By his first birthday, your baby should be sleeping about 13 hours a day. However, sleep does not always come easily for all babies — particularly 1-year-olds, who are just learning skills like crawling and walking.

If your baby starts acting fussier than usual after you change his formula, it's natural to look to the formula as the cause. Infant formulas, while similar in their nutritional value, can differ significantly in composition.

Many babies vomit or spit up after every feeding. This can be both messy and distressing to parents. While most spit up is normal, it is important to know the signs of abnormal spit up so that you can report these occurrences to your pediatrician.

As a new parent, you might have prepared yourself for a lack of sleep when your baby arrived. While you likely aren't well rested, you might find that your baby sleeps more than you expected. Babies don't sleep for long intervals, but they do sleep often. Newborns often sleep from 14 to 18 hours a day.

Infants with very stiff muscles may clench their hands and feet, such as clenching their fingers into a fist or curling their toes, or cross their legs in a scissor-like fashion when picked up.

A food allergy means your child's immune system is hypersensitive to a protein in a specific food. If your baby is allergic to bananas, his body will attack the food when it comes in contact with his digestive system, sending white blood cells to defend the body and kill the allergen.

Children reach many different milestones in the first couple years of life, with one of the most memorable being the ability to walk. Most children gain the ability to walk independently between the ages of 11 and 15 months. If your child is not walking by 18 months, his progress is considered delayed.

Mucus lines the inside of the nasal passages, preventing germs and infection from entering your baby's nose. But when your infant is sick, a build-up of mucus in her nasal passages might make breathing and sleeping uncomfortable.

Your 5-month-old baby will still need to nurse or bottle feed approximately six times per day. However, it's the ideal age to start introducing your baby to solid foods. For best results, it is imperative to expose your baby to a variety of safe, healthy foods that are not likely to upset her stomach.

While most parents now know that babies shouldn't have raw honey, decisions about foods baked with honey are more complex. Raw honey, including pasteurized honey, can be contaminated with botulism spores.

Chlamydia, among the most common sexually transmitted diseases, affects an estimated 100,000 pregnant women each year, according to the Centers for Disease Control and Prevention. This disease not only poses substantial risks to women but also to their babies during delivery.

Random contractions in pregnancy can be worrying when you first experience them. When you are seven months pregnant, these contractions are usually just a slight, brief tightening. You might find them uncomfortable, or you may not feel them at all.