PRENATAL ASSESSMENTA. Maternal Assessment The purpose of this course is to provide staff development in the area of clinical nursing practice. The course contains a series of self-contained learning material to be used for the care of the low-risk pregnant client. The material herein, should be used in conjunction with any policies or procedures already in effect in your facility. This course is intended only as a guide for those nurses perhaps unfamiliar with protocol relating to the pregnant client. It is also hoped that this course will help plant the seed of cooperation between departments at your facility. Blood Pressure Considerations This section will present the importance of assessment of the vital signs of the woman, in particular the blood pressure. Monitoring the blood pressure is one of the most important dimensions of prenatal care. A sustained elevation of the blood pressure can indicate a threat to the mother and/or fetus. Normally, pregnancy brings about a slight decrease in the woman’s blood pressure. The cardiac output increases, in some cases, up to 50%. The higher cardiac output is due to an increase in blood volume, body weight, and increased metabolism during normal pregnancy. This usually continues throughout the entire pregnancy, except during the late phase of pregnancy, due to impeded blood return to the heart because of an enlarged uterus. A baseline blood pressure reading is important. The Pressure is recorded early in the pregnancy and all subsequent readings are also recorded at regular intervals. It will be normal for the blood pressure to fluctuate during the confinement, however, large fluctuations may mean the existence of such problems as preeclampsia. MEASURING THE BLOOD PRESSURE Determination of the blood pressure is not difficult. It should follow the same procedure of any blood pressure determination.
Blood pressure is affected by position during the reading. Brachial artery pressure is highest when sitting, lowest when in the lateral recumbent position. The best position for measuring the pressure is in the sitting position; or the left lateral recumbent position. Supine readings should be avoided due to fluctuations, especially during late pregnancy. Be sure to use the same position each time the pressure is taken. HYPERTENSION DURING PREGNANCY Elevated blood pressure, as we already stated, can indicate a severe risk for the mother and fetus. Normal elevations are common for very short time periods. However, any time the pressure is above 140/systolic, or /90 diastolic, it can be a risk to both mother and fetus. Intensive monitoring of the pressure is necessary as soon as the hypertension is noted. As soon as the pressure begins to reach that point (136/80), the woman is watched closely. Each person is evaluated as an individual. If the woman has had blood pressure problems in their past pregnancies, she will be watched more carefully than someone who has not had problems in the past. Since it is difficult to actually pinpoint one specific blood pressure reading that you can say is sure. It is important when determining the significance of the elevated pressure reading, that you look for such things as adema, proteinuria and neuro changes. If some other adverse sign/symptom is also present, it might indicate severe pathology. Toxemia is a well-known term, it is not very often used today except as a very general term describing one of the hypertensive-related disorders of pregnancy. More properly the terms are:
These disorders, rather than just “toxemia”, are the ones which we are discussing in this section. When hypertension is present, there is a decreased blood flow to the fetus at the uteroplacental junction. This condition causes a number of problems including intrauterine growth retardation, platenta abruptio or fetal-neonatal depression. Each of these hypertensive disorders will be discussed next. In order to determine if the woman has hypertension which may affect the fetus, the “roll-over” test was developed by Gant and Associates in 1974. The woman is placed on her left side and the blood pressure is taken every 5 minutes until two identical diastolic readings are obtained. The woman then rolls over to a supine position where her blood pressure is taken immediately and in 5 minutes. If the pressure is found to be 20mm Hg or more, over the left lateral recumbent reading, the test is considered to be positive for hypertension. These women then, may be at risk for preeclampsia. This test is not very well known, as its reliability has not been researched thoroughly yet. The mechanism by which this test predicts the risk of hypertension is that hypersensitivity in some women predisposes to develop pregnancy-induced hypertension. PREGNANCY-INDUCED HYPERTENSION Preeclampsia is defined as the development of hypertension with edema and/or preteinuria after the 20th week of gestation. Most authorities agree with this definition, using 20, 22, or 24th week as the time frame. Preeclampsia is divided into two types, mild or severe. It is most often found in women who are you primigravidas, or diabetics, or over age 35, or who have chronic hypertension. Mild preeclampsia may very rapidly progress to severe type, so all cases are treated aggressively. Mild Preeclampsia ….or….systolic elevation of 30 mm Hg or more 2. Proteinuria: 1+ or 2+ 3. Sudden weight gain or edema (hands or face) These symptoms