HIGH-RISK PREGNANCY pps

7 HIGH-RISK PREGNANCY CHAPTER 199199 Although pregnancy can be classified as a normal physiologic con- dition, it is fraught with considerable risk to both mother and off- spring. Fortunately, most of the risk occurs to a minority of patients. Thus, it is prudent to identify those at risk and attempt to prevent the morbidity and mortality. Some factors contributing to risk are quite obvious, but others are very subtle. Thus, care must be taken in definitions, screening programs, and application of the tools available for diagnosis and treatment. The following is but one of the ways to approach this multifaceted set of circumstances. DEFINITION, INCIDENCE, AND IMPORTANCE A high-risk pregnancy is one in which the mother or perinate is or will be in jeopardy (death or complications) during gestation or in the puerperium/neonatal interval. Estimates of the incidence of high-risk pregnancy vary widely depending mainly on the criteria used for definition and the accuracy of the data collection. Never- theless, by most standards, ~20% of established pregnancies in the United States are at some risk and ~5% are at high risk. About half can be identified antenatally and another quarter during labor (Table 7-1). For example, the majority of perinatal deaths are as- sociated with prematurity or congenital anomalies. If these two con- ditions are excluded, 60% of fetal and Ͼ50% of neonatal deaths are associated with only five obstetric complications: breech presenta- tion, premature separation of the placenta, preeclampsia-eclampsia, multiple pregnancy, and urinary tract infection. Certain less com- mon complications (e.g., cord prolapse) also cause an inordinately high proportion or perinatal losses. Of course, a low-risk pregnancy (not endangered by present or foreseeable complications) can be- come high risk at any time. The early identification of risk factors is vital for both avoid- ance of serious problems and proper treatment of complications Copyright 2001 The McGraw-Hill Companies. Click Here for Terms of Use. BENSON & PERNOLL’S 200 HANDBOOK OF OBSTETRICS AND GYNECOLOGY T ABLE 7-1 IDENTIFICA TION OF SPECIFIC OBSTETRIC RISK F ACTORS I NITIAL EV ALUATION Biologic F actors High Risk Some Risk Maternal age Ͻ15 or Ն35 Maternal age 15–19 years years Morbid obesity Ͼ20% of standard height Poor nutrition for weight Maternal malignancy Ͻ20% of standard height Ovarian neoplasms for weight Genetic or familial Short stature (Յ60 inches) disorder Uterine leiomyomata Incompetent cervix Pelvic or spinal deformity Cervical malformation Uterine malformation Congenital anomaly Genital tract anomalies Obstetric History High Risk Some Risk Parity of Ն8 Parity of Ͼ5 Three or more abortions Prolonged labor or dystocia Stillborn or neonatal loss Infertility Previous pregnancy with: Prior ABO incompatibility Premature labor Prior fetal malpresentation Birth weight Ͻ2500 g Previous PIH Birth weight Ͼ4000 g Genital tract infections Genetic disorder Human papillomavirus Congenital anomaly (HPV) Isoimmunization Herpes Eclampsia Gonorrheal Birth damaged infant Chamydia Special neonatal care Group B Streptococcus Medically indicated pregnancy termination Molar gestation CHAPTER 7 HIGH-RISK PREGNANCY 201 Hypertension (moderate to Mild hypertension severe) Class I heart disease Severe renal disease Gestational diabetes Class II–IV heart disease Recurrent urinary Insulin-regulated diabetes infections Endocrine ablation (thyroid) Positive serology Abnormal cervical cytology Sickle cell trait Sickle cell disease Epilepsy Pulmonary disease Emotional disorders Liver disease Smoking Recurrent pyelonephritis Pelvic inflammatory Collagen vascular disease disease Malignancy Previous ectopic Gastrointestinal disease pregnancy Substance abuse Physical abuse Heavy smoking (Ͼ10 day) EV ALUATION ON EACH PRENATAL V ISIT,EARLY PREGNANCY (Յ20 WEEKS ) High Risk Some Risk Teratic exposure Antenatal diagnosis Failure of uterine growth indicated Isoimmunization Unresponsive urinary Severe anemia tract infection (Յ9 g Hgb) Possible ectopic gestation Multiple gestation Missed abortion Fetal anomalies Severe hyperemesis Cervical incompetence gravidarum