Male pregnancy

Male pregnancy refers to the incubation of one or more embryos or fetuses by male members of any species. In nearly all heterogamous animal species, offspring are ordinarily carried by the female until birth, but in fish of the Syngnathidae family (pipefish and seahorses), males perform this function. By some definitions of male identity, human men have done so in certain instances, and male humans incubating fetuses are a recurring theme in speculative fiction.

In non-human animals
The Syngnathidae family of fish has the unique characteristic where females lay their eggs in a brood pouch on the male's chest, and the male incubates the eggs. Fertilization may take place in the pouch or before implantation in the water. Included in Syngnathidae are seahorses, the pipefish, and the weedy and leafy sea dragons. Syngnathidae is the only family in the animal kingdom to which the term "male pregnancy" has been applied.

Ectopic implantation
Biological human males do not have the anatomy needed for natural embryonic and fetal development. The theoretical issue of male ectopic pregnancy (pregnancy outside the uterine cavity) by implantation in biological males has been addressed by experts in the field of fertility medicine, who stress that the concept of ectopic implantation, while theoretically plausible, has never been attempted and would be difficult to justify – even for women lacking a uterus – owing to the extreme health risks to both the parent and child.

Robert Winston, a pioneer of in-vitro fertilization, told London's Sunday Times that "male pregnancy would certainly be possible" by having an embryo implanted in a man's abdomen – with the placenta attached to an internal organ such as the bowel – and later delivered by Caesarean section. Ectopic implantation of the embryo along the abdominal wall, and resulting placenta growth would, however, be very dangerous and potentially fatal for the host, and is therefore unlikely to be studied in humans. Gillian Lockwood, medical director of Midland Fertility Services, a British fertility clinic, noted that the abdomen is not designed to separate from the placenta during delivery, hence the danger of an ectopic pregnancy. "The question is not 'Can a man do it?'" stated bioethicist Glenn McGee. "It’s ’If a man does have a successful pregnancy, can he survive it?’"

Since 2000, several hoax web sites have appeared on the Internet purporting to describe the world's first pregnant man. While sometimes relying on legitimate scientific claims, in reality, no such experiment has ever been attested. Fertility clinician Cecil Jacobson claimed to have transplanted a fertilized egg from a female baboon to the omentum in the abdominal cavity of a male baboon in the mid-1960s, which then carried the fetus for four months; however, Jacobson did not publish his claims in a scientific journal, and was subsequently convicted on several unrelated counts of fraud for ethical misconduct.

Transgender people
Some trans men (female-to-male transgender people) who interrupt hormone replacement therapy can become pregnant, while still identifying and living as men. This is possible for individuals who still have functioning ovaries and a uterus.

For example, Matt Rice, a transgender man, bore a son named Blake in October 1999 following random sperm donations from three male friends during his relationship with transgender writer Patrick Califia.

Thomas Beatie, another transgender man, has borne three children. He chose to become pregnant because his wife Nancy was infertile, doing so with cryogenic donated sperm and a syringe, at home. He wrote an article about the experience in The Advocate. The Washington Post further broadened the story on March 25 when blogger Emil Steiner called Beatie the first "legally" pregnant man on record, in reference to certain states' and federal legal recognition of Beatie as a man. In 2010, Guinness World Records recognized Beatie as the world's "First Married Man to Give Birth." Beatie gave birth to a girl named Susan Juliette Beatie on June 29, 2008. Barbara Walters announced Beatie's second pregnancy on The View, and Beatie gave birth to a boy named Austin Alexander Beatie on June 9, 2009. Beatie gave birth to his third child, a boy named Jensen James Beatie, on July 25, 2010.

Scott Moore, a transgender man, gave birth to a child on March 9, 2010.

Fetus in fetu
Fetus in fetu, though not an actual pregnancy, is an extremely rare condition in which a mass of tissue resembling a fetus forms inside the body. This is a developmental abnormality in which a fertilised egg splits as if to form identical twins, but one half becomes enveloped by the other, and an entire living organ system with torso and limbs can develop inside the host. The abnormality occurs in 1 in 500,000 live births in humans.

The case of Sanju Bhagat, a man from Nagpur, India, attracted attention in 1999 for the length of time (36 years) he had carried his parasitic twin inside his body, and the size of the growth. Since Bhagat had no placenta, the growth had connected directly to his blood supply.

In popular culture
Thematically, pregnancy can be similar to the issues of parasitism and gender. Some science fiction writers have picked up on these issues, in "cross-gender" themes &mdash; e.g., Octavia E. Butler's Bloodchild. Ursula K. Le Guin's novel The Left Hand of Darkness contains the sentence "The king was pregnant", and explores a society in which pregnancy can be experienced by anyone, since individuals are not sexually differentiated during most of their life and can become capable of inseminating or gestating at different times. Lois McMaster Bujold's Ethan of Athos features an all-male society in which men use artificial wombs, but experience many of the psychological effects of pregnancy (anticipation, anxiety, etc.). In Marge Piercy's feminist utopian novel Woman on the Edge of Time, neither men nor women get pregnant, leaving that to artificial wombs, but both sexes may lactate and nurse the infant; the specifically female experiences of pregnancy and nursing were opened to men in the cause of gender equality.

The concept of male pregnancy has been the subject of popular films, generally as a comedic device. The 1978 comedy film Rabbit Test stars Billy Crystal as a young man who inexplicably becomes pregnant instead of his female sex partner. The 1990 BBC television comedy drama Frankenstein's Baby features a Dr. Eva Frankenstein helping a male patient to become the world's first pregnant man. The 1994 science fiction comedy/drama Junior stars Arnold Schwarzenegger as a fertility researcher who experiments on himself; the screenplay was inspired by a 1985 article in Omni magazine.

The concept appears frequently as a comedic gag in movie and television programs. In Monty Python's 1979 film, Life of Brian, there is a political satire scene in which a character demands that any man has a "right to have babies if he wants them," which is ridiculed as impossible. In the BBC science fiction comedy series Red Dwarf, a character becomes pregnant after having sex with a female version of himself in an alternate universe. In an episode of Sliders, the quartet "slides" into an alternate world in which babies develop during their final months in the father because a worldwide disease has kept women from being able to carry children beyond their first trimester.

The possibility of extraterrestrial life having different reproductive sexuality is the basis for many references. In the Star Trek: Enterprise episode "Unexpected", a human male becomes pregnant with the offspring of a female of another species. In the video game The Sims 2 male characters can be impregnated via cheat codes or alien abduction. In the American Dad episode "Deacon Stan, Jesus Man", the boy Steve becomes impregnated after giving the mouth-to-mouth resuscitation to the extraterrestrial Roger, then unwittingly passes it on to his girlfriend via a kiss. In the animated series Futurama the extraterrestrial Kif can be impregnated by a touch. In the SciFi Channel miniseries, Farscape: The Peacekeeper Wars, the extraterrestrial Rygel becomes impregnated with human John and Aeryn's baby.

Virgil Wong, a performance artist, created a hoax site featuring a fictitious male pregnancy, claiming to detail the pregnancy of his friend Lee Mingwei.