High-Risk Pregnancy: Nursing Care Management

A high-risk pregnancy is one where a preexisting condition, a complication, or a social or psychological factor raises the odds of a bad outcome for mother, fetus, or both. Your job on the unit is early detection, tight monitoring, and acting fast when the picture shifts. This guide walks the conditions you will actually see and what to do about each.

Identifying a High-Risk Pregnancy

More than one factor can push a pregnancy into the high-risk category, and a woman who already carries a disorder before conceiving starts with a greater than normal risk. Risk is graded as minimal, moderate, or extensive, and the contributing factors break down into psychological, social, and physical.

Psychological factors: history of drug dependence, intimate partner abuse, or mental illness; loss of a support person; poor acceptance of the pregnancy; being severely frightened by the labor and birth experience; inability to participate because of anesthesia; illness in the newborn.

Social factors: an occupation involving toxic materials, environmental contaminants, isolation, low economic level, poor transportation, poor housing, refused or neglected prenatal care, a disruptive family incident, conception less than one year after the last pregnancy, lack of a support person, an inadequate home for infant care, and no access to continued health care.

Physical factors: pelvic inadequacy or misshape, uterine incompetence or abnormal position or structure, a secondary major illness, poor gynecologic or obstetric history, obesity, underweight, PID, potential blood incompatibility, age younger than 18 or older than 35, cigarette smoking, substance abuse, trauma, bleeding disruption, gestational diabetes, nutritional deficiency, infection, hemorrhage, cephalopelvic disproportion, and retained placenta.

Pregnant Women with Special Needs

A pregnant woman with a special need takes more attention than the average patient. Pregnancy is harder for her, so thorough assessment and extra teaching are what keep it safe.

The Pregnant Adolescent

Adolescent girls are not yet fully mature physically or emotionally, so they need targeted teaching to reach a safe delivery.

Adolescents carry higher rates of iron deficiency anemia, pregnancy-induced hypertension, premature labor, low birth weight infants, cephalopelvic disproportion, and intimate partner abuse. During the prenatal period she is often more comfortable with primary nursing or case management, since it limits the number of providers she sees. Take the first prenatal history without the parents present so you get a detailed, honest account. Encourage her to keep her prenatal visits, especially if she presented late, because staying in care protects the pregnancy.

If a parent comes along, ask them separately about their concerns, as they may be anxious about their daughter's health. The baby's father may attend the diagnosis visit, but he has no legal right in decisions about abortion or adoption because he is not married to her. Let him offer support and use the opening to teach him how to prevent further pregnancies until he is more mature.

Teach the adolescent the normal signs and symptoms of pregnancy and reassure her they are expected, so she does not self-treat with drugs that could harm the fetus. Some adolescents struggle to tell their parents, and roleplay or simulation can help her rehearse that conversation. Health teaching is mandatory here, because she has not gleaned the care measures that older women pick up through experience.

Push a nutrient-dense, mineral-rich diet to feed both the fetus and her own still-growing body, and show her how to assemble quick healthy meals or pick a nutritious cafeteria lunch if she is still in school. Remind her to take her vitamins and supplements, since adolescents are often poor at consistent dosing. Assess her activity and sports participation to decide what to discontinue, and suggest alternatives so she does not lose companionship, plus planned rest periods. Give her solid teaching on the physiologic changes of pregnancy and on labor and delivery so she treats the pregnancy as a growth experience. Encourage breastfeeding like any other patient and reassure her that her breast tissue will mature enough to feed.

The Pregnant Woman over the Age of 40

The danger after 40 comes mostly from complications and preexisting conditions, and starting prenatal care early steadily lowers the serious risks.

Women over 40 often already understand the value of early care and usually carry adequate insurance. Ask about current symptoms and how they fit her lifestyle to confirm she is not self-medicating. Assess her income source and whether stopping work would cut family income sharply, since she may need extra emotional support if she feels responsible for many people. Review her job, recent diet, and exercise to decide what needs modifying.

Ask about cigarette smoking and alcohol use to gauge whether she needs counseling to cut back. Do a thorough physical at the first visit to catch health problems, especially circulatory ones. Assess her breasts, fetal heart sounds, and fetal movements at each visit, because H-mole is also more common after 40. Obtain a urine specimen for specific gravity, glucose, and protein to evaluate renal function and the chance of gestational or type 2 diabetes. Review her meals, especially those eaten out, and suggest how to match home nutrition when she eats in restaurants. Suggest prenatal classes so she feels part of a group and sets aside time for breathing exercises. Encourage triple screen testing (AFP, hCG, and unconjugated estriol levels) to detect a chromosomal defect or open spinal cord in the fetus.

