Prenatal Gender Picking - TV Tropes

"Tonight, at sunset, take a little drinking-cup with two handles, and put it bottom upwards on the ground in the northwest corner of your garden. Then go and lift it up tomorrow morning at sunrise, and you will find two roses underneath it, one red and one white. If you eat the red rose, a little boy will be born to you: if you eat the white rose, a little girl will be sent. But, whatever you do, you mustn’t eat both the roses, or you’ll be sorry, that I warn you! Only one: remember that!"

• In Steins;Gate the protagonist group sends a temporal message to Luka Urushibara's mother's pager recommending eating vegetables so Luka will be born a girl. It works.

• Our Lady Suspiriorum: Elia is the mortal form of Mother Suspiriorum, one of the three mother-goddesses of Valyria. Her husband Rhaegar wants a son to name Aegon after his famous ancestor, but Elia bears him two daughters instead, Shiera and Aelinor. Her inner monologue makes it plain that she could have a son if she felt like it, but she feels Westeros has been male-dominated for too long.
• Triptych Continuum: Mytilene's Truest Love, or The Most Special Spell, is a spell that allows two mares to conceive a foal. One side-effect of it is that any foal conceived by the spell will be a filly. Frequent use of the spell over many centuries skewed the gender ratio of Equestria's population in favor of mares over stallions.
• Wish Carefully: Male selection spells are used by the more elitist pureblood families to ensure male firstborns. Pansy has trouble conceiving a child with Draco when his family insists on using the spells. Without them, she is able to conceive a daughter. In hindsight, her father-in-law Lucius notes that they should have been grateful the child was at least a witch, considering the Generational Magic Decline in their society that followed. Widespread use of this spell also causes problems for Voldemort-ruled Magical Britain on a wide scale; most of the Dark pureblood families conceived their sons using the same spells and didn’t have any more children, with the consequence that there weren't enough women of childbearing age to marry when that generation reached adulthood.

• Dragons: A Fantasy Made Real: Dragon eggs have their gender determined by temperature, similar to the alligator example in Real Life below (albeit inverted — low temperatures are more likely to result in female dragons).
• Gattaca: A more realistic example. Vincent's parents went for an In-Vitro facility that successfully inseminated and pre-screened four of Vincent's mother's ovum and got two boys and two girls, plus removed all inherent diseases and modified the genetics for maximum potential. Vincent's parents then chose to carry one of the boys to term.
• The Pod Generation: It's established that families who decide to conceive using the pod can choose ahead of time whether they want a boy or a girl. Rachel and Alvy are apparently outliers by deciding to "leave it up to nature."

• Dune: The mental arts of the Bene Gesserit allow them to consciously select the sex of children they conceive, which enables them to both use Altar Diplomacy to shape the politics of the Imperium and to further their Super Breeding Program to produce the Kwisatz Haderach. An important plot point in the original Dune came from the fact that Lady Jessica disobeyed orders and bore Duke Leto Atreides a son, main protagonist Paul, rather than a daughter who could be married off to House Harkonnen and prevent the war that takes up most of the book.
• The Garden of Sinners: Played With. To be eligible as the head of the Ryougi family, a potential heir must manifest two personalities — a male and a female one. To this end, before each heir's birth, the family performs a secret ritual that attempts to split the unborn baby's personality into an opposite-gender pair. If this fails, the next child is subjected to the same ritual, and so on, until it succeeds. Shiki's older brother, for example, failed to manifest a second personality, therefore she, the younger and biologically female sibling, is first in line to succeed their father as family head (even after her male personality, SHIKI, died — the fact that he had manifested in her body at some point is enough to make her eligible).
• In the Old Kingdom series the vast majority of the prophetic bloodline of the Clayr are female, and author Garth Nix stated in an interview that this trope is at work.
• Prince Lindworm: The queen and soon-to-be-mother of the titular beast is told by a witch that she needs to choose between two plants that will grow in her garden if she wants to have children (in some versions it's roses, in others it's onions). If she eats the white one, she'll give birth to a girl, and a boy if she eats the red one. The queen initially only sticks to eating the white, but she found it so delicious that she ate the other one along with it.
• A Song of Ice and Fire:
  • Among the Dothraki, a pregnant khaleesi (queen) must participate in a ritual where she eats the raw heart of a freshly killed stallion with her bare hands, while the crones of the dosh khaleen chant, "Rakh, rakh, rakh haj!" (A boy, a boy, a strong boy!). If she can keep it all down, it is said she will have a strong, healthy son, but if she chokes on it or throws up, she will have a stillborn, a weak or deformed child, or a daughter.
  • In Fire & Blood, it is lightly implied (but never confirmed) that Queen Visenya used magic to conceive her son, Maegor. After ten years of being married to her brother-husband King Aegon without ever getting pregnant, people start whispering that she is infertile (and bringing up the possibility of marrying their daughters to Aegon instead), but suddenly she is pregnant and correctly predicts that she is having a boy.
• In the Vorkosigan Saga, galactic technology makes it trivial to choose the sex of one's offspring. After Uterine Replicators are introduced to the planet Barrayar, this tech gets used to produce an imbalance of boys. Kou and Dru Koudelka, on the advice of Cordelia, choose to have four daughters to take advantage of the foreseen imbalance and make advantageous marriages. All four daughters go on to marry very successful men in different fields.
  • In A Civil Campaign, Count Vormuir uses this tech to produce 118 acknowledged bastard offspring — all daughters for legal and social reasons.
  • In Gentleman Jole and the Red Queen, Cordelia has daughters and Jole has sons with sperm samples from the deceased Aral Vorkosigan in part because Barrayarian law by default grants custody of daughters to the mothers (or other female relatives) and custody of sons to the fathers (or other male relatives).
• Princesses of the Pizza Parlor: The Most Boringest Gnome in the World: The Sororitas can apply a Hereditary Curse to a person, "never a daughter born to thee", ensuring only sons were born from their direct lineage, "not to thy lineage for ten and three".

