Most babies settle into a head-down position by the end of pregnancy, but about 3 to 4% remain breech at full term, meaning their bottom or feet are positioned to come out first. In many cases, there’s no single clear reason. Breech presentation results from a combination of factors related to the shape of your uterus, how much room your baby has to move, and sometimes the baby’s own characteristics.
Breech Is Common Earlier in Pregnancy
If you’re reading this before 36 or 37 weeks, there’s a good chance your baby will still turn on their own. Between 22 and 25% of babies are breech before 28 weeks, simply because they’re small enough to float and rotate freely. By 32 weeks, that number drops to 7 to 15%. By full term, only 3 to 4% remain breech. Your baby has the most room to flip during the second trimester and early third trimester, and many do so without you even noticing.
The later you get in pregnancy, the less space your baby has, and the harder it becomes for them to make that final turn. A baby who is still breech at 36 weeks is less likely to flip spontaneously, which is why your provider will start discussing options around that time.
Factors That Make Breech More Likely
Researchers have identified several things that contribute to breech presentation, though in plenty of cases none of these apply and the position is simply a matter of chance.
Uterine shape and space. Your uterus isn’t always a perfectly symmetrical space. Some people have a uterus with an unusual shape from birth, such as one that’s partially divided or heart-shaped. These structural differences can limit how much room the baby has to rotate. Uterine fibroids, which are noncancerous growths in the uterine wall, can also take up space and make it harder for the baby to settle head-down.
Placenta location. When the placenta attaches low in the uterus (a condition called placenta previa), it physically blocks the lower part of the uterine cavity. The baby’s head can’t engage in the pelvis because the placenta is in the way, making breech positioning more likely.
Amniotic fluid levels. Too much amniotic fluid gives the baby extra room to keep changing positions late into pregnancy, which can mean they don’t settle head-down when they otherwise would. Too little fluid creates the opposite problem: there isn’t enough cushioning for the baby to make the big rotation needed to go head-down.
Multiple pregnancies. Carrying twins or more means each baby has less room to maneuver. It’s common for at least one twin to be breech at delivery.
Previous pregnancies. If you’ve been pregnant before, your uterine muscles are more relaxed, which can actually give the baby more room to stay in a non-head-down position. Paradoxically, first-time mothers also have a slightly elevated risk, possibly because the uterine muscles are very tight and may restrict the baby’s ability to rotate.
Baby-related factors. Certain fetal conditions, particularly those affecting muscle tone or movement, can prevent the baby from turning normally. Premature babies are more often breech simply because they haven’t yet reached the gestational age when most babies flip. A baby who is especially small for their gestational age may also be more likely to remain breech.
Recurrence in Future Pregnancies
If you’ve had a breech baby before, you’re more likely to have another one. Research shows the odds of a repeat breech are about four times higher after one breech delivery compared to someone who has never had one. After three breech deliveries, the odds jump dramatically, roughly 28 times higher. This pattern suggests that some of the causes, whether genetic or related to the persistent shape of a person’s uterus, tend to recur from pregnancy to pregnancy.
How Breech Is Detected
Your provider checks your baby’s position during routine prenatal visits by feeling your abdomen, a technique called Leopold’s maneuvers. They’re looking for the hard, round shape of the baby’s head near your pelvis. But this method isn’t perfect. Studies have found that roughly 8% of breech presentations go undetected until labor begins, even when providers combine abdominal palpation with vaginal exams. Ultrasound is far more reliable, and many clinics now use bedside ultrasound to confirm position in the final weeks of pregnancy.
Turning a Breech Baby
If your baby is still breech around 36 to 37 weeks, your provider will likely discuss a procedure called external cephalic version, or ECV. During an ECV, a doctor places their hands on your abdomen and manually guides the baby into a head-down position using firm, steady pressure. It typically happens in a hospital setting, and you’ll usually be given medication to relax your uterine muscles.
The average success rate is about 58%, so it works a little more than half the time. When spinal or epidural anesthesia is used during the procedure, success rates climb to nearly 60%, up from about 38% without it. Successfully turning the baby reduces the chance of needing a cesarean delivery by about 43%. ECV is only performed in settings where a cesarean can be done quickly, just in case complications arise during the attempt.
You may also come across suggestions like positioning exercises (hands and knees, pelvic tilts) or techniques like moxibustion. While some people find these worth trying, the evidence behind them is limited compared to ECV.
What Happens if Your Baby Stays Breech
If ECV doesn’t work or isn’t an option, the main decision is how your baby will be delivered. For most people with a breech baby at term, a planned cesarean delivery is recommended. This is largely because fewer providers are trained in vaginal breech delivery, making it difficult to find experienced support for that option.
Vaginal breech delivery is still considered reasonable in specific circumstances. The typical criteria include being past 37 weeks, the baby being in a frank breech position (bottom down, legs folded up toward the head), an estimated weight between about 5.5 and 8.8 pounds, no fetal abnormalities visible on ultrasound, and adequate pelvic size. These deliveries follow strict protocols, and labor must progress normally without the use of medications to speed contractions.
The decision between cesarean and vaginal breech delivery depends on your specific situation, your preferences, and the experience of your care team. If vaginal breech birth is something you’re interested in, it’s worth asking your provider directly about their experience and whether your hospital has a protocol for it.