5 Strange Pregnancies

OK, so this isn't technically pregnant, but it's a pregnancy complication that is rare but documented in twin gestations: Pregnant with your own twin. Fetus in fetu (literally, baby within baby) is like a host and parasite setup. A set of identical twins is conceived but in the very early stages of the first trimester, something goes wrong with the separation. Sometimes that results in conjoined twins, and in rare instances, it can result in one fetus being absorbed through the umbilical cord and undeveloped abdomen of the other. The absorbed twin does not undergo much development before absorption; generally, it's a mass of cells and maybe body parts. It becomes like a tumor to the surviving twin, a parasite that feeds on the blood supply of the host. Most fetus in fetu cases are discovered when an abdominal mass or tumor is suspected, usually when the surviving twin is still a baby or toddler.

When you're trying to get pregnant, it may seem that everyone around you is suddenly in her third trimester while you wait, month to month, for your happy news. Some women, however, are pregnant but unaware of it -- and we don't mean in the first few weeks of the first trimester.

There are a few reasons women might not be clued in to their pregnancies. Take home pregnancy tests, for example. Home pregnancy tests aren't perfect, especially if used too early in the pregnancy when there hasn't been enough time for the pregnancy hormone levels to build. Monthly periods can be misleading, too. Bleeding can be a common occurrence for some women during their pregnancies. And if your periods aren't regular (because of stress, intense exercise and strict diet, or conditions such as polycystic ovarian syndrome), this breakthrough bleeding can make you think you're having monthly cycles.

Constipation, gas, mood swings -- if you have no idea that you might be pregnant, all of these can easily be attributed to something else. What about the big one -- weight gain? If a woman is not trying to get pregnant or thinks she's infertile, the cause of pregnancy weight gain might be attributed to recent slacking off in diet and exercise, especially if the woman is heavy naturally or is carrying a small baby.

The National Center for Health Statistics' National Vital Statistics Reports estimate that in 2007, there were more than 4,300,000 births in the United States -- the highest recorded number of American births in one year. But the number of pregnancies, that's much higher. Roughly, one third of all pregnancies end in miscarriage in the early weeks, often before a woman knows she's pregnant, and the American Academy of Pediatrics estimates that there's about a 25 percent chance of miscarriage after the pregnancy has been confirmed.

Early pregnancy failure is one reason a woman may think she's pregnant only to find out that the gestational sac she saw on the ultrasound monitor failed to develop -- there is no embryo. This is also known as a blighted ovum. In these cases, the placenta begins to develop, pregnancy hormones are secreted and a pregnancy test will turn positive. By the end of the first trimester, however, the body will expel a blighted ovum.

Chemical pregnancy is another reason a woman may think she's pregnant. During a chemical pregnancy, an egg is fertilized and implants in the uterine wall, but the levels of pregnancy hormones remain low -- although the home pregnancy test turned faintly positive, the pregnancy isn't viable.

Maybe you've been trying to get pregnant for months or maybe this was a happy accident -- whatever the case, that little stick says you're on your way to motherhood. To determine how far along you are, your doctor may schedule you for a sonogram -- you find out you're about seven weeks into your pregnancy, and also, congratulations, you're having twins! But when you return for your 12-week checkup, there's no sign of Baby B. What's going on? Vanishing twin syndrome.

While the cause of vanishing twin syndrome is unknown, doctors have some theories: Sometimes the vanishing fetus may have had chromosomal abnormalities; others may be due to implantation problems. In most cases, the vanishing twin does a disappearing act during the first trimester (it's rare, but it can happen later on). When a twin vanishes during the first trimester, the associated tissue and fluids are often reabsorbed by the mother's body, and the remaining fetus is often healthy and carried to term.

The American Pregnancy Association estimates that between 21 to 30 percent of women carrying multiples experience vanishing twin syndrome, whether they're aware of it or not. How could you not be aware? Unless there is a problem, such as a history of miscarriage or other fertility issues, most women don't have their first ultrasound until the second trimester, between 16 and 20 weeks into the pregnancy.

Have you heard the story of Thomas Beatie, a man who has given birth twice (and is currently expecting his third due this year)?

Beatie is a transsexual man -- a biologically born female who identifies as a man and has taken the steps to become a legal male. Gender reassignment is a long, individual process -- for Beatie, it was a 10-year journey -- typically consisting of a diagnostic assessment and diagnosis of gender identity disorder, psychotherapy, real-life experience, hormone replacement and surgery.

Female to male transgendered patients may elect to have multiple surgeries, including a hysterectomy and others to remove the vagina, construct a neophallus and place testicular prostheses. Beatie chose to retain his functional female reproductive organs during his transition from female to male, knowing that he would one day like to have children.