Certain health conditions may complicate a pregnancy. But with the correct care, you can have a healthy pregnancy even with health challenges. If you are concerned about a medical problem during pregnancy, talk to your doctor or midwife.

Diabetes is a health problem where the body doesn't make enough insulin. Or the body is not able to use the insulin that is made. Insulin is the hormone that lets blood sugar (glucose) enter the cells of the body to make fuel. When glucose can't enter the cells, it builds up in the blood, and the body's cells do not get the fuel they need.

Diabetes in pregnancy can have serious results for you and your growing baby. How serious the problems are depends on how serious your diabetes is. This is especially true if you have blood vessel (vascular) problems and your blood sugar (glucose) is not in good control.

When diabetes happens during pregnancy, it's described as:

• Gestational diabetes. This is when you develop a resistance to insulin because of the hormones of pregnancy. If you develop gestational diabetes, you may be noninsulin dependent or insulin dependent.
• Pregestational diabetes. This is when you already have diabetes and become pregnant.

Gestational diabetes is a type of diabetes that is first diagnosed during pregnancy. With gestational diabetes, you have a high (elevated) glucose level and other diabetic symptoms. In most cases, all diabetic symptoms go away after the baby is born. But if you have gestational diabetes, you have an increased risk of developing diabetes later in life. This is especially true if you were overweight before pregnancy.

Unlike other types of diabetes, gestational diabetes is not caused by a lack of insulin. It's caused by other hormones that block the insulin that is made. This is called insulin resistance.

The cause of gestational diabetes isn't known. But there are some theories as to why it happens.

The placenta supplies a growing baby with nutrients and water. It also makes a variety of hormones to maintain the pregnancy. Some of these hormones are estrogen, cortisol, and human placental lactogen. These hormones can block insulin. This often starts about 20 to 24 weeks into the pregnancy.

As the placenta grows, more of these hormones are made. Insulin resistance becomes greater. Normally, the pancreas is able to make more insulin to overcome insulin resistance. But when not enough insulin is made to overcome the effect of the placental hormones, gestational diabetes results.

Anyone may have gestational diabetes during pregnancy. But these factors may raise the risk:

• Family history of diabetes
• Obesity
• Having given birth before to a very large infant, a stillbirth, or a child with a birth defect
• Being older than 25

A higher level of glucose in the urine is often included in the list of risk factors. But it isn't believed to be a reliable sign for gestational diabetes.

A glucose screening test is often done between 24 and 28 weeks of pregnancy. For this test, you drink a special glucose beverage. Your blood sugar level is then measured 1 hour later.

If this test shows an increased blood sugar level, you may need a 3-hour glucose tolerance test after a few days of eating a special diet. If results of the second test are in the abnormal range, gestational diabetes is diagnosed.

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

Treatment for gestational diabetes focuses on keeping blood glucose levels in the normal range. Treatment may include:

• A special diet.
• Exercise.
• Daily blood glucose monitoring.
• Insulin injections or prescription medicines.

Unlike other types of diabetes, gestational diabetes generally doesn't cause birth defects. Birth defects often show up during the first trimester of pregnancy. They are more likely to happen with pregestational diabetes, which can cause changes in blood sugar during that time. With gestational diabetes, you generally have normal blood sugar levels during the first trimester.

Problems from gestational diabetes can often be managed and prevented. The key to prevention is to carefully control your blood sugar as soon as your doctor diagnoses gestational diabetes.

Gestational diabetes can put an infant at risk for several chemical imbalances. These include low levels of calcium and magnesium in the blood. But the main problems of gestational diabetes are the following.

This is when a baby is much larger than normal. All of the nutrients your baby gets come directly from your blood. If your blood has too much glucose, the baby's pancreas senses the high glucose levels and makes more insulin to try to use this glucose. The baby converts the extra glucose to fat. Even when you have gestational diabetes, your baby is able to make all the insulin they need. The combination of high blood glucose levels from you and high insulin levels in the baby results in large deposits of fat. This causes your baby to grow very large.

Birth injury may occur because of a baby's large size and problems being born.

Hypoglycemia is when the baby has low blood sugar right after birth. This problem happens if your blood sugar levels have been high. This causes the baby to have a high level of insulin in their circulation. After birth, the baby still has a high insulin level. But the baby no longer has the high level of sugar from you. This results in the newborn's blood sugar level becoming very low. The baby's blood sugar level is checked after birth. If the level is too low, the baby may need glucose given by I.V. (intravenously).

