The shortest known gestation is that of the Virginian opossum, about 12 days, and the longest that of the Indian elephant, about 22 months. In the course of evolution the duration of gestation has become adapted to the needs of the species.
Pregnancy lasts for about 280 days or 40 weeks. A preterm or premature baby is delivered before 37 weeks of your pregnancy. Extremely preterm infants are born 23 through 28 weeks. Moderately preterm infants are born between 29 and 33 weeks.
Share: Elephants have the longest pregnancy period of any living mammal. If you – or someone you know – has experienced a pregnancy that seemed to go on forever, spare a thought for the elephant. It's the animal with one of the longest gestation periods of all living mammals: nearly two years.
Rabbit has the shortest gestation period of one month or less. Rabbits are prolific animals.
The Virginia opossum (the only marsupial in Michigan) has a gestation period of only 13 days, and the young are only the size of a question mark when they are born.
The shortest known gestation is that of the Virginian opossum, about 12 days, and the longest that of the Indian elephant, about 22 months.
Shark pregnancy
Sharks typically give birth after 11–12 months of pregnancy, but some, such as the frilled shark, are pregnant for more than three years. In some sharks, a placenta develops during pregnancy.
On the other end of the spectrum, the animal with the shortest known gestational period is the Virginia opossum. North America's only marsupial can give birth to an average of eight to nine infants just 11 to 13 days after mating; each of these “pinkies”—so called for their fingerlike appearance—are the size of a dime.
The tailless tenrec of Madagascar has litters of up to 32, according to the IUCN, while the naked mole rat has an average of 28.
A woman's peak reproductive years are between the late teens and late 20s. By age 30, fertility (the ability to get pregnant) starts to decline. This decline becomes more rapid once you reach your mid-30s. By 45, fertility has declined so much that getting pregnant naturally is unlikely for most women.
There's a higher risk of stillbirth if you go over 42 weeks pregnant, although most babies remain healthy. At the moment, there's no way to reliably predict which babies are at increased risk of stillbirth, so induction is offered if you do not go into labour by 42 weeks.
The takeaway
While it's true your baby can cry in the womb, it doesn't make a sound, and it's not something to worry about. The baby's practice cries include imitating the breathing pattern, facial expression, and mouth movements of a baby crying outside of the womb. You shouldn't worry that your baby is in pain.
Pregnancy normally lasts about 40 weeks – that's around 280 days from the first day of your last period. Labour usually starts a week either side of this date, but you might go overdue.
WARSAW (Reuters) - A Polish woman lay nearly upside down in labor for 75 days to save the lives of her two premature babies after the first of three fetuses growing inside her was born prematurely and died.
Squirrel monkey infants have such large heads compared to the size of their mothers' pelvises that they face a very high rate of birth complications. Perhaps the most horrifying birth is that of the spotted hyena.
For some, of course, it's normal to only have one or a couple of offspring in a lifetime. But swamp wallabies, small hopping marsupials found throughout eastern Australia, are far outside the norm: New research suggests that most adult females are always pregnant.
BACKGROUND: Labor pain is one of the most severe pains which has ever evaluated and its fear is one of the reasons women wouldn't go for natural delivery. Considering different factors which affect experiencing pain, this study aimed to explain women's experiences of pain during childbirth.
Swamp wallabies have two uteruses, so they can conceive a new baby before birthing another, scientists have discovered.
Aphid. Aphids, tiny insects found the world over, are “essentially born pregnant,” says Ed Spevak, curator of invertebrates at the St.
These small leathery pouches are the cast-off egg capsules of some sharks and their kin. Most fish release their eggs and sperm into the ocean, leaving survival of their offspring to chance.
While carrying a baby for nine months may seem like long enough for some human mothers, spare a thought for giraffes who have gestation periods of 15 months!
Other scientists believe that the big sharks, like some other species, change sex when they reach a certain size: males become females. The switch may ensure survival by allowing the largest, most experienced sharks to give birth to young.
Frilled Shark
These primitive, eel-like animals have extraordinarily slow-growing embryos, which put on only about a half-inch (1.4 cm) each month. At that rate, the total pregnancy length of a frilled shark is estimated at three and a half years.
The spiny dogfish shark can carry young for about two years, while basking sharks can do so for as long as three years. The frilled shark can wait 3.5 years before giving birth.