Pregnancy stretch marks most commonly appear during the sixth and seventh months, roughly weeks 24 through 28 of the second and third trimesters. This is when your belly is growing fastest and the skin is stretching beyond what its deeper layers can keep up with. Not every pregnant person gets them, but they affect a majority of pregnancies, and the timeline can shift earlier or later depending on your body, your age, and how quickly you gain weight.
The Typical Timeline
Stretch marks show up as pink or purple lines along the areas where skin is under the most tension. They tend to appear on the abdomen, breasts, hips, buttocks, and thighs. Most women first notice them around months six and seven, but breast stretch marks can appear earlier in pregnancy as breast tissue expands in the first and second trimesters. On the belly, marks rarely show up before the skin starts stretching significantly in the late second trimester.
The first sign is often not a visible mark at all. You may notice itchiness in an area where the skin is becoming thinner and more taut. That itching can precede the actual lines by days or weeks. If you start feeling persistent itchiness on your belly or hips that wasn’t there before, stretch marks may be forming beneath the surface.
Why They Form
Stretch marks happen when your skin stretches faster than its structural fibers can adapt. The middle layer of skin contains proteins that give it elasticity and strength. During pregnancy, rapid growth of the uterus and weight gain pull that layer apart, creating small tears that show through as visible lines. Pregnancy hormones also play a role by softening these fibers, making them more vulnerable to tearing under tension.
This is why the marks cluster in the late second and third trimesters. That’s the period of fastest growth, when the baby is putting on significant weight and your body is expanding to accommodate it. The combination of hormonal changes and physical stretching is what makes pregnancy stretch marks different from those caused by, say, a growth spurt during puberty.
Who Gets Them and Who Doesn’t
Several factors influence your likelihood of developing stretch marks, but the two strongest predictors are age and weight gain. In one study published in the American Journal of Obstetrics and Gynecology, women who developed stretch marks were significantly younger on average (about 26.5 years old) compared to those who didn’t (about 30.5 years old). Women who gained more weight during pregnancy were also significantly more likely to develop them.
Family history matters too. If your mother or sister got stretch marks during pregnancy, you’re more likely to develop moderate or severe marks yourself. The baby’s birth weight and how far along you are at delivery also correlate with severity: carrying a larger baby means more stretching, and going closer to or past your due date gives the skin more time under tension.
Other proposed risk factors include race, skin type, pre-pregnancy BMI, and nutrition, though research hasn’t consistently confirmed all of these. The factors with the clearest evidence behind them remain your age, how much weight you gain, your family history, and your baby’s size.
Where They Appear First
The abdomen is the most common location, particularly along the sides and lower belly where the skin stretches the most. But many women notice their first marks on the breasts, since breast growth begins earlier in pregnancy. Hips, buttocks, and thighs are also common sites, especially if you carry weight in those areas or gain weight rapidly.
The marks follow your skin’s natural tension lines, so they typically run vertically on the abdomen and radially on the breasts. They start out pink, red, or purple depending on your skin tone, and they may feel slightly raised or textured compared to the surrounding skin.
Do Creams and Oils Actually Work?
This is where the news is disappointing. A Cochrane review, the gold standard for evaluating medical evidence, analyzed six clinical trials involving 800 pregnant women and found no evidence that any topical preparation prevented stretch marks. The products tested included formulations containing vitamin E, hyaluronic acid, olive oil, and cocoa butter. None showed a statistically significant difference compared to placebo or no treatment. Even when researchers looked specifically at severity rather than just prevention, there was no clear benefit.
That doesn’t mean moisturizing is pointless. Keeping skin hydrated can help with the itching and discomfort that come with stretching. But if a product claims to prevent stretch marks during pregnancy, the clinical evidence doesn’t back that up. The factors that matter most, like your genetics, age, and rate of weight gain, aren’t things a cream can change.
What Happens After Delivery
Stretch marks don’t disappear after birth, but they do change significantly. The pink or purple color gradually fades over months, eventually becoming paler and less noticeable. For lighter skin tones, they typically settle into silvery-white lines. For darker skin tones, they may appear lighter or darker than surrounding skin before fading.
This fading process takes time. Most women notice the color shifting within the first year postpartum, but the timeline varies. The marks themselves become flatter and thinner as they mature. They won’t return to the texture of unmarked skin, but for most women they become subtle enough that they’re easy to overlook. The most dramatic visual change, from vivid streaks to faint lines, typically happens in the first six to twelve months after delivery.
What You Can Actually Control
Since genetics and age aren’t modifiable, the main factor within your influence is weight gain. Gaining weight at a steady, moderate pace rather than in rapid surges gives your skin more time to adapt. This doesn’t mean restricting calories during pregnancy, which carries its own risks. It means following the weight gain guidelines your provider recommends for your starting BMI and being aware that very rapid gain, particularly in the third trimester, increases your chances of more pronounced marks.
Staying well hydrated and eating a balanced diet supports skin health in general, even if it won’t prevent marks outright. And if itching becomes severe or widespread rather than localized to stretching areas, that’s worth mentioning at your next prenatal visit, since generalized itching in pregnancy can occasionally signal other conditions unrelated to stretch marks.