Too much insulin or too much glucose in a baby's system may delay their lungs from becoming fully mature. This can cause breathing problems. This is more likely if a baby is born before 37 weeks of pregnancy.

High blood pressure can happen in pregnancy in two forms. It may be a preexisting health problem called chronic hypertension. Or it can develop during pregnancy. It's then known as gestational hypertension. It is also called toxemia or preeclampsia. It happens most often in young people with a first pregnancy. It is more common in twin pregnancies and in people who had blood pressure problems in a previous pregnancy.

High blood pressure can lead to placental problems and slowed fetal growth. If untreated, severe high blood pressure can be dangerous to you and your baby. It may cause unsafe seizures and even death.

If you have preeclampsia, you may need bed rest. If you have moderate or severe preeclampsia or eclampsia (preeclampsia complicated by seizures), you will probably need to stay in the hospital and be treated with medicines.

If you had high blood pressure before pregnancy, you will likely need to keep taking your blood pressure medicine. Your doctor may switch you to a safer medicine during pregnancy.

If you have high blood pressure during pregnancy, you may have kidney function tests and ultrasounds done more often. These help monitor your health and your baby's growth and development.

Infections during pregnancy can be dangerous for the baby. Even a urinary tract infection, which is common during pregnancy, needs to be treated right away. An infection that goes untreated can lead to preterm labor and rupture of the membranes surrounding the baby. Some infectious diseases are listed below.

Toxoplasmosis is an infection caused by a single-celled parasite called Toxoplasma gondii. It's found in cat feces, soil, and raw or undercooked meat. Many people may have toxoplasma infection, though very few have symptoms. This is because the immune system often keeps the parasite from causing illness. But babies who were infected before birth can be born with serious mental or physical problems.

Toxoplasmosis often causes flu-like symptoms, swollen lymph glands, or muscle aches and pains that last for a few days to several weeks. You can be tested to see if you have developed an antibody to the illness. Testing on the baby may include an ultrasound or testing of amniotic fluid or cord blood. Treatment may include antibiotics.

Here are some things you can do to help prevent toxoplasmosis infection:

• Wear gloves when you garden or do anything outdoors that involves handling soil. Cats may pass the parasite in their feces. They often use gardens and sandboxes as litter boxes. Wash your hands well with soap and clean, running water after outdoor activities. Do this especially before you eat or prepare any food.
• Have someone who is healthy and not pregnant change your cat's litter box. If this isn't possible, wear gloves and clean the litter box daily. The parasite found in cat feces can only infect you a few days after being passed. Wash your hands well with soap and clean, running water afterward.
• Have someone who is healthy and not pregnant handle raw meat for you. If this isn't possible, wear clean, latex gloves when you touch raw meat. Wash any cutting boards, sinks, knives, and other utensils that might have touched the raw meat. Wash your hands well with soap and clean, running water afterward.
• Cook all meat thoroughly. This means until it's no longer pink in the center or until the juices run clear. Don't taste meat before it's fully cooked.

During pregnancy, don't eat undercooked or raw foods because of the risk of food poisoning. Food poisoning can dehydrate you and keep your baby from getting nourishment. It can also cause meningitis and pneumonia in the baby during pregnancy, ending in possible death. Here are tips for preventing food poisoning:

• Thoroughly cook raw food from animal sources, such as beef, pork, or poultry.
• Wash raw vegetables before eating.
• Keep uncooked meats separate from vegetables and from cooked foods and ready-to-eat foods.
• Don't drink raw (unpasteurized) milk or eat foods made from raw milk.
• Wash your hands, knives, and cutting boards after handling uncooked foods.

Infections, such as chlamydia, may be linked to premature labor and rupture of the membranes.

This is a virus that causes inflammation of the liver. It may result in liver cell damage and destruction. There are five main types of the hepatitis virus. The most common type that happens in pregnancy is hepatitis B (HBV). This type spreads mainly through contaminated blood and blood products, sexual contact, and contaminated I.V. needles. HBV goes away in most people. But about 1 in 10 people will have chronic HBV. Hepatitis B virus can lead to chronic hepatitis, cirrhosis, liver cancer, liver failure, and death. If you are infected, you can pass the virus to the baby during pregnancy and at birth.

