Diagnosing pregnancy

a) The possible symptoms: these are changes in the woman's body that she can identify herself and tell you whether or not she is pregnant. It is possible that these symptoms can also be caused by something else. The health history is only the woman's subjective report which may contribute to your diagnosis. However, at the Health Post level, the possible symptoms are often all the evidence that is available to you in the first three to six months.

b) The probable signs and symptoms. some of these indicators are reported by the woman, but you can also see them for yourself. There is also a pregnancy test that you may be able to conduct, or that could be done at the next level health facility.

c) The positive or presumptive signs: these are absolute proof of pregnancy, based on objective findings.

a) Nausea and Vomiting: this common symptom occurs in approximately 50% of pregnancies and is most marked at 2 - 12 weeks' of gestation. It is usually most severe in the morning but can occur at any time during the day and may be precipitated by cooking odours and pungent smells. Extreme nausea and vomiting may be a sign of multiple gestation or molar pregnancy. Protracted vomiting associated with dehydration and ketonuria (Hyperemesis Gravidarum) may require hospitalisation and relief of symptoms with antiemetic therapy.

Treatment for uncomplicated nausea consists of light, dry foods or small, frequent meals the remedy of which is mainly emotional support. Some improvement can be seen with the addition of high-dose of vitamin B6 therapy and the preconception use of prenatal vitamins. Antiemetic medications and alternative therapies, such as acupressure or ginger, are used for women whose symptoms interfere with daily life. The nausea is probably related to rapidly rising serum levels of human chorionic gonadotropin (HCG), although the mechanism is not understood.

b) Breast tenderness: it may range from tingling to frank pain caused by hormonal responses of the mammary ducts and alveolar system. The increase in circulatory results in breast engorgement and venous prominence. Similar tenderness may occur just before menses.

c) Enlargement of circumlacteal sebaceous glands of the areola (Montgomery's Tubercles): expansion of these glands occurs at 6 - 8 weeks' of gestation and is a result of hormonal stimulation.

d) Colostrum secretion: colostrum secretion may begin after 16 weeks' of gestation.

e) Secondary breasts: secondary breasts may become more prominent both in size and in coloration. It occurs along the nipple line. Hypertrophy of axillary breast tissue often causes an asymptomatic lump in the axilla.

f) Quickening: the first awareness of the foetal movement occurs at 18 - 20 weeks in primigravida and at 14 - 16 weeks in multigravidas. Intestinal peristalsis may be mistaken for foetal movement; therefore, perceived foetal movement alone is not a reliable symptom of pregnancy, although it may be useful in determining the duration of pregnancy.

g) Changes in the urinary tract

• a) Bladder irritability, frequency, and nocturia: these conditions occur because of increased bladder circulation and pressure from the enlarging uterus.
  
• b) Urinary tract infection: urinary tract infection must always be ruled out because pregnant women are more likely than non-pregnant women to have significant bacteriuria which may be asymptomatic (7% versus 3%). Asymptomatic bacteriuria can also lead to pyelonephritis, which is associated with miscarriage, preterm birth, and intrauterine foetal death.
  
• c) Increased basal body temperature: persistent elevation of basal body temperature over a 3-week period usually indicates pregnancy if temperatures have been carefully charted.
  

f) Changes of the skin

• Chloasma: chloasma, or the mask of gestation,- is a darkening of the skin over the forehead, bridge of the nose, or cheekbones and is most marked in those with dark complexions /appearance. It usually occurs after 16 weeks' of gestation and is intensified by exposure to sunlight.
  
• Linea Nigra: Linea Nigra is a darkening of the nipples and lower midline of the abdomen from the umbilicus to the pubis (darkening of the linea alba). The basis of these changes is stimulation of the melanophores caused by an increase in the melanocyte-stimulating hormone.
  
• Stretch marks: stretch marks, or striae of the breast and abdomen, are caused by separation of the underlying collagen tissue and appear as irregular scars. This is probably an adreno-corticosteroids response. These marks appear later in pregnancy when the skin is under greater tension.
  
• Spider telangiectasias: spider telangiectasias are common skin lesions that result from high levels of circulating oestrogen. These vascular stellate marks blanch when compressed. Palmar erythema is often an associated sign. Both of these signs are also seen in patients with liver failure.
  

a) Pelvic organs: any changes in the pelvic organs are perceivable to the experienced physician, including the following.

b) Chadwick's Sign: congestion of the pelvic vasculature causes bluish or purplish discoloration of the vagina and cervix.

c) Leukorrhea: an increase in vaginal discharge consisting of epithelial cells and cervical mucus due to hormone stimulation. Cervical mucus that has been spread on a glass slide and allowed to dry no longer forms a fernlike pattern but has a granular appearance.

d) Hegar's Sign: a widening of the softened area of the isthmus, resulting in compressibility of the isthmus on bimanual examination. This occurs from the 6 - 8 weeks.

e) Bones and ligaments of the pelvis: the bony and ligamentous structures of the pelvis also change during pregnancy. There is a slight but definite relaxation of the joints. Relaxation is most pronounced at the pubic symphysis, which may separate to an astonishing degree.

f) Abdominal enlargement: there is progressive abdominal enlargement from 7 - 28 weeks with rapid growth at 16 - 22 weeks as the uterus rises out of the pelvis and into the abdomen (see fig 9 - 2).

g) Uterine contractions: As the uterus enlarges, it becomes globular and often rotates to the right. Painless uterine contractions (Braxton Hicks contractions) are felt as tightening or pressure. They usually begin at about 28 weeks' of gestation and increase regularly. These contractions usually disappear with walking or exercise, whereas true labour contractions become more intense.

a) Urine Pregnancy Test: this is the most common method used to confirm pregnancy. Using antibodies, the test identifies the subunit of HCG, minimising cross-reaction with similarly structured hormones. The test is affordable, reliable and fast (1 - 5 minutes to obtain results) tool to diagnose pregnancy even in the office.

b) Foetal heart tones (FHTs): it is possible to detect FHT by handheld Doppler as early as ten weeks' of gestation. The normal foetal heart rate is 120 - 160 beats per minute. It may be detected by fetus-cope by 18 - 20 weeks' of gestation, although this device is rarely used at present.

c) Palpation of the foetus: after 22 weeks, the foetal outline can be palpated through the maternal abdominal wall. Foetal movements may be palpated after 18 weeks.

a) Uterine size: an early first-trimester examination usually correlates well with the estimated gestational age. The uterus is palpable just at the pubic symphysis at 8 weeks. At 12 weeks, the uterus becomes an abdominal organ and at 16 weeks is usually at the midpoint between the pubic symphysis and the umbilicus. The uterus is palpable at 20 weeks at the umbilicus. Fundal height (determined by measuring the distance in centimetres from the pubic symphysis to the curvature of the fundus) correlates roughly with the estimated gestational age at 26 - 34 weeks (Fig 9.2). After 36 weeks, the fundal height may decrease as the foetal head descends into the pelvis

b) Quickening: the first foetal movement is usually appreciated at 17 weeks in the average multipara and at 18 weeks in the average primipara.