of the mild type can quickly progress to the severe type described on the next page. Mild preeclampsia can usually be treated at home with close supervision by a family member or reporting to the physician on a regular basis. Bedrest is usually quite effective in relieving the symptoms. Since the hypertension impairs circulation to the fetus, bedrest can increase blood flow to the uterus. By laying in the left lateral recumbent position, the uterus is kept off the maternal inferior vena cava and the right iliac artery. This causes a spontaneous diureses within 24 hours due to increased renal blood flow. This position also increases the return blood flow to the heart, and raises cardiac output which was compromised due to the hypertension. These two factors will lusually decrease the symptoms dramatically. In addition to prescribing bedrest, the physician may give tranquilizers to help the mother stay in bed. And a high protein diet with plenty of fluids. Any other signs/symptoms the woman has, will also be treated with either drug therapy or other methods safe to the fetus. Diuretics are usually not used unless absolutely unavoidable. They all tend to deplete soldium and that will add to the hypertension. Phenobarbital is usually the sedative of choice, it is safe and will let the mother rest in bed which can be very difficult at times. The only one immediate danger of the drug is that it has long-lasting effects and can cause neonatal respiratory depression. The high protein in the diet will have lower incidence of preeclampsia. In summary, mild preeclampsia is usually treated at home. The woman must be taught to recognize the warning signs/symptoms to report to the physician. They are:
The woman should also be taught how to collect her urine at home and even to test it for protein. Eclampsia is characterized by convulsions and/or coma. It almost always can be prevented with the proper treatment of preeclampsia. In most cases, preeclampsia symptoms will disappear upon delivery or death of the fetus, in utero. Only in some rare cases will the woman continue to have symptoms after the delivery. In even more rare cases, symptoms have been noted up to a week after the delivery. GESTATIONAL HYPERTENSION This type of hypertension is also called transient hypertension. It is defined as hypertension with no other symptoms present, noted in the second half of pregnancy or the first 24 hours after the delivery. The elevated blood pressure usually disappears a week after the delivery. It is treated like preeclampsia, with bedrest and sedation. Drugs are avoided unless it is severe; and it can become severe. In those severe cases, drug therapy may be used. The woman is carefully watched for signs of preeclampsia/eclampsia during the treatment of gestational hypertension. THROPHOBLASTIC DISEASE If the previously mentioned symptoms of preeclampsia develop prior to the 20th week of gestation, the cause of the hypertension may be due to a hydatidform mole. In this condition, the trophoblastic cells fail to form normal chorionic villi. Instead, the villi degenerate and form the hydatidiform mole, a mass of grape-like structures that may possibly become malignant in time. The symptoms to watch for are:
CHRONIC HYPERTENSION This condition exists when there is blood pressure above any of the previously mentioned readings of 140 mm Hg systolic and/or 90 mm Hg, diastolic, prior to the 20th week of gestation, and no other significant findings are present. When these signs of hypertension are present, the woman is checked every two weeks until about the 28th week, when the visits will be once weekly if the blood pressure remains high. The nurse should stress to the patient, the need for rest periods during the day while at home, at least one house in the morning and one hour in the afternoon. In the second trimester, at least 2 hours in the morning and afternoon should be taken. In the third trimester, even more rest is needed. The treatment then, includes frequent rest periods. The woman was probably taking some oral form of antihypertensive drug prior to the pregnancy, and will usually continue it. The antihypertensive drugs are preferred over the use of diuretics, due to the fact that diuretics will tend to deplete the person of one or more electrolytes. Diet is also important, usually a low-salt diet will be used. Sedatives may also be prescribed in order to help the person to rest the required amount of times during the day. Careful monitoring of the patient’s status is vital. The blood pressure must not fall too low or get too high; both conditions will deprive the fetus of blood flow and thus nutrients and the removal of wastes. The kidney function is monitored by routinely collecting urine and monitoring the output daily. The nurse should instruct the patient on the use of the medications, the diet therapy and resting. The nurse should also teach the patient’s family as to the side effects of drugs the patient will be taking and how to notify the physician if any problems occur. If the woman should have chronic hypertension and then develop symptoms of preeclampsia, immediate treatment and/or hospitalization is needed. These signs would be an increased elevation of blood pressure over 160/110. edema, and/or proteinuria. Again, preeclampsia can develop at any time, this stresses the importance of the family being taught how and what to do in