DIAGNOSIS OF PREGNANCY AND PRENATAL CARE potx

103 The correct early diagnosis of pregnancy is often urgent. For ex- ample, a diagnosis is essential to institute studies or treatment of problems that may jeopardize the life or health of mother or off- spring. Today this is usually accomplished by early beta-subunit hCG testing or ultrasonic scanning because a definite clinical di- agnosis of pregnancy before the second missed period is possible in only about two thirds of patients. However, the practitioner must be familiar with the signs and symptoms of pregnancy to properly test for and treat the early pregnancy. CLINICAL DIAGNOSIS OF PREGNANCY Traditionally, the clinical criteria for the diagnosis of pregnancy have been categorized into presumptive, probable, and positive (Table 5-1). The differential diagnosis of the common signs and symptoms of pregnancy involves other conditions associated with similar com- plaints or alteration (Table 5-2). PELVIC FINDINGS OF EARLY PREGNANCY Critical to the diagnosis of pregnancy by physical examination are the pelvic findings. The presumptive indications of pregnancy include the following. Cyanosis of the vagina (Chadwick’s sign, Jacquemier’s sign) is present by about 6 weeks. 5 DIAGNOSIS OF PREGNANCY AND PRENATAL CARE CHAPTER Copyright 2001 The McGraw-Hill Companies. Click Here for Terms of Use. BENSON & PERNOLL’S 104 HANDBOOK OF OBSTETRICS AND GYNECOLOGY TABLE 5-1 PRESUMPTIVE OR PROBABLE SIGNS AND SYMPTOMS OF PREGNANCY* Symptoms Signs Amenorrhea Leukorrhea Nausea, vomiting Changes in color Breast tingling, mastalgia consistency, size, or Urinary frequency, urgency shape of cervix or Quickening uterus Temperature elevation (usually by BBT) Enlargement of abdomen Breasts enlarged, engorged, nipple discharge Pelvic souffle (bruit) Uterine contractions (with enlarged corpus) * Although these may be suggestive, even Ն2 are not diagnostic of pregnancy. Softening of the tip of the cervix (Fig. 5-1) occasionally is noted by the 4th–5th week of pregnancy. However, infection or scar- ring may prevent softening until late pregnancy. Softening of the cervicouterine junction often occurs by 5–6 weeks. A soft spot may be noted anteriorly in the middle of the uterus near its junction with the cervix (Ladin’s sign) (Fig. 5-2). A wider zone of softness and compressibility in the lower uterine segment (Hegar’s sign) is the most valuable sign of early pregnancy and can usually be noted at ϳ6 weeks (Fig. 5-3). Ease in flexing the fundus on the cervix (McDonald’s sign) gen- erally appears by 7–8 weeks. Irregular softening and slight enlargement of the fundus at the site of or on the side of implantation (Von Fernwald’s sign) occur by ϳ5 weeks. Similarly, if implantation is in the re- gion of a uterine cornu, a more pronounced softening and sug- gestive tumor like enlargement may occur (Piskacek’s sign) (Fig. 5-4). Generalized enlargement and diffuse softening of the uterine corpus usually occur Ն8 weeks of pregnancy (Fig. 5-5). CHAPTER 5 DIAGNOSIS OF PREGNANCY 105 TABLE 5-2 COMPARATIVE DIFFERENTIAL DIAGNOSIS OF PRESUMPTIVE SYMPTOMS AND SIGNS OF PREGNANCY Cause(s) if Differential Diagnosis Pregnant (Not Pregnant) Symptoms Amenorrhea hCG, etc. Pseudocyesis or other psychoneurosis, endocrinopathies (including premature menopause), metabolic disorders (e.g., anemia, malnutrition), obliteration of the uterine cavity, systemic disease (e.g., acute or chronic infection), malignancy Nausea, hCG, etc. Emotional vomiting disorders (e.g., pseudocyesis, anorexia nervosa), GI disorders (gastroenteritis, peptic ulcer, hiatal hernia, appendicitis, intestinal obstruction, food poisoning), acute infections (e.g., influenza, encephalitis) (Continued) BENSON & PERNOLL’S 106 HANDBOOK OF OBSTETRICS AND GYNECOLOGY TABLE 5-2 (Continued) Cause(s) if Differential Diagnosis Pregnant (Not Pregnant) Mastalgia, Estrogen Estrogen with breast tingling (duct anovulation, stimulation), fibrocystic progesterone breast disease (alveolar stimulation) Urinary urgency, Estrogen Urinary tract frequency (cystourethral infection (UTI), turgescence) cystourethritis or cystocele, anxiety, diabetes, pelvic tumors, emotional tension Quickening Fetal movements Increased Ͼ14 weeks peristalsis, free (approx.) adnexal cyst, pseudocyesis, gas, contractions Constipation Altered diet; Low fluid, low hypoperistalsis fiber diet Fatigue Progesterone Overwork effect Weight gain Gestational Overeating anabolism Signs Leukorrhea Estrogen Vaginitis, cervicitis, genital foreign body, tumor Pelvic organ alterations Cyanosis of Hormones Vascular anomaly cervix or of pregnancy or tumor of Chadwick’s