Insulin-regulated Positive serology diabetes Sexually transmitted Fetal anomalies disease Nonimmune hydrops Unresponsive anemia Renal agenesis Vaginal bleeding (Potter’s) Diet-regulated diabetes T ABLE 7-1 (Continued) Medical and Sur gical History High Risk Some Risk (Continued) BENSON & PERNOLL’S 202 HANDBOOK OF OBSTETRICS AND GYNECOLOGY EV ALUATION ON EACH PRENATAL V ISIT,LATER PREGNANCY (Ͼ20 W EEKS) High Risk Some Risk IUGR Pregnancy Ն41 1/2 weeks Anemia (Յ9 g Hgb) Preeclampsia Severe preeclampsia Breech (for vaginal Eclampsia delivery) Isoimmunization Placenta previa Oligohydramnios Premature onset of labor Hydramnios (Ͻ36 weeks) Thromboembolic disease Premature rupture (Ͻ38 Abruptio placentae weeks) Abnormal antepartum test Chronic or acute (NST, CST, BPP) pyelonephritis Prolonged membrane rupture Abnormal fetal position Fetal infections INTRAPARTUM EV ALUATION High Risk Some Risk High-risk factors above Mild PIH Severe PIH or eclampsia Rupture of membranes Hydraminos or Ͼ12 h oligohydramnios Primary dysfunctional Amnionitis labor Prolonged membrane Secondary arrest of rupture (Ͼ24 h) dilatation Uterine rupture Labor Ͼ20 h Abruptio placentae Second stage Ͼ2.5 h Placenta previa Precipitous labor Meconium in amniotic fluid Prolonged latent Abnormal presentation phase Multiple gestation Uterine tetany Fetal weight Ͻ1500 g Induction of labor Fetal weight Ͼ4000 g Operative forceps FHR patterns indicating Vacuum extraction compromise Nonreassuring FHR patterns T ABLE 7-1 (Continued) CHAPTER 7 HIGH-RISK PREGNANCY 203 responsible for increased maternal and perinatal mortality and mor- bidity. Despite steady improvement, at least three quarters of ob- stetric deaths (9/100,000 births) and at least one half of newborn deaths (10/1000 births) in the United States are preventable. PRENATAL CARE: A DIAGNOSTIC AND THERAPEUTIC PROGRAM Good prenatal care is preventive medicine of a high order. It pro- vides an opportunity to identify the individual’s risk status and ap- propriately individualize care for each patient. Moreover, it has been amply demonstrated that those gravidas who receive good prenatal care materially improve both their own and their offspring’s chance of successfully negotiating this most hazardous interval of life. Maternal, fetal, or neonatal hazard often can be foretold by crit- ical assessment of the gravida’s history, physical examination, and antenatal course. Dozens of factors during pregnancy, labor, deliv- ery, and the early puerperium suggest added risk; for example, unwanted pregnancy, ignorance, exposure to toxic products, and un- willingness or inability to obtain good early obstetric care relate to high-risk pregnancy. Whatever the problem, prevention, early di- agnosis, and proper treatment will greatly reduce the perinatal mor- tality and morbidity rates. Thus, most clinicians include these fac- tors in their plan for prenatal care (Chapter 5) and actively search for and treat them as the pregnancy progresses. Additionally, several risk scoring systems to predict jeopardy have been suggested. Although risk scoring systems are not as sensitive or Breech delivery General anesthesia Prolapsed cord Abnormal maternal vital Fetal acidosis signs Shoulder dystocia Fetal presentation not Maternal distress descending with labor T ABLE 7-1 (Continued) INTRAPARTUM EV ALUATION High Risk Some Risk BENSON & PERNOLL’S 204 HANDBOOK OF OBSTETRICS AND GYNECOLOGY as specific as originally thought, they may provide a useful method to ensure that most of the risk-producing states are screened in each gestation. HISTORICAL SCREENING Poverty, ignorance, substance abuse, and unwanted pregnancy are sociologic conditions associated with high-risk pregnancy. These may take years to alleviate, and their solutions have little to do with medicine. For example, low socioeconomic and single marital sta- tus (in an adolescent) are two important obstetric high-risk factors. Although physicians cannot do much to remedy the underlying problem, proper diet, rest, social support, proper antenatal care, and good patient cooperation can improve the prognosis of such an ado- lescent to approximate that of most middle-income gravidas. Thus, our