the case where the woman herself is unable to get help. The edema and high blood pressure can incapacitate the patient, so that she cannot recognize the need for help. The nurse should provide for home support either through the family or visiting nurse if no family is available. URINALYSIS Urine evaluation is an important part of every office visit. The woman should bring in a specimen to every office visit. If the pregnancy is uneventful, routine urinalysis procedure is sufficient. If there is a known complication, the physician* may request more frequent urine evaluations. Each woman should be instructed as to the procedure used at your facility. It is, however, desirable to obtain a “clean catch” and midstream specimen. Explain to the woman how to obtain the specimen. Do not assume that they know how to do it, just by reading the direction; show the patient their first few times. The urinalysis is many cases, will consist of using the reagent strips manufactured by many different companies. Some strips will have multiple reagents, and tests for many factors in the urine: pH, protein, glucose, ketones, blood and others, can be test in just a few minutes. Do take precautions when handling and reading the results of the strips. They must be protected from moisture when being stored and you should always follow the instructions on the package for use and storage. Also be aware that there are many sources of false readings from the strips. If the patient is on any medications, check with a reference source to see if that drug will interfere with the results of the reagent strips. Contaminants in the urine and/or the specimen container can also give false readings. Preeclampsia, as we discussed, can cause abnormal constituents to be present in the urine. Protein is not normally found in the urine except in minute amounts. With preeclampsia, renal disease and others, protein will be found in the urine. Any other abnormal constituent in the urine will cause the practitioner to investigate and perhaps run further tests to determine the nature of the problem. A change in the urine specific gravity, or pH or color may indicate preeclampsia or other problem. * When we refer to the “physician” we are also referring to any health care practitioner who is caring for the patient. Today, nurse practitioners and other types of health professionals may be taking the responsibility for following and treating the patient for a “routine” pregnancy. The nursing responsibilities include instructing the patient, which we discussed, and collecting and testing the specimen. Always use a fresh specimen. If the urine will not be tested for several hours, refrigerate it and/or add an approved preservative. Urine will sometimes give false results if it is left standing for an hour or more. Another responsibility of the nurse is the complete assessment of the patient. Especially if there is an abnormal result, the nurse will thoroughly assess the patient. A patient history is vital for reasons why the urinalysis is abnormal. Perhaps the patient ate a “strange” meal before the specimen was obtained. Foods may temporarily color the urine and even cause other changes. Exercise, drugs, and body temperature may also cause abnormal urinalysis results. The nurse should be alert to anything out of the ordinary, and report it as a possible cause. URINARY INFECTIONS An infection in the urinary tract will cause one of the several abnormal constituents to appear in the urine. Protein, blood, cells and discoloration are just a few. Infection can also be asymptomatic. Normal physiological changes of pregnancy make the urinary tract more susceptible to infection; such as dilation of ureters and kidney pelvis and general hypokinesis (slowed function) of the tract. These changes lead to stasis of urine, thus the increased risk of infection. If infections are mild, there is usually no affect on the fetus. However, severe and untreated infections can lead to pyelonephritis. This is a severe condition which may affect the fetus, research is still being conducted in these areas. The urinalysis still remains the most reliable method of screening for infection of the urinary tract. It will detect up to 90% of all cases, since these infections will show abnormal test results. Of course, there can always be some error in the urinalysis testing, due to improper storage, temperature, and others discussed previously, but if the nurse follows all safe procedures for sampling, error will be kept to a minimum. The following are symptoms which might indicate an infection:
The nursing actions include the following:
