Most guidelines recommend waiting at least 60 seconds after birth to clamp the umbilical cord, and many practitioners wait until the cord stops pulsing entirely, which can take anywhere from one to five minutes. The World Health Organization recommends clamping no earlier than one minute after birth, while current resuscitation guidelines from the American Heart Association also support deferring clamping for at least 60 seconds for both term and preterm infants.
What Happens During That Wait
When the cord stays intact after delivery, blood continues flowing from the placenta into the baby. This “placental transfusion” increases the newborn’s blood volume by roughly 20 to 30 percent and boosts red blood cell volume by about 50 percent. Most of this transfer happens in the first one to three minutes, which is why guidelines center on that window.
The extra blood isn’t just volume. It carries iron that the baby will use over the coming months. A randomized controlled trial published in The BMJ found that infants whose cords were clamped later had 45 percent higher ferritin (the body’s stored iron) at four months compared to infants whose cords were clamped right away. Iron deficiency dropped dramatically too: less than 1 percent of the delayed group was iron deficient at four months versus nearly 6 percent of the early-clamping group. A separate trial in Mexico found a similar pattern at six months, with 34 percent higher ferritin in the delayed group.
The Minimum vs. the Maximum
There’s a meaningful difference between “at least 60 seconds” and “until the cord stops pulsing.” The WHO defines early clamping as anything in the first 60 seconds, and late clamping as anything beyond one minute or when pulsation stops. In practice, many birth teams wait two to three minutes or simply let the cord go white and limp, which signals that the transfer is essentially complete.
There’s no hard upper limit that applies to every situation. Some families practicing “lotus birth” leave the cord entirely uncut until it dries and separates naturally over days, though this is uncommon and carries its own infection considerations. For most hospital and birth center deliveries, the practical range is one to five minutes.
When the Cord Needs to Be Cut Sooner
Certain situations call for faster clamping. If a baby needs significant resuscitation at birth, the team may need to move the infant to a warming station with specialized equipment. The 2025 American Heart Association guidelines note that basic steps like drying, stimulating breathing, and clearing the airway can all be done while the cord is still attached. But for infants who need more advanced support, the evidence on ideal timing is still limited, and the medical team will make a judgment call based on the baby’s condition.
Placental abruption, significant bleeding, or concerns about the parent’s stability can also prompt earlier clamping. These are rare, and in most deliveries, waiting poses no added risk to parent or baby.
The Jaundice Question
The most common concern about delayed clamping is jaundice, the yellowish skin tint caused by the breakdown of extra red blood cells. A WHO review of seven trials covering over 2,300 infants found that clinical jaundice rates were not significantly different between early and late clamping groups. However, the number of infants who needed phototherapy (light treatment for jaundice) was modestly higher in the delayed clamping group. The difference is small enough that major medical organizations still recommend delayed clamping as the default, viewing the iron and blood volume benefits as outweighing a slightly increased chance of needing a day or two under phototherapy lights.
Delayed Clamping During a C-Section
Delayed clamping is possible during a cesarean delivery, and most guidelines support it in that setting too. The logistics are slightly different because the surgical team is managing an open incision, but a one-to-two-minute delay is routinely practiced. The baby is typically held at or slightly below the level of the placenta while the cord continues to pulse. If you’re planning a cesarean and want delayed clamping, it’s worth discussing with your surgical team beforehand so they can plan accordingly.
If You’re Planning to Bank Cord Blood
Delayed clamping and cord blood banking can coexist, but there are trade-offs. A study of 2,000 cord blood collections found that a one-minute delay reduced the total volume collected by 6 to 21 percent and the white blood cell count by 9 to 31 percent. A separate study from a public cord blood bank found that even with delayed clamping, 60 percent of collections still met the high threshold for usable cell counts.
The practical takeaway: a 30-to-60-second delay typically reduces collection volume by around 10 percent, which still leaves enough for banking in most cases. Waiting much longer than a minute can allow the blood in the cord to clot, potentially making collection impossible. If cord blood banking is a priority for your family, a shorter delay of about one minute offers a reasonable balance between the baby’s iron stores and a viable collection.
Cord Milking as an Alternative
When delayed clamping isn’t practical, some providers use a technique called cord milking, where they gently squeeze blood from the cord toward the baby two to four times before cutting. This delivers a portion of the placental blood in seconds rather than minutes. It’s sometimes used in preterm deliveries or emergencies where a longer wait isn’t safe, though the research on its safety and effectiveness compared to delayed clamping is still evolving, particularly for very premature infants.