The widening of the hips, known medically as pelvic growth, is a natural part of female development that occurs as girls go through puberty and transition into womanhood. This widening prepares the female body for childbearing by allowing room for a baby to pass through the birth canal. Pelvic growth does not happen all at once but rather occurs gradually over several years surrounding puberty. There is no one exact age when it begins or ends, as the timing varies from girl to girl. However, there are some general timelines for when hip widening typically happens.
Pelvic Growth in Early Puberty
For most girls, the first noticeable widening of the hips begins between the ages of 10 and 12. This coincides with the early stages of puberty, when girls start to develop breasts and get their first period. At this stage, the widening of the hips is usually very subtle and gradual. The pelvis may grow just a centimeter or less over one to two years. Often, girls themselves do not notice this initial widening phase. It is preparing their bodies for the more rapid pelvic expansion still to come.
Main Pelvic Growth Phase
The most significant widening of the female hips occurs between the ages of 12 and 16, as girls go through the main phase of puberty. During this period, their bodies take on more womanly proportions as fat deposits increase in the buttocks, thighs, and hips. The pelvis itself also widens and becomes more flared. Each hipbone, known as the iliac crest, spreads further apart from the other.
The amount of pelvic growth during this time varies from girl to girl, but averages 4 to 7 centimeters. For most girls, the peak of their growth spurt happens between 12 and 14 years old. Some may reach their maximum hip width a bit earlier or later, depending on when they go through puberty. Generally, earlier maturing girls finish pelvic growth sooner while late bloomers widen more around 15 or 16 years old.
Final Pelvic Growth Phase
After the main pubertal widening of the hips is complete, there remains a final phase of subtle pelvic expansion over the next several years. This happens as girls transition from puberty into their late teens and early 20s. The hips may grow another 1 to 2 centimeters in width during this time.
Pelvic growth slows down significantly after age 16, with only about 0.5 cm of added width per year. By age 18, most of a woman’s pelvic development is complete. The hips typically reach their widest point between 18 and 20 years old. After the early 20s, the pelvis remains relatively stable or may narrow slightly with age.
Factors Influencing Pelvic Growth
While the average timelines give a general idea of hip widening, many factors influence the exact timing and amount for each girl. These include:
- Genetics – Girls tend to follow the pattern of their mothers and other female relatives. Those from families that mature early will likely widen sooner.
- Body fat – More fat on the hips and thighs creates an illusion of wider hips.
- Nutrition – Adequate nutrition supports healthy bone growth and development.
- Physical activity – Sports and impact exercise may promote pelvic growth.
- Ethnicity – On average, black girls enter puberty earlier and have wider hips than white girls.
Medical problems or conditions such as malnutrition, hormonal imbalances, and genetic disorders can also affect the timing and amount of pelvic growth during puberty.
Changes in Pelvic Shape
In addition to widening, the female pelvis also changes shape as it matures. Two key changes happen:
- The pelvic inlet, or top opening, becomes more rounded and oval-shaped to accommodate a baby’s head.
- The pelvic outlet widens and becomes more circular to allow the baby to pass through the birth canal.
These adaptations create the gynecoid or “female” pelvis better optimized for childbirth. They result from a shift in the angle of the pubic arch and other structural modifications. This pelvic transformation also contributes to the wider hip appearance as girls go through puberty.
Widening Hips and Childbirth
A wider pelvis does not necessarily make childbirth easier. Its size and shape are more important factors. A pelvis that is too small or oddly shaped can make vaginal delivery difficult or impossible. This is known as cephalopelvic disproportion.
However, a wider and more gynecoid pelvis does often indicate a better fit for birthing babies. Very narrow hips may signal potential obstruction down the road and need to be monitored.
Changes in Mobility and Posture
Hip widening also impacts mobility and posture. The changing pelvic alignment and center of gravity requires girls to adjust their movement patterns through puberty.
Common effects of a widening pelvis include:
- Wider stance when standing, walking, or running
- Increase in lumbar curve of the lower spine
- More swaying of the back and hips when walking
- Feeling less stable or coordinated initially
Core and hip strength are important to maintain good posture and balance as the hips widen. Joint hypermobility is also more common around puberty and may contribute to altered mechanics. Physical therapy or training can help girls adapt to their changing bodies.
Psychological Impact of Hip Widening
Rapid changes to hip width and body shape can be challenging psychologically for young girls. Some may feel self-conscious or uneasy about their new curves and sense of unfamiliarity in their body.
However, wide hips are a normal and healthy part of female development. Positive messaging helps girls to embrace their maturing figures with confidence. Support from other women who have gone through the same changes can provide reassurance as well.
Clothing Considerations
As the pelvis and hips expand, girls will need to accommodate wider hip measurements when dressing. Tight pants or skirts may become uncomfortable or unflattering. Choosing stretchy fabrics and cuts with a flare or A-line shape allows room through the hips and butt.
Undergarments also need to fit properly through the hip area. Bras, panties, slips, and shapewear that are too small can create bulges, ridges, and discomfort. Buying new bras is especially important, as the band size goes up along with hip/torso growth.
Is My Daughter’s Pelvic Growth Normal?
Moms may wonder if their daughter’s hip growth seems normal versus cause for concern. Here are some general benchmarks:
- Hip widening begins between ages 10-12 for most girls
- The hips grow 4-7 cm wider over 2-4 years surrounding puberty
- Black girls typically start pelvic growth 1 year earlier than white girls
- Complete pelvic maturity by age 18-20 years old
- Very little pelvic expansion after early 20s
Dramatic hip widening over a short period, such as more than 3 cm in one year, can indicate a growth disorder like gigantism. Lack of any noticeable pelvic expansion by age 14 or Tanner Stage 4 breast development should be evaluated by a doctor.
Measuring Hip Width
Measuring hip width yearly through puberty can help track pelvic growth. This is done by measuring the distance between the widest points of the iliac crests. To find these bony landmarks, locate the uppermost outer bone of the hip by placing thumbs on the side of the waist and spreading the fingers downwards. The crests can be felt as a curved ridge on each side. Their widest point is typically right in line with the navel.
A tailor’s measuring tape is ideal for accurately measuring between the iliac crests. Make sure the tape lies flat across the back at waist/navel level. Record the hip width in centimeters to monitor the progression each year. Comparing measurements to standard growth charts helps determine if pelvic development is on track.
Conclusion
The widening of a girl’s hips is a hallmark of female puberty. It occurs gradually over several years surrounding adolescence as the pelvis expands and the body takes on more womanly proportions. While the exact timing varies, most girls see their hips grow wider from ages 10-16, with 4-7 cm of expansion. Pelvic widening reflects the maturation of the reproductive system and preparation for childbearing. With proper support, girls can embrace these natural changes that accompany the transition into womanhood. Monitoring hip growth patterns through puberty helps determine if pelvic development is on a normal course.
| Age Range | Stage of Pelvic Growth | Average Amount of Widening |
|---|---|---|
| 10-12 years | Early | 0-2 cm |
| 12-16 years | Main phase | 4-7 cm |
| 16-early 20s | Final phase | 0-2 cm |