Tuesday, 28 July 2015
If you're confused about whether it's safe to eat seafood during your pregnancy, you're not alone. Understand the guidelines for pregnancy and fish.
By Mayo Clinic Staff
If you're pregnant, you might feel like you need to become a nutrition expert overnight. After all, what you eat and drink — and what you avoid — influences your baby's development. Some choices are logical, such as eating plenty of fruits and vegetables and eliminating alcohol from your diet. But what about seafood?
Here, Roger W. Harms, M.D., a pregnancy specialist at Mayo Clinic, Rochester, Minn., and medical editor of "Mayo Clinic Guide to a Healthy Pregnancy," offers practical advice about pregnancy and fish.
What's the link between pregnancy and fish?
Seafood can be a great source of protein, iron and zinc — crucial nutrients for your baby's growth and development. In addition, the omega-3 fatty acids in many fish can promote your baby's brain development.
But some types of seafood — particularly large, predatory fish such as shark, swordfish, king mackerel and tilefish — can contain high levels of mercury. Although the mercury in seafood isn't a concern for most adults, special precautions apply if you're pregnant or planning to become pregnant. If you regularly eat fish high in mercury, the substance can accumulate in your bloodstream over time. In turn, too much mercury in your bloodstream could damage your baby's developing brain and nervous system.
How much seafood is recommended?
The Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) say pregnant women can safely eat up to 12 ounces (340 grams) of seafood a week. Similarly, the 2010 Dietary Guidelines for Americans recommend 8 to 12 ounces of seafood a week for pregnant women — or about two average meals.
Not all researchers agree with these limits, however, citing a study that noted no negative effects for women who ate more seafood than the FDA-approved guidelines.
What's safe to eat?
Eat a variety of seafood that's low in mercury and high in omega-3 fatty acids, such as:
Atlantic and Pacific mackerel
Other safe choices include shrimp, pollock and catfish. However, limit albacore tuna and tuna steak to no more than 6 ounces (170 grams) a week. Also, be aware that while canned light tuna on average appears safe, some testing has shown that mercury levels can vary from can to can.
Are there other guidelines for pregnancy and fish?
Consider these precautions:
Avoid large, predatory fish. To reduce your exposure to mercury, don't eat shark, swordfish, king mackerel or tilefish.
Avoid uncooked fish and shellfish. To avoid ingesting harmful bacteria or viruses, avoid uncooked fish and shellfish, including sushi, sashimi and refrigerated uncooked seafood labeled nova style, lox, kippered, smoked or jerky.
Understand local fish advisories. If you eat fish from local waters, pay attention to local advisories. If advice isn't available, limit fish from local waters to 6 ounces (170 grams) a week and don't eat other fish that week.
Cook seafood properly. Cook fish to an internal temperature of 145 F (63 C). The fish is done when it separates into flakes and appears opaque throughout. Cook shrimp, lobster and scallops until they're milky white. Cook clams, mussels and oysters until their shells open. Discard any that don't open.
Are there other ways to get omega-3 fatty acids?
Beyond seafood, other sources of omega-3 fatty acids include:
Foods. Flaxseed — ground seeds or oil — canola oil, walnuts, sunflower seeds, pine nuts and soybeans (edamame) are all good sources of omega-3 fatty acids.
Fortified foods. Yogurt, milk and eggs can be fortified with omega-3 fatty acids.
Supplements. Supplements typically contain fish oil or omega-3 fatty acids from marine plant sources. Talk to your doctor before taking any supplement.
Keep in mind, however, that researchers haven't yet determined whether omega-3 fatty acids from plant sources can promote fetal brain development. While pregnant women can get omega-3 fatty acids from many sources, most experts recommend eating seafood for this purpose.
What's the bottom line?
Though mercury can harm a developing baby's brain, eating average amounts of seafood containing low levels of mercury during pregnancy hasn't been shown to cause problems. And the omega-3 fatty acids in many types of fish — especially salmon and tuna — can promote healthy cognitive development. As long as you avoid fish known to be high in mercury or contaminated with pollutants, fish can be a regular part of your healthy-eating plan during pregnancy.
Source: Mayo Clinic
Toxemia of pregnancy, known medically as preeclampsia, has sometimes been called "first pregnancy disease." Maybe not any more. A new study suggests that later pregnancies get just as risky if a woman waits 10 years between babies.
