Most pregnancy stretch marks appear during the third trimester, typically somewhere between weeks 25 and 32, when your belly is growing most rapidly. About 50 to 90 percent of pregnant women develop them, with studies consistently landing around 60 to 70 percent. The timing varies from person to person, and some women notice faint lines earlier in the second trimester, but the final months are when the majority show up.
Why the Third Trimester Is Peak Time
Stretch marks form when your skin stretches faster than its deeper layers can keep up with. The middle layer of skin, which gives it structure and elasticity, tears under the strain. During the third trimester, your baby is gaining the most weight, your uterus is expanding significantly, and your body is retaining more fluid. All of this adds up to rapid skin stretching over a short period.
Hormonal shifts during pregnancy also play a role. Your body produces higher levels of stress hormones that can weaken the elastic fibers in your skin, making it more prone to tearing even before the physical stretching reaches its peak. This combination of hormonal changes and mechanical stretching is why pregnancy stretch marks tend to be more pronounced than those caused by other types of weight gain.
Where They Typically Show Up
The belly is the most common location, especially along the sides and lower abdomen where the skin stretches the most as your bump grows. But stretch marks aren’t limited to your stomach. Many women also develop them on the breasts, which can start growing and changing as early as the first trimester. The upper thighs and hips are another common spot, particularly if you carry weight in those areas during pregnancy.
The NHS notes that marks tend to appear progressively as your bump grows, so you might notice breast stretch marks weeks before any appear on your abdomen.
What Fresh Stretch Marks Look Like
New stretch marks can be pink, red, purple, blue, or dark brown depending on your skin tone. They often feel slightly raised or ridged to the touch and may itch as the skin stretches. Over time, after your baby is born, they gradually fade to a lighter, silvery or white color and flatten out. This transition happens at different speeds for everyone. Some women see significant fading within a few months postpartum, while for others the process takes a year or longer.
Who Is More Likely to Get Them
The single strongest predictor is family history. If your mother had stretch marks during her pregnancies, your chances go up significantly. A study of 151 women found that maternal stretch mark history was the only risk factor with a statistically significant link to developing them. Researchers have looked into whether specific genes related to collagen production explain the connection, but so far that link hasn’t been confirmed. It seems to be a broader inherited trait related to skin elasticity rather than one specific gene.
Other factors that increase your risk include:
- Younger maternal age: Women who are pregnant in their teens or early twenties tend to develop more stretch marks, possibly because their skin has different collagen composition.
- Higher pre-pregnancy weight: Starting pregnancy at a higher weight is associated with greater likelihood of developing marks.
- Larger baby or more weight gain: Anything that increases how much your skin has to stretch raises the odds.
- Previous stretch marks: If you developed them during puberty or a previous pregnancy, you’re more likely to get them again.
A study of first-time mothers found stretch marks in 67 percent of participants, and the condition negatively affected how those women felt about their bodies. That emotional impact is real and worth acknowledging, even though stretch marks pose no medical risk.
Can You Prevent Them?
The honest answer is that no cream or oil has been proven to reliably prevent stretch marks in the general pregnant population. One clinical trial tested a cream containing an Asian plant extract (Centella asiatica), vitamin E, and collagen compounds against a placebo. The cream did reduce stretch mark development, but only in women who had already had stretch marks in a previous pregnancy. For first-time mothers or women without prior marks, there was no measurable benefit.
Keeping your skin well-moisturized can help with the itching that comes with rapid stretching, and gradual, steady weight gain rather than sudden jumps may reduce severity. But given how strongly genetics drive the process, prevention has real limits. If your skin is predisposed to tearing under stretch, topical products can only do so much.
How They Change After Delivery
Most stretch marks fade naturally once your baby is born and your skin begins to recover. The red or purple color softens first, typically over several months, and the texture flattens over time. They rarely disappear completely, but many women find that after a year or two, their marks are only visible up close as faint, lighter lines.
How quickly yours fade depends on their initial severity, your skin tone, and your body’s healing tendencies. Darker or deeper marks take longer to lighten. Some women pursue treatments like laser therapy or prescription creams postpartum to speed the process, but results vary widely and these options work best when started while the marks are still in their early, colored stage rather than after they’ve already turned white.