The Pregnant Woman Who Is Physically or Mentally Challenged

Women with disabilities were once discouraged from pregnancy, but with current technology and provider support they now plan pregnancies and have their concerns addressed at any facility. Careful planning tailors the pregnancy to exactly what she needs.

At the first visit, explore the nature of her disability to identify what must be adapted. A woman who is house bound must stay compliant with a vitamin D supplement, since she may not get adequate sun exposure. Assess her ability to reach emergency contacts and to get to prenatal visits or drive alone.

A woman who uses a wheelchair should press against the armrests and lift her buttocks off the seat for five seconds every hour to prevent pressure ulcers as the fetus gets heavier. Encourage increased fluid intake to prevent urinary tract infections and frequent voiding even when mobility is an effort. Physical exams may need modifying to accommodate her.

A woman who is cognitively challenged may not know how she became pregnant, so if she was sexually abused, give ample time before a pelvic exam, and limit instructions to the few items tied to safety. For a visually challenged woman, a trained guide dog may attend visits, but remember the dog has protective instincts and may feel threatened when people pet it. Use demonstration aids she can feel or touch, and because she cannot read pamphlets, have her support person read them or supply recorded information. Center nutrition counseling on foods that need no cooking. If mobility is limited, frame walking around her home as the equivalent of walking around the block. Encourage childbirth preparation classes when possible so she can practice breathing exercises.

For a hearing impaired woman, show printed words alongside your lip motions. If she uses a sign language interpreter, face the woman while you talk, not the interpreter. For a woman with spinal cord injury, teach her to palpate her abdomen for uterine contractions so she knows when she is in labor. Cesarean and forceps birth may be necessary with muscle spasticity or spinal cord injury. A woman who cannot assume a lithotomy position can deliver in a dorsal recumbent or Sims' position.

The Pregnant Woman Who Is Substance Dependent

A woman is substance dependent if she has withdrawal symptoms after stopping the drug. Screen for it at the prenatal visit, because illicit drug use is one of the major problems in this population.

She may present late for care, afraid her use will be discovered and reported. She may also struggle to follow nutrition instructions when she lacks money for food, drugs, and supplemental vitamins. Illicit drugs cross the placenta, and the fetus of a substance dependent woman carries a drug concentration of about 50% of the mother's. Drug abuse drives preterm birth and fetal abnormalities, and injected drug use raises the risk of hepatitis and HIV.

Cocaine is the most frequently abused drug in pregnancy. It causes extreme vasoconstriction that compromises placental circulation, leading to premature separation of the placenta and ultimately preterm labor or fetal death. Infants of cocaine-dependent women can suffer intracranial hemorrhage and withdrawal syndrome. Newborns exposed to amphetamines show jitteriness, poor feeding at birth, and growth restriction. A woman who uses marijuana or hashish cannot breastfeed because of reduced milk production and drug excretion in the milk. Narcotic agonists such as heroin cause fetal opiate dependence and severe withdrawal in the infant after birth.

An opiate-dependent woman can enroll in a methadone maintenance program during pregnancy. The infant still will not escape withdrawal, and methadone withdrawal runs more severe than heroin, but the fetus gains better nutrition, better prenatal care, and less exposure to pathogens because the drug is given legally. Buprenorphine is an option where methadone programs are not available.

Musculoskeletal Disorders in Pregnancy

The pregnant woman needs full musculoskeletal function throughout. The disorders below interfere with daily tasks and need active management.

Scoliosis

Scoliosis is the lateral curve of the spine. Left uncorrected, it progresses to deformity, with interference in respiration and heart function from chest compression. Pelvic distortion can interfere with birth, especially at the pelvic inlet, and makes epidural or spinal anesthesia difficult.

Scoliosis becomes more noticeable in girls at 12 to 14 years, and a body brace is recommended to maintain erect posture. The brace cannot be worn during the last half of pregnancy. Surgically implanted rods placed on both sides of the vertebrae do not interfere with pregnancy, and the back pain in women with steel rods matches what the average woman feels. When pelvic distortion and cephalopelvic disproportion occur with scoliosis, cesarean birth is necessary, though vaginal birth may be permitted with close monitoring of labor.

Cancer and Pregnancy

The most common malignancies during the childbearing years are cervical, breast, ovarian, thyroid, leukemia, melanoma, and lymphomas. Women who bear children at age 30 and above are more at risk, especially for breast cancer.

