Pregnancy glow is caused by two main changes happening simultaneously: a significant increase in blood flow to your skin and a rise in oil production from your sebaceous glands. These aren’t cosmetic accidents. They’re direct results of the hormonal shifts your body undergoes to support a growing pregnancy, and together they create that characteristic dewy, flushed radiance.
How Blood Volume Creates the Flush
One of the most dramatic changes during pregnancy is the sheer amount of blood your body produces. Total blood volume rises by roughly 45% above pre-pregnancy levels, though it can range anywhere from a 20% to 100% increase depending on the person. Your heart pumps harder and faster to circulate all of that extra blood, and a meaningful share of it flows to your skin’s surface.
Estrogen is the primary driver here. It widens blood vessels and increases circulation throughout the body, including the tiny capillaries just beneath the surface of your face. The result is a visible warmth and rosiness, similar to what your skin looks like after a brisk walk or a hot shower, but sustained over weeks and months. On lighter skin tones this reads as a pinkish flush. On darker skin tones it often appears as a warm, even-toned radiance that wasn’t there before.
Why Your Skin Looks Dewier Than Usual
The second half of pregnancy glow comes from oil. Hormonal fluctuations stimulate your sebaceous glands to produce more sebum, the natural oil that coats your skin. A thin, even layer of sebum acts like a built-in highlighter, reflecting light and giving skin a smooth, luminous finish. This is essentially what expensive “dewy finish” skincare products try to replicate, and your body does it for free during pregnancy.
Water retention also plays a supporting role. Your body holds onto more fluid during pregnancy, and some of that fluid sits in the soft tissue beneath your skin. This subtle puffiness can temporarily smooth out fine lines and make your face look fuller and more rested, adding to the overall impression of healthy, glowing skin.
When Pregnancy Glow Typically Appears
There’s no exact week when the glow switches on. Some people notice it early in the first trimester, while others never experience it at all. That said, the second trimester is the most common window. This is when hormonal changes, blood volume expansion, and oil production are all peaking at the same time, creating the strongest visible effect.
The glow fades after delivery. Once hormone levels drop back to their pre-pregnancy baseline and blood volume normalizes, the extra flush and dewiness gradually disappear. For most people this happens within the first few weeks postpartum.
When “Glow” Tips Into Skin Problems
The same hormonal forces that create the glow can overshoot and cause unwanted skin changes. Extra sebum production is great in moderate amounts, but too much can clog pores and trigger acne breakouts, particularly along the jawline and chin. If you had acne-prone skin before pregnancy, there’s a good chance the increased oil will aggravate it rather than just make you look radiant.
Hormonal shifts can also cause melasma, sometimes called “the mask of pregnancy.” This shows up as dark, blotchy patches on the forehead, cheeks, or upper lip. It’s driven by the same estrogen surge responsible for the glow, but instead of boosting blood flow, it overstimulates the cells that produce skin pigment. Melasma is especially common in people with medium to dark skin tones and tends to worsen with sun exposure.
So the line between “glowing” and “breaking out” or “developing dark patches” is really a matter of how your individual skin responds to the same set of hormonal changes. Two people at the same stage of pregnancy can have completely opposite experiences.
Not Everyone Gets the Glow
Pregnancy glow is real in a physiological sense, but it’s far from universal. Nausea, fatigue, poor sleep, and stress can all dull your complexion and counteract whatever radiance the extra blood flow might provide. If you’re spending the first trimester vomiting and the second trimester exhausted, your skin is unlikely to look magazine-cover luminous, regardless of what your hormones are doing underneath.
Genetics and baseline skin type matter too. People with naturally oilier skin may notice a more dramatic glow (or more dramatic acne). People with drier skin might see less of a visible change. The glow is also easier to spot on some skin tones than others, which means it gets perceived and commented on unevenly.
If you’re pregnant and not glowing, nothing is wrong. It simply means your body is expressing the same hormonal changes in a different, less visible way.