Research on the existence of "baby brain" is mixed. The term refers to memory problems, poor concentration and absent-mindedness reported by many women during pregnancy and early motherhood.

A recent review of 20 studies assessing more than 700 pregnant and 500 nonpregnant women concluded that general cognitive functioning, memory and executive functioning were significantly poorer in pregnant women. However, the changes are likely to be noticeable only to the pregnant women and those close to them and less likely to affect job performance.

Other research suggests that memory problems during pregnancy aren't as widespread as believed, but can be seen in women experiencing depression shortly before childbirth.

Beyond the relationship between pregnancy and memory, some researchers are looking at the ways pregnancy might positively change a woman's brain. Another recent study compared the MRI scans of women's brains before pregnancy and after giving birth to the brain scans of women who have never given birth. The scans of women after pregnancy showed changes in brain structure that might help women adapt to motherhood.

If you're pregnant or a new mother, don't assume that you're experiencing a cognitive decline. Becoming a mother involves an emotional and physical transition. If you have any concerns about your moods, talk to your health care provider.

Be wary of any product that claims to be a natural form of Viagra. Herbal supplements aren't held to the same standards as prescription and over-the-counter medications — so it can be difficult to know which ones are safe or effective.

Prescription medications used to treat erectile dysfunction — sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), and others — work by increasing blood flow to the penis when you become sexually aroused. Some "herbal viagra" supplements are advertised as a cheaper alternative, available without a prescription.

Some of these products do contain substances that improve blood flow by relaxing the walls of blood vessels. However, none of them focuses specifically on blood vessels in the penis, as do Viagra and similar prescription drugs. As a result, these "herbal viagra" supplements can cause dangerously low blood pressure in some men — particularly men who take nitrate medications for heart problems.

In addition, some products marketed as "herbal viagra" have been pulled off the market because they contain undeclared prescription medications. It can be dangerous to take supplements that contain unknown amounts of prescription medications or other unidentified ingredients.

If you have erectile dysfunction, see your doctor to make sure it isn't caused by an underlying health problem or isn't a side effect of medications you take. Your safest bet in treating erectile problems is to rely on your doctor's evaluation and recommendations. Before using any herbal remedy or supplement, check with your doctor to make sure it's safe for you.

Sperm morphology — the size and shape of sperm — is one factor that's examined as part of a semen analysis to evaluate male infertility. Sperm morphology results are reported as the percentage of sperm that appear normal when semen is viewed under a microscope.

Normal sperm have an oval head with a long tail. Abnormal sperm have head or tail defects — such as a large or misshapen head or a crooked or double tail. These defects might affect the ability of the sperm to reach and penetrate an egg. However, having a large percentage of misshapen sperm isn't uncommon. Typically, only around 4% to 10% of the sperm in a semen sample are normal, meaning that the vast majority don't look perfect under the microscope.

Sperm morphology is poorly understood, and it can be subjective. Scores can vary on the same semen sample, in the same lab, using the same scoring techniques. Most male fertility experts agree that the role of sperm morphology in predicting pregnancy is unclear, and that it's a poor predictor of infertility unless nearly 100% of the sperm are abnormal.

Along with sperm morphology, a typical semen analysis also assesses:

• Semen volume
• Total sperm number
• Sperm concentration
• Vitality (percent alive)
• Movement (motility)

An abnormal semen analysis doesn't mean that you are infertile. Many men with low semen analysis values can still father children — it just might take longer. If you and your partner aren't able to conceive through sexual intercourse, assisted reproductive technology such as in vitro fertilization might be an option.

Generally, elective abortion isn't thought to cause fertility issues or complications in future pregnancies. However, some studies suggest a possible link between pregnancy termination and an increased risk of premature birth and low birth weight.

Risks may depend on the type of abortion performed:

• Medical abortion. Medication is taken in early pregnancy to abort the fetus. Medical abortions do not appear to increase the risk of future pregnancy complications.
• Surgical abortion. A surgical procedure removes the fetus from the uterus through the vagina. It's typically done using suction and a sharp, spoon-shaped tool (curet). Rarely, this can cause scarring of the uterine wall (Asherman syndrome), which may make it difficult to get pregnant. Women who have multiple surgical abortion procedures may also have more risk of trauma to the cervix.

