Anemia, Iron & Blood Health

Sickle Cell Trait and Sickle Cell Disease in Pregnancy: What to Know

By the Find Her Doctor editorial team · Updated November 1, 2026 · 5 min read

Sickle cell trait means you carry one sickle cell gene. It usually causes no health problems and rarely affects pregnancy, but if your partner also carries a sickle gene, your baby could have sickle cell disease. Sickle cell disease itself makes pregnancy higher risk and calls for care from a maternal-fetal medicine specialist and a hematologist.

Many people find out they carry the trait for the first time from prenatal blood work, and the phone call can be scary. Here's what it means and what to ask next.

Trait vs. disease: what's the difference?

Hemoglobin is the protein in red blood cells that carries oxygen. You inherit one hemoglobin gene from each parent.

Sickle cell genes are most common in people whose ancestors came from sub-Saharan Africa, the Caribbean, Central and South America, the Mediterranean, the Middle East and India. In a city as diverse as New York, that's a lot of families, and many people don't know their status.

Carrier screening, step by step

Step 1: The right test. ACOG recommends a complete blood count (CBC) for every pregnant person. A hemoglobin analysis, such as hemoglobin electrophoresis, is recommended if your ancestry puts you at higher risk, or if your CBC shows small red cells without iron deficiency. A CBC alone can't detect sickle cell trait. If you're not sure which test you had, ask.

Step 2: Test your partner. If you carry a sickle gene or another hemoglobin variant, your partner should be tested too, as quickly as possible. Timing matters, because some options during pregnancy have windows.

Step 3: If you're both carriers. In each pregnancy:

• 1 in 4 chance the baby has sickle cell disease
• 1 in 2 chance the baby has sickle cell trait
• 1 in 4 chance the baby has neither

Those odds reset every pregnancy; having one child with the disease doesn't change the chances for the next.

Step 4: Genetic counseling. A counselor can explain options, including prenatal diagnostic testing (CVS or amniocentesis) and, for people planning a pregnancy, IVF with preimplantation genetic testing.

Every baby born in New York, as in every U.S. state, is screened for sickle cell disease at birth as part of newborn screening.

Sickle cell trait in pregnancy

Most people with trait have no extra pregnancy complications. ACOG notes trait is associated with a higher rate of urinary tract infections and bacteria in the urine, so your provider may check your urine during pregnancy. Call right away for burning with urination, fever or back pain.

Sickle cell disease in pregnancy

People with sickle cell disease can and do have healthy pregnancies, but risks are higher. Pregnancy can make pain crises more frequent, and sickle cell disease is associated with higher rates of:

• Preeclampsia
• Blood clots (see blood clots in pregnancy and postpartum)
• Infections, including urinary tract infections and pneumonia
• Acute chest syndrome
• Worsening anemia
• Preterm birth
• Babies who are small for gestational age
• Pregnancy loss

Before pregnancy

A preconception visit is especially valuable. Your team may:

• Review your medicines, since some, like hydroxyurea, are usually stopped or changed before or during pregnancy
• Check your kidney, heart, lung and eye health
• Update vaccines
• Check for antibodies if you've had transfusions
• Recommend folic acid, often more than a standard prenatal vitamin has (your clinician will tell you how much)

During pregnancy

Typical care includes:

• Co-management by maternal-fetal medicine and hematology
• More frequent visits and blood tests
• Ultrasounds to track your baby's growth
• A written pain plan for crises, so you're not explaining your history from scratch in the ER
• A discussion of whether transfusions are needed
• Planning to prevent blood clots, especially after delivery

Iron supplements aren't automatically right for people with sickle cell disease. Some people have plenty of iron, especially after transfusions, so testing should guide whether you take it.

A tip many patients share: keep a one-page summary on your phone (your genotype, baseline hemoglobin, usual pain medicines, hematologist's contact) and show it at any new hospital or urgent care.

After delivery

The weeks after birth carry higher risk of pain crises, infection and blood clots. Plan close follow-up with your hematologist before you go into labor.

Trait or iron deficiency?

Some hemoglobin conditions, especially thalassemia trait, cause small red blood cells that can look like iron deficiency on a CBC. If your red cells are small but your iron and ferritin are normal, ask about a hemoglobin analysis. See anemia in pregnancy.

Questions to ask at a carrier screening visit

• Was my hemoglobin tested with electrophoresis or a similar test, or just a CBC?
• Do I carry sickle cell trait, thalassemia trait or another hemoglobin variant?
• Should my partner be tested, and how fast can that happen?
• If we're both carriers, what are our options during this pregnancy?
• Can I meet with a genetic counselor?
• What will my baby's newborn screening show?

Already know you have trait? Tell each new provider, since records don't always follow you.

Breastfeeding and sickle cell disease

Breastfeeding is usually possible with sickle cell disease. Staying hydrated and rested helps, since dehydration can contribute to pain crises. Ask your hematologist which medicines are compatible with breastfeeding, and when it's safe to restart anything you stopped during pregnancy.

When to call your provider

If you have sickle cell disease and are pregnant, call your care team or go to labor and delivery right away for:

• A pain crisis you can't manage at home
• Fever
• Chest pain or trouble breathing
• Severe headache, weakness or vision changes
• Swelling or pain in one leg
• Your baby moving less

With sickle cell trait, call for signs of a urinary tract infection.

Haven't been tested? Ask your OB/GYN about carrier screening, or search for a provider near you, such as OB/GYNs in the Bronx.

Seeing a hematologist in New York

A hematologist should be involved throughout pregnancy. Many New York academic medical centers have dedicated sickle cell programs, and community hematology practices also provide care. Premier Hematology & Oncology, which sponsors our professional resources, offers hematology consults at centers across NYC, Long Island and the Hudson Valley. Clinicians can find referral details on our hematology partners page.

Frequently asked questions

Sources

• ACOG — Practice Bulletin 78: Hemoglobinopathies in Pregnancy
• ACOG — Committee Opinion 691: Carrier Screening for Genetic Conditions
• CDC — Sickle Cell Trait
• CDC — Data and Statistics on Sickle Cell Disease
• NHLBI — Sickle Cell Disease

This article is for general education and is not medical advice. It does not replace an evaluation by a licensed clinician who knows your history. If you think you have a medical emergency, call 911.