the College, is professor and. Chairman of the Department of. Family Medicine at McMaster. University, Hamilton.Dr. Feldman is professor of. Pediatrics at the ...
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W.W. Rosser, MD, CCFP W. Feldman, MD, FRCP(C) P. McGrath, PhD
Preventive Health Examinations Part I: Preconception to Birth
SUMMARY
RESUME
The family physician may conduct preventive screening of children yet unborn, beginning with assessing the rubella-immunity status of 12-year-old females and continuing through the preconception period, the prenatal period, and the process of birth. Knowledge of both parents and their family history allows family physicians to deal effectively with the very sensitive issues of risks of congenital disorders and the effects of teratogenic drugs during pregnancy. Prenatal monitoring for various disorders and risks and assessing the growth curve of pregnancy will help to improve fetal outcomes. Proper use of suctioning, oxygen, and application of the Apgar score to monitor and detect evidence of asphyxia at birth can result in healthier babies. (Can Fam Physician 1988; 34:1119-1123.) Key words: preventive health examinations, prenatal management
La position privilegiee du medecin de famille, comme dispensateur de soins, l'amene a proceder au depistage preventff chez des enfants qui ne sont pas encore nes, debutant par lI"valuation de l'etat immunitaire contre la rubeole des filles de 12 ans, et se poursuivant tout au long de la periode de preconception, la periode prenatale et la periode de l'accouchement. Le fait de connaltre les deux parents et leur histoire familiale permet aux medecins de famille d'aborder efficacement certaines questions delicates soulevees par la discussion des risques du syndrome de Down, de la rubeole, du syndrome alcoolique foetal et des effets des medicaments teratogenes pendant la grossesse. Pendant la periode prenatale, la surveillance du diabete gestationnel, la discussion du tabagisme maternel, le depistage de l'incompatibilite Rh et l'appreciation de la courbe de croissance de la grossesses contribueront a ameliorer les chances de survie du foetus. Au moment de l'accouchement, l'utilisation appropriee de la succion, de l'oxygene et du decompte de l'indice d'Apgar pour surveiller, et deceler les signes d'asphyxie peuvent favoriser une meilleure sante chex les bebes. Si tous les medecins de famille pouvaient se servir adequatement de ces techniques et incorporer dans leur pratique les nouvelles metodes de depistage comme les alphfoetoproteines, aussitAt terminee leur evaluation critique et obtenue leur approbation, notre prochaine generation jouira d'une meilleure sante.
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Dr. Rosser, a Fellow of the College, is professor and Chairman of the Department of Family Medicine at McMaster University, Hamilton. Dr. Feldman is professor of Pediatrics at the University of Ottawa and Director of Ambulatory Care at the Children's Hospital of Eastern Ontario, Ottawa. Dr. McGrath is adjunct professor of Psychology and Pediatrics at the University of Ottawa, and senior psychologist and Ministry of Health Clinical Scholar at the Children's Hospital of Eastern Ontario, Ottawa. Requests for reprints to: Dr. W.W. Rosser, Department of Family CAN. FAM. PHYSICIAN Vol. 34: MAY 1988
Medicine, 1200 Main St. W., Hamilton, Ont., L8N 3Z5
FAMILY
PHYSICIANS are uniquely placed among healthcare providers to influence complete health care of our children. Since preconception consultation is important for preventive screening and the initiation of care for children, the opportunity to influence complete health care begins with confirming presence of rubella antibodies in 12-year-old girls. Preventive care continues to be important as future mothers progress through the reproductive cycle. There are a number of steps that should be taken early in pregnancy to detect potentially serious outcomes that call for consideration of whether termination
of pregnancy is justified and acceptable. At the time of birth, several preventive steps are indicated. Monitoring the well baby from birth to adolescence provides a number of opportunities for screening and effective prevention. With our emerging understanding of genetics and the potential of gene manipulation when abnormalities are detected, preconception and prenatal screening is becoming increasingly important. This paper reviews current knowledge of screening procedures that should be dealt with from preconception to birth. The purposes of preventive health examination in the preconception and prenatal period are threefold: *to reassure and to educate the parents; 1119