The later in pregnancy you get the virus, the greater the chance for infection in the baby. Signs and symptoms of HBV are:

• Yellowing of the skin, eyes, and mucous membranes (jaundice).
• Severe tiredness (fatigue).
• Stomach pain.
• Loss of appetite.
• Nausea that comes and goes.
• Vomiting.

A blood test for hepatitis B is part of routine prenatal testing. If you are HBV positive, you may get a medicine called hepatitis B immune globulin. And your newborn baby should get hepatitis B immune globulin and the hepatitis B vaccine in the first 12 hours of birth. If you don't know your HBV status, your baby should get the hepatitis B vaccine in the first 12 hours of birth. If you are negative for HBV, your baby should be vaccinated before leaving the hospital.

Premature infants weighing less than 4.5 pounds (2,000 grams) born to people with negative HBV should have their first vaccine dose delayed until 1 month after birth or leaving the hospital. All babies should complete the hepatitis B vaccine series to be fully protected against hepatitis B infection.

A person who has HIV and is pregnant has a 1 in 4 chance of infecting their baby. According to the National Institutes of Health, HIV can be passed to a baby during pregnancy, labor, and birth, or by breastfeeding. This makes up nearly all AIDS cases in children in the United States.

AIDS is caused by HIV. This virus kills or harms cells of the immune system. Over time it destroys the body's ability to fight infections and certain cancers. The term AIDS is used for the most advanced stages of an HIV infection. HIV is spread most often by sexual contact with an infected partner. HIV may also be spread through contact with infected blood. This happens mostly by sharing needles, syringes, or drug use equipment with someone who has the virus.

Some people may develop a flu-like illness within a month or two after exposure to the HIV virus. But many people don't have any symptoms at all when they first get infected. Lasting or severe symptoms may not show up for 10 years or more after HIV first enters the body in adults. Or they may show up within 2 years in children born with an HIV infection.

The American College of Obstetricians and Gynecologists advises HIV testing of all pregnancies. Prenatal care for people with HIV that includes HIV counseling, testing, and treatment saves lives and resources. Current advice is for people who are HIV-positive to take medicines during pregnancy and during labor. Blood tests are also done to check the amount of virus. Newborn babies born to HIV-positive people may also get medicine. Studies have found that giving someone antiretroviral medicines during pregnancy, labor, and birth can lower the chance of passing the virus to the baby. This reduction is from 25% to less than 2%. Since the CDC began advising routine HIV screening for all pregnancies in 1995, the estimated numbers of people passing HIV to their children has dropped by about 85%. Cesarean delivery is often advised for those who are HIV-positive and have a high level of the virus. Because breast milk contains the virus, people who are HIV positive should not breastfeed their babies. Studies show that breastfeeding increases the risk for spreading the virus.

Genital herpes can be spread to your baby during birth if you have an active infection at that time. Herpes is caused by the herpes simplex virus (HSV). Herpes infections can cause blisters and ulcers on the mouth or face (oral herpes), or in the genital area (genital herpes). HSV is a life-long infection. Symptoms of HSV may include painful blisters or open sores in the genital area. A tingling or burning feeling in the legs, buttocks, or genital region may happen first. The herpes sores often go away in a few weeks. But the virus stays in the body, and the lesions may return from time to time.

It's important not to get herpes during pregnancy. A first episode during pregnancy raises the risk of passing it to your newborn. You may be treated with an antiviral medicine if the infection is severe. Genital herpes can cause a possibly deadly infection in your baby if you have active genital herpes (shedding the virus) at the time of birth. Cesarean section is often advised for active genital herpes. Fortunately, infection of a baby is rare among people with genital herpes infection.

Protection from genital herpes includes not having sex when you have symptoms and always using latex condoms between outbreaks.

The Zika virus is spread mainly by infected mosquitoes. You can also get the Zika virus by having unprotected sex with someone who has the Zika virus. Babies who are infected before birth can have birth defects, such as microcephaly. This is when the baby's head and brain are smaller than expected when compared to babies of the same sex and age. It may also cause other birth defects that affect the brain.

Don't travel to places with the risk of the Zika virus while you are pregnant. Use condoms with a partner who has the Zika virus or who has traveled to places with it. If you have to travel, talk with your doctor about ways to prevent the spread of the virus.