Many expecting families are handed a clipboard and a brochure asking for their baby’s cord blood, with little explanation of who wants it, why, or what the alternatives are. It’s a point of confusion even for families who have been through delivery more than once.

The requests come from different directions. Private banks market collection kits to expectant parents as an “insurance policy” for their child. Some hospitals ask families to donate the placenta and cord tissue for research. And if nothing is collected or donated, the majority of the time, the tissue goes to the hospital incinerator.

IMA Senior Fellow in OB-GYN Dr. Kimberly Biss made this video to answer two questions she hears from a lot of parents: should cord clamping be delayed, and should they collect their baby’s cord blood? She answers both plainly, starting with how long to wait before the cord is clamped.

We’re sharing her answers here, along with her slides, so the next time you’re handed that form, you’ll know what it’s asking.

Dr. Kimberly Biss presentation slides: Umbilical Cord Stem Cell Collection

Download Dr. Biss’s presentation slides (PDF)

In This Post

  1. How Long Should We Wait Before the Cord Is Clamped?
  2. What Does Waiting Do for Our Baby?
  3. When Does the Cord Need to Be Clamped Right Away?
  4. What Can Cord Blood Treat?
  5. Will Our Baby Ever Use Their Own Banked Cord Blood?
  6. What’s the Difference Between Private and Public Banking?
  7. How Is Cord Blood Collected?
  8. What Happens to the Placenta If We Don’t Bank or Donate?
  9. Research and Sources

1. How Long Should We Wait Before the Cord Is Clamped?

The first moments after birth move fast, and you want to get this right for your baby. Dr. Biss’s guidance is clear: for babies born at term, 37 weeks or later, the cord should wait at least 30 seconds before it’s clamped. For babies born before 37 weeks, it’s at least 60 seconds, if not longer. For most babies, she recommends 30 to 60 seconds.

If you’ve read about families waiting much longer, you’re not imagining it. The World Health Organization recommends 2 to 3 minutes. Dr. Biss says a 2023 meta-analysis doesn’t support that recommendation and found no benefit to waiting longer than 60 seconds. For preterm babies, her slides note that more research is needed.

Then there’s cord milking, where the practitioner pushes the cord’s blood toward the baby after delivery. Here, more isn’t better. Dr. Biss says it isn’t recommended:

“Studies have shown that that actually may cause too much blood to go to the baby and could potentially lead to neonatal jaundice.” — Dr. Kimberly Biss

2. What Does Waiting Do for Our Baby?

A lot! Those seconds let your baby take in blood that would otherwise stay behind in the placenta:

“There’s a lot of blood in the placenta after the baby is delivered, and you’re basically giving an autotransfusion to the baby.” — Dr. Kimberly Biss

Her slides put the boost to your baby’s blood volume at as much as 30%. For a baby born at term, that means:

  • Less need for a blood transfusion while your baby is in the hospital
  • Lower odds of developing iron deficiency anemia over the first 3 to 6 months of life

For a baby born early, there’s even more to gain. On top of those benefits, waiting means:

  • Fewer intraventricular hemorrhages, or brain bleeds
  • Less necrotizing enterocolitis, an intestinal inflammatory problem that can lead preterm babies to need surgery

3. When Does the Cord Need to Be Clamped Right Away?

When you or your baby needs care that can’t wait. Dr. Biss names two situations:

  • Your baby needs resuscitation or other care that the nurse practitioner, neonatologist, or pediatrician can’t provide on mom’s belly
  • Mom is bleeding or has another issue that needs emergency attention

If either happens, clamping right away is what lets your care team help.

4. What Can Cord Blood Treat?

Cord blood is real medicine. It contains hematopoietic stem cells, the beginning of the blood cells made in the bone marrow.

Its first success came in 1988 in Paris, when cord blood from a newborn girl essentially cured her 5-year-old brother of a genetic disorder called Fanconi anemia. By Dr. Biss’s count, there have been more than 35,000 transplants worldwide since.