cervix or uterus sign (Ͼ6 weeks) CHAPTER 5 DIAGNOSIS OF PREGNANCY 107 Softening of Hormones Chronic cervicitis cervix of pregnancy (Ͼ4–5 weeks) Softening of Hormones Vascular uterine lower uterine of pregnancy anomaly or segment (Ͼ5–6 tumor weeks), Landin, Hegar’s sign Irregular Hormones Myoma fundal of pregnancy softening, enlargement (Ͼ5 weeks) Generalized Hormones Adenomyosis or corpus of pregnancy myomata softening, enlargement (Ͼ8 weeks) Temperature Progesterone Infection, corpus elevation basal luteum cyst, body temperature hCG or (BBT) Ͼ2 weeks progestogen therapy, faulty thermometer Abdominal Uterine size Obesity, pelvic or enlargement abdominal tumor, ascites, obesity, relaxation of abdominal muscles, pelvic and abdominal tumors, ascites, or ventral hernia (Continued) TABLE 5-2 (Continued) Cause(s) if Differential Diagnosis Pregnant (Not Pregnant) BENSON & PERNOLL’S 108 HANDBOOK OF OBSTETRICS AND GYNECOLOGY Breast changes Enlargement, Estrogen and Mastitis, engorgement, progesterone malignancy, secondary PMS, areola pseudocyesis (Ͼ6–8 weeks) Colostrum Prolactin, Hypothalamic (Ͼ16 weeks) progesterone galactorrhea excess Pelvic souffle Increased pelvic Pelvic tumor or (bruit) blood flow vascular anomaly (aneurysm) Uterine Braxton-Hicks Pseudocyesis, contractions contractions tightening– (with enlarged relaxation of uterus) abdominal muscles Skin Pituitary pigmentation melanotropin Ultraviolet (chloasma, linea exposure nigra) (tanning) Epulis Progesterone Gingivitis (Ͼ12 weeks) TABLE 5-2 (Continued) Cause(s) if Differential Diagnosis Pregnant (Not Pregnant) ABDOMINAL FINDINGS OF EARLY PREGNANCY Active movements usually are palpable Ն18 weeks. By the 16th– 18th week, passive movements of the fetus may be elucidated by abdominal and vaginal palpation. A firm tap on the uterine wall or vaginal fornix displaces the fetus as a floating body. An impulse then can be felt as a thrust as the fetus moves back to its former position (ballottement). Ascites and tumors must be excluded. After the 24th week, the fetal outline may be palpated in many pregnant women. CHAPTER 5 DIAGNOSIS OF PREGNANCY 109 FIGURE 5-1. Softening of the cervix. FIGURE 5-2. Ladin’s sign. FIGURE 5-3. Hegar’s sign. FIGURE 5-4. Piskacek’s sign. 110 No subjective evidence of pregnancy is totally diagnostic, how- ever, and laboratory diagnosis is essential. LABORATORY EVIDENCE OF PREGNANCY BETA-SUBUNIT hCG Assays for beta-subunit hCG, commonly used to diagnose preg- nancy, have an admitted failure rate (ϳ1%). Moreover, they may be positive in nongestational ovarian choriocarcinoma or in un- common gastrointestinal or testicular tumors. Nevertheless, a pos- itive beta-subunit hCG test may be considered reasonable proof of pregnancy. A true positive followed by a true negative pregnancy test may indicate abortion. The major methods for determining the beta-subunit hCG are as follows. CHAPTER 5 DIAGNOSIS OF PREGNANCY 111 FIGURE 5-5. Bimanual pelvic examination. BENSON & PERNOLL’S 112 HANDBOOK OF OBSTETRICS AND GYNECOLOGY IMMUNOLOGIC TESTS Immunologic tests for pregnancy (Table 5-3) are based on hCG’s antigenic potential (direct or indirect agglutination of sensitized RBC or latex particles). These tests require slides or test tubes for reagents and take from a few minutes to over an hour to complete. Test sensitivities vary widely (250–1400 mIU/mL). Radioimmunoassay (RIA) The hCG radioimmunoassay (RIA) requires a gamma counter for the highest sensitivity. The test, reportable in Ͻ90 min is extremely accurate (ϳ20 mIU/mL.) Thus, it usually is used when sensitivity is crucial. Radioreceptor Assay (RRA) The RRA measures the biologic activity by in vitro binding of hCG to bovine corpus luteum membrane. Unfortunately, hCG and hLH cannot be separated by RRA. A commercially available RRA, Bio- cept G, has set its negative endpoint high to avoid false positive re- ports. The accuracy does not approach that of RIA or ELISA. Enzyme-Linked Immunoabsorbent Assay (ELISA) A specified monoclonal antibody produced by hybrid cell technol- ogy is used for the ELISA assay. With ELISA, the enzyme induces a color change indicating the hCG level. ELISA is simple and rapid TABLE 5-3 IMMUNOLOGIC TESTS FOR PREGNANCY Method Materials Results Direct Latex particles Coagulation if coagulation coated with anti- hCG is present hCG ϩ serum or (pregnant) urine Inhibition of Anti-hCG ϩ serum Coagulation if coagulation or urine hCG is absent plus (not pregnant); Sensitized red cells inhibition if or hCG is present Latex particles (pregnant) coated with hCG [...]