DIABETES MELLITUS & PREGNANCY

G.M Punarbawa

IntroductionMost common medical complication of pregnancy The Centers for Disease Control and Prevention estimated: 20.8 million persons (USA) had diabetes in 2005.Diabetes is undiagnosed: 1/3 of adults Preexisting (type 1 or type 2) DM affects 13/1000 pregnancies

GDMDef: any degree of glucose intolerance with first recognition during pregnancyComplicates: 4% of pregnanciesWomen + GDM: 50% risk of developing T2DM over the next 10 yearsDM during pregnancy: significant risks to the mother & fetus

GDM..- Poorly controlled diabetes:risk of spontaneous abortion rate of major congenital anomalies is 612% among women with pregestational diabetes.Diabetic ketoacidosis (DKA) is an immediate threat to maternal and fetal life: Fetal death (10% ), 3050% in the past

GDMGDM: risk fetal macrosomia operative delivery, shoulder dystocia, birth trauma risk neonatal complications (hypoglycemia, RDS, hypocalcemia, & hyperbilirubinemiaBefore insulin (1922): diabetic patients often died during the course of their pregnancy 20 years ago, delivery of an unexplained stillbirth from a mother with type 1 diabetes >>>. Today this tragedy is rare, with a reduction in perinatal mortality rate to less than 5%.

Diabetic patients receive preconception care: medical nutrition therapy insulin therapy achieve near-normal glycemic goals morbidity % mortality uncomplicated pregnancies

Accessibility of self-monitoring of blood glucose level with its concomitant effect on glycemic control

Fetal Effects

Elevated glucose levels toxic (developing fetus): miscarriages & major malformations Birth defects: fatal or seriously deleterious QOL; preventable by preconceptional glucose controlMalformations (first 8 weeks): preconceptional care: essential for women with diabetes Hb A1c level: reflects blood glucose concentration over previous 2 months, can predict the risk for malformations when measured in the first trimester

Fetus continues experience effects of hyperglycemia beyond the period of organogenesis glucose crosses the placenta; insulin does not fetal insulin production (compensate hyperglycemic environment)Higher insulin levels fetal somatic growth (macrosomia & central fat deposition; & enlargement of heart)

Diagnostic Criteria for Diabetes Mellitus Prior to Pregnancy

1. Symptoms of diabetes + random plasma glucose > 200 mg/dL. Classic symptoms (polyuria, polydipsia, unexplained weight loss)2. Fasting plasma glucose (FPG) > 126 mg/dL3. Two-hour postload glucose level >200 mg/dL during an oral glucose tolerance test (OGTT); glucose load (75 g anhydrous glucose in water)

Diagnostic Criteria for GDM

Risk assessment for GDM is performed atthe first prenatal visit in all women who do not already have diagnosed diabetes Women with risk factors should be screened as soon as feasibleRisk factors: obesity (nonpregnant BMI 30), history of GDM, heavy glycosuria (> 2+), unexplained stillbirth, prior infant with major malformation, family history of diabetes in a first-degree relative.If the results of testing (-) retested (24 & 28 weeks)All women should be screened between 24 and 28 weeks

USA: 2-step approach; 1st step: screening test (50-g oral glucose challenge test/GCT). Serum glucose measured 1 hour laterThe GCT can be performed at any time of day and without regard to time of prior meal. Cutoff: 140 mg/dL (sensitivity 80%) If the GCT >180 mg/dL FPG next day

GDMScreening for women with low risk:

During ANC:fetal weight 70% /> for gestational age; or polyhydramnios (AFI 24 cm) re-evaluation for GDM.

TYPE:Type 1 DM (T1DM): results from beta cell destruction, usually leading to absolute insulin deficiencyType 2 DM (T2DM): insufficient insulin receptors to effect proper glucose control after insulin is released (insulin resistance)

GDMGDM: any degree of glucose intolerance with onset or first recognition during pregnancy Majority of GDM cases: glucose levels return to normal after deliveryRisk of recurrence in future pregnancies: 60%Risk of miscarriages, congenital malformations, preterm birth, pyelonephritis, preeclampsia, in utero meconium, fetal heart rate abnormalities, cesarean deliveries, and stillbirths Increasing obesity, metabolic syndrome, & prediabetes incidence GDMPathophysiologyGDM: pathophysiologically similar to T2DM. Women most likely develop GDM: overweight, "apple shape."

APPROACH TO DIABETES IN PREGNANCY

Prevention hyperglycemia /control of glucose level: mainstay of treatment GDM. Careful preconceptional counseling & normal Hb A1c levels Pre- pregnancy (pregestational diabetics), frequent (usually 45x per day) home glucose level monitoring, adjustment of diet, regular exercise.Regular exercise: nonweight-bearing or low-impact exercise initiated or continued. Short episodes of exercise will sensitize the patient's response to insulin for approximately 24 hours.Diet: soluble fiber satiety & improves number of insulin receptors & their sensitivity.

