Ultrasound scans in the first 14 weeks reduced short-term maternal worries about the pregnancy.
We found 13 studies including 85,265 women. We searched for randomised controlled trials. The alternative is selective scans for specific reasons. It has been assumed that routine scans before 24 weeks' gestation will result in the earlier detection of problems and improve management and the pregnancy outcome. The aim of this review is to compare routine with selective or no scans. Later scans, typically done around 18 to 24 weeks, recheck all the above, and also examine the baby's anatomy and whether the placenta (afterbirth) is in the correct place. Both types of scan may cause parental anxiety and a false positive diagnoses could lead to harm. Early scans (before 14 weeks) mainly aim to count the number of babies, to check they are growing in the correct place and check the pregnancy dates. This review considers two types of scan in the first half of pregnancy. Ultrasound scans send out high-frequency sound waves directed to the area being examined, and use the reflected sound to make an image. This was in comparison to no scan at all, or scans only when a clinical problem was suspected, such as if the woman has vaginal bleeding, or the baby is at high risk of having an abnormality.
#Sonogram pregnant full#
The full study can be found in the Journal of Aquatic Biology, here.We set out to determine the effect of routine ultrasound scans early in pregnancy (before 24 weeks). When this study came up we wanted to prove it for ourselves. People at the time said the tech’s not out there. “In 2011, James and I published a paper saying we need to come up with these non-lethal alternatives. "I think a lot of people have been waiting for this,” Hammerschlag told TakePart earlier this year. This vital intel can help us ensure that these cosmopolitan swimmers don't overlap with fisheries during the most critical stages of life.ĭata from the sharks' satellite tags – which will pop off on their own and cause the sharks no pain – will help the team better understand where these females are going. Learning where these threatened animals go to breed, and how they use that environment, is a crucial step in better protecting them. Research has shown that although tiger sharks produce large litters, the pups are inefficient swimmers, and extremely vulnerable to predation as they grow – especially by other sharks. Sharks are quite sensitive to stress, so "check-ups" like this must be done quickly and gently. Getting the sharks on board and prepped for the procedure is something that takes an incredible amount of finesse and teamwork. A screen was replaced with goggles and waterproof casings were added. The team used the same imaging technology used by medical professionals on pregnant women, only modified for use at sea. "Our data suggests that Tiger Beach may function as a refuge habitat for females to reach maturity as well as a gestation ground where pregnant females benefit from calm, warm waters year-round that help incubate the developing embryos and speed up gestation,” says Hammerschlag. So Hammerschlag and UNE marine biologist Dr James Sulikowsky put on their thinking caps, taking inspiration from human over-the-counter and in-hospital pregnancy tests to develop a non-invasive method to look for shark "baby bumps". Where do they go to mate? How many pups do they have? When do they become sexually mature? In the past, scientists had to rely on observations of dead animals during necropsies when trying to answer such questions.
We've come to learn much about sharks over the years, but the details of their reproduction remain a mystery for most species. It all started back in 2003, when UM shark biologist Dr Neil Hammerschlag made an interesting observation: many of the sharks in the area were female. The site is known for its year-round abundance of tiger sharks, and thanks to these new methods, we're beginning to form a clearer picture (pun intended) of why they hang out here. This incredible sonogram of a pregnant tiger shark was recorded by researchers from the University of Miami (UM) and University of New England (UNE), during an expedition to study shark behaviour at Tiger Beach in the Bahamas.
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