It is important that all of the above actions be followed. In those cases of asymptomatic infection, be sure to investigate even the smallest complaint, as it may be the only warning of an infection. Always use the recommended procedure for collecting specimens, to avoid contamination and to obtain best results. GLUCOSURIA Glucose and Lactose may normally filter through the kidneys of the pregnant woman, in small amounts. Lactose is usually of no significance. During pregnancy, the renal threshold is lowered and the glomerular filtration rate is increased, these lead to some glucose being filtered into the urine. It usually is of no concern, but should be carefully monitored on each visit to the office or clinic. Urine test strips should be used, or any other reagent which tests for glucose only, should be used. A 1+ glucose level is almost always significant and should be referred for medical follow-up. There are some authorities who feel that even a trace of glucose should be treated aggressively, so please use the protocol at your facility. Nursing Assessment for glucosuria: 1. History and Subjective Data Include any diabetes in the family, previous infant of 4,000 grams or more, previous history of infant death or placental problems, any infant with congenital anomalies, late abortions, infertility, hydramnios, prepregnancy obesity, any symptoms of thirst, weakness or sweating. Record: urinalysis results, any related symptoms of diabetes, recurrent candidiasis, weight gain pattern during pregnancy, hydramnios during pregnancy, and any other significant lab tests related to blood sugar levels or postprandial blood sugars. 2. Nursing Actions If any of the above suggests diabetes, obtain fasting urine specimen and repeat the urinalysis or follow the protocol at your facility and refer the patient immediately for medical consultation, which ever is the appropriate procedure at your facility. KETONURIA Ketonuria is the presence of ketone bodies in the urine. Ketone bodies are the products of incomplete fat metabolism. There is only weak evidence that ketone bodies in blood will adversely affect the fetus. Some studies show that brain damage might occur, but reliable evidence is absent at this time. Ketones are present in the woman’s blood in diabetes, severe dieting, hyperemesis gravidarum and other conditions. Routine testing for ketones is generally accepted as good, due to the fact that in certain disease conditions, ketones are present. Ketonuria in diabetic women, indicates the presence of ketoacidosis, and can be a sign of possible impending coma. Young adults are more prone to ketoacidosis, especially in conjunction with other problems or infections. Nursing Assessment:
In summary, always be accurate with testing procedures and your assessment of data. If there is an abnormal result, follow established protocol, and also anticipate the type of tests which may be used as follow-up for the woman. EVALUATION OF LABORATORY TESTS General Considerations
This chapter will present the most commonly used tests for screening certain “abnormal” conditions in the pregnant woman. It goes without saying that these are not all of the tests that can be used. There are many other tests that could possibly be performed, especially in the case of complications of pregnancy. Always be aware of the fact that each facility or physician will have a different protocol, be informed of that and use that, we well as using your nursing skills of assessment learned in this booklet. TESTS MOST COMMONLY USED FOR SCREENING
In the following part of the text, we will present lab values for the pregnant and non-pregnant woman. Usually, you will note that the lab values for most blood tests for the pregnant woman will be lower than the values for the non-pregnant woman. This does not always hold true, and the assessment for the nurse is vitally important for the diagnosis of problems during the pregnancy. Routine blood studies may reveal many potential problems. This routine screening is usually done at the first prenatal visit and then only if there is a suspected problem, will the entire series be repeated. Once this baseline is obtained, only the minimum number of tests will be performed at each visit due to the expense and inconvenience. Hemoglobin (Hgb) and Hermatocrit Hct) These tests are part of the CBC (complete blood count) test, and are usually performed as a baseline test in order to detect the gross anemias. Some clinics perform only the Hct because it alone will give indication of anemia, and it is much faster and cheaper to perform than the Hgb. The Hgb and Hct can be affected by changes during pregnancy. There is a rise in total blood volume (35% to 50%), which can affect results. Normal Hgb is 12-16 for non-pregnant women, 11-12 for pregnant women (gm/100ml). The Hct for the non-pregnant women is 37-47%, for pregnant women, 32-42%. Anemia is a general term and there is disagreement as to what value indicates anemia. Certainly, the lower the lab value, the worse is the anemia. However, if the Hgb or Hct is lowered, the woman will need to be assessed further for the type of anemia, the cause and the treatment. WBC, White Blood Cell Count This is another baseline test, usually performed only on the first visit unless otherwise indicated. It is used to detect blood abnormalities such as leukemia and to screen for such conditions as infection. The normal non-pregnant woman is 4,500 to 10,000. The pregnant woman will usually show an increase in the neutrophils and then the total white count will be about 5,000 to 15,000. During labor and immediately postpartum, the count may be as high as 20,000 to 25,000. The pregnant woman is usually not treated “routinely” with antibiotics as any other person would be with a high white count. The woman with an elevated WBC should be carefully assessed for signs and symptoms before any treatment should be instituted. Differential Smear (diff) With this test, the individual types of WBC’s are examined. The proper ratio and amounts of each type should be present. Of course, if one type of WBC is high or lower than normal, it could indicate a specific type of infectious process. RBC’s are