If a malignancy is diagnosed in the first trimester, the couple chooses among delaying treatment to reduce teratogenic effects, ending the pregnancy to start treatment, or continuing both pregnancy and treatment knowing the fetus might end up with birth anomalies. In the second and third trimesters, chemotherapy can be given safely, but direct radiation puts the fetus at risk. The cancer will not metastasize to the fetus, because the placenta acts as a barrier and the fetus resists foreign cells. Surgery to remove a tumor during pregnancy carries a risk of fetal anoxia during anesthesia, and cervical conization can disrupt the pregnancy. Cervical cancer incidence may fall in the future because of the HPV vaccine.

Mental Illness and Pregnancy

Schizophrenia most commonly first appears in young pregnant women, but depression is the most common mental illness in pregnancy. Childbirth and stress can unmask mental illness for the first time, since normal stress levels can still overwhelm coping.

A woman with an existing mental disease needs a psychiatric team plus a prenatal group so the pregnancy does not exacerbate the disease and depression does not complicate the pregnancy. Evaluate any psychotropic medications first, because they may be teratogenic. Mental illness can also surface during the postpartum period.

Trauma in Pregnancy

Trauma is uncommon in pregnancy because women take more precautions, but accidents still happen, so be ready to manage them.

Assessment

Assess fast but thoroughly, covering both physiologic and physical status.

Assess the injured woman while giving supportive reassurance, both to ease her fear of fetal damage and to remind her that she herself may be injured. Reduce anxiety first so she can cooperate during the interview. Take the pregnancy history and the trauma history. Document the circumstances: what happened, the time of injury, the signs and symptoms she has, and the actions she took. Judge whether the extent of injury matches the history, and assess her awareness of common safety measures. Evaluate the lungs, heart, kidney, and brain first, because injury to these systems puts the fetus in jeopardy.

Open Wounds

Use serial WBC measurements to detect infection, because the WBC count is normally elevated in pregnancy. Halt a bleeding laceration with pressure at the edges. For puncture wounds, give tetanus immunization if she has not had one within 10 years, and tetanus toxoid for women who have had one within the past 10 years. A fistulogram determines wound depth and extent. Pregnant women bitten by animals or snakes can receive rabies immune globulin and vaccine, plus anti-venom serum for snake bites, since these are not contraindicated. Caution her to avoid unfamiliar dogs and not to feed wild animals while camping.

Blunt Abdominal Trauma

Blunt abdominal trauma usually comes from an automobile accident when the abdomen strikes the steering wheel or dashboard, or from a kick or punch. Injured tissue becomes edematous, broken vessels form ecchymoses or hematomas, and there is no visible break in the skin. Assess for abdominal bleeding with a diagnostic peritoneal lavage or ultrasound, and work carefully because a traumatic blow can dislodge the placenta. A pelvic exam checks for vaginal bleeding or ruptured membranes. Confirm the fetus is unharmed by listening to the fetal heartbeat with Doppler. If preterm labor starts, give a tocolytic and attach fetal and uterine monitors.

Gunshot Wounds

Inspect both the entry point and the exit point of the bullet. If the uterus is punctured, there may be no entry point, because the uterine walls are very thick. Surgically clean and debride the wound and give a high-dose antibiotic that is safe in pregnancy, such as Ampicillin. Fetal mortality runs high if the bullet entered the uterus, especially if the placenta is torn. Stay with the woman as she recounts the history to law enforcement.

Poisoning

Have the woman contact the local poison control center, state that she is pregnant and what she swallowed, then follow their instructions. Activated charcoal is the drug of choice to neutralize stomach poison. Investigate the circumstances afterward so you can teach safety with medications and food and rule out suicidal intent.

Choking

Dislodging the object is harder in pregnancy because of the limited space between the uterus and the end of the sternum, and the average rescuer cannot reach around her enlarged abdomen from the rear. Use successive chest thrusts instead late in pregnancy.

Orthopedic Injuries

A woman late in pregnancy has poor balance and falls easily, and reaching out a hand to cushion the fall can cause serious wrist injury. Apply ice to decrease swelling as first aid. A radiograph determines whether a fracture is present, and it is safe as long as the abdomen is shielded during exposure. Help her identify calcium-rich foods so both she and the fetus get adequate calcium for new bone growth. A woman with a previous knee injury should be reevaluated early, because a knee immobilizer may be needed for the last 3 months to prevent the joint from dislocating or the ligament from tearing again.

Burns

Burns cause thermal injury and inhalation of carbon monoxide, which can drive extreme fetal hypoxia. Prostaglandins released in response to severe trauma can trigger preterm labor. If more than 50% of body surface area is burned, both mother and fetus are in grave danger. Burn tissue heals quickly in pregnancy, probably from the overall increase in metabolism and corticosteroid levels.

Respiratory Disorders in Pregnancy

A respiratory disorder in pregnancy can be fatal for both fetus and mother, so the respiratory system gets close attention.

