High Risk OB Flashcards
What is the difference between GDMA1 and GDMA2?
A1 refers to GDM that is diet-controlled while A2 refers to GDM that requires medical therapy
What hormone causes insulin resistance during pregnancy, leading to GDM?
human placental lactogen
What are the two primary effects of human placental lactogen?
- reduce insulin sensitivity/reduce glucose uptake
- promote lipolysis
Why is the use of urinary glucose levels of little help in the management of diabetes during pregnancy?
because there is an increase RBF and normal glucosuria of pregnancy in all patients
What causes glycosuria of pregnancy?
an increase in renal blood flow
What are the major fetal complications of gestational diabetes?
- congenital anomalies, particularly affecting the heart, CNS, kidneys, and limbs; possibly sacral agenesis
- spontaneous abortion or stillbirth
- macroscomia or intrauterine growth restriction secondary to placental insufficiency
- polyhydramnios
- neonatal hypoglycemia, hyperbilirubinemia, hypocalcemia, or polycythemia
- respiratory distress syndrome
Gestational diabetes is associated with what kinds of congenital anomalies?
- cardiac, CNS, renal, and limb
- sacral agenesis is a rare but unique complications
Polyhydramnios is a risk factor for what three pregnancy complications?
- placental abruption
- preterm labor
- postpartum uterine atony
What are the major maternal risks associated with pregestational diabetes during preganncy?
- pre-eclapsia
- progression from diabetic nephropathy to end-stage renal disease
- worsening diabetic retinopathy
How do we screen for gestational diabetes?
- a 50g, 1-hour oral glucose challenge between 24-28 weeks to start
- patients whose glucose value exceeds the cut-off then undergo a 100g, 3-hour oral glucose tolerance test
- two or more abnormal results of the 3-hour test establish the diagnosis
What are the blood sugar goals for patients with gestational diabetes?
- fasting levels less than 95 mg/dL
- 1-hour post-prandial levels less than 140 mg/dL or 2-hour post-prandial levels less than 120 mg/dL
How is gestational diabetes managed during pregnancy?
- patients should obtain morning fasting glucose levels as well as pre- and post-prandial levels throughout the day
- the goal is fasting levels less than 95 and 1-hour postprandial levels less than 140 or 2-hour postprandial levels less than 120
- the mainstay for therapy is insulin because oral hypoglycemics are thought to provide less optimal outcomes and more long-term effects on those exposed in utero
- Glyburide and metformin are the preferred agents when oral hypoglycemics are used in pregnancy
How is gestational diabetes managed during labor, delivery, and the postpartum period?
- most patients undergo induction at 39 weeks if well-controlled
- once active labor begins or glucose levels decrease to 70 mg/dL, a constant glucose infusion of D5 is initiated at a rate of 100-150 mL/hr to maintain a glucose level of 100 mg/dL
- we also monitor for material ketonuria
- glucose tolerance screening is re-performed at 4-12 weeks postpartum and again every 1-3 years thereafter
Gestational Diabetes
- divided into A1 and A2 depending on if it is diet- or medically controlled
- caused by human placental lactogen which promotes lipolysis and inhibits glucose uptake
- screen for using a 1-hour, 50g oral glucose challenge with a threshold between 130-140; diagnose with a 3-hour, 100g challenge if two time points are abnormal
- risks to the fetus include cardiac, CNS, renal, and limb anomalies, including sacral agenesis; spontaneous abortion or stillbirth; macrosomia