routinely examined at this time just to screen for abnormalities. The platelets are also “loosely” examined just to ensure an adequate number. Blood Grouping This blood typing is routinely performed, even though the woman may say she knows her blood type. Often they are mistaken, and the type they submit is not their type. Incompatibility may exist for the infant if, for instance, her type is O, and the male partner is A, B, or AB. This incompatibility is rare, but can happen. Rh Factor Determination Erythroblastosis fetalis can be avoided by determining the Rh factor and treating those whose mother is Rh negative and the male is Rh positive. This is a common situation, and easily treated today. Antibody Screen This test is usually performed on the first visit in order to determine whether or not the mother has any antibodies which may be harmful to the fetus. A woman can build up antibodies to a number of factors. They can occur naturally, or in response to antigens or even rare blood factors. Even in primigravidas the screen should be done because the woman could have been sensitized before even the first pregnancy by some external factor. SEROLOGY FOR SYPHILIS Syphilis treated by the 16th to 18th week of gestation will usually leave the fetus unaffected. If the infection is allowed to go longer than 18 weeks, the fetus may die in utero or be born with the infection. This test is always a part of the routine screening tests done on the first visit. RUBELLA SCREENING A baseline rubella titer is usually a routine test at the first visit. It is important to establish a rubella antibody titer. During the first 5 months of pregnancy, the fetus can be adversely affected if the mother contracts rubella. In fact, there are major risks in the first trimester. Most women do not know for sure if they have ever had rubella. This is due to the mild symptoms which are typical of the disease. Therefore, if the titer is high (1:16), it suggests that the woman is immune to the disease. If the titer is low (1:8 or less), it suggests that the woman is susceptible. Generally, women of child-bearing age are not routinely immunized against rubella, due to the risk to the fetus if they should happen to be pregnant. The vaccine will have the same bad effect upon the fetus as the disease would. Therefore, the best time to immunize the woman is immediately after delivery, since it is sure she is not pregnant. If this is the case, she should not become pregnant for at least 3 months after the immunization. Two-hour Postprandial Blood Sugar This test is usually a routine test at the first visit only. The non-pregnant woman of child-bearing years will usually metabolize glucose in the normal way. If the woman has hidden tendencies toward diabetes mellitus, it will be more likely to appear during pregnancy due to the changes in the process of glucose metabolism at this time. The test is usually performed during the 26th-30th weeks of gestation. This test is also preferred over the full glucose tolerance test because of less expense and time involved. Findings of greater than 145 mg/100ml may indicate further assessment is needed. The test should also be definitely performed on these:
With any of these historical findings, the woman should always be screened for diabetes. If the nurse should encounter any other signs or historical facts which might suggest glucose intolerance, the patient should be carefully assessed and further screening should be performed. CERVICAL TESTS Pap Smear (Papanicolaou Smear), is used to detect cervical cancer or asymptomatic cervical herpes. If the test is positive, further evaluation is necessary, even if the woman is pregnant at CULLTURE OF GONORRHEA Due to the rise in the numbers of persons who develop the resistant strains of gonorrhea, it is very important that all clients have this test performed on the first visit. If there are symptoms later on in the pregnancy, the test should be repeated thereafter. There is conflicting data as to when the test should be performed in order to obtain the best results. Some authorities say it should be performed only in the first trimester, others say only late in the third trimester. Use the guidelines at your facility, and always be alert for the symptoms of the infection. OTHER SPECIFIC TESTS The tests listed below, will be used for only selected women who are at high risk for the particular problem. Always keep in mind the possible effects upon the fetus of any woman with any health problem.
This concludes the section on maternal prenatal assessment. We have concentrated upon the lab tests which are the most useful and commonly used tools for screening. There are many other tests available, both invasive and non-invasive, which can be used for diagnosing and accessing problems with the mother or the fetus. The nurse should use these available resources at your particular facility, in order to fully be able to assess the person completely. Always follow established guidelines at your facility and always keep the patient informed as to the purpose of the tests and their outcomes. Patient education can and should be a “routine” procedure at your facility. If the mother feels at ease with the testing procedure, the nurse will be better able to assess the woman and will usually gain the full cooperation of the mother-to-be, making the process much easier for the client. Next: FETAL ASSESSMENT |