Birth weight is the first weight of your baby, taken just after being born. A low birth weight means that the baby is less than 5 pounds, 8 ounces. A high birth weight means that the baby is more than 8 pounds, 13 ounces.

A normal pregnancy lasts nine months. Each three-month period of pregnancy is called a trimester. During each trimester, the fetus grows and develops. Regular medical checkups and prenatal tests are very important. They can:

• Help keep you and your baby healthy
• Spot problems with your baby (if there are any). In some cases, health care professionals can treat the problem before your baby is born. But even when they cannot, it can still be helpful to know about the problem early on. That gives you time to learn about your baby's condition and prepare for any challenges you may face after the baby is born.
• Prevent problems during delivery. For example, if your baby is breech (bottom first or feet first, instead of head first), you may need to have a Cesarean section to avoid complications.

Besides getting medical care, there are other things you can do to keep your baby as healthy as possible. It's important not to drink or smoke. Try to eat a healthy diet and make sure to take care of any health problems you have during pregnancy.

A baby with a low birth weight can be born too small, too early (premature), or both. This can happen for many different reasons. They include:

• Health problems in the pregnant parent
• Taking certain medicines during pregnancy
• Substance use during pregnancy
• Infections during pregnancy
• Being pregnant with multiple babies
• Problems with the placenta, the organ that brings oxygen and nutrients to the baby
• Having small parents
• Genetic conditions in the baby
• Birth defects

Every pregnancy has some risk of problems. You may have problems because of a health condition you had before you got pregnant. You could also develop a condition during pregnancy. Other causes of problems during pregnancy can include being pregnant with more than one baby, a health problem in a previous pregnancy, substance abuse during pregnancy, or being over age 35. Any of these can affect your health, the health of your baby, or both.

If you have a chronic condition, you should talk to your health care provider about how to minimize your risk before you get pregnant. Once you are pregnant, you may need a health care team to monitor your pregnancy. Some common conditions that can complicate a pregnancy include

• High blood pressure
• Polycystic ovary syndrome
• Kidney problems
• Autoimmune disorders
• Obesity
• HIV/AIDS
• Cancer
• Infections

Other conditions that can make pregnancy risky can happen while you are pregnant - for example, gestational diabetes and Rh incompatibility. Good prenatal care can help detect and treat them.

Some discomforts, like nausea, back pain, and fatigue, are common during pregnancy. Sometimes it is hard to know what is normal. Call your health care provider if something is bothering or worrying you.

Not all medicines are safe to take when you are pregnant. Some medicines can harm your baby. That includes over-the-counter or prescription drugs, herbs, and supplements.

Always speak with your health care provider before you start or stop any medicine. Not using medicine that you need may be more harmful to you and your baby than using the medicine. For example, many pregnant women take prescription medicines for health problems like diabetes, asthma, seizures, and heartburn. The decision about whether or not to take a medicine depends on the risks and benefits. You and your health care provider should make this choice together.

Pregnant women should not take regular vitamins. They may have too much or too little of the vitamins that you need. There are special vitamins for pregnant women. It is important to take 0.4 mg of folic acid every day before you become pregnant through the first part of your pregnancy. Folic acid helps to prevent birth defects of the baby's brain or spine.

During pregnancy, there are many things you can do to keep yourself and your baby healthy. They include getting regular prenatal care, eating healthy, and staying active. But it's also very important to avoid substances that could be harmful to you and your baby, such as tobacco, alcohol, and drugs.

Tobacco

Smoking during pregnancy passes nicotine, carbon monoxide, and many other harmful chemicals to your baby. Nicotine is not only a health danger for you, but it can also damage your developing baby's brain and lungs. Carbon monoxide can keep the developing baby from getting enough oxygen.

If you smoke while pregnant, it raises the risk of your baby being born too small, too early, or with birth defects. During the first year of life, there is a higher risk of your baby dying from sudden infant death syndrome (SIDS). And later in life, your child may be more likely to have health problems, such as asthma and obesity.

Other tobacco products, including e-cigarettes, also contain nicotine and are not safe to use during pregnancy. And some of the flavorings used in e-cigarettes may be harmful to developing babies.

You will also want to try to avoid secondhand smoke, which has some of the same risks as smoking during pregnancy.

Alcohol

There is no known amount of alcohol that is safe for you to drink during pregnancy and while trying to get pregnant. All types of alcohol are equally harmful, including all wines and beer. The risks from drinking during pregnancy include problems with the growth of the developing baby and fetal alcohol spectrum disorders (FASD). FASD is a life-long condition that can cause a mix of physical, behavioral, and learning problems.

Illegal drugs

Using illegal drugs, such as cocaine, methamphetamines, and club drugs, during pregnancy can cause problems for both you and your baby. They may cause low birth weight babies, birth defects, or miscarriage. Your child may be more likely to have learning and developmental disabilities. And if you are injecting the drugs, that puts you at risk for HIV. HIV can be passed along to your baby during pregnancy.

