Paramedic • Tunneler)
Combatants (Centurion • Legionary • Militor • Scorcher • Tesseron)
Commanders (Apocriton • Diabolus • War queen • War urchin)
Mechanitors: Control (Mechlink • Band node • Mech boosters • Mech signallers • Control pack • Airwire headset)
Mechanoid creation (Basic subcore • Standard subcore • High subcore • Subcore encoder • Subcore softscanner • Subcore ripscanner • Mech gestator)
Maintenance (Mech recharger)
Genetics: Xenohumans (Dirtmoles • Genies • Highmates • Hussars • Impids • Neanderthals • Pigskins • Sanguophages • Wasters • Yttakin • Starjack)
Genes Germline • Xenogene • Metabolic efficiency
Genetic Modification Genepack • Gene extractor • Gene bank • Gene assembler • Gene processor • Xenogerm • Archite capsules
Deathrest (Deathrest accelerator • Deathrest capacity serum • Deathrest casket • Glucosoid pump • Hemogen amplifier • Hemopump • Psychofluid pump)
Pollution: Nature (Toxalope • Toxipotato plant • Waste rat • Gray pine tree • Pebble cactus • Rat palm tree • Witchwood tree • Stasis cocoon)
Mitigation (Wastepacks • Atomizers • Pollution pumps • Polux trees)
Adaptation Face mask • Gas mask • Tox grenades • Tox pack • Tox shell • Toxic needle gun • Toxbomb launcher • Detoxifier kidney • Detoxifier lung
Nonchalance Toxifier generator

[1] Although birth parents are considered on the same level as biological parents, they aren't genetically related to the child they birth, and thus run no risk of inbreeding despite the game's warnings that they do.

[1]