... developed, creases cover sole 128 BENSON & PERNOLL’S HANDBOOK OF OBSTETRICS AND GYNECOLOGY HISTORY AND PHYSICAL EXAMINATION A complete medical history and physical examination early in pregnancy provides the baseline for diagnosis and the treatment of disorders that may compromise pregnancy HISTORY OF PRESENT PREGNANCY Obtain the last menstrual period (LMP) and previous menstrual period (PMP) Then, calculate... may be more exact DURATION OF PREGNANCY AND EXPECTED DATE OF CONFINEMENT ESTIMATED DATE OF CONFINEMENT After a positive diagnosis, the duration of pregnancy and the estimated date of confinement (EDC) must be determined Because it is uncommon to know the exact onset of pregnancy, these calculations start from the first day of the last menstrual period (LMP) Pregnancy in women lasts about 10 lunar months... angle formed by the pubic arch (the angle of the rami at the pubis) is usually 110–120 degrees In an android pelvis, the angle is narrow (, degrees), and the BI is 90 narrow Spines of the ischium Consider the degree of prominence, sharpness, and extent of encroachment of the spines into the birth canal CHAPTER 5 DIAGNOSIS OF PREGNANCY 133 Sacrum The contour, depth, and irregularities (e.g., false promontory)... and fissures DIAGNOSIS Record the duration of pregnancy and any anticipated complications PROGNOSIS Record an initial prediction of the EDC and outcome of the pregnancy (vaginal or cesarean delivery) together with the likelihood of medical or surgical complications (e.g., diabetes mellitus, inguinal hernia) The prognosis must be altered if obstetric problems develop PLAN AND TREATMENT Project the care. .. bleed at delivery Cervix and uterus Examine as described in Chapter 16 Near term, it is essential to note cervical consistency, position, and degree of effacement and dilatation Record the site and extent of previous lacerations of the cervix because tears may recur at these sites during delivery CHAPTER 5 DIAGNOSIS OF PREGNANCY 131 Pelvic masses Distinguish between ovarian and other pelvic or retroperitoneal... HEIGHT AND STAGE OF GESTATION Week of Pregnancy Approximate Height of Fundus 12 15 Just palpable above symphysis Midpoint between umbilicus and symphysis At the umbilicus 6 cm above the umbilicus 6 cm below the xiphoid 2 cm below the xiphoid 4 cm below the xiphoid 20 28 32 36 40 CHAPTER 5 DIAGNOSIS OF PREGNANCY 117 Unusually large measurements suggest an incorrect date of conception, multiple pregnancy, ... pubis), and consistency of the uterine fundus and its relationship to other organs or landmarks Record the location of the fetal heart and its rate Abdominal organs that are palpable should be identified and abnormalities or extraneous masses identified These include hernias (umbilical, inguinal, femoral, and lumbar) Hernias often become larger during pregnancy Extremities Note development, deformity, and. .. these measures, record the position of the fetus, the 136 ● ● BENSON & PERNOLL’S HANDBOOK OF OBSTETRICS AND GYNECOLOGY engagement of the presenting part, and an estimate of the weight of the fetus Rectal or vaginal examinations may be done at virtually any time (in the absence of bleeding) to confirm the presenting part, establish its station, and determine the status of the cervix When the EDC, calculated... stability to assist in individualizing care Is she uncertain or confident? PHYSICAL EXAMINATION Conduct a complete general examination with special emphasis on the reproductive organs and systems most influenced by pregnancy Examination of the head, ears, eyes, nose, and throat should be recorded Careful auscultation of the heart and lungs is mandatory Serious diseases often are first noted during an obstetric...CHAPTER 5 DIAGNOSIS OF PREGNANCY 113 (5 min), no isotopes are used, and it can be an office (serum) test (e.g., Prognosis slide test, which measures to 1.5–2.5 mIU/mL) The tube, office or home test (e.g., Preco Rapid Care) measures only to 1.0 mIU/mL Nevertheless, even ELISA home kits are at least 90% accurate within the range mentioned RIA, RRA, or ELISA can be used for the diagnosis of pregnancy . 6 weeks. 5 DIAGNOSIS OF PREGNANCY AND PRENATAL CARE CHAPTER Copyright 2001 The McGraw-Hill Companies. Click Here for Terms of Use. BENSON & PERNOLL’S 104 HANDBOOK OF OBSTETRICS AND GYNECOLOGY TABLE. more exact. DURATION OF PREGNANCY AND EXPECTED DATE OF CONFINEMENT ESTIMATED DATE OF CONFINEMENT After a positive diagnosis, the duration of pregnancy and the esti- mated date of confinement (EDC). of pregnancy. Softening of the tip of the cervix (Fig. 5-1) occasionally is noted by the 4th–5th week of pregnancy. However, infection or scar- ring may prevent softening until late pregnancy. Softening of