If you have had an abortion and you are concerned about its possible impact on a future pregnancy, talk to your health care provider. He or she can help you understand the potential risks and the steps you can take to help ensure a healthy pregnancy.

The acai (ah-sigh-EE) berry is a grapelike fruit harvested from acai palm trees, which are native to the rainforests of South America. Like other berries, acai berries contain antioxidants and fiber.

Acai berries are widely touted as a so-called superfood, with proponents claiming that they are helpful for a variety of health concerns, including arthritis, weight loss, high cholesterol, erectile dysfunction, skin appearance, detoxification and general health. However, research on acai berries is limited, and the claims about their health benefits haven't been proved.

Acai is usually safe to consume. But avoid acai if you're pregnant or breast-feeding because there's insufficient information on its safety for women who are pregnant or breast-feeding.

If you'd like to try acai, check your local health food or gourmet stores. Acai can be consumed raw or in:

• Tablet form
• Beverages, such as juice, smoothies or energy drinks
• Food products such as jelly or ice cream

If you're taking amounts of acai higher than you'd normally eat as food, such as in dietary supplements, be sure to tell your health care provider. It's also important to let your doctor know that you've been eating acai berries if you're scheduled to have an MRI. Very large doses of acai might affect the results of the test.

Currently, there isn't enough evidence to know whether acetyl-L-carnitine helps improve fatigue associated with multiple sclerosis (MS) or not. More study is needed.

Acetyl-L-carnitine is a form of L-carnitine, an amino acid that is found in nearly all cells of the body. L-carnitine plays a critical role in the production of energy from long-chain fatty acids. In addition, it increases the activity of certain nerve cells in the central nervous system.

Fatigue is a common symptom in people with multiple sclerosis. But the cause of the fatigue isn't well-understood.

As for treating fatigue with acetyl-L-carnitine, some studies have suggested that supplements could ease MS-related fatigue in people with low blood levels of L-carnitine.

Other research found that acetyl-L-carnitine works better than certain medications used to treat fatigue. But additional studies have had inconclusive results, showing a possible, but not statistically significant, benefit to acetyl-L-carnitine in MS-related fatigue.

Although acetyl-L-carnitine generally has few or mild side effects, it can interfere with blooding-thinning medications and other drugs. So, if you decide to try acetyl-L-carnitine or any other dietary supplement, be sure to talk with your doctor first.

Acid reflux and gastroesophageal reflux disease (GERD) are closely related, but the terms don't necessarily mean the same thing.

Acid reflux, also known as gastroesophageal reflux (GER), is the backward flow of stomach acid into the tube that connects your throat to your stomach (esophagus). During an episode of acid reflux, you might feel a burning sensation in your chest (heartburn). This can occur after eating a big meal or drinking coffee or alcohol.

Sometimes acid reflux progresses to GERD, a more severe form of reflux. The most common symptom of GERD is frequent heartburn —two or more times a week. Other signs and symptoms can include regurgitation of food or sour liquid, difficulty swallowing, coughing, wheezing, and chest pain — especially while lying down at night.

If you have occasional acid reflux, lifestyle changes can help. Lose excess weight, eat smaller meals, don't eat two to three hours before bedtime, raise the head of your bed, and avoid foods that seem to trigger heartburn — such as fried or fatty foods, chocolate, and peppermint. Don't wear tight clothing around your abdomen, and avoid alcohol and tobacco.

If necessary, occasional acid reflux can be treated with over-the-counter medication, including:

• Antacids, such as Tums or Maalox
• H-2-receptor blockers, such as cimetidine (Tagamet HB) or famotidine (Pepcid AC)

If you suspect that you have GERD, your signs and symptoms worsen, or you have nausea, vomiting or difficulty swallowing, talk to your doctor. Prescription medications might help. In a few cases, GERD might be treated with surgery or other procedures.