Acute Nasopharyngitis

Estrogen stimulation causes nasal congestion, which makes nasopharyngitis more severe in pregnancy. Avoid aspirin, since it interferes with clotting in both mother and fetus and can prolong pregnancy. Have the woman clear any over-the-counter cough syrup with her provider first. Antibiotics are unnecessary unless they are preventing a secondary infection.

Influenza

Influenza spreads in epidemic form and is caused by viruses A, B, or C. Symptoms are high fever, back and extremity pain, and sore throat. It can cause preterm labor but is not linked to congenital anomalies. Give antipyretics like Tylenol to control fever. Women can be safely immunized in pregnancy because the vaccine contains only killed virus.

Pneumonia

Bacterial and viral pathogens such as S. pneumonia, H. influenza, and Mycoplasma pneumonia invade the lung tissue, triggering an acute inflammatory response in the alveoli. Trapped pathogens fill the lung with fluid and block the breathing space. Treat with antibiotic therapy and oxygen. Ventilation support is needed only in severe cases. Preterm labor can occur late in pregnancy from oxygen deficit, so give oxygen for the fetus.

Severe Acute Respiratory Syndrome

SARS presents with persistent fever, muscle aches, chills, dry cough, malaise, headache, and dyspnea. Decreased lymphocyte and platelet counts are common lab findings. The pathogen is the coronavirus, which originated in southern China, and it transmits by close person-to-person droplet contact. Treat with intravenous antibiotic and respiratory support. SARS in pregnancy is associated with spontaneous miscarriage, intrauterine growth restriction, and preterm labor.

Asthma

Asthma is reversible airflow obstruction with airway hyperreactivity and inflammation, and it carries perinatal complications. Inhaled allergens trigger symptoms by releasing histamines and leukotrienes from an IgE/immunoglobulin interaction. Bronchial constriction and thick secretions narrow the air passage lumen. The drop in oxygen reaching the fetus can start preterm labor or restrict growth. Inhaled corticosteroids such as beclomethasone and budesonide are safe in pregnancy, and cromolyn sodium and leukotriene receptor antagonists can be continued.

Endocrine Disorders in Pregnancy

Hormones drive pregnancy, so endocrine disorders demand close monitoring.

Diabetes Mellitus

In diabetes mellitus the pancreas cannot produce adequate insulin to regulate glucose, and the core problem is balancing glucose against insulin to prevent both hypoglycemia and hyperglycemia. Infants of diabetic women are 5 times more likely to have heart anomalies. Type 1 begins in childhood with inadequate insulin production; type 2 occurs in older adults with gradual insulin failure that comes with aging.

As pregnancy progresses, the glucose-insulin regulatory system shifts. At about week 24, the diabetic woman must increase her insulin dosage as advised to prevent hyperglycemia. Continued fetal glucose use can leave the mother hypoglycemic between meals. Fetal hypoglycemia raises fetal urine output, which increases amniotic fluid, so the woman may develop hydramnios and risk hemorrhage from poor uterine contractions. Pregnancy-induced hypertension and infection can occur with poor glucose control.

Infants of poorly controlled diabetic mothers are large for gestational age, with high rates of congenital anomalies such as caudal regression syndrome, spontaneous miscarriage, and stillbirth. At birth, neonates are at risk for hypoglycemia, respiratory distress syndrome, hypocalcemia, and hyperbilirubinemia.

Schedule more frequent prenatal visits for close monitoring of mother and fetus. Management includes insulin pump therapy, blood glucose monitoring, tests for placental function and fetal wellbeing, and good timing for birth. Teach a reduced-fat diet, and a nighttime snack of protein and complex carbohydrates for slower digestion. If nausea and vomiting keep her from eating, she should notify her provider for intravenous fluid supplementation. A fasting blood glucose below 95 mg/dL to 100 mg/dL and a 2-hour postprandial level below 120 mg/dL show good control.

Hypothyroidism

Hypothyroidism is rare in pregnancy because it causes anovulation and inability to conceive. When a hypothyroid woman does conceive, she struggles to raise thyroid function to the level pregnancy demands, which can lead to spontaneous miscarriage. Manifestations include fatigue, dry skin, and cold intolerance, with an increased incidence of nausea and vomiting or hyperemesis gravidarum. Levothyroxine dosage needs to rise by as much as 20% to 30% for the duration of pregnancy. Separate thyroxine from calcium, iron, or soy products by about 4 hours to avoid absorption problems.

Neurological Disorders in Pregnancy

Seizure Disorder

Most recurrent seizures are idiopathic, though some follow head trauma or meningitis. There is no contraindication to pregnancy as long as the medication is kept at the lowest effective dose and serum levels are carefully monitored. Early in pregnancy, have the woman continue the anti-seizure medications approved by both her obstetrician and primary care provider. The risk of adverse maternal or fetal outcomes from seizures during pregnancy is greater than the risk of teratogenicity from anticonvulsants.