purpose is to deal primarily with factors that can be influenced by medical management and the currently available diagnostic and therapeutic modalities. A uniform perinatal record is very useful to assist the physician in evaluating high-risk pregnancy. Some commercially available forms may use risk lists, whereas others rate factors according to their importance. Whatever system is used, it must be applied as- siduously. MATERNAL AGE The lowest rates of maternal and perinatal morbidity and mortality occur at maternal age 20–29 years. Thus, younger and older women are at greater risk. Adolescent pregnancy has a higher frequency of low birth weight infants, and in those younger than 16 years, there is increased risk of pregnancy-induced hypertension. Mothers age 35 or older are at high risk, and those over 40 years are at extraordinary risk. The most common problems are increased chromosomal abnormalities, chronic hypertension, pregnancy-induced hypertension, obesity, uterine leiomyomas, increased incidence of age-related medical problems (e.g., diabetes), and an increased risk of being delivered by cesarean section. The risk of trisomy is directly related to age, rising from 0.9% at age 35–36 years to 7.8% at age 43–44 years. Prenatal diagnosis screening questions (Table 7-2) should be asked of each older gravida and the follow-up documented. Starting the screening as early as maternal age 32 has merit. Women with a low level of serum alpha-fetoprotein (AFP), regardless of age, should CHAPTER 7 HIGH-RISK PREGNANCY 205 T ABLE 7-2 PRENA T AL DIAGNOSIS SCREENING QUESTIONS Circle Appropriate Answer 1. Will you be age 35 or older Yes No when the baby is due? 2. Have you or the baby’s father or anyone in either of your families ever had a. Down syndrome? Yes No b. Spina bifida or Yes No meningomyelocele (open spine)? c. Hemophilia Yes No (blood will not clot)? d. Muscular dystrophy? Yes No 3. Have you or the baby’s father Yes No had a child born dead or alive with a birth defect not listed in Question 2? If yes, describe: 4. Do you or the baby’s father Yes No have any close relatives who are mentally retarded? If yes, list cause if known: 5. Do you or the baby’s father Yes No or close relative in either of your families have any inherited genetic or chromosomal disease or disorder not listed above? 6. Have you or the spouse of Yes No this baby’s father in a previous marriage had three or more spontaneous pregnancy losses? 7. Do you or the baby’s father Yes No have any close relatives descended from Jewish people who lived in Eastern (Continued) BENSON & PERNOLL’S 206 HANDBOOK OF OBSTETRICS AND GYNECOLOGY T ABLE 7-2 (Continued) Circle Appropriate Answer Europe (Ashkenazi Jews)? If yes, have either you or the Yes No baby’s father been screened for Tay-Sachs disease? If yes, indicate results and who screened: 8. If patient or spouse is African Yes No American: Have you or the baby’s father or any close relative been screened for sickle cell trait and found to be positive? I have discussed with my doctor the above questions which are answered yes and understand that I am at increased risk for: and that it is usually possible to diagnose an affected fetus by testing amniotic fluid at about 16 weeks of pregnancy or placental tissue at an earlier time in pregnancy and I DO NOT want the test. (Patient Signature) (Date) Patient wants amniocentesis and fetal diagnoses for: Patient referred for further testing or counseling concerning: * Modified from Antenatal Diagnosis, NIH Publication No. 79-193, April 1979. be considered for amniocentesis because they have an increased risk of trisomic offspring. In summary, it is important to ascertain the following. Does the patient, her husband, or their family have heritable disorders (see Table 7-2)? What is the health of first-degree relatives (siblings, parents, and offspring), second-degree relatives (uncles, aunts, nephews, nieces, and grandparents), and third-degree relatives (first cousins)? What are the probable reproductive outcomes? Is there drug exposure (both husband and wife)? What are the parental ages (paternal risk Ն55)? What is the ethnic origin (be- cause of enhanced risk of several