People with acne might see better results if they avoid these common skin care mistakes:

• Using oily products. Avoid oily or greasy cosmetics, moisturizers, sunscreens and acne cover-ups. Prefer products that are water based and not likely to block pores (noncomedogenic).
• Forgetting to wash your face daily. Problem areas need gentle cleansing with lukewarm water and mild soap. Do this twice a day and after sweating.
• Being too rough with your skin. Scrubbing too hard or using harsh products such as astringents and masks can worsen acne.
• Touching your face. Keep your hands, phone and hair away from your face. Too much contact can cause flare-ups.
• Picking or squeezing pimples. This can cause an infection or scar.

Acne scars are stubborn, and no single treatment is best for everyone. Various methods may help improve your complexion. Your doctor may suggest one or a combination of these.

• Home skin care. The appearance of scars that change your skin color may be improved with over-the-counter bleaching agents and use of sunscreen to limit contrast.
• Soft tissue fillers. Injecting collagen or fat under the skin and into indented scars can fill out or stretch the skin. This makes the scars less noticeable. Results are temporary, so you would need to repeat the injections periodically.
• Laser resurfacing. This is a skin procedure that uses a laser to improve the appearance of your skin.
• Other energy-based procedures. Pulsed light sources and radiofrequency devices help make scars less noticeable without damaging the outer layer of skin. Results are subtle and you may need to repeat the procedure.
• Dermabrasion. This procedure is usually reserved for more severe scarring. It involves removing the top layer of skin with a rapidly rotating wire brush. Surface scars may be completely removed, and deeper acne scars may appear less noticeable.
• Chemical peeling. High-potency acid is applied to your skin to remove the top layer and minimize deeper scars.
• Needling or rolling. This involves rolling a needle-studded device over the skin to stimulate underlying tissue. It's a safe, simple and possibly effective technique for acne scarring. The result is subtle, and you may need to repeat the treatments.
• Surgery. Using a minor procedure called punch excision, your doctor cuts out individual acne scars and repairs the wound with stitches or a skin graft. Another technique called subcision involves your doctor inserting needles under the skin to loosen fibers below a scar, to help improve its appearance.
• Botox injections. Sometimes the skin around acne scars puckers. Relaxing the area with an injection of botulinum toxin (Botox) helps improve the skin's appearance. You'd need to repeat the injections periodically.

To determine what's best for you, discuss the pros and cons of each procedure with your doctor or dermatologist.

Activity trackers, often worn on the wrist or waist, are designed to encourage more movement throughout the day. And people who wear them do seem to be more physically active. However, these people don't necessarily lose more weight than others.

A group of scientists designed a study to test if activity trackers are helpful for weight loss and maintenance. Study participants received the same weight-loss counseling (diet, exercise and support) for six months and lost similar amounts of weight. After the initial six months, all participants received telephone counseling, text message prompts and access to online weight-loss information.

Some participants also received wearable devices and access to an accompanying website to monitor physical activity and diet. Both groups were able to maintain weight loss up to 24 months. However, the group with the wearable technology lost 2-3 percent less weight over the course of the study.

One possible explanation for this difference is that those wearing trackers chose to reward themselves for meeting exercise goals with dietary indulgence. In other words, if the tracker said they burned 400 calories or completed a certain amount of exercise, they might choose to eat dessert. This could lead to slower weight loss or even weight gain.

From this study, it appears that activity trackers aren't a guarantee of weight-loss success. So should you give up on your tracker? No. A tracker can be a useful tool for getting you to move more.

Here are some tips on how to make an activity tracker work for — and not against — your weight-loss goals:

• Use the tracker to get a baseline of your daily movement and then set a goal 2,000-3,000 steps higher.
• Use it as a motivational tool to encourage movement and as a historical record. If you have a bad day, you can look back and see that it was only one day among many good days. This perspective may keep you from falling off the wagon because of "all or nothing" thinking.
• Use the information from the tracker as a guide but not as permission to throw dietary discretion out the window.