~
* to conduct appropriate screening which rise with the age of the fetus. In tests or procedures; and the near future, alpha-fetoprotein blood * to counsel parents in the interpreta- sampling may be introduced as a tion of these procedures. screening procedure for all women at 14-16 weeks of pregnancy. If the samA screening procedure may be de- ple in an appropriate laborafined as a procedure or test, the purpose tory,is analysed the procedure, in combination of which is early detection of an illness with ultrasound, will detect neural in an asymptomatic person. The proce- tube defects and 40% of most Down syndure can be justified only if the test is drome in women under age 35. Prenaacceptable, cost effective, specific, and tal chromosome analyses using highsensitive, and if, given positive results, resolution banding techniques may dean intervention can be made that will al- tect other genetic abnormalities such as ter the natural history of the disease. Prader-Willi syndrome, in which there Canada, through the Task Force on is a demonstrated deletion involving the Periodic Health Examination, has chromosome 15. an organized approach to determining which of the available procedures ful- Rubella Syndrome fill these criteria. The tests discussed in Theoretically, rubella syndrome bethis paper have been chosen on the basis came entirely preventable with the adof these criteria. 1 vent of the rubella vaccine. This syndrome, resulting from maternal infection contracted, usually, in the first triDown Syndrome Down syndrome was the first genetic mester of pregnancy, is characterized syndrome to be made readily detectable by congenital cataracts, congenital early in pregnancy. Preconception- heart anomalies, mental retardation, counselling of mothers is particularly microcephaly, and deafness. When the important in relation to this syndrome. syndrome results from infection conFigure 1 outlines the age-related risks tracted in the second trimester, it is usuof Down syndrome. In spite of the sig- ally marked by mental and motor retarnificant increase in incidence after ma- dation and deafness. Of women who ternal age 35, the incidence of Down contract the rubella infection in the first eight weeks of pregnancy, 50%-80% syndrome remains relatively low at are likely to have babies affected by ruabout 8/1000 live births by maternal bella syndrome. The percentage deage 40. The incidence is increased if the creases thereafter. mother has previously given birth to a child with Down syndrome: the recurThe key to prevention of rubella synrence rate is as high as 1.5 % in women drome is rubella immunization. Ruover 35 who have already delivered one bella immunization by means of the child with this disorder.2 Genetic RV27 attenuated rubella-virus immunicounselling is recommended for any zation vaccine,3 is most effective in parent with a family history of Down children under the age of 12 years. Afsyndrome, trisomy 18, trisomy 13, or ter this age there is a decreasing likeliother autosomal anomalies, and it is a hood of an antibody-titre response to standard recommendation that amnio- the immunization vaccine. A 25-yearcentesis be conducted in all pregnant old woman who receives the vaccine women over the age of 35. However, has a 25 % chance of showing no antithere is minimal value in conducting an body-titre response to the immunizaamniocentesis unless the parents are tion. 4 generally accepting of the option of a It is ideal to establish a woman's rutherapeutic abortion. bella antibody-titre before pregnancy is Chorionic villus sampling, which contemplated. In the absence of antican be performed as early as eight to bodies, it is recommended the vaccine nine weeks gestation, is currently un- be given three months before concepdergoing evaluation for its sensitivity tion. A titre should be conducted six and specificity as a procedure for de- weeks subsequent to the immunization tecting genetic anomalies. This test to verify immunity to rubella. In may be preferred to amniocentesis, women known to be immune to rubella, since it is done earlier in pregnancy. An it is valuable to do a rubella titre before antenatal diagnosis made later in preg- conception or early in pregnancy so nancy and followed by a therapeutic that if a rash or exposure occurs during abortion increases the maternal risks, pregnancy, the titre can be remeas1120
ured. A three-fold rise in the antibody titre during pregnancy indicates exposure that is likely to have a significant effect on the fetus.