disease states, e.g., Tay-Sachs disease in Ashkenazi Jews, ␤-thalassemia in Italians and Greeks, sickle cell anemia in African Americans, and ␣-thalassemia in Southeast Asians)? OBSTETRIC HISTORY The number of previous pregnancies is important. To para 5, there is increased chance of successful pregnancy. However, after 5, the risk from uterine inertia, postpartum hemorrhage, placenta previa, and abruptio placenta begins an almost exponential increase. A his- tory of infertility places a patient at increased risk because of a greater incidence of fetal wastage. There is a correlation between the outcome of previous pregnancies and what may happen to the current pregnancy. Thus, the following obstetric historical findings signal risk: in- duced hypertension, baby with known or suspected genetic disor- der or congenital anomaly, and birth-damaged infant or infant re- quiring special neonatal care. Other historical risk factors include operative deliveries (cesarean section, midforceps or breech ex- traction), prolonged labor or dystocia, severe psychiatric distur- bances associated with pregnancy, and closely spaced pregnancies (Ͻ3 months). REPRODUCTIVE TRACT DISORDERS Abnormalities of the reproductive tract cause at least 25% of re- cidive reproductive losses. Thus, a history of incompetent cervix, septate uterus, bicornuate uterus, or uterine leiomyomas may warn of pregnancy risk. Other reproductive tract aberrations that may place the pregnancy at risk because they can require therapy dur- ing pregnancy include cervical dysplasia and ovarian tumors. Should intervention be necessary, the safest time to perform sur- gery is during the second trimester, when both post surgical abor- tion and preterm labor have the lowest incidence. EXPOSURE TO FETOTOXIC AGENT For discussion of the topic, see Chapter 5. CHAPTER 7 HIGH-RISK PREGNANCY 207 BENSON & PERNOLL’S 208 HANDBOOK OF OBSTETRICS AND GYNECOLOGY MEDICAL COMPLICATIONS OF PREGNANCY Some of the systemic diseases creating risk in pregnancy include: blood disorders (e.g., coagulopathy, sickle cell disease), cancer, cere- bral aneurysms or tumors, chronic hypertension, connective tissue disease (e.g., systemic lupus erythematosus), diabetes mellitus, en- docrine ablation, epilepsy, gastrointestinal and liver disease, heart disease, pulmonary disease, renal disease (e.g., glomerulonephritis), and thyroid disorders (both hyperthyroidism and hypothyroidism). FAMILY HISTORY A detailed family history keyed to mental retardation (with partic- ular attention to males—potential fragile X syndrome), multiple ges- tation, and heritable diseases is mandatory. Risk assessment is aided by a three-generation pedigree. PHYSICAL EXAMINATION STATURE Women less than 5 feet (150 cm) tall have increased fetopelvic dis- proportion. Thus, short stature is an indication for careful bony pelvis assessment. WEIGHT Ideal weight is necessarily predicated on height and body habitus, and abnormalities of weight must be individualized. Both under- weight and overweight signal risk for the perinate. Moreover, the maternal prepregnancy weight and gain during pregnancy are re- lated directly to birth weight. The woman who weighs Ͻ100 pounds (45 kg) when not pregnant has an increased chance of having an SGA infant. Women who are obese for height have a greater chance of gestational diabetes as well as pregnancy complicated by LGA birth, dysfunctional labor, shoulder dystocia, and birth trauma. Mor- bidly obese gravidas increase their risk even further. BLOOD PRESSURE Hypertension poses risk to pregnancy and requires evaluation (Chapter 13). Although occasional hypotension from orthostasis or [...]