Final answer:
Positive signs of pregnancy assessed by a nurse include the enlargement of the uterus, bluish color of the cervix, detection of fetal heart tones, and positive hCG test results. These reflect the significant physiological changes that occur during pregnancy, driven by hormones like estrogens, progesterone, and hCG, and manifest as increased blood volume and targeted weight gain.
Step-by-step explanation:
The nurse assesses the woman for positive signs of pregnancy, which include several physiological changes due to the adaptation to pregnancy. The positive signs of pregnancy are:
- Enlargement of the uterus: As the fetus grows, the uterus expands to accommodate the developing baby, which is a clear anatomical change.
- Bluish color of the cervix and upper vagina: This condition, known as Chadwick's sign, is due to increased blood flow to the area.
- Detection of fetal heart tones by Doppler auscultation: The sound of the fetal heartbeat is a definite indication that a fetus is developing inside the uterus.
- Positive test results for human chorionic gonadotropin (hCG): This hormone is produced by the placenta shortly after the embryo attaches to the uterine lining and builds up rapidly in the early stages of pregnancy.
These physiological changes are part of the significant adaptations during pregnancy, such as increased maternal blood volume and weight gain primarily in the breasts and abdominal region. Hormones such as estrogens, progesterone, and hCG play a crucial role in these changes, promoting fetal viability and supporting the pregnancy.