A high-risk pregnancy is one where the mother, the baby, or both face a greater chance of health problems during pregnancy or delivery than in a typical pregnancy. The label doesn’t mean something will go wrong. It means your medical team will monitor you more closely and may adjust your care plan to catch and manage complications early. Several factors can place a pregnancy in this category, from chronic health conditions and maternal age to issues that develop during the pregnancy itself.
Conditions That Existed Before Pregnancy
Chronic health problems are one of the most common reasons a pregnancy is classified as high risk. High blood pressure tops the list because it can lead to serious complications for both mother and baby, including preeclampsia, stroke, placental abruption (where the placenta separates from the uterine wall), preterm delivery before 37 weeks, and low birth weight under 5 pounds 8 ounces. If you had high blood pressure before becoming pregnant, your provider will track it throughout pregnancy and adjust treatment to keep it in a safe range.
Diabetes, kidney disease, thyroid disorders, and autoimmune conditions like lupus or multiple sclerosis also raise risk. Lupus in particular increases the chance of developing preeclampsia. Polycystic ovary syndrome (PCOS), HIV, and obesity each carry their own set of potential complications. Obesity raises the likelihood of needing a C-section and of the baby being larger than average at birth, which can complicate delivery and increase recovery time for the mother.
How Maternal Age Affects Risk
Age at both ends of the spectrum matters. Teen pregnancies carry higher rates of certain complications, while first-time pregnancy after age 35 is one of the most well-studied risk factors. Women 35 and older are two to four times more likely to have chronic high blood pressure and nearly twice as likely to have type 2 diabetes compared with women aged 25 to 29. After 40, the risk of gestational diabetes is two to three times higher than in younger pregnancies.
Older maternal age also increases the chance of chromosomal differences in the baby, which is why genetic screening and diagnostic testing are routinely offered to women in this age group. None of this means a healthy pregnancy at 35 or 40 is unlikely. It means the odds of certain complications rise enough that closer monitoring makes a real difference in outcomes.
Complications That Develop During Pregnancy
Some high-risk factors don’t exist until the pregnancy itself creates them. Gestational diabetes, for example, develops when the body can’t produce enough insulin to handle the metabolic demands of pregnancy. It usually appears in the second or third trimester and is managed through diet, exercise, and sometimes medication.
Preeclampsia is another pregnancy-specific condition, defined by a blood pressure reading of 140/90 mm Hg or higher along with signs of organ stress, often detected through protein in the urine or abnormal blood work. It can progress to eclampsia, which involves seizures and is a medical emergency. Preeclampsia is more common in first pregnancies, in women over 35, and in those with pre-existing high blood pressure or lupus.
Carrying twins, triplets, or more automatically places a pregnancy in the high-risk category. Multiple gestations increase the strain on the mother’s body and raise the likelihood of preterm labor, gestational diabetes, and preeclampsia. A history of preterm birth in a previous pregnancy also elevates risk for subsequent pregnancies.
Placental Problems
The placenta is the organ that delivers oxygen and nutrients to the baby, and problems with its position or attachment can create serious complications. Placenta previa occurs when the placenta covers part or all of the cervix, which can cause heavy bleeding. Placenta accreta spectrum is a condition where the placenta grows too deeply into the uterine wall and doesn’t detach normally after delivery. This can lead to severe, sometimes life-threatening hemorrhage that requires blood transfusion.
When placenta accreta is suspected, delivery is typically planned in advance at a hospital with specialized surgical teams, blood bank access, and critical care resources. These cases often require a C-section, and in some situations removal of the uterus is the safest approach. The key factor in outcomes is early detection and planning, which is why imaging and monitoring are so important in high-risk pregnancies.
Lifestyle Factors That Increase Risk
Alcohol, tobacco, and drug use during pregnancy, including marijuana, all raise the chance of complications. These substances can affect fetal development, increase the risk of preterm birth, and contribute to low birth weight. If you use any of these, your provider can help you find safe ways to stop or reduce use during pregnancy. Being honest about substance use allows your care team to monitor for specific risks and intervene early if needed.
What High-Risk Care Looks Like
A high-risk pregnancy typically means more frequent prenatal visits, additional testing, and sometimes referral to a maternal-fetal medicine specialist. These are obstetricians with advanced training in managing complex pregnancies. They work alongside your regular OB or midwife rather than replacing them.
The extra monitoring can include specialized ultrasounds (2D, 3D, or 4D imaging), fetal echocardiograms to check the baby’s heart for abnormalities, and screening for preterm birth risk. Depending on your specific situation, you may also be offered amniocentesis, which tests amniotic fluid for genetic conditions, or chorionic villus sampling, which tests a small piece of placental tissue. If there’s a risk of preterm delivery due to a weakened cervix, a procedure called cervical cerclage can be used to hold the cervix closed.
For most women, high-risk care means more appointments and a longer list of things being tracked, but the day-to-day experience of pregnancy doesn’t change dramatically. The goal is to identify problems early enough that they can be managed before they become dangerous. Many women with high-risk pregnancies deliver healthy babies at or near full term, particularly when complications are caught and treated promptly.
When Multiple Risk Factors Overlap
Risk factors rarely exist in isolation. A woman over 35 with obesity and gestational diabetes faces a different level of monitoring than someone whose only risk factor is age. The more factors that overlap, the more tailored the care plan becomes. Your provider weighs the combination of risks to decide how often you need to be seen, which tests to run, and whether specialist involvement is warranted. This is why two women who are both labeled “high risk” can have very different pregnancy experiences. The term covers a wide spectrum, from mildly elevated risk that requires a few extra blood draws to complex situations involving multiple specialists and early delivery planning.