Pregnancy is a period of up to 41 weeks in which a fetus develops inside a woman’s womb. NICHD conducts and supports research and training to help promote healthy pregnancies, with a focus on the important events that occur before, during, and after pregnancy.
General Information
Pregnancy is the period during which a fetus develops inside a woman’s womb. Pregnancy usually lasts about 40 weeks, or just over 9 months, as measured from last menstrual period to delivery.
A primary sign of pregnancy is missing 1, 2, or more menstrual periods in a row, but many women experience other symptoms of pregnancy, such as fatigue or nausea, before they miss a period.
Home pregnancy tests are often the first way women learn they are pregnant. If a home test is positive, a woman should call a health care provider to make an appointment and confirm the test.
Early and regular prenatal care, health care during pregnancy, improves the chances of a healthy pregnancy and birth.
Common complications of pregnancy include high blood pressure, gestational diabetes, infections, preeclampsia, preterm labor, pregnancy loss, and stillbirth.
A high-risk pregnancy is one that threatens the health or life of the mother or her fetus. High-risk pregnancies often require specialized care from specially trained providers.
Infections that can affect the health of the pregnant woman, the pregnancy, and the baby after delivery can include chlamydia, gonorrhea, HIV/AIDS, human papillomavirus, syphilis, and Zika.
Labor and delivery are the processes by which the fetus and the placenta leave the uterus. Delivery can occur vaginally (through the vagina) or by a cesarean or surgical delivery.
A cesarean delivery is a surgical procedure in which a fetus is delivered from the womb through an incision in the mother’s abdomen and uterus.
“Postpartum depression” is not just depression and is not just postpartum. Women can experience depression, anxiety, and other mental health issues during pregnancy and after the baby is born.
Research
NICHD investigates pregnancy and complications of pregnancy.
Find a Study
NICHD conducts and supports a variety of clinical research projects related to pregnancy and complications of pregnancy.
More Information
Find answers to other common questions about pregnancy, such as how much weight a woman should gain during pregnancy and what challenges pregnant women with disabilities face.