Pre-eclampsia strikes one in 20 pregnant U.S. women. This sudden rise in blood pressure threatens both the unborn child and even the mother. In severe cases, the only cure is immediate induced delivery or C-section.
Furthermore, pre-eclampsia is a serious condition of pregnancy characterised by high blood pressure, protein in the urine and swelling of the hands, feet and face. Most women with pre-eclampsia don't have obvious symptoms, so regular antenatal check-ups are vital. The only cure is delivery of the baby
More so, pre-eclampsia is a serious disorder of pregnancy characterised by high maternal blood pressure, protein in the urine and severe fluid retention. It is the most common serious medical complication of pregnancy, affecting around five to 10 per cent of all pregnancies in Australia. One to two per cent of cases are severe enough to threaten the lives of both the mother and her unborn child.
Pre-eclampsia accounts for one in five inductions and one in six Caesarean sections. The mechanisms behind the condition are mysterious, but genetic factors and the placenta seem to play significant roles. For reasons unknown, pre-eclampsia tends to be more common in first, rather than subsequent, pregnancies. The mother’s blood pressure usually returns to normal after the baby and placenta are delivered.
Effects on the mother
Pre-eclampsia may develop at any time during the second half of pregnancy, but commonly develops during the later stages of pregnancy. Pre-eclampsia most commonly causes high blood pressure and protein in the urine. It can also have a large spectrum of effects and potentially involve most body organs. In its most severe forms, it can cause problems in the kidneys, liver, brain and blood (in particular, the coagulation system). It is difficult to predict who will be affected, but certain women appear to be more at risk than others, including:
Women experiencing their first pregnancy
Those with pre-existing high blood pressure or some other types of vascular disease
Women with a family history of the condition
Women pregnant with multiple fetuses.
The disorder can be asymptomatic
Contrary to popular belief, there is no evidence that pre-eclampsia is caused by emotional stress, working too hard or not getting sufficient bed rest. Pre-eclampsia initially has no obvious symptoms and most women with the condition feel fine. That’s why regular antenatal checks are so important. Pre-eclampsia is suspected if there is:
A sudden elevation in blood pressure (above levels at the start of pregnancy)
Proteinuria (protein in the urine).
If left untreated, pre-eclampsia can lead to convulsions, kidney failure, liver failure, clotting problems or death. Some of the advanced symptoms of the disorder include:
Visual disturbances, such as flashing lights
Abdominal pain just below the ribs
Nausea and vomiting.
Effects on the unborn baby
Around five to 10 per cent of pre-term deliveries in Australia are due to pre-eclampsia or its associated complications. In utero, the baby is sustained by a special organ of pregnancy called the placenta. This organ allows oxygen and nutrients to pass from the mother’s bloodstream to the baby, and waste products (such as carbon dioxide) to pass from the baby’s bloodstream to the mother.
In pre-eclampsia, blood flow to the placenta becomes sluggish. In severe cases, the baby can be gradually starved of oxygen and nutrients, which may affect its growth. This growth restriction threatens the life of the baby and it is then necessary to deliver the baby prematurely. Another serious complication of pre-eclampsia is abruptio placentae, which means the placenta separates from the uterine wall and the woman experiences vaginal bleeding and abdominal pain. This is a medical emergency.
Diagnosis and treatment
Some symptoms of pre-eclampsia, such as fluid retention, are also typical of normal pregnancy. This means that some women may dismiss the early warning signs. Regular antenatal checks are vital. At present, there is no way to cure pre-eclampsia. Sometimes medication is needed to control blood pressure and prevent convulsions, and the woman may benefit from resting. The only cure is to deliver the baby and the placenta.
Maternal deaths are very rare; however, pre-eclampsia and its associated complications are responsible for around 15 per cent of maternal deaths. Medical researchers are looking for ways to predict pre-eclampsia, in order to further minimise the risks for susceptible mothers and their babies. Since pre-eclampsia tends to run in families, scientists are currently looking for the specific gene(s) which predispose a person to this condition. If discovered, it is hoped there will eventually be a pre-pregnancy test for the condition.
Where to get help
Things to remember
Pre-eclampsia is a serious condition of pregnancy, usually characterised by high blood pressure, protein in the urine and swelling.
Most women with pre-eclampsia feel fine, which means that regular antenatal check-ups are vital.
There is no cure for the condition, except delivery of the baby and the placenta.