Austrian research geneticist Dr. Alex Hesse and his
OB/
GYN colleague Dr. Larry Arbogast invent a
fertility drug, "Expectane", designed to reduce the chances of a
miscarriage. With the drug unapproved by the
FDA, the colleagues are not authorized to test it and are unable to continue their research. Noah Banes, the director of the laboratory, informs Larry that while the FDA denied human experimentation, the team has received a donation from geneticist Dr. Diana Reddin from the
ovum cryogenics department. Alex plans to start over in Europe, but Larry suggests they can still perform the experiment, with Canadian firm Lyndon Pharmaceutical offering to fund them provided they find a volunteer. Alex questions the likelihood of a pregnant woman taking an unapproved drug, but Larry suggests omitting the volunteer's gender and convinces him to impregnate himself with an ovum codenamed "Junior". That night, Alex dreams his potential offspring has his own face. As weeks go by, he complains to Larry of
morning sickness and sore nipples, and chats incessantly about walks, massages, and naps. Contemplating fatherhood after watching television commercials, Alex breaks down sobbing. When the time comes for Alex to end the experiment and release the results to Lyndon Pharmaceutical, he continues taking the drug as he has decided to carry the pregnancy to term; initially annoyed, Larry agrees to keep it hidden. Alex develops a relationship with Diana, and reveals his pregnancy to Angela, Larry's ex-wife, who also happens to be pregnant by
Aerosmith's personal trainer. Diana is stunned and angry when it is revealed that the "Junior" ovum is hers, and Banes attempts to take credit for the experiment. Disguised as a woman, Alex hides in a retreat for expectant mothers, blaming his masculine appearance on anabolic steroid use. Diana visits Alex at the resort and the two reconcile, telling each other it does not matter who is pregnant because she is the mother and he is the father. Larry reveals the experiment's data to Lyndon Pharmaceutical, who agree to partner with them. Alex experiences abdominal pain from the start of labor, calling for Larry and Diana. As Diana rushes to the resort, Larry tells a fellow doctor to prepare for an emergency
c-section. A janitor overhears and alerts Banes, who summons the media, hoping to take credit for the world's first pregnant man. Warned by his colleague, Larry distracts the press by arriving with Angela, discrediting Banes, who is fired by the university president, while Diana and Alex enter the hospital by the fire escape. Larry and his colleague take Alex away for his operation: sent to keep Angela company in the waiting room, Diana finds her in labor and becomes her delivery coach. Alex gives birth to a healthy baby girl, and Larry announces the arrival to Diana, who is assisting Angela with contractions. Diana leaves Angela with Larry and rushes to see the baby, whom she and Alex name Junior. Larry delivers Angela's child and they reconcile to raise the boy, Jake, as their own. One year later, the families all go on vacation together and celebrate the birthdays of Junior and Jake. Diana is pregnant with their second child, and Angela mentions wanting another baby but not wishing to endure pregnancy again; at Alex's suggestion, they all try to convince a reluctant Larry to carry the child. ==Cast==