Fetal Alcohol Syndrome The fetal alcohol syndrome was first described a decade ago. Unfortunately, the ratio of alcohol consumed to adverse affects in the fetus is not well established. It remains uncertain whether the early developing fetus is more sensitive to alcohol than the fetus after three months gestation. At present there is no clear evidence that maternal consumption of less than three ounces of alcohol a day results in fetal defects. 5 It has been documented, however, that pregnant women who consume more than six ounces of alcohol a day on a regular basis have a 50 % -60 % chance of delivering a child suffering from fetal alcohol syndrome. The syndrome typically involves specific facial characteristics, congenital heart anomalies, and mental retardation. Since the risks of its occurrence in babies whose mothers consume less than six ounces of alcohol daily remain unclear, the most conservative policy is to recommend that women planning conception consume no alcohol. Further difficulties associated with fetal alcohol syndrome arise from the lack of a method of prenatal detection of the anomalies relating to this syndrome, as they rarely involve gross congenital characteristics detectable by ultrasound. There is evidence that education of women about the risks of the fetal alcohol syndrome has reduced consumption of alcohol by one group of women at least fivefold.6 Currently, the family physician's responsibility is to inform patients before conception, or early in pregnancy about the current information relating to the syndrome.
Teratogenic Drugs Preconception counselling about drug use is essential. The list of known teratogenic drugs includes thalidomide, aminopterin, metholtrexate, trimeth-oprim sulfamethoxazole, clotrimazole, androgens, and accutane. A very useful booklet called The Handbook for Prescribing During Pregnancy7 provides guidance for discussing the risk of all other drug use, especially early in pregnancy. Each individual illness or case must be carefully evaluated for the risks of the adverse affects to the fetus of high fever CAN. FAM. PHYSICIAN Vol. 34: MAY 1988
or extreme illness as compared to the risks of using drugs or medications early in pregnancy. Since drug interactions during pregnancy are not well understood, the most prudent policy is to minimize drug use. It is wise to inform women planning pregnancy that no drugs, dispensed either over the counter or by prescription, should be taken without discussing potential risks with their physician.
Malnutrition There is firm evidence that hypoproteinemic diets during pregnancy can reduce development ofnerve tissue in the fetus and will likely cause long-term adverse affects. Counselling and instruction about diet, combined with monitoring of both maternal and fetal growth curves, are important during pregnancy. It is especially important to monitor the fetal growth curve. Early evidence of fetal growth retardation should prompt a physician to take a diet history and give appropriate advice, especially if there is need to increase the protein content of the diet. There is no clear evidence that vitamin deficiencies in North American diets cause significant fetal problems. Although many physicians advise the prospective mother to use iron supplements throughout her pregnancy to prevent anemia, there is no clear evi-
dence that a well-nourished woman diabetes be managed in collaboration needs to overcome the net loss of 1500 with a high-risk prenatal-care centre or mg of iron during pregnancy and deliv- an obstetrician experienced in dealing ery. Nor is there as yet any clear evi- with this condition. dence that taking folic acid or other vitamin supplements in pregnancy al- Maternal smoking ters the outcome in the newborn. Any woman planning a pregnancy or pregnant who smokes more than two or three cigarettes per day should be inPrenatal Screening formed of the risks of adverse affects Gestational diabetes mellitus on the fetus. Smoking 20 cigarettes a The perinatal mortality rate in unde- day or more has been directly related to tected gestational diabetes is between a higher-than-average perinatal mor5% and 8%. If an appropriate screen- tality rate and an infant birth weight that ing program is implemented, 25 in is lower than average to a statistically 1000 women screened will be found to significant degree. Some studies have have gestational diabetes. There is firm indicated the occurrence of perceptual evidence that increased surveillance and other developmental problems in during the pregnancy and early deliv- seven-year-olds born of smoking mothery will significantly reduce the risks ers. Unfortunately, there are few studfor the fetus. ies in the literature that demonstrate The two most important screening major benefits from intensive antiprocedures during pregnancy are docu- smoking programs targeted to pregnant menting the family history for diabetic women, but there is some evidence that risk and monitoring the mother's urine women will respond to their physifor sugar. 