Common seizure drugs are trimethadione, valproic acid, carbamazepine, and phenytoin sodium. Phenytoin lowers vitamin K coagulation factors, so the infant may be prone to hemorrhagic disease, and the woman should be prescribed vitamin K during labor or for the last 4 weeks of gestation.

Myasthenia Gravis

Myasthenia gravis is an autoimmune disorder with IgG antibodies against acetylcholine receptors in striated muscle, so the muscle fails to contract, particularly in the oropharyngeal, facial, and extraocular groups. Prescribed drugs are Mestinon or Prostigmin, which can be continued in pregnancy with no fetal effects. Plasmapheresis (removal and replacement of plasma) can reduce symptoms by clearing immune complexes from the bloodstream. Avoid magnesium sulfate, because it diminishes the acetylcholine effect and worsens symptoms. Labor proceeds normally since smooth muscle is not affected, but the infant may show symptoms at birth from transferred antibodies.

Multiple Sclerosis

MS demyelinates nerve fibers, which lose their function, producing fatigue, numbness, blurred vision, and loss of coordination. ACTH strengthens nerve conduction and is safe in pregnancy. Plasmapheresis can continue as long as the exchange volume is controlled. Pregnancy does not affect the long-term course of MS, and the disease may actually improve from the rise in circulating corticosteroid levels.

Gastrointestinal Diseases in Pregnancy

Pregnancy brings plenty of GI discomfort, but some symptoms signal a worsening condition.

Appendicitis

Appendicitis is inflammation of the appendix. Symptoms are nausea, abdominal discomfort, vomiting, and sharp, peristaltic, lower right quadrant pain, with the pain and the nausea and vomiting growing more intense. In a pregnant woman the pain can displace upward and be mistaken for gallbladder disease. She may have an elevated temperature and ketones in the urine, and ultrasound reveals the inflamed appendix.

Tell her not to take food, liquid, or laxatives while awaiting evaluation, because increased peristalsis can rupture the inflamed appendix. If she is almost past 36 weeks and the fetus is mature, a cesarean birth may be done and the appendix removed at the same time. Appendicitis in early pregnancy can be removed by laparoscopy. A ruptured appendix can spill fecal material toward the fallopian tube to the fetus, and the resulting peritonitis is more than the body can handle alongside pregnancy.

Gastroesophageal Reflux Disease

GERD is the reflux of acidic stomach secretions into the esophagus. Symptoms include heartburn, gastric regurgitation, dysphagia, weight loss, and hematemesis with extreme esophageal irritation. Diagnose by direct endoscopy or ultrasound. Antacids relieve pain and ranitidine inhibits gastric acid production. Have her wear loose clothing and sleep with her head elevated to confine stomach secretions. After pregnancy, symptoms ease or disappear as uterine pressure drops.

Hepatitis

Hepatitis is a liver disease from invasion by the A, B, C, D, or E virus. Hepatitis A spreads by fecal-oral contact or by ingesting fecally contaminated water or shellfish, and an exposed pregnant woman may receive prophylactic gamma globulin. Hepatitis B and C are acquired through contaminated blood, blood products, and other body secretions, with maternal-fetal transmission an important route, so the Hepa B vaccine may be given to high-risk women.

Symptoms include nausea and vomiting, a liver area tender on palpation, dark yellow urine, light-colored stools, and jaundice as a late sign, with noted hepatomegaly and an elevated bilirubin level. Put the woman on bed rest and a high-calorie diet. Cesarean birth can reduce mother-to-fetus transmission. Hepatitis can lead to spontaneous abortion or preterm labor. After birth, wash the infant well to remove maternal blood and give Hepa B immunoglobulin. The mother may still breastfeed but should be watched for signs of infection during the first few months.

Renal Diseases in Pregnancy

The woman's kidneys clear waste for both her and the fetus, so renal function matters for both.

Urinary Tract Infection

The ureters dilate from the effect of progesterone, causing urinary stasis. Escherichia coli is the most common organism behind UTI. Symptoms are frequency and pain on urination, sometimes with nausea and vomiting, malaise, and elevated temperature. Infection usually strikes the right side, where compression and stasis are greater because the uterus is pushed by the bulk of large intestine on the left.

Have her collect a clean catch sample for culture and sensitivity. Amoxicillin, ampicillin, and cephalosporins are effective and safe. For prevention, teach her to void at least every 2 hours, wipe front to back after voiding and bowel movements, wear cotton rather than synthetic underwear, void immediately after intercourse, and increase fluids to about 3 to 4 L per day to flush the tract.

