The “pregnancy glow” is a visible, physiological change rooted in the body’s adaptation to pregnancy. This radiance, characterized by flushed cheeks, a smoother complexion, and a dewy appearance, is a manifestation of internal biological shifts. The glow typically appears during the second trimester and is primarily a result of two major concurrent changes: a dramatic increase in blood circulation and the significant fluctuation of reproductive hormones. These internal adjustments work together to alter the skin’s surface appearance, giving the face a vibrant, healthy look.
The Vascular Explanation
The most immediate cause of the flushed, rosy appearance associated with the pregnancy glow is the profound change in the circulatory system. To support the developing fetus and the placenta, the pregnant body significantly increases its total blood volume. This volume typically rises by up to 50% more than the pre-pregnancy state.
This substantial increase in circulating blood means the heart must work harder, pumping a greater quantity of blood throughout the body. Concurrently, pregnancy hormones induce vasodilation, which is the widening of blood vessels. This combination of increased volume and dilated vessels brings a higher concentration of blood closer to the skin’s surface, particularly in areas with dense capillaries like the face and neck.
The enhanced blood flow delivers more oxygen and nutrients to the skin cells, giving the complexion a warmer, more vibrant tone. This constant, high-volume circulation results in the characteristic rosy flush. The increased circulation also plays a role in speeding up cell turnover, which contributes to a fresher skin surface by shedding old cells more efficiently.
Hormones and Sebaceous Gland Activity
The second major contributor to the pregnancy glow is the surge in reproductive hormones, primarily estrogen and progesterone, which directly influence the skin’s texture and oil balance. High levels of these hormones stimulate the sebaceous glands, the microscopic glands in the skin that secrete an oily substance called sebum. This increased stimulation results in a ramped-up production of sebum.
For many women, this higher oil production acts as a natural moisturizer, providing a protective and hydrating film over the skin. The resulting slight oiliness can smooth the appearance of fine lines and impart a desirable dewy, polished look. Estrogen also helps the skin retain moisture and can stimulate cells that synthesize hyaluronic acid, collagen, and elastin, which collectively improve skin elasticity and plumpness.
While this extra sebum can create a luminous complexion for some, it can also lead to the less desirable effect of clogged pores and acne flare-ups. Women who naturally have dry skin often benefit most from this hormonal effect. The overall effect, however, is a complexion that appears smoother, more hydrated, and reflective of light.
Related Visible Skin Changes
Alongside the glow, the same hormonal shifts responsible for the radiant skin can trigger other, non-glowing visible changes in the skin’s pigmentation. These changes are collectively known as hyperpigmentation and are caused by an increase in melanocyte-stimulating hormone (MSH) and estrogen. MSH promotes the production of melanin, the pigment that gives skin its color.
One common manifestation is melasma, often called the “mask of pregnancy,” which presents as dark, patchy areas on the face, typically on the cheeks, forehead, and upper lip. Another frequent change is the darkening of the linea alba, the faint line running down the center of the abdomen, which becomes the more prominent, brownish streak known as the linea nigra.
The darkening of the areolas and external genitalia is also attributed to the same elevated hormone levels. While these changes are not part of the glow, they are a normal and temporary result of the body’s hormonal response to pregnancy. These pigmentation changes typically fade significantly after childbirth as hormone levels return to their pre-pregnancy state.