Sunburn only goes skin deep, so it can't directly affect your baby if you're pregnant; however, the side effects of a severe sunburn could have undesirable effects on your pregnancy. Because pregnancy can increase your sun sensitivity, take extra precautions to avoid sunburn by using sunblock and limiting your time in the sun. The full effect of sunburn takes between 12 to 24 hours to show up, the Skin Laboratory warns.
Rise in Body Temperature
Sunburn affects your body's ability to regulate temperature by releasing excess heat. An inability to control your body temperature makes you more susceptible to heat-related diseases such as heatstroke. A bad sunburn or prolonged time in the sun can raise your body temperature, which can affect your baby. In both animals and humans, mild temperature rises before the embryo implants and high fevers during embryonic development can cause birth defects, researchers from The University of Sydney Veterinary Science Department report in the July 2006 issue of "Birth Defects Research."
Dehydration and Cramping
Sunburn or just exposure to high temperatures can cause fluid loss, or dehydration. In temperatures over 90 degrees F, you could lose as much as a half-gallon of fluid in 10 minutes, The Weather Channel warns. Dehydration can lead to a rise in temperature and also can increase your risk of uterine contractions, which could cause miscarriage or preterm labor. If you stay out in the sun, drink approximately 1 to 1.3 gallons of fluid during the day to offset fluid losses, travel specialist Dr. Charlie Easmon of NetDoctor suggests.
Fluid loss and fever can increase your risk of light-headedness, nausea, dizziness and fainting after sunburn or prolonged sun exposure. Sit down and drink fluids if you start to feel light-headed, since you're more likely to fall and possibly injure yourself, if not your baby, when you're feeling dizzy from dehydration.
A severe burn that covers you whole body might require medical attention, especially if you develop large blisters called bullae. Serious dehydration can occur with severe sunburn, just like any other bad burn. You might need intravenous fluids to keep up with fluids lost through large blisters. Heat stroke also can accompany a bad burn; you lose the ability to sweat, so your body temperature rises dangerously to 105 F or more, a life-threatening situation for you and your baby.