Today, it’s approved for treating a relative or another matched patient with conditions like:

  • Blood cancers, such as leukemias and lymphomas
  • Bone marrow failure
  • Immune deficiencies
  • Inherited metabolic disorders
  • Sickle cell disease and thalassemia

For sickle cell disease, she points to cures:

“There have been successful transplants where people have been cured of sickle cell.” — Dr. Kimberly Biss

As for your own child, most uses for the donor are still being studied, including cerebral palsy in severely preterm babies, type 1 diabetes, and spinal cord injury.

5. Will Our Baby Ever Use Their Own Banked Cord Blood?

If you’re weighing private banking, you’re thinking about the worst case: a serious illness down the road, and whether your child’s own cells could help. That’s a fair thing to worry about, and it’s exactly the worry the private banking pitch speaks to.

When cord blood companies first marketed their kits to OB-GYNs, Dr. Biss says, they sold them as an insurance policy for the child. If the child developed a malignancy later in life and needed a bone marrow transplant, the banked cells would be a perfect match.

The reality is more complicated, and Dr. Biss explains why. The genetics in a child’s own stem cells can be the same genetics that caused the cancer or condition being treated, so there are very few conditions where a child can receive their own cells. Banked cord blood is far more likely to be a match for a sibling or another family member, just as the very first transplant helped a little boy through his sister’s cells.

The numbers bear that out. Published rates of a child using their own sample range from 1 in 400 to 1 in 2,500 over a lifetime, with some as low as 1 in 200,000. Roughly 2 million transplants have been performed worldwide using stem cells from bone marrow, blood, or cord, against a population of billions.

“These are heavily marketed to obstetric patients, but the odds that this sample is ever going to be used is not very high.” — Dr. Kimberly Biss

If someone in your family already has a condition that would respond to a transplant, that’s a different situation. The next question covers it.

6. What’s the Difference Between Private and Public Banking?

The collection is the same. The difference is who the cord blood is for.

Private banks store your baby’s cord blood for your family alone. The big commercial companies, like Cryo-Cell, ViaCord, and Cord Blood Registry (CBR), charge about $2,000 up front plus about $125 to $150 a year for storage, and Dr. Biss notes the likelihood the sample is ever used is low.

Public banks make it available to other patients who could match, including families who can’t afford private banking, and to research. To donate, your hospital needs to partner with a public bank, and you register between 28 and 34 weeks. There are public banks in 19 states, and if yours doesn’t have one, you may be able to donate by mail.

“These banks are opening the opportunity for other people that could match to the samples, and also allow for more potential research for what these stem cells could be used for.” — Dr. Kimberly Biss

Dr. Biss notes that both the American College of Obstetricians and Gynecologists (ACOG) and the American Academy of Pediatrics (AAP) recommend public banking. They advise against banking as an “insurance” policy, but support it when a relative has a known condition that would respond to a transplant.

7. How Is Cord Blood Collected?

Collection is done on the cord, not your baby, and only after the cord is clamped:

“We don’t collect the sample ever when the cord is still attached to the baby.” — Dr. Kimberly Biss

You’ll usually be counseled on banking at your prenatal appointments, and Dr. Biss says OB-GYNs don’t give preference to one company over another. You get the information, and you make the decision.

For private banking, you bring the company’s kit to the delivery room. For public donation, the hospital supplies the equipment. After delivery, blood is drawn from the umbilical vein, where most of the stem cells are, and a sample of mom’s blood is taken too. A courier takes both to the bank, where they’re tested for infections and for matching, and the stem cells are frozen until they’re needed. The bank is looking for 60 cc or more, with enough cells to be considered for transplant.

Her slides, linked above, walk through every step if you want the details.

8. What Happens to the Placenta If We Don’t Bank or Donate?

This is the part many families never hear about, and the default is blunt:

“The majority of the time, the tissue is sent to the hospital incinerator, actually.” — Dr. Kimberly Biss

There are a few exceptions. If your baby has poor Apgar scores or an unexpected NICU stay, or infection is suspected, the placenta may go to pathology, where the findings can help the doctors treating your baby. Some parents sign a hospital form to take it home for encapsulation. And some hospitals ask families to donate the tissue for research.

Whatever you decide, it’s your call to make. Now you know what’s on the table.

9. Research and Sources

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