Chronic Renal Disease

A woman with chronic renal disease may develop severe anemia in pregnancy because her kidneys cannot produce erythropoietin, though synthetic erythropoietin is now available. Many women with kidney disease run an elevated blood pressure. Those on corticosteroid maintenance continue their medications through pregnancy, but the infant may be hyperglycemic at birth from corticosteroid suppression of insulin activity. Dialysis may be needed to support kidney function, with a risk of preterm labor, and peritoneal dialysis is preferred over hemodialysis because it causes less fluid shift. Arrange nutrition consultation, especially for a low-potassium diet, to avoid potassium buildup the kidneys cannot excrete.

Cardiovascular Diseases in Pregnancy

Cardiac Disease: Left-Sided Heart Failure

Left-sided heart failure occurs when the left ventricle cannot push forward the blood it received from the left atrium and the pulmonary circulation, usually failing at the mitral valve. The back pressure on the pulmonary circulation produces pulmonary hypertension, which can precipitate spontaneous miscarriage, preterm labor, or maternal death. Decreased peripheral circulation can leave the placenta underperfused.

The woman has trouble sleeping from worsening pulmonary edema, so advise her to sleep with chest and head elevated. Heart action is more effective at rest, so interstitial fluid returns to the circulation and overburdens it, worsening left-sided failure and pulmonary edema. Complications can impair blood flow to the uterus, causing poor placental perfusion, intrauterine growth restriction, and fetal mortality. She needs serial ultrasound and nonstress tests on the 30th to 32nd week to monitor fetal health.

Cardiac Disease: Right-Sided Heart Failure

Right-sided heart failure occurs when the right ventricle's output is less than the blood volume received from the vena cava. The back pressure congests the systemic venous circulation and drops cardiac output. High vena cava pressure leads to jugular vein distention and increased portal circulation. The enlarged liver, pressed upward by the enlarged uterus, places extreme pressure on the diaphragm and causes severe dyspnea and pain.

Eisenmenger syndrome is the congenital anomaly most likely to cause right-sided failure in women of reproductive age. It is a right-to-left atrial or ventricular septal defect with pulmonary stenosis, and women with it are advised to avoid pregnancy. If she does conceive, give oxygen and assess arterial blood gas frequently to support fetal growth. During labor, watch closely for hypotension after epidural anesthesia.

Chronic Hypertensive Vascular Disease

A woman with chronic hypertensive vascular disease already runs an elevated blood pressure (140/90 mmHg and above) in pregnancy. Poor placental perfusion compromises both mother and fetus. The provider may prescribe beta-blockers and ACE inhibitors to lower the pressure by peripheral dilation, but not below the threshold that still allows good placental circulation.

Venous Thromboembolic Disease

Venous thromboembolic disease is more likely in pregnancy because of blood stasis in the lower extremities from uterine pressure plus the hypercoagulability driven by elevated estrogen. The triad of stasis, vessel damage, and hypercoagulation forms a thrombus in the lower extremities. Women 30 years and older have an increased risk of deep vein thrombosis leading to pulmonary emboli. Pain and redness in the calf usually signal thrombus formation.

Prevent thrombus formation by avoiding constrictive knee-high stockings, not crossing the legs at the knee, and not standing in one position too long. Diagnose a pregnancy thrombus by Doppler ultrasonography and history. Place the woman on bed rest with intravenous heparin for 24 to 48 hours. Women on heparin are not candidates for routine episiotomy or epidural anesthesia, to prevent hemorrhage, and PTT determination should continue during labor. A breastfeeding woman cannot take heparin, and Coumadin should be used cautiously or not at all.

The main danger of thrombophlebitis is pulmonary embolism, a clot that lodges in the pulmonary artery and blocks circulation to the lungs and heart. Symptoms include chest pain, sudden onset of dyspnea, cough with hemoptysis, tachycardia, and severe dizziness or fainting. Pulmonary embolism is an immediate emergency.

Hematologic Disorders in Pregnancy

Childbirth involves heavy blood loss, so a coagulation or blood-formation disorder makes hemorrhage especially dangerous.

Iron-Deficiency Anemia

Iron-deficiency anemia is the most common anemia in pregnancy, mainly because many women enter pregnancy already deficient in iron stores from low intake. A hemoglobin level below 12mg/dl with hematocrit below 33% is a possible sign. It is a microcytic, hypochromic anemia, because inadequate iron is unavailable for incorporation into red blood cells, and it is mildly associated with low birth weight and preterm birth. Expect extreme fatigue and poor exercise tolerance because she cannot transport oxygen effectively.

