DIAGNOSIS OF PREGNANCY
DIAGNOSIS OF PREGNANCY-
The diagnostic confirmation of pregnancy is based on a combination of the presumptive, probable, and positive changes/signs of pregnancy.
Presumptive Signs of Pregnancy-
The presumptive signs of pregnancy include all subjective signs of pregnancy (i.e.,physiological changes perceived by the woman herself):
- Amenorrhea-Absence of menstruation
- Nausea and vomiting-Common from week 2 to 12
- Breast changes-Changes begin to appear at 2 to 3 weeks
- Enlargement, tenderness, and tingling of breast
-Increased vascularity of breast
- Fatigue-Common during the first trimester
- Urination frequency-Related to pressure of enlarging uterus on bladder; decreases as uterus moves upward and out of pelvis.
- Quickening- A women first awareness of fetal movement, occur around 18 week gestation.
Probable Signs of Pregnancy-
The probable signs of pregnancy are objective signs of pregnancy and include all physiological and anatomical changes that can be perceived by the health care provider.
- Chadwick’s sign- Bluish-purple coloration of the vaginal mucosa, cervix, and vulva seen at 6 to 8 weeks
- Goodell’s sign-Softening of the cervix and vagina with increased leukorrheal discharge; palpated at 8 weeks
- Hegar’s sign- Softening of the lower uterine segment; palpated at 6 weeks
- Uterine growth and abdominal growth
- Skin hyperpigmentation-
- Melasma (chloasma) ,also referred to as the mask of pregnancy-Brownish pigmentation over the forehead, temples, cheek, and/or upper lip
- Linea nigra-Dark line that runs from the umbilicus to the pubes
- -Nipples and areola-Become darker; more evident in primigravid as and dark-haired women
- Ballottement-A light tap of the examining finger on the cervix causes fetus to rise in the amniotic fluid and then rebound to its original position; occurs at 16 to 18 weeks
- Positive pregnancy test results-
- Laboratory tests are based on detection of the presence of human chorionic gonadotropin (HCG) in maternal urine or blood.
- The tests are extremely accurate, but not 100%.There can be both false-positive and false-negative results. Because of this, a positive pregnancy test is considered a probable rather than a positive sign of pregnancy.
- A urine pregnancy test is best performed using a first morning urine specimen, which has the highest concentration of HCG, and becomes positive about 4 weeks after conception.
- A maternal blood pregnancy test can detect HCG levels before a missed period.
- Home pregnancy tests are also accurate (but not 100%) and are simple to perform. These urine tests use enzymes and rely on a color change when agglutination occurs, indicating a pregnancy. The home tests can be performed at the time of a missed menstrual period. If a negative result occurs, the instructions suggest that the test be repeated in one week if a menstrual period has not begun.
Positive Signs of Pregnancy-
The positive signs of pregnancy are the objective signs of pregnancy that can only be attributed to the fetus:
- Auscultation of the fetal heart, by 10 to 12 weeks
- Observation and palpation of fetal movement by the examiner
- Sonographic visualization of the fetus- Cardiac movement noted at 4 to 8 weeks Ultrasound visualization of a pregnancy has increasingly become a routine and expected part of prenatal care. The gestational sac can be seen at 5 weeks’ gestation and fetal cardiac activity can be observed between 6 and 7 weeks’ gestation. Indications for ultrasound examination of an early pregnancy for purposes of diagnosis include-
- Pelvic pain or vaginal bleeding in the first trimester
- History of repeated pregnancy loss or ectopic pregnancy (the implantation of a fertilized ovum outside the uterus)
- Uncertain menstrual history
- Discrepancy between actual size and expected size of pregnancy based on history