...CHAPTER 7 HIGH-RISK PREGNANCY 209 from the supine hypotensive syndrome is of concern, it is easily managed symptomatically BREASTS When a mass is found, the usual breast cancer workup cannot be delayed by the pregnancy HEART Diastolic murmurs, systolic murmurs Նgrade 3, and arrhythmias always require a medical evaluation VASCULAR SYSTEM Severe varicosities tend to thrombose during pregnancy (p 441)... enhancing outcome COURSE OF PREGNANCY ANTENATAL VISITS Antenatal visits must be more frequent for high-risk than for normal obstetric patients to accurately appraise the pregnancy and identify and correct problems Antenatal visits also provide an opportunity for education about problems, their solution, and counseling The etiologies of many serious problems that develop during pregnancy are reviewed elsewhere... detailed in Chapter 14 PROBLEMATIC SYMPTOMS OR SIGNS Symptoms or signs of greatest concern during the course of pregnancy include vaginal bleeding, uterine growth out of proportion to dates, and the untimely termination of pregnancy Uterine bleeding in early or late pregnancy warns of jeopardy to the pregnancy (Chapters 10 and 11) A discrepancy in uterine size for dates requires ultrasonic scanning for explanation... Preterm termination of pregnancy, with or without rupture of membranes, is second only to congenital anomalies as a cause of morbidity and mortality Postterm pregnancy termination poses risks of uteroplacental insufficiency, meconium-containing amniotic fluid, and complicated labor or trauma during labor and delivery (from excessive size) SURGERY DURING PREGNANCY Although not increased by pregnancy, acute... during gestation The major pregnancy CHAPTER 7 HIGH-RISK PREGNANCY 211 complications of acute appendicitis (similar to all abdominal surgery) include premature delivery and peritonitis If all physical trauma (e.g., assault, motor vehicle accidents, and falls) were categorized as surgical emergencies, trauma would head the list The patient with significant physical trauma during pregnancy has a marked risk... examination and fundal measurements may be influenced CHAPTER 7 HIGH-RISK PREGNANCY 221 by maternal habitus, imprecise calculations of gestational duration, multiple pregnancy, hydramnios, or uterine tumor Ultrasonographic measurements of both general obstetric patients and those at risk for macrosomia are no more precise than clinical estimates The pregnancy suspected (or known) to be complicated by macrosomia... declines in heart rate (from the baseline), usually in response to uterine contractions Indeed, CHAPTER 7 HIGH-RISK PREGNANCY 233 FIGURE 7-3 Fetal heart rate tracings (A) Schematic tracing (B) Early deceleration (C) Late deceleration (D) Variable deceleration (From S.G Babson et al., Management of High-Risk Pregnancy and Intensive Care of the Neonate, 3rd ed Mosby, 1975.) 234 BENSON & PERNOLL’S HANDBOOK OF... vital signs signaling risk during pregnancy are abnormal weight or blood pressure As noted previously, 210 BENSON & PERNOLL’S HANDBOOK OF OBSTETRICS AND GYNECOLOGY failure to gain weight during pregnancy often is associated with an SGA perinate, and excessive weight gain is associated with an LGA perinate Fever can trigger preterm labor and can injure the fetal CNS Pregnancy- induced hypertension (PIH)... or adult is only one detail that must be evaluated with other available information CHAPTER 7 HIGH-RISK PREGNANCY 231 BASAL FETAL HEART RATE The fetal heart rate (FHR) in early gestation is higher than at term, when it is 120–160 bpm Gradual slowing amounts to ϳ20 bpm and occurs linearly throughout the pregnancy The baseline or basal FHR is the average rate prevailing apart from beat-to-beat variability... immune globulin plus toxoid CHAPTER 7 HIGH-RISK PREGNANCY 213 T ELBA 7-3 (Continued) Typhoid Varicella Yellow fever Recommended if traveling to endemic area Varicella-zoster immune globulin for exposure Indicated for newborns whose mothers developed varicella within 4 days before or 2 days after delivery Postpone travel if possible but immunize before travel to high-risk areas Commonly, uterine dystocia . 5. CHAPTER 7 HIGH-RISK PREGNANCY 207 BENSON & PERNOLL’S 208 HANDBOOK OF OBSTETRICS AND GYNECOLOGY MEDICAL COMPLICATIONS OF PREGNANCY Some of the systemic diseases creating risk in pregnancy. Chamydia Special neonatal care Group B Streptococcus Medically indicated pregnancy termination Molar gestation CHAPTER 7 HIGH-RISK PREGNANCY 201 Hypertension (moderate to Mild hypertension severe). each gestation. HISTORICAL SCREENING Poverty, ignorance, substance abuse, and unwanted pregnancy are sociologic conditions associated with high-risk pregnancy. These may take years to alleviate, and their solutions