Advise prenatal vitamins containing an iron supplement of 60 mg elemental iron, plus a diet high in iron such as green leafy vegetables, meat, legumes, and fruit. A woman who develops anemia during pregnancy is prescribed 120 to 200 mg elemental iron per day as ferrous sulfate or ferrous gluconate. Iron is best absorbed in an acidic medium, so have her take it with orange juice or a vitamin C supplement. Side effects include constipation and gastric irritation, and ferrous sulfate turns stool black, so warn her.

Folic Acid-Deficiency Anemia

Folic acid is vital for normal red blood cell formation in the mother and prevents neural tube defects in the fetus. Folic acid anemia is a megaloblastic anemia with an elevated mean corpuscular volume, most apparent in the second trimester, and it may contribute to early miscarriage or premature separation of the placenta. Women planning pregnancy are advised to take 400 µg of folic acid daily and to eat folacin-rich foods such as green leafy vegetables, oranges, and dried beans.

Sickle Cell Anemia

Sickle cell anemia is a recessively inherited hemolytic anemia caused by an abnormal amino acid in the beta chain of hemoglobin. Most red blood cells are sickle-shaped and cannot carry the same hemoglobin load as normal cells. At high altitudes the blood grows more viscous as the irregular cells clump, and the vessel blockage reduces blood flow to the organs. The cells hemolyze and drop in number, causing severe anemia.

A pregnant woman with sickle cell anemia is more prone to bacteriuria, so collect a clean catch urine sample to detect the disease while asymptomatic. Her diet must contain sufficient folic acid to build new red blood cells, and emphasize fluid intake because dehydration can trigger a sickle cell crisis. Have her elevate her legs while sitting or lie on her left side while sleeping to encourage venous return, and avoid standing for long periods. Monitor fetal health by ultrasound at 16 to 24 weeks for intrauterine growth restriction. An exchange transfusion replaces sickled cells with non-sickled cells. Do not give iron supplements to a woman already in sickle cell crisis, because she cannot incorporate the iron and it may build up. When a crisis occurs, the essential interventions are pain control, oxygen administration, and increasing circulatory fluid volume to lower viscosity. To detect whether the fetus has the disease, perform electrophoresis of red blood cells by percutaneous umbilical blood sampling or amniocentesis to reveal it on the beta chains in utero.

Anomalies of the Cord

Two Vessel Cord

A normal cord has one vein and two arteries. An absent umbilical artery may signal congenital heart and kidney anomalies, because the insult that cost the vessel may have affected other mesoderm germ layer structures. Inspect the cord for vessel count immediately after birth before it dries, since drying distorts the vessels and makes counting hard, and document the count. An infant with only two vessels needs careful observation for other anomalies through the newborn period.

Unusual Cord Length

Cord length varies, and abnormal lengths occur. An unusually short cord can predispose the fetus to premature separation of the placenta or an abnormal fetal lie. An unusually long cord tends to twist or knot. A cord naturally forms a knot, but the pulsations of blood and the muscular vessel walls usually keep flow adequate. A cord wrapped once around the fetal neck is not unusual and should not interfere with fetal circulation.

Anomalies of the Placenta

Placenta Succenturiata

The normal placenta weighs approximately 500 g and is 15 to 20 cm in diameter and 1.5 to 3.0 cm thick. Placenta succenturiata has one or more accessory lobes connected to the main placenta by blood vessels. It is not a fetal abnormality, but it must be recognized after birth, because retained small lobes lead to severe maternal hemorrhage. Look for a placenta torn at the edge or torn vessels extending beyond the edge. Remove remaining lobes manually to prevent hemorrhage from poor uterine contraction.

Placenta Circumvallata

Normally the chorion membrane begins at the edge of the placenta and spreads to cover the fetus, leaving the fetal side uncovered by chorion. In placenta circumvallata, the fetal side is covered with chorion. The umbilical cord enters at the usual midpoint, and large vessels spread out and end abruptly where the chorion folds back into the surface. In placenta marginata, the chorion fold reaches just to the edge of the placenta.

Placenta Accreta

Placenta accreta is an unusually deep attachment of the placenta to the uterine myometrium, so the placenta will not loosen and deliver. Never attempt to remove it, because the deep attachment can cause extreme hemorrhage. The treatment of choice is hysterectomy or methotrexate to destroy the still-attached tissue.

Battledore Placenta

Battledore placenta has the cord inserted marginally rather than centrally. It is rare and has no known clinical significance.

Velamentous Insertion of the Cord

In velamentous insertion, the cord separates into small vessels that reach the placenta by spreading across a fold of amnion instead of entering directly. It is most common with multiple gestations and can be associated with fetal anomalies, so examine such an infant carefully.