Prescription drug misuse

Misusing prescription drugs can also be harmful. Misuse can include taking more than your prescribed dose or taking it more often, using it to get high, or taking someone else's medicines. The possible effects of misusing a medicine during pregnancy will depend on which medicine you are misusing.

Opioids

One type of drug that is a concern during pregnancy is opioids. Opioids include strong prescription pain relievers such as oxycodone, hydrocodone, fentanyl, and tramadol. The illegal drug heroin is also an opioid. Taking opioids during pregnancy can cause problems for you and your baby. The risks include birth defects, preterm birth, the loss of the baby, and neonatal abstinence syndrome (NAS). NAS causes withdrawal symptoms in newborn babies.

If you have pain and your health care provider suggests that you take prescription opioids during pregnancy, first discuss the risks and benefits with the provider. Then if you both decide that you need to take the opioids, you can work together to try to minimize the risks.

Cannabis (marijuana)

Cannabis (marijuana) is another drug that could be harmful to your baby. Some research shows that using cannabis during pregnancy is linked to developmental problems in children and teens. More research is needed, but the safest thing to do is stop using it if you are pregnant. The U.S. Centers for Disease Control and Prevention (CDC) advises that people should not use cannabis while they are pregnant.

Getting help

If you are pregnant and using any of these substances, contact your provider. Together you and your provider can find the right treatment to help you quit.

If you are taking opioids or are addicted to drugs, don't stop taking them suddenly. That can be dangerous to you and the baby. Instead, contact your provider for help with getting off the drugs safely.

During pregnancy, some common infections like the common cold or a skin infection do not usually cause serious problems. But other infections can be dangerous to you, your baby, or both. Some infections may lead to preterm birth and low birth weight babies. Others can cause serious illness, birth defects, and lifelong disabilities, such as hearing loss or learning problems.

Some of the infections that can be dangerous during pregnancy include

• Bacterial vaginosis (BV)
• Group B strep (GBS)
• Hepatitis
• Sexually transmitted diseases
• Toxoplasmosis
• Urinary tract infections
• Yeast infections
• Zika virus

To try to prevent infections,

• Don't eat raw or undercooked meat
• Don't share food or drinks with other people
• Wash your hands frequently
• Don't empty cat litter. Cats can transmit toxoplasmosis.

If you do get an infection during pregnancy, contact your health care provider about how best to protect you and your baby. Only some medicines are safe during pregnancy.

If you are pregnant with more than one baby, you are far from alone. Multiple births are up in the United States. More women are having babies after age 30 and more are taking fertility drugs. Both boost the chance of carrying more than one baby. A family history of twins also makes multiples more likely.

Years ago, most twins came as a surprise. Now, most women know about a multiple pregnancy early. Women with multiple pregnancies should see their health care providers more often than women who are expecting one baby. Multiple pregnancy babies have a much higher risk of being born prematurely and having a low birth weight. There is also more of a risk of disabilities. Some women have to go on bed rest to delay labor. Finally, they may deliver by C-section, especially if there are three babies or more.

Parenting multiples can be a challenge. Volunteer help and support groups for parents of multiples can help.

Genes are the building blocks of heredity. They are passed from parent to child. They hold DNA, the instructions for making proteins. Proteins do most of the work in cells. They move molecules from one place to another, build structures, break down toxins, and do many other maintenance jobs.

Sometimes there is a mutation, a change in a gene or genes. The mutation changes the gene's instructions for making a protein, so the protein does not work properly or is missing entirely. This can cause a medical condition called a genetic disorder.

You can inherit a gene mutation from one or both parents. A mutation can also happen during your lifetime.

There are three types of genetic disorders:

• Single-gene disorders, where a mutation affects one gene. Sickle cell anemia is an example.
• Chromosomal disorders, where chromosomes (or parts of chromosomes) are missing or changed. Chromosomes are the structures that hold our genes. Down syndrome is a chromosomal disorder.
• Complex disorders, where there are mutations in two or more genes. Often your lifestyle and environment also play a role. Colon cancer is an example.

Genetic tests on blood and other tissue can identify genetic disorders.

What problems can low birth weight cause?

Babies with low birth weight may be more at risk of certain health problems. They include immediate problems, such as:

• Breathing problems
• Infections
• Hypoglycemia (low blood sugar)
• Jaundice
• Trouble keeping warm

There is also a higher risk of longer-term problems, including:

• Delayed motor and social development
• Learning disabilities
• Certain health conditions as an adult, such as heart disease, high blood pressure, diabetes, and obesity

Hypoglycemia means low blood glucose, or blood sugar. Your body needs glucose to have enough energy. After you eat, your blood absorbs glucose. If you eat more sugar than your body needs, your muscles, and liver store the extra. When your blood sugar begins to fall, a hormone tells your liver to release glucose.

