exam 2 - DM Flashcards
historical significance of DM in pregnancy
-Before the synthesis of insulin in 1921 by Banting (above, r.) and Best (l.) and before Dr Priscilla White founded the Joslin Clinic in 1924, fewer than 50% of diabetic patients delivered live fetuses
-By 1974, over 90% of babies born to diabetic mothers survived
-One of their research dogs, Dog 408, a Smooth Collie, is pictured to r.
epidemiology of DM
-Approximately 7% of pregnancies are affected by any form of diabetes mellitus
-Approximately 86% of pregnant patients with diabetes mellitus have gestational diabetes mellitus (GDM)
gestational diabetes mellitus (GDM)
-Due to physiologic changes in carbohydrate and glucose intolerance in pregnancy, as well as other individual risk factors, and generally limited to the pregnancy itself
-Physiologic increase in insulin resistance occurs in pregnancy due to human placental lactogen
GDM dx
-Today, all pregnant patients not known or suspected to have PGDM are screened during prenatal care between 24-28 weeks gestational age (GA)
-This is generally accomplished by a 2 step process
- step 1: 1 hr GCT,
- if elevated: 3 hr OGTT
first step of testing for GDM
-1 hour glucose challenge test (GCT)
-50 gm glucose load, followed by a venous glucose level
-No absolute cutoff, but under 130-140 mg/dL
-Lower (130-135 mg/dL) thresholds have not proved to be significantly more sensitive
-Fewer false positive results with use of a normal level of 140 mg/dL
-May screen high risk patients with 1 hour GCT at first prenatal visit
-Consider in patients with past obstetric history of complications associated with undiagnosed and unmanaged gestational diabetes mellitus
second step of testing for GDM (what are the names of the parameters)
-If the 1 hour GCT is elevated (certainly >140 mg/dL), proceed to a 3 hour oral glucose tolerance test (OGTT)
-Patient fasts for 8 hours and a fasting glucose level is drawn
-A 100 gm glucose load is administered
-1, 2 and 3 hour glucose levels are drawn
interpretating 3 hour OGTT:
-Either the Carpenter-Coustan or the National Diabetes Data Group conversion may be used, but practitioners should use the same parameters consistently
-dx of GDM is made when a patient has >1 abnormal value on the 3 hour OGTT
-However, having even one abnormal value increases the risk of a perinatal complication
normal values for oral glucose tolerance test in pregnancy
dont memorize will be on test
diabetes mellitus: complications of the parturient
-Birth injury- tend to be bigger (shoulders!!)
-Poor wound healing
-Hypertensive disorders of pregnancy
-Postpartum hemorrhage
-Frank diabetes mellitus later in life (50%)
-baby is acting diabetic
birth injury to the parturient
-Due to the maneuvers and techniques employed in reducing a shoulder dystocia, diabetic patients are at risk of traumatic birth injury
-shoulder dystocia- head is out but cant get the rest of the baby -> birth injury to mom and hypoxia
-These include a fourth degree perineal laceration (r.) that extends through the anus and into the rectal mucosa
diabetes mellitus: common fetal complications
-baby is polydipsic -> drink amniotic fluid -> pee -> cycle -> increase in fluid -> baby is floating around and displaces!
-Spontaneous abortion
-Congenital anomalies
-!Macrosomia
-!Polyhydramnios
-!Shoulder dystocia
-!Erb’s palsy- injury to brachial plexus
-Birth trauma
-Neurological injury
-Neonatal hypoglycemia
-Respiratory distress syndrome
-Death
spontaneous abortion: how does DM affect risk
-The risk of spontaneous loss in any clinically recognized pregnancy is about 10%
-This risk is the same in diabetic and nondiabetic gravidas
-However, the risk of loss is higher if the patient’s diabetes is poorly controlled at the time the pregnancy is diagnosed
macrosomia
-def: fetal wt > 4000-4500
-occurs in about 8% of all live infants
assoc with worse neonatal outcomes:
-lower 5 minute apgar scores
-higher risk of assisted ventilation
-birth injuries
-mortality
fetal complications of macrosomia: shoulder dystocia
-!MC complication of macrosomia is shoulder dystocia***
-shoulder stuck in pubic symphysis
-when you require special maneuver to get baby out OR
-when the shoulder and head deliver are > 1min apart
Shoulder dystocia occurs when the fetal shoulders do not deliver:
-Within a minute of delivery of the fetal head, or
-Without the use of special maneuvers
-Incidence: 0.2-0.3% of all vaginal deliveries
-Shoulder dystocia will result in umbilical cord compression -> complications: acidemia, asphyxia, neuropological injury, death
Complications due to attempts to reduce shoulder dystocia include:
-Erb’s palsy- loss of limb for rest of life
-Humeral fracture
