All Elsevier items and derived items 2014, 2010, 2006, 2002, Mosby, Inc., an imprint of Elsevier Inc.

CHA P T E R

11 High Risk Perinatal Care: Preexisting Conditions

K E Y P O I N T S Diabetes mellitus, currently the most common endocrine disor-

der associated with pregnancy, occurs in approximately 4% to 14% of pregnant women. The perinatal mortality rate for well-managed diabetic pregnancies, excluding major congenital malformations, is approximately the same as for any other pregnancy.

The current diabetes classification system includes four groups: type 1 diabetes, type 2 diabetes, other specific types (e.g., diabetes caused by genetic defects in beta cell function or insulin action, disease or injury of the pancreas, or drug-induced diabetes), and gestational diabetes mellitus (GDM).

Dr. Priscilla White developed a classification system. Whites system was based on the following: age at diagnosis; duration of illness; and presence of end-organ involvement, especially eye and kidney. Her classification system is still used frequently to assess both maternal and fetal risk. Women in classes A through C generally have positive pregnancy outcomes as long as their blood glucose levels are well controlled. However, women in classes D through T usually have poorer pregnancy outcomes because they have already developed the vascular damage that often accompanies long-standing diabetes.

Careful monitoring of blood glucose levels, insulin, or oral hypo-glycemic medication administration when necessary and dietary counseling are used to create a normal intrauterine environment for fetal growth and development in the pregnancy complicated by pregestational diabetes or GDM.

Poor maternal glycemic control before conception and during pregnancy may be responsible for fetal congenital malformations and maternal complications such as miscarriage, infection, and dystocia (difficult labor) caused by macrosomia.

Preconception counseling is recommended for all women of reproductive age who have diabetes because it is associated with less perinatal mortality and fewer congenital anomalies.

Maternal insulin requirements increase as the pregnancy pro-gresses and may quadruple by term as a result of insulin resis-tance created by placental hormones, insulinase, and cortisol.

In the immediate postpartum period insulin requirements decrease substantially because the major source of insulin resis-tance, the placenta, has been removed. Women may require only one third to one half of their last pregnancy insulin doses on the first postpartum day, provided they are eating a full diet.

Although most women are screened for GDM between 24 and 28 weeks of gestation, those with strong risk factors should be screened earlier in pregnancy. Women with morbid obesity, a strong family history of diabetes, a history of GDM in a previous pregnancy, or a history of giving birth to a macrosomic stillborn infant or an infant weighing more than 4500 g are candidates for early screening.

Thyroid dysfunction during pregnancy requires close monitor-ing of thyroid hormone levels to regulate therapy and prevent fetal insult.

Hyperthyroidism in pregnancy is rare. Clinical manifestations of hyperthyroidism include heat intolerance, diaphoresis, fatigue, anxiety, emotional lability, and tachycardia. Many of these symp-toms also occur with pregnancy; thus the disorder can be diffi-cult to diagnose.

Hypothyroidism occurs in two to three pregnancies per 1000. Because severe hypothyroidism is often associated with infertility and an increased risk of miscarriage, it is not often seen during pregnancy.

Education of the pregnant woman with thyroid dysfunction is essential to promote compliance with the plan of treatment. Important points for the nurse to discuss with the woman and her family include the following: the disorder and its potential effect on her, her family, and her fetus; the medication regimen and possible side effects; the need for continuing medical super-vision; and the importance of compliance.

High levels of phenylalanine in the maternal bloodstream cross the placenta and are teratogenic to the fetus. Damage can be prevented or minimized by dietary restriction of phenylalanine.

The stress of the normal maternal adaptations to pregnancy on a heart the functions of which are already taxed may cause cardiac decompensation.

Currently cardiomyopathy and congenital heart disease are the major causes of cardiac disease in pregnant women.

Common congenital heart defects are ASD, VSD, coarctation of the aorta, and tetralogy of Fallot. Acquired cardiac diseases include mitral value prolapse, mitral stenosis, and aortic stenosis.

Anemia is a common medical disorder of pregnancy that affects at least 20% of pregnant women.

CHAPTER 11 High Risk Perinatal Care: Preexisting Conditions e13

Women with sickle cell trait usually do well in pregnancy. However, they are at increased risk for preeclampsia, intrauterine fetal death, preterm birth and low-birth-weight infants, and postpartum endometritis. They are also at increased risk for UTIs and may be deficient in iron.

Asthma may be the most common potentially serious medical condition to complicate pregnancy. The prevalence and morbid-ity rates are increasing, although the asthma-related mortality has dropped in recent years.

Cystic fibrosis is a common autosomal recessive genetic disorder in which the exocrine glands produce excessive viscous secre-tions, which cause problems with both respiratory and digestive functions.

The pregnant woman with a neurologic disorder must deal with potential teratogenic effects of prescribed medications, changes of mobility during pregnancy, and impaired ability to care for the baby. The nurse should be aware of all medications the woman is taking and the associated potential for producing con-genital anomalies.

A pregnant woman with epilepsy should take only one anticon-vulsant medication, at the lowest dose level that is effective at keeping her seizure free if at all possible.

Many autoimmune disorders (e.g., SLE and MG) are often diag-nosed in women during their reproductive years; therefore they may occur during pregnancy.

Women with SLE are advised to wait until they have been in remission for at least 6 months before they attempt to become pregnant.

Alcohol and other drugs easily pass from a mother to her baby through the placenta. Smoking during pregnancy has serious health risks, including bleeding complications, miscarriage, still-birth, prematurity, low birth weight, and sudden unexplained infant death. Congenital anomalies have occurred in infants of mothers who have taken drugs.

Support from a variety of sources, including family and friends, health care providers, and the recovery community, is needed to help perinatal substance abusers achieve and maintain sobriety.

All Elsevier items and derived items 2014, 2010, 2006, 2002, Mosby, Inc., an imprint of Elsevier Inc.