In most people, this raises blood sugar. If it doesn't, you have hypoglycemia, and your blood sugar can be dangerously low. Signs include :

• Hunger
• Shakiness
• Dizziness
• Confusion
• Difficulty speaking
• Feeling anxious or weak

In people with diabetes, hypoglycemia is often a side effect of diabetes medicines. Eating or drinking something with carbohydrates can help. If it happens often, your health care provider may need to change your treatment plan.

You can also have low blood sugar without having diabetes. Causes include certain medicines or diseases, hormone or enzyme deficiencies, and tumors. Laboratory tests can help find the cause. The kind of treatment depends on why you have low blood sugar.

Jaundice causes your skin and the whites of your eyes to turn yellow. Too much bilirubin causes jaundice. Bilirubin is a yellow chemical in hemoglobin, the substance that carries oxygen in your red blood cells. As red blood cells break down, your body builds new cells to replace them. The old ones are processed by the liver. If the liver cannot handle the blood cells as they break down, bilirubin builds up in the body and your skin may look yellow.

Many healthy babies have some jaundice during the first week of life. It usually goes away. However, jaundice can happen at any age and may be a sign of a problem. Jaundice can happen for many reasons, such as

• Blood diseases
• Genetic syndromes
• Liver diseases, such as hepatitis or cirrhosis
• Blockage of bile ducts
• Infections
• Medicines

What is a learning disability?

Learning disabilities are conditions that affect the ability to learn. They can cause problems with

• Understanding what people are saying
• Speaking
• Reading
• Writing
• Doing math
• Paying attention

Often, children have more than one kind of learning disability. They may also have another condition, such as attention deficit hyperactivity disorder (ADHD), which can make learning even more of a challenge.

What causes learning disabilities?

Learning disabilities don't have anything to do with intelligence. They are caused by differences in the brain, and they affect the way the brain processes information. These differences are usually present at birth. But there are certain factors that can play a role in the development of a learning disability, including

• Genetics
• Environmental exposures (such as lead)
• Problems during pregnancy (such as the mother's drug use)

How do I know if my child has a learning disability?

The earlier you can find and treat a learning disability, the better. Unfortunately, learning disabilities are usually not recognized until a child is in school. If you notice that your child is struggling, talk to your child's teacher or health care provider about an evaluation for a learning disability. The evaluation may include a medical exam, a discussion of family history, and intellectual and school performance testing.

What are the treatments for learning disabilities?

The most common treatment for learning disabilities is special education. A teacher or other learning specialist can help your child learn skills by building on strengths and finding ways to make up for weaknesses. Educators may try special teaching methods, make changes to the classroom, or use technologies that can assist your child's learning needs. Some children also get help from tutors or speech or language therapists.

A child with a learning disability may struggle with low self-esteem, frustration, and other problems. Mental health professionals can help your child understand these feelings, develop coping tools, and build healthy relationships.

If your child has another condition such as ADHD, he or she will need treatment for that condition as well.

Causes of high birth weight can include:

• Having big parents
• Diabetes in the pregnant parent
• Certain genetic conditions
• Too much weight gain during pregnancy

Diabetes is a disease in which your blood glucose, or blood sugar, levels are too high. When you are pregnant, high blood sugar levels are not good for your baby.

About seven out of every 100 pregnant women in the United States get gestational diabetes. Gestational diabetes is diabetes that happens for the first time when a woman is pregnant. Most of the time, it goes away after you have your baby. But it does increase your risk for developing type 2 diabetes later on. Your child is also at risk for obesity and type 2 diabetes.

Most women get a test to check for diabetes during their second trimester of pregnancy. Women at higher risk may get a test earlier.

If you already have diabetes, the best time to control your blood sugar is before you get pregnant. High blood sugar levels can be harmful to your baby during the first weeks of pregnancy - even before you know you are pregnant. To keep you and your baby healthy, it is important to keep your blood sugar as close to normal as possible before and during pregnancy.

Either type of diabetes during pregnancy increases the chances of problems for you and your baby. To help lower the chances talk to your health care team about

• A meal plan for your pregnancy
• A safe exercise plan
• How often to test your blood sugar
• Taking your medicine as prescribed. Your medicine plan may need to change during pregnancy.

High birth weight can be a concern because it can make delivery of the baby difficult and raise the risk of birth injuries. The baby is at higher risk of problems with:

• Blood sugar
• Breathing problems
• Jaundice

You may be able to prevent some birth weight problems by:

• Getting regular checkups during pregnancy
• Getting the right amount of nutrition and calories during pregnancy
• Controlling your blood sugar if you have diabetes
• Avoiding substance use during pregnancy

Prenatal care is the health care you get while you are pregnant. It includes your checkups and prenatal testing. Prenatal care can help keep you and your baby healthy. It lets your health care provider spot health problems early. Early treatment can cure many problems and prevent others.

Your doctor or midwife will give you a schedule for your prenatal visits. If you are over 35 years old or your pregnancy is high risk because of health problems like diabetes or high blood pressure, your doctor or midwife will probably want to see you more often. You can also expect to see your health care provider more often as your due date gets closer.