-Clavicular fracture
Polyhydramnios
-Defined as an amniotic fluid index (AFI) of >25 cm
-Measured via ultrasound
-May occur in poorly controlled pregestational or gestational diabetes due to hyperglycemia-induced symptoms in the fetus
-Polyuria
-Polydipsia- Amniotic fluid is primarily comprised of fetal urine in the latter half of pregnancy
-Due to the relatively weightless state because of the increased fluid, this can lead to malpresentation
breech presentation
transverse lie
section
neonatal hypoglycemia
-Caused by high circulating fetal insulin levels because of a hyperglycemic state due to poorly controlled maternal diabetes mellitus
-After delivery, without maternal hyperglycemia and without careful neonatal care, hypoglycemia may result
white classification of DM in pregnancy (dont memorize)
dont memorize
-class A is GDM
-everything else is DM before pregnancy
- T -> not having a vaginal delivery
monitoring of glycemic control
-1 or 2 hour postprandial glucose values
-1 hour postprandial: <140
-2 hour postprandial: <120 mg/dL
-If desired, may follow fasting values as well (<92 mg/dL)
-Initially, follow fingerstick glucose measurements 4x/day
-May individualize, but usually ongoing surveillance requires at least 2 readings daily
-review findings weekly
38 year old gravida 3, para 2002 is gx with GDM at 26 wks GA. What 1 hour postprandial fingerstick glucose measurement would be most appropriate
<80
-<100
-<120
-<140!!!!!!!!
management of GDM
-begin with diet
-refer to dietician for nutritional counseling
diet that yields best perinatal outcomes is unknown:
-increase daily caloric intake by 300 kcal/day in 2nd and 3rd trimesters
-33-40% carbohydrates- Complex carbohydrates are preferred
-40% fat
-20% protein
-3 meals/day
-2 snacks/day
exercise: moderate intensity aerobic exercise for 30mins per day at least 5 days per week
-!!Insulin continues to be the pharmacotherapy recommended by the American Diabetes Association for management of hyperglycemia in gravidas with gestational diabetes when diet and exercise alone are insufficient (expensive and painful)
-Oral agents were found to be effective and safe in 2000, but have not yet been approved for this purpose by the FDA
-However, they are very commonly used in pregnancy
management of GDM: use of insulin when is it indicated
-Indicated when blood glucose measurement is consistently elevated
-Fasting: >95 mg/dL
-1 hour postprandial: >140 mg/dL
-2 hour postprandial: >120 mg/dL
use of oral agents in the management of GDM: glyburide
-A sulfonylurea that stimulates pancreatic beta cell ATP channel receptors to release insulin
-Does not cross the placenta significantly
-Evidence has suggested an increased risk of fetal macrosomia and in hypoglycemia compared with insulin
use of oral agents in the management of GDM: metformin
-a biguanide that inhibits hepatic gluconeogenesis and glucose absorption
-stimulates glucose uptake and utilization in peripheral tissues
-crosses the placenta -> uncertainty persists about long-term effects on children treated in utero with metformin
-dosage:
-500 mg PO QHS x 1 week, then
-500 mg PO BID
-Titrate as needed
-Maximum dose: 2000-3000 mg in divided doses daily
-26-46% of pts taking metformin will eventually require insulin during pregnancy
-Metformin may be used as an alternative medication in patients who cannot or will not use insulin, or cannot afford insulin
-Thus, while metformin can be and is used to manage GDM, patients do need to be aware that:
-Metformin is generally not considered to be superior to insulin
-The potential is currently unknown for long-term sequelae on children exposed to metformin
fetal assessment in pts with GDM: when is it used
-Appropriate in patients with poorly controlled GDM beginning at 32 weeks GA, or earlier, if indicated
-There is no recommendation for testing in patients with well controlled GDM managed by diet alone
intrapartum care of pts with GDM (dont memorize)
-dont need to know
-past 41 weeks- placenta calcifies and gets old -> not good for baby
-intrapartum and postpartum concerns with the patient with GDM
-Discuss with the patient the risks and benefits of prophylactic Caesarean section for patients with estimated fetal weight (EFW) of at least 4,500 gm
-Screen for diabetes mellitus at 4-12 weeks postpartum
-Fasting venous glucose followed by 2 hour, 75 gm oral glucose tolerance test (OGTT)
postpartum eval of glucose metabolism in the pt with recent GDM
Perform 2 hr, 75 gm OGTT or fasting plasma glucose at 4-12 weeks postpartum
which is the most severe intrapartum complication of GDM
-polyhydraminos
-maternal hyperglycemia
-shoulder dystocia!!!!!!!!!!
-postdates gestations
