Plasma makes up a portion of the blood that contains electrolytes and proteins to support clotting, blood pressure, and cellular function.

Some 6,500 units of plasma are needed for transfusions each day in the United States — it’s a biological fluid in great demand. And if you have donated blood in the past, the process for donating plasma isn’t much different.

But can you donate plasma when you’re pregnant? Here’s what you need to know about plasma donation during and after pregnancy, what the issues are, and some other ways you can support your community through donation.

Unfortunately, pregnant people cannot donate plasma.

First, there’s not much research about how donating plasma might affect a growing fetus. Some sources suggest that donating plasma (or blood) can put you at a higher risk of anemia.

While that’s never a good thing, this is especially concerning during pregnancy. That said, the main reason not to donate plasma during pregnancy is because it may be dangerous for the recipient.

During pregnancy, blood cells from the baby — which contain different genetic information from your own — mix with your blood through the placenta. As a result, your body releases a protein called human leukocyte antigens (HLA). These antigens help suppress your immune system enough to allow the presence of “foreign” material in your body.

During a transfusion to another person, HLAs can cause a life threatening complication called transfusion-related acute lung injury, or TRALI. Even a small amount of plasma may cause TRALI in rare cases.

For this reason, people cannot donate plasma if:

  • they were recently pregnant
  • they are currently pregnant
  • they test positive for HLA antibodies in their blood for some other reason

If you have ever been pregnant, many donation centers will require HLA tests — regardless of how long it’s been since your pregnancy.

Is HLA harmful to me?

While HLA antibodies can be harmful to transfusion recipients, they are not harmful to you.

Having HLA antibodies does not mean you or your baby are sick. It does not mean you or your baby will get sick, either. It’s simply part of how the body responds to pregnancy.

In other words: If your body is the body making the antibodies, you cannot be harmed by them.

You may be able to donate plasma while breastfeeding.

All plasma donation centers are different and may have different guidelines for donation. So, be sure to check with the one near you with questions over eligibility, as you may not see this situation detailed on their website.

However, the World Health Organization (WHO) advises against donation while you’re still nursing.

This is because donating plasma may affect breastfeeding. It can cause certain side effects, like lowering the levels of electrolytes in your body and dehydration. These issues may impact your milk supply.

Be sure to consult with your doctor about whether you should donate, how often you can safely donate, and the best way to hydrate and restore electrolytes after donation.

When you go to your donation appointment, tell the staff you’ve recently had a baby and that you are nursing. You will most likely need to supply a small sample of your blood for testing to see whether HLA antibodies are still present.

The WHO advises waiting at least 9 months after giving birth to donate blood or plasma.

Again, all donation centers are different, but you must also be in generally good health and meet other eligibility requirements that may include:

  • being between 18 and 75 years old
  • weighing more than 110 pounds
  • having no tattoos or piercings in the last 6 months

If you’ve had a miscarriage or termination of pregnancy (some donation centers specify before 12 weeks), you may be eligible to donate after just 6 weeks. And some centers may accept plasma donations after full-term pregnancies sooner as well.

In all cases, eligibility depends on the center you visit and their individual rules and guidelines.

After pregnancy — nursing or not — you will be screened for HLA antibodies before donation to ensure that your plasma is safe for use.

If donating plasma isn’t currently an option, there are other ways you can help your community through the donation of other biological materials.

Cord blood donation

After delivery, your doctor usually tests your placenta and umbilical cord before disposing them. If you request, the blood (cord blood) inside these products of conception can be collected and donated for use in treating more than 70 conditions, like leukemia, lymphoma, and sickle cell disease.

Unlike storage at family and private cord blood banks, there is no cost to donate blood to public banks. More information about cord blood donation can be found at Be the Match.

Breast milk donation

Some people choose to donate their excess breast milk to donor banks. The milk is used for babies in hospital settings or outpatient families in need. For example, premature infants may drink as little as 1 ounce per feeding, but donor milk may decrease the risk of health issues like necrotizing enterocolitis.

The Human Milk Banking Association of North America explains that donor milk is collected from qualifying donors, screened, pooled, and then pasteurized so it is safe for use. Milk banks take care of the costs of screening donors and shipping milk.

Contact a milk bank near you for more information about becoming a donor.

While you cannot donate plasma during pregnancy or soon after, there are other ways you can help your community through donation. Be sure to get the green light to donate plasma once your blood is free from HLA antibodies, which is usually within the year after you deliver your baby.

Your local plasma donation center is your best resource for eligibility requirements. And if you have further questions about the safety of plasma donation, contact your doctor.