Dear Doctor: I just had my first baby, and I'm breastfeeding him. I really enjoy the experience, and our pediatrician says he's hitting his weight milestones. But my mother-in-law is afraid he's not getting enough nutrients and is pressuring me to switch to formula. How do I know if my newborn is getting enough breast milk?

Dear Reader: Congratulations on your new baby and on the good reports from your pediatrician. We hope we can help you quiet your mother-in-law's concerns.

If you're healthy and are eating a balanced diet, then your breast milk has everything your baby needs to grow and thrive. It contains protein, fat, carbohydrates, vitamins, minerals and water for hydration. Breast milk is also a rich source of bioactive compounds that help strengthen your baby's brand-new immune system.

When your son nurses, he's taking in a remarkable food source that, in addition to being easily digested, helps him to absorb the nutrients that it contains.

It's not unusual to wonder whether your baby is getting adequate nutrition. We live in a world of food pyramids and portion sizes. Food and the nutrients it contains have become things that we measure down to the last ounce, gram and calorie. So the process of feeding an infant from one's own body, where it's hard to quantify exactly what and how much a baby is getting, can cause anxiety.

Your pediatrician's reassurance that your baby's weight is on target means he is getting the nourishment he needs. There are also some solid useful hallmarks that indicate whether things are going well.

In the first four or five days after birth, you should be getting four to six wet diapers per day. Babies who are well-hydrated will have pale or clear urine. If the baby's urine turns deep yellow or orange, like the color of apple juice or weak tea, it's a sign that he's not getting enough milk to support hydration.

How much stool a baby produces is another sign of how well breastfeeding is going. Within the first month, breastfed babies will be producing two or three bowel movements per day. Some, because breast milk can act as a natural laxative, may have a bowel movement with each feeding. After that, as the bioactive compounds we mentioned earlier help the baby's gut to mature, you'll notice that the number of bowel movements drops to about one (and occasionally fewer) per day.

With their tiny stomachs (at birth, a baby's tummy can hold about a teaspoonful or 2), newborns need to eat frequently. At 10 days old, they can comfortably hold up to 2 ounces. Newborns need to feed every two to three hours. As they get older, the frequency drops, and each baby will develop her or his own feeding pattern.

Being a new mother is challenging enough. Having a family member add to your worries makes things even harder. Perhaps introducing your mother-in-law to the excellent information available at womenshealth.gov (enter the word "breastfeeding" into the search box) can help calm her fears.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Do marijuana users really have more sex? Why would that be? I ask out of simple curiosity, of course.

Dear Reader: I suspect you're referring to a recent, much-publicized study in the Journal of Sexual Medicine. Before I answer your question, however, let's consider: Why is sex so important? From a biological perspective, male-female sex is necessary for procreation and, without it, none of us would be here. But aside from the sperm-meets-egg function of intercourse, greater amounts of sex with one partner have indeed been linked to greater happiness.

A 2015 study in the journal Social Psychology and Personality Science analyzed data from three studies totaling more than 30,000 people. The study looked at sex frequency, relationship satisfaction and happiness. The authors found that, although sexual frequency led to greater relationship satisfaction and happiness, those factors plateaued when sex occurred four to six times per month -- meaning that having sex more than once a week did not alter relationship satisfaction or happiness compared to having intercourse once a week.

This brings us to the latest study in the Journal of Sexual Medicine. The authors analyzed data from a health questionnaire called the National Survey of Family Growth. Participants ages 15 to 44 were asked about their frequency of intercourse four weeks prior to the survey. The participants also were asked about their frequency of marijuana use; 28,176 women and 22,943 men participated in the study, with an average age of about 30.

Granted, the study's parameters were narrow, featuring only questions about male-female sex. Still, marijuana use did correlate with higher sexual frequency. In a four-week time period, men who had never used marijuana had sex an average of a little more than five times; men who used marijuana weekly had intercourse an average of six times; and men who used marijuana daily had sex an average of seven times. Among women, those who had never used marijuana had intercourse an average of six times, while those who used it weekly or daily had intercourse an average of seven times.

Keep in mind, however, that the link between marijuana and sex is a correlation -- it doesn't reflect causation. The true connection between the two may simply be risky behavior. That said, for many people, marijuana is a relaxant, helping them forget their anxieties. It also decreases inhibition, and many users report that sexual experiences are more pleasurable with the drug. So it's simple to deduce how marijuana could increase sexual frequency.

Regardless, an increase in sexual frequency of one to 1 1/2 sex events per month hardly seems enough to warrant regular marijuana use. It certainly seems unlikely to increase the happiness we referenced earlier.

For starters, users can become dependent upon the drug, needing it before they have sex. Also, marijuana, like alcohol and other drugs, can lead to more promiscuous behavior, especially in younger adults. This can lead to intercourse with multiple partners and a failure to use condoms, raising the risk of sexually transmitted diseases.

So yes, marijuana use may lead to slightly more sex -- but also more risk.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My dad is 65 years old and has Type 2 diabetes. He recently developed pain in his feet, which his doctor says is peripheral neuropathy. What is that, and what treatments are available?

Dear Reader: Neuropathy is a condition in which the nervous system malfunctions due to either disease or some kind of damage. The addition of the word "peripheral" means the problem lies in the vast and complex network of nerves that serves the body.

The peripheral nervous system collects and sends vital sensory information to the central nervous system, which is made up of the brain and the spinal cord. When you drop that hot frying pan handle, break into a sweat on a hot day or keep your balance with your eyes closed, that's all thanks to information your peripheral nervous system has sent to your brain.

It's estimated that 20 million people in the United States experience some kind of peripheral neuropathy. Sometimes the damage is limited to a single nerve, but most often the condition affects groups of nerves. Symptoms include numbness, twitching, throbbing or tingling, burning sensations, problems with balance, or skin sensitivity so acute that ordinary stimuli, like the touch of a shirt on bare skin, are interpreted as pain.

When the motor nerves are affected, peripheral neuropathy causes muscle weakness and can often lead to the loss of muscle mass. If the nerves that serve the organs or glands are involved, it can result in impaired digestion, perspiration, urination or sexual function. At its most extreme, peripheral neuropathy causes breathing difficulties, or leads to organ failure. Fortunately, this is rare.

Diabetes is the most common cause of peripheral neuropathy. Other factors include infections such as shingles or the Epstein-Barr virus, certain kidney disorders, vitamin deficiencies, physical damage, cancers that press on or infiltrate nerve fibers, or autoimmune diseases that cause the body to attack its own tissues. Exposure to toxic industrial and environmental substances such as lead, arsenic or pesticides as well as medical agents like chemotherapy drugs can also lead to the condition. So can heavy alcohol consumption.

Your father's symptoms began in his feet, which is common among people with diabetes. He may also experience numbness, a decrease in foot and ankle reflexes, trouble with balance and coordination, and an increase in foot problems like ulcers and infections. This is due to tissue damage resulting from chronic high blood glucose levels, as well as decreased circulation, which occurs because diabetes causes the blood vessels in the foot and leg to become stiff and grow narrow.

Treatment for your father's condition will focus on two things -- carefully controlling his diabetes to prevent further nerve damage, and giving him relief from the existing pain. Mild pain often responds to over-the-counter NSAIDs. Medications like antidepressants, anticonvulsants and narcotics are used for chronic pain. Procedures like electrical nerve stimulation have shown promise. Physical therapy and specialized footwear can also help.

Pain treatment is often most effective when there's an ongoing dialogue. Be sure your dad shares all his symptoms with his doctor, and follows up with regular progress reports.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)