8 Any woman with 2 + glu- cian's advice and support in pregnancy cose on urine testing and a family his- and reduce cigarette smoking. 9 tory of diabetes should undergo a glucose-tolerance test. Recently, some ob- Risk assessment ofpregnancy The purpose of assessing risk early stetricians have suggested that all pregnant women undergo a modified glu- in pregnancy is to detect women who cose-tolerance test at the end of the sec- are at significant risk of having perinaond trimester. There is no clear evi- tal difficulties or problems that place dence of the efficacy of this procedure the fetus at high risk during gestation. in the current literature. It is recom- Assessing fetal risk is especially impormended that women with gestational tant for physicians practising in rural or Figure 2 Monitoring Fetal Growth
Figure 1 Frequency of Down syndrome per 1000 live births according to maternal age
1/50
10 9
o
8
0
7
S y
m
p h y s
0 0 0 a
s
.4 u
n
4
d u
s
25
30
35
40 45 Maternal Age
50
H e
h 22 24 26 28 30 32 34 Gestational Age (weeks)
Zones 1 and 6 are high risk. A change of two zones up or down may be significant. Source: Courtesy of the Ontario Medical Association. CAN. FAM. PHYSICIAN Vol. 34: MAY 1988
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remote areas, where the need to anticipate intrapartum difficulties is great.
this adverse effect. II meconium staining is observed during If a child is severely asphyxic, it is labour or at the time of delivery, immeThere is evidence that early detec- essential that immediate intubation be diate tube suctioning of the infant's tion and referral to high-risk-manage- carried out, followed by a prolonged nose and throat prior to the first gasps ment centres results in improved fetal artificial inspiration with the first may clear the meconium and reduce the outcomes. There is also evidence that breath. This manoeuvre usually stimu- risks of meconium aspiration. 12 It has separating a woman from her family lates the cardio-respiratory system. been demonstrated that direct visualiand social support for the last few Meconium staining of the amniotic zation of the larynx and endotrachial weeks of a pregnancy increases perina- fluid occurs in 9%-15% of births. If suctioning until all meconium is retal risks. Studies demonstrating that social support is the most important pre- Table 1 dictor of perinatal outcomes for both The Apgar Score mother and child suggest that balancing Apgar Score these risks requires careful consideration. 0 2 1 Figure 2 is a simple chart used to Characteristic monitor the fetal growth and detect Heart rate < 100 > 100 0 perinatal fetal-growth retardation. De- Respiratory effort Apnea & crying Vigorous gasping shallow Irregular viation across two of the six zones indiPink Pale blue Pale or blue extremities cates a fetus that is at high risk. Only if Colour Active movement Weak, passive tone Absent the fetus is at risk or if the dates are im- Muscle tone portant, should a combination of ultra- Reflex irritability Active avoidance Grimace Absent sound and lecithin:sphingomyelin ratio be used to predict, with good accuracy, Table 2 the optimum time to deliver the baby. Management of Acute Resuscitation of the Newborn on the Basis of the Apgar Score Screening for RH incompatibility Management A simple and important step to be Apgar Score taken early in pregnancy is to deter- Step A-8,9,1 0 1. Gentle suction with bulb syringe only. mine maternal RH. If a mother is RH 2. Maintain body temperature. (no asphyxia) negative and has no evidence of anti3. Conduct brief physical examination. 4. Assign Apgar score. bodies, screening should be done again at 24 weeks, and the mother should re1. Repeat gentle suction with bulb syringe. Step B-5,6,7 ceive RH-immune globin at 28 and 38 2. Maintain body temperature. (mild asphyxia) weeks, as well as in the first 48 hours 3. Stimulate breathing by slapping soles of feet post partum. This procedure reduces or rubbing spine or sternum. 4. Provide enriched oxygen by bag and mask the risk of RH antibodies in 90% of subnear baby's face. sequent pregnancies.
