Pregnancy week 12
At week 12 of pregnancy the baby is around 2 1/2 inches long and about ½ an ounce in weight. Although the movement of the baby wont be felt until a little further along, the baby is developing, growing, and moving around rapidly. At this point in the pregnancy, the brain will be developing and releasing hormones while the genitals begin distinguishing weather the baby is male or female.
By the end of this week, the uterus will bulge out above the pubic bone and continue to grow rapidly enough to support the growing baby inside. Many women report skin changes that occur during this week. Freckles tend to darken, a vertical line down the abdomen, referred to as the linea nigra, may form, the areolas will darken, patches of brown skin on the face and neck may appear. Discontinue use of any creams that may have a large dose of vitamin A because it could harm the liver and jaundice of the baby. The increase of progesterone during pregnancy causes the valve between the stomach and esophagus to loosen up, therefore heartburn is often a complaint. Some suggested way to help with the heartburn include eating less at each meal and having more meals thorough the day, drinking liquids prior to or after the meal instead of during, watching the junk food intake, and not eating before going to bed.
Some safety concerns during the period where the stomach begins to bulge includes the use of a seatbelt at all times. Seatbelts are life savers which are very important during pregnancy. Although most often when the uterus appears to be larger than normal the cause is from miscalculation, by twelve weeks the physician can perform an ultrasound to determine whether the cause is twins. Multiple pregnancies involve a higher level of risk but the risks reduce after week 12. For example, it is possible that both twins do not make it to term, but, if one twin is lost before week 12, it will reabsorb back into the body to prevent any damage to the other twin or to the mother.
Current guidance (today's medical sources): By the end of week twelve the baby has developing reflexes and can open and close its hands. The end of the first trimester is approaching, and for many people nausea begins to ease around this time. A first-trimester scan often falls around weeks eleven to fourteen. As the first trimester closes, the chance of miscarriage decreases.
Contact your healthcare provider promptly about heavy vaginal bleeding, severe or persistent abdominal pain, a high fever, severe or sudden headache, vision changes, or fainting. Seek urgent care if you are worried — these can be signs that need medical attention.
Sources: NHS — 12 weeks pregnant; Mayo Clinic — Fetal development: The 1st trimester; ACOG — Prenatal Genetic Screening Tests. Informational only. See our sources & medical-review policy.
Frequently asked questions
How many months is 12 weeks pregnant?
Week 12 falls in the first trimester. Pregnancy is usually counted in weeks (about 40 in total) rather than months, because weeks are more precise.
What is happening to the baby at 12 weeks?
Reflexes develop; the baby can open and close its hands; the digestive system practises contractions.
What symptoms are common at week 12?
Many people feel nausea easing; the risk of miscarriage drops as the trimester ends. Symptoms vary a lot from person to person; discuss anything that worries you with your healthcare provider.
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See the week-by-week guide →Informational only — not medical advice. Pregnancy Week to Week is a general educational reference. It is not a substitute for professional medical care, diagnosis, or treatment. Every pregnancy is different: always consult your doctor, midwife, or other qualified healthcare provider about your own pregnancy, and never disregard or delay professional advice because of something you read here. In an emergency, contact your maternity unit or local emergency number immediately.