Carbohydrate restriction. Calories: 2535 kcal/kg of actual body weight, generally 18002400 kcal/day. Diet: 4050% carbohydrate, 3040% fat, 20% protein.Morbidly obese women may have a lower metabolism rate; therefore, begin low and increase calories as needed. When postprandial values exceed the targets, review all recent food intake to adjust food choice, preparation, and portion size.Self-monitoring of fasting, 1- or 2-hour postprandial, and nighttime blood glucose levels using a glucose meter provides instant feedback to assess the patient's diet and behavior. Optimal glucose levels: fasting 7095 mg/dL & 1-hour postprandial < 140 mg/dL or 2-hour postprandial values < 120 mg/dL.

A minimum of 2 visits to a dietitian improves education and active participation regarding dietInsulin therapy is added when necessary to achieve goalsInsulin: rational step to achieving worthwhile glycemic goalsSubcutaneous insulin pumps better control of hyperglycemia Recent evidence: glyburide or metformin are safe & effective alternatives. Treatment with oral hypoglycemics should be limited & individualized

ANTEPARTUM CARE

Comprehensive eye examination for retinopathy: performed annually. Renal function test. In patients with T1DM, thyroid function test: because of increased rates of thyroid disease. ECG: > 30 years or have disease > 5 yearsSupplemen: 0.4 mg of folate dailyGestational age should be confirmed with a first-trimester ultrasound examinationPregestational diabetics: USG for anatomy completed at 1820 weeksTests to screen anomalies (1st-trimester nuchal translucency & serum screening; 2nd-trimester triple or quadruple screening

ANTEPARTUM CAREDMG: 3x rate of asymptomatic bacteriuria vs N pregnant women. Urine culture: at the initial visit. R/AB A a repeat culture (test of cure). The development of edema risk of preeclampsia Evaluation of maternal glycemic control (self-monitoring) & fetal growth (USG) are essential Poor glycemic control (macrosomia / polyhydramnios) risk poor outcome. Fetal well-being begins 32 weeks': NST / modified BPP: 2x weekly DMG with diet-controlled: testing at 3640 weeks until delivered.Maternal fetal movement monitoring ("kick counts"): a count to 10 or similar method is recommended to reduce stillbirthWhen fetal assessment not reassuring mature fetus delivered. Cases near term amniocentesis (pulmonary maturity)

ANTEPARTUM CAREAssessment lung maturity recommended for elective delivery < 38 weeks' or glycemic control inadequate risk delay lung maturityPreterm labor: >> among. R/ tocolysis glucocorticoid (lung maturation over 48 hours). Magnesium sulfate, Nifedipine Adrenergic mimetics (terbutaline): avoided may cause severe hyperglycemia &, rarely, ketoacidosisGlucocorticoids: cause hyperglycemia + continuous iv insulin (maintain normal glucose levels)>> obstetricians induce at 39 weeks' gestation

SEVERE HYPERGLYCEMIA & KETOACIDOSIS

Treated the same as in the nonpregnant state. R/ Insulin, careful monitoring of potassium level, fluid replacement CTG: often demonstrates recurrent late decelerations, but improve as maternal ketoacidosis is corrected

INTRAPARTUM MANAGEMENT

Glucose infusion in labor (D5% in RL): 125 mL/h (6.25 g of glucose per hour) Monitor glucose levels @ 24 h (early labor) & @ 12 h (active labor)Patients requiring insulin: continuous infusion (regular insulin), 25 U in 250 mL saline (0.1 unit/mL)Continuous CTG: abnormalities scalp stimulation / fetal oxygen saturation monitoringRisk shoulder dystocia (adequate personnel, obstetric anesthesia, neonatal resuscitation)CS: evening insulin doses on the preceding night, morning dose (-)The morning of surgery, glucose level is monitored with continuous intravenous insulin to maintain glucose 70 - 120 mg/dL

POSTPARTUM CARE

Dose of insulin should be reduced (insulin sensitivity increases markedly postpartum)two-thirds of prepregnancy dose or one-half of the present doseIf the patient underwent surgery: glucose levels should be kept < 140150 mg/dL to assist the patient in healingBreastfeeding is encouraged, and snacks can be used to decrease the risk of hypoglycemiaInsulin is continued for those women who are breastfeeding, whereas oral agents can be used in nonbreastfeeding mothers

CONTRACEPTION

Contraceptive: DMG without vascular complications = nondiabetic womenIf increased risk for embolism, hormonal contraception containing estrogen not recommended, but progesterone-only methods, including the levonorgestrel intrauterine system, can be offeredPermanent sterilization should be made available to women with diabetes who have completed childbearing