Intrapartum Prevention Prevention at birth At the time of birth, there are a number of steps that can lower the risk of asphyxia. As soon as the baby is delivered, the cardio-respiratory status should be assessed by means of the Apgar Score (Table 1). Tube suctioning of the newborn in the absence of respiratory problems is contraindicated, since the procedure results in bradycardia and hypoxia in 10%-15% of healthy babies. Ifthere are no respiratory problems, the procedure recommended is to bulb suction the mouth and nose when the head is born. 0 If the Apgar Score indicates moderate asphyxia at one minute after birth, oxygen should be administered. There is firm evidence that cold dry oxygen blown directly into a newborn's nose will stimulate bradycardia and hypoxia, whereas room temperature, humidified oxygen blown across the baby's face prevents
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Step C-3 or 4 (moderate asphyxia)
Step D-1 or 2 (severe asphyxia)
5. If score rises to 8 +, carry out steps A-3 and A-4. 6. If heart rate falls to below 100, initiate step C. 1. Repeat steps A-1 and A-2. Call for help to monitor heart rate, manage airway; provide cardiac massage. 2. Provide a brief trial of stimulation (B-3) and provide pure 02 by mask for 1 minute only; if no response, proceed to C-3. 3. Ventilate with bag and mask using 100% 02 and pressure adequate to move chest. Continue until heart rate is > 100, colour is pink, and breathing is spontaneous. If chest does not move with ventilation, intubate. 4. If heart rate is 100 after 2 minutes, insert intravenous umbilical catheter and administer intravenous fluids, starting with NAHCO3 -dextrose. 4. Seek pediatric assistance or anesthesia assistance.
CAN. FAM. PHYSICIAN Vol. 34: MAY 1988
PRESCRIBING INFORMATION: moved significantly lowers the incidence of aspiration pneumonia that leads to significant morbidity and mortality. Table 2 outlines the sequential management of varying degrees of asphyxia as determined by repeat Apgar Scoring. Repeated assessment of the baby's respiratory status using the Apgar Score immediately post partum until the score is a stable 9 or 10 will ensure the optimum outcome for the child.
Conclusions In most pregnancies, the family physician can provide preconception planning and advice, as well as optimum prenatal and intra partum care. As technological advances occur during the next few years, preconception and prenatal screening will become increasingly important in preventing serious long-term disorders in children. By focusing on effective screening procedures now in use and incorporating new steps provided by genetic engineering and other advances, we have the opportunity to facilitate the optimum outcomes for coming generations of children. Current projections suggest that by the year 2000, most children in Canada will be cared for by family physicians. Our children and grandchildren deserve our best attempts to increase preventive screening from preconcepU tion to birth.