• How I Met Your Mother: When Marshall and Lily first start trying to conceive, a conversation about names leads Marshall to realise he wants only boys, out of fear of boys lusting after his daughter in high school (since every name Lily pitches reminds him of a girl he did something stupid over). His father gives him a list of things to do, such as eating herring and pointing northwards during conception, to guarantee to conceive a son, insisting that this is why the Eriksons have had only boys for generations. When Marshall tries to put these methods into effect, however, he finds that Lily is using similar methods — eating lemons and trying to point Marshall southwards — to ensure a girl, as the same conversation made her realise every difficult student she's ever had has been male. They end up leaving it to chance.

• Ars Magica:
  • Long-lost fertility magic allows a mage to predetermine all kinds of features for a baby at the moment of conception. Choosing the baby's sex is one of the simplest options.
  • The Archmage Philippus Niger has accumulated many Marks of the Supernatural from overexposure to magic, including the strange trait that all children conceived in a place where he lives will be male.

• Fallout 3: The character creation segment happens while your mother is in labor. They use the computer to scan your genetics and predict what you'll end up looking like as an adult.
• Harvest Moon:
  • Harvest Moon: The Lost Valley has your spouse ask if you prefer to have a boy or a girl before it's born. There's no random option, so it's only one or the other.
  • Harvest Moon: Light of Hope again has your spouse ask if you prefer a boy or girl before birth, but now there is a random option.
  • Harvest Moon: One World also has your spouse ask before birth if you prefer a boy or girl, with the either option meaning it's randomized.
  • Harvest Moon: The Winds of Anthos: You'll be given the option — either by the Harvest Goddess or shortly after the pregnancy event — on whether to have a boy, girl, or randomized.
• The Sims:
  • The Sims 3: You can pick the gender of a baby by eating lots of apples for a boy or a lot of watermelon for a girl.
  • The Sims 4: You can choose the sex of your Sim's baby by having the pregnant Sim either eat carrots and listen to alternative music (for a boy) or eat strawberries and listen to pop music (for a girl).
• Story of Seasons:
  • The Harvest Moon: A Wonderful Life Updated Re-release is the first game in the series that allows the player to choose to have either a son or daughter. The son is the default, but by speaking to a pot in the Harvest Sprite's hut 100 times, you can choose one or the other.
  • Harvest Moon: Animal Parade lets your spouse ask you which you would like for each of your two children, a boy or a girl. If you leave the choice to them, you'll get what they pick.
  • Story of Seasons: Friends of Mineral Town: The day after the pregnancy event for opposite-gender couples, the Harvest Goddess shows up and asks if you hope to have a boy, a girl, or are happy with either; whatever you pick will be the sex at birth. For same-sex couples, you're asked the same questions 90 days after marriage, but then the baby is magically poofed into your house. "Either" means the gender is random.
  • Story of Seasons: A Wonderful Life has your spouse ask during your private wedding ceremony if in the future you'd rather have a son, a daughter, or if you don't care. If you pick that you don't care, it's randomized.
• In Village Life, you can spend Gems on fertility potions to guarantee the birth of a baby boy or girl or boy-girl twins.

• Steins;Gate: An example where a character does this to themselves, retroactively. Luka is a very feminine man who wishes that he was born a woman, and uses the time machine that Okabe built to send a message back in time to their mother in an attempt to change their gender by encouraging her to eat more vegetables. It works, somehow.

• Kill Six Billion Demons: The God-Emperor Solomon David chooses to conceive only sons, apparently via the Master of Your Domain abilities he has as a Supernatural Martial Arts grandmaster.

• This post from r/TwoSentenceHorror: “My wife wept as the doctor told her our daughter wouldn’t survive past birth and should be aborted. Buying his co-operation hadn’t been cheap, but my firstborn will be a son, no matter what.”

• Worldwide, statistically significant numbers of baby girls are variously aborted, killed at birth, and abandoned by parents who would prefer a son.
  • When China instituted the One-Child Policy in 1979, most parents preferred having a son over a daughter. Part of the reason is that in Chinese culture, men are expected to care for their parents when they get old, while women aren't.
  • In India, sons are preferred over daughters because a son is seen as an asset to the family since he can work and support them, while a daughter is seen as a liability because she will marry into a different family and her parents will have to pay her husband's family an expensive dowry.
• It's possible to sort out sperm with X chromosomes from those with Y chromosomes in a centrifuge since the former are slightly heavier. Such a practice is common in the livestock industry since cows are more valuable than bulls.
• The sexes of certain species are determined by temperatures experienced during embryonic development. For instance in alligators, eggs were kept at around 30° Celsius (86° Fahrenheit) will all be male, but around 34° Celsius (93° Fahrenheit) will all be female.
• In this Reddit story, a woman was assaulted and accused of cheating by her mother-in-law when she had a second daughter because, for a long time, the husband's family had only had sons. At first her husband was on her side, but then he started believing his mother, which wrecked their marriage and led to a divorce. (Ironically, after she got remarried, her next child was a boy. Then her ex-husband went completely off the rails.)
• Kangaroos can choose the sex of their joeys. Does deliberately have daughters as young adults, and only start having sons when they get older.