Gestational diabetes occurs when a woman who didn't have diabetes before pregnancy develops the condition during pregnancy.

Normally, the body digests parts of your food into a sugar called glucose. Glucose is your body's main source of energy. After digestion, the glucose moves into your blood to give your body energy.

To get the glucose out of your blood and into the cells of your body, your pancreas makes a hormone called insulin. In gestational diabetes, hormonal changes from pregnancy cause the body to either not make enough insulin, or not use it normally. Instead, the glucose builds up in your blood, causing diabetes, otherwise known as high blood sugar.

Managing gestational diabetes, by following a treatment plan outlined by a health care provider, is the best way to reduce or prevent problems associated with high blood sugar during pregnancy. If not controlled, it can lead to high blood pressure from preeclampsia and having a large infant, which increases the risk for cesarean delivery

Infections, including some sexually transmitted infections (STIs), may occur during pregnancy and/or delivery and may lead to complications for the pregnant woman, the pregnancy, and the baby after delivery. Some infections can pass from mother to infant during delivery when the infant passes through the birth canal; other infections can infect a fetus during the pregnancy.1 Many of these infections can be prevented or treated with appropriate pre-pregnancy, prenatal, and postpartum follow-up care.

Some infections in pregnancy can cause or contribute to: Pregnancy loss/miscarriage (before 20 weeks of pregnancy), ectopic pregnancy (when the embryo implants outside of the uterus, usually in a fallopian tube), preterm labor and delivery (before 37 completed weeks of pregnancy), low birth weight, birth defects, including blindness, deafness, bone deformities, and intellectual disability, stillbirth (at or after 20 weeks of pregnancy), illness in the newborn period (first month of life), newborn death, maternal health complications

If you are planning to get pregnant, talk with your health care provider about getting vaccines and vaccine boosters for chicken pox (also called varicella) and rubella (also called German measles) before you conceive. You can also get some vaccines, such as the flu shot, while you are pregnant. If you know you have an infection, such as an STI, talk with your health care provider about it before you conceive to increase your chances of a healthy pregnancy.

Early prenatal testing for STIs and other infections can determine if the infection can be cured with drug treatment. Or, if you know you have an infection, tell your pregnancy health care provider about it as early as possible in your pregnancy. Early treatment decreases the risk to the fetus and infant.2 Even if the infection can't be cured, you and your health care provider can take steps to protect your health and your infant's health.

Preeclampsia is a serious medical condition that can lead to preterm delivery and death. Its cause is unknown, but some women are at an increased risk. Risk factors include:

First pregnancies, preeclampsia in a previous pregnancy, existing conditions such as high blood pressure, diabetes, kidney disease, and systemic lupus erythematosus, being 35 years of age or older, carrying two or more fetuses, obesity

High blood pressure, also called hypertension, occurs when arteries carrying blood from the heart to the body organs are narrowed. This causes pressure to increase in the arteries. In pregnancy, this can make it hard for blood to reach the placenta, which provides nutrients and oxygen to the fetus.1 Reduced blood flow can slow the growth of the fetus and place the mother at greater risk of preterm labor and preeclampsia.

Women who have high blood pressure before they get pregnant will continue to have to monitor and control it, with medications if necessary, throughout their pregnancy. High blood pressure that develops in pregnancy is called gestational hypertension. Typically, gestational hypertension occurs during the second half of pregnancy and goes away after delivery.

Research shows that as many as 13% of U.S. women reported frequent symptoms of depression after childbirth, and that anxiety co-occurs in up to 43% of depressed pregnant and postpartum women, making pregnancy-related depression and anxiety among the more common pregnancy complications. These medical conditions can have significant effects on the health of the mother and her child. But the good news is that these are treatable medical conditions. The NICHD-led Moms’ Mental Health Matters initiative is designed to educate families and health care providers about who is at risk for depression and anxiety during and after pregnancy, the signs of these problems, and how to get help.

Miscarriage is the term used to describe a pregnancy loss from natural causes before 20 weeks. Signs can include vaginal spotting or bleeding, cramping, or fluid or tissue passing from the vagina. However, bleeding from the vagina does not mean that a miscarriage will happen or is happening.9 Women experiencing this sign at any point in their pregnancy should contact their health care provider.