of Supply and Services, 1980; 24-30, 31-32, 49-50. 2. Burgio GR, Fraccar OM, Tipoco L, et al. Trisomy 21. New York: Springer-Verlag, 1981; 214. 3. Balfour H, Groth R, Edelam C. RA27/3 rubella vaccine: a four year follow-up. Am J Dis Child 1980; 134:350-3. 4. Balfour H, Groth R, Edelman C. Rubella viremia and antibody response to rubella vaccination and re-immunization. Lancet. 1981; 1:8229; 1078-1080. 5. Sokol R. Alcohol and abnormal outcomes of pregnancy. Can Med Assoc J 1981; 125:143-8. 6. Ashley M. Symposium: alcohol and the fetus. Can Med Assoc J 1981; 125:141-2. 7. Berkowitz R, Coustan D, Mochizuke J. Handbook for prescribing medication during pregnancy. Boston: Little, Brown, 1981. 8. O'Sullivan J, Mahan C, Charles D. Screening criteria for high risk gestational diabetic patients. Am J Obstet Gynec 1973; 116:895-900. 9. Oussula J, Fried PA. Effects of maternal social smoking and drinking on offspring at 13 months. Neurobehav Toxicol Terotol 1984; 8:13-7. 10. Carderol B, Hon E. Neonatal bradycardia following nasopharyngeal stimulation. J Physiol 1971; 78:441-6. 11. Brown W, Ostheimer G, Bell G, et al. Newborn response to 02 blown over the face. Anesthesiol 1976; 44:535-6. 12. Carson B, Losey B, Bowers W, et al. Combined obstetric and pediatric approach to prevent meconium aspiration syndrome. Amer J Obstet Gynecol 1976; 83:967-73.
References
For Further Reading
1. Canada. Ministry of Health and Welfare. Periodic health examination. Report of Task Force to the Conference of Deputy Minister's of Health. Ottawa: Department
Feldman W, Rosser WW, McGrath R. Primary Medical Care of Children andAdolescents. New York: Oxford University Press, 1987.
BENADRYL* (Diphenhydramine Hydrochloride)
Indications: The symptomatic relief of allergic diseases such as urticaria, atopic dermatitis, contact dermatitis, angioedema, pruritus, reactions to injection of contrast media, serum sickness, reactions to therapeutic preparations, gastrointestinal allergies, allergic transfusion reactions, allergic rhinitis, hayfever, vasomotor rhinitis; also post-operative nausea and vomiting, motion sickness, parkinsonism, and quieting emotionally disturbed children. Parenteral administration is indicated where, in the judgement of the physician, prompt action is necessary and oral therapy would be inadequate. Antiallergic, antiemetic and antispasmodic. Precautions: Avoid subcutaneous or perivascular injection. Single parenteral dosage greater than 100 mg should be avoided, particularly in hypertension and cardiac disease. Safety for use in pregnancy and lactation has not been established. Its use therefore in such patients should involve consideration of expected benefits and possible risks. Patients should be cautioned not to operate vehicles or hazardous machinery until their response to the drug has been determined. Since the depressant effects of antihistamines are additive to those of other drugs affecting the central nervous system, patients should be cautioned against drinking alcoholic beverages or taking hypnotics, sedatives, psychotherapeutic agents or other drugs with CNS depressant effects during antihistaminic therapy. Diphenhydramine has an atropine-like effect which should be considered when prescribing Benadryl. Rarely, prolonged therapy with antihistamines can produce blood dyscrasias. Adverse Effects: Drowsiness, dizziness, dryness of mouth, nausea and nervousness may occur. Other infrequently reported effects are vertigo, palpitation, blurring of vision, headache, restlessness, insomnia and thickening of bronchial secretions. Allergic reactions, diarrhea, vomiting and excitation may also occur.
Dosage: Oral: Average adult dose is 25 to 50 mg, 3 or 4 times daily. Children up to 12 years, 12.5 mg to 25 mg, 3 or 4 times
daily. Parenteral: 10 to 50 mg intravenously or deeply intramuscularly not to exceed 400 mg daily. High dosage for adults (300 to 400 mg daily) may be required in acute, generalized or chronic urticaria and allergic eczema. Supplied: Capsules of 25 and 50 mg; Elixir, 12.5 mg per 5 mL; Ampoules, 50 mg per mL; Steri-Dose Syringes, 50 mg per mL; Steri-Vials, 10 mg or 50 mg per mL. Product Monograph available on request.
PARKE-DAVIS
Parke-Davis Canada Inc., Scarborough, Ontario
FP^B i
|CP
CAN. FAM. PHYSICIAN Vol. 34: MAY 1988
Reg. T.M. Parke, Davis & Company Parke-Davis Canada Inc., auth. user