Vasa Previa

In vasa previa, the umbilical vessels of a velamentous cord insertion cross the cervical os and deliver before the fetus. The vessels can tear with cervical dilatation, just as a placenta previa can. Identify the structures before inserting any instrument to prevent accidental tearing of a vasa previa, which can cause sudden fetal blood loss. With either placenta previa or vasa previa, there is sudden, painless bleeding at the onset of cervical dilatation. Confirm vasa previa by ultrasound, and if confirmed, the infant must be born by cesarean delivery.

Sudden Pregnancy Complications

Hydramnios and Oligohydramnios

Hydramnios

The usual amount of amniotic fluid at term is 500 to 1000 mL, and excess fluid of more than 2000 mL is hydramnios. Too much fluid can cause fetal malpresentation, premature rupture of membranes, infection from PROM, and preterm birth. The first sign is rapid enlargement of the uterus, with difficulty palpating the small parts of the fetus because the uterus is unusually tense, and difficult fetal heart rate auscultation from the surrounding fluid. The woman may develop extreme shortness of breath as the uterus presses up the diaphragm, and poor venous return produces lower extremity varicosities and hemorrhoids.

Ultrasound confirms hydramnios and the reason for the excess fluid. Advise bed rest to increase uteroplacental circulation and reduce pressure on the cervix. Help her avoid constipation, since straining raises uterine pressure and can rupture the membranes, so encourage a high-fiber diet and stool softeners if diet alone fails. Assess vital signs and lower extremity edema frequently. Amniocentesis can reduce the fluid volume, and tocolysis may be started to prevent preterm labor. After birth, fully assess the infant for factors that interfered with effective swallowing in utero.

Oligohydramnios

Oligohydramnios is less than the average amount of amniotic fluid, usually from a fetal bladder or renal disorder that interferes with voiding. It can produce in utero growth restriction, weak muscles at birth, lungs that fail to develop with severe breathing difficulty, and distorted facial features, a cluster called Potter's syndrome. Suspect it when the uterus fails to meet its expected growth rate, and confirm by ultrasound showing pockets of fluid below average. Amnioinfusion (instillation of fluid into the uterus by amniocentesis) can relieve it. Infants need careful observation at birth to rule out kidney disease and compromised lung development.

Post-Term Pregnancy

A term pregnancy is 38 to 42 weeks, and a pregnancy that exceeds these limits is post-term or prolonged. The infant is considered post mature or dysmature, especially if placental insufficiency has interfered with growth. Prolonged pregnancy may occur with high salicylate intake, which interferes with prostaglandin synthesis that helps initiate labor.

Meconium aspiration is likely as fetal intestinal contents reach the rectum, and macrosomia is a problem if the fetus keeps growing. The fetus faces decreased blood perfusion, since the placenta only functions adequately for 40 to 42 weeks, and it may suffer a lack of oxygen, fluid, and nutrients. A maternal vaginal fibronectin level, a nonstress test, and a biophysical profile document placental perfusion and the amount of amniotic fluid. Prostaglandin gel or misoprostol may be applied to ripen the cervix, or stripping of membranes followed by an oxytocin infusion. Cesarean birth is necessary if all measures fail. Monitor the fetal heart rate closely during labor so placental insufficiency does not develop from an aging placenta.

Rh Incompatibility

Rh incompatibility occurs when an Rh-negative mother carries an Rh-positive fetus, with the father homozygous or heterozygous Rh-positive. The Rh-positive fetus is treated as a foreign body, and the mother forms antibodies against it as if it were a virus. Those maternal antibodies cross the placenta and destroy fetal red blood cells, cutting oxygen transport to body cells, a condition called hemolytic disease of the newborn or erythroblastosis fetalis.

At the first pregnancy visit, draw an anti-D antibody titer. If normal, repeat it at week 28 with no therapy needed. If elevated, monitor fetal wellbeing every 2 weeks or more often by Doppler velocity of the fetal middle cerebral artery, which predicts when fetal red blood cells are being destroyed. A high artery velocity means the fetus is not developing anemia and is most likely Rh-negative. A low reading means the fetus is in danger, and immediate birth is carried out if it is near term; if not near term, efforts begin to reduce the woman's antibodies or replace damaged fetal red cells. Give Rh (D) immune globulin to Rh-negative women at 28 weeks of pregnancy, and give RhIG as an injection within the first 72 hours after the birth of an Rh-positive child to keep the woman from forming natural antibodies.

High-risk pregnancy will not touch most childbearing women, but no one can predict when these conditions appear. Early education for couples planning pregnancy is what gives the mother and baby the best shot at a safe pregnancy from start to finish.