Fetal Presentation Just Before Birth
Baby Positioned Head-First, Looking Down
In the head-first, face-down position, the baby’s back of the head faces the front of the parent’s body. This is called the occiput anterior position. Most babies move into this posture by the end of pregnancy.
This position lets the smallest part of the baby’s head enter the birth canal first, making labor and delivery smoother. About 95% of babies arrive this way. Some key details of the head-first, face-down position include:
- Type: Cephalic presentation, vertex presentation
- Lie: Longitudinal
- Facing: Anterior (toward mother’s spine)
- Delivery: Most often vaginal
Table: Advantages of Head-First, Face-Down Position
| Feature | Description |
|---|---|
| Easiest for delivery | Fits anatomy of pelvis well |
| Least complications | Lower risk for interventions |
| Best for vaginal birth | Most likely to avoid C-section |
This position lets the head flex, helping the baby move through the pelvis.
Baby Positioned Head-First, Looking Up
Some babies are head-down but looking up, which is called the occiput posterior position. In this position, the back of the baby’s head faces the parent’s back. Deliveries often take longer and may be more uncomfortable because the baby’s head can have trouble moving under the pubic bone. Many babies turn to the face-down side during labor, but some stay face-up.
The health team may help the baby turn by gently reaching inside, a process called manual rotation. Sometimes, special tools like forceps or a vacuum device help with delivery. In a few cases, a C-section is needed if progress is too slow or if other concerns come up.
Table: Features of Head-First, Face-Up Position
| Feature | Description |
|---|---|
| Possible complications | Longer labor, more back pain |
| Interventions may be needed | Manual rotation, forceps, vacuum, or C-section |
| Still can be vaginal birth | Many can still be born without surgery |
Notable Positions
- Left occiput posterior (LOP)
- Right occiput posterior (ROP)
Some babies born in this position need extra monitoring and support.
Buttocks-First with Legs Up (Classic Breech)
In the frank breech position, the baby’s bottom points down towards the birth canal, and the legs are straight up in front of the body with feet near the head. This is the most common breech presentation, seen in about 3% to 4% of babies near delivery.
Many health care professionals try to turn the baby head-down using a procedure called external cephalic version (ECV), where gentle pressure is used on the belly. If ECV does not work or is not recommended, a planned C-section is usually advised, as breech vaginal births carry more risks.
Quick Facts
- Type: Frank breech (knees straight, feet up)
- Complications: Higher risk for umbilical cord prolapse, head entrapment
Table: Frank Breech Position Essentials
| Aspect | Description |
|---|---|
| Most common breech type | Yes |
| External version option | Often tried after 36 weeks |
| Typical delivery method | C-section often planned |
A frank breech position is less likely to bring the feet into the birth canal first, but still needs careful planning, usually with a surgical birth.
Bent Legs (Complete & Incomplete Breech)
Some babies have their buttocks down but legs bent or mixed. Complete breech means the baby’s knees are bent, thighs drawn up, and feet near the buttocks. Incomplete breech (also called footling breech) means one or both legs or feet will come out first.
Footling breech raises the risk of feet or knees entering the birth canal before the rest of the body. Both types increase the chances of umbilical cord prolapse, which can reduce oxygen supply. Approach to delivery:
- ECV may be tried if the baby is not too large and there are no other risks.
- If ECV fails or is not advised, a planned C-section is usually used.
Different Variations and Their Features
| Type | Description | Delivery Plan |
|---|---|---|
| Complete breech | Buttocks down, knees bent, feet near butt | Often C-section |
| Incomplete breech | One/both feet or knees come first | Usually C-section |
| Footling breech | Feet below the buttocks | High C-section rate |
Common Signs
- Kicking lower in the belly
- May feel foot or knee near the cervix
Vaginal delivery in these positions is rare and usually not recommended due to higher risk.
Baby Lying Sideways (Transverse Lie)
A transverse lie means the baby is lying sideways across the uterus. The shoulders, back, or arms may point toward the birth canal instead of the head or buttocks. Transverse position is rare near delivery, but common earlier in pregnancy as the baby moves more freely.
If the sideways position remains at week 37, external cephalic version may be tried to turn the baby head-down. If turning the baby doesn’t work or if there are any warning signs, a C-section is recommended.
Details of Sideways Position
- Type: Transverse lie
- Presentation: Shoulder, back, or limbs may enter birth canal first
- Risks: Cord prolapse, delivery blockage
Table: Transverse Lie Features
| Aspect | Description |
|---|---|
| Vaginal birth | Not possible |
| ECV option | Usually attempted at term |
| Delivery method | C-section is standard |
Babies in this position cannot be delivered vaginally due to the risk of the shoulder or arm blocking exit or the cord coming out first.
Pregnancies with More Than One Baby (Twins)
For twin pregnancies, fetal presentation becomes more complex because each baby can be in a different position. The lower twin (closest to the birth canal) usually determines the delivery plan.
Common Patterns
- Both Twins Head-Down: Vaginal birth may be considered.
- First Twin Head-Down, Second Breech or Transverse: The team may attempt vaginal birth for the first, and try to turn the second or deliver breech.
- First Twin Not Head-Down: Planned C-section is often chosen, especially if other risks are present.
Sometimes the second twin needs to be delivered by C-section even if the first is born vaginally, depending on position changes or complications.
Decision Factors for Twins Delivery
| Presentation Pattern | Possible Delivery Options |
|---|---|
| Both head-down | Usually vaginal birth possible |
| Lower twin head-down, upper breech | Try vaginal for first, then ECV or breech or C-section for second |
| Both breech or not head-down | Usually planned C-section |
| Large weight difference/other concerns | C-section for safety |
Other Facts
- Turning a twin within the womb (ECV) is sometimes tried with the second twin.
- If one twin’s position is not favorable or there are worries about their size, placenta, or cord, a C-section is typically recommended.
Common Terms
- Vertex Presentation: Head-down
- Non-Vertex: Breech, transverse, or other
- Multiple Gestation: Carrying more than one baby
Each case with twins needs a detailed delivery plan, often discussed late in pregnancy, as changes can happen even during labor.
Summary Table: Fetal Presentations Before Birth
| Position | Medical Term(s) | Delivery Plan | Main Risks or Needs |
|---|---|---|---|
| Head-first, face down | Occiput anterior | Vaginal | Fewest complications |
| Head-first, face up | Occiput posterior | Vaginal/C-section/assisted | Longer labor, more interventions |
| Buttocks first, legs up | Frank breech | C-section | Cord issues, head entrapment |
| Buttocks+legs/knees bent | Complete/incomplete breech | C-section | Higher for cord problems, injury |
| Lying sideways | Transverse lie | C-section | Cord prolapse, cannot deliver vaginally |
| Twins (varies) | Multiple gestation | Depends | Presentation & weight affect delivery |
Early identification and close monitoring of baby position before birth help guide the safest birth plan. Procedures like external cephalic version can sometimes help babies turn head-down, but some positions require surgery for safety. Decisions are made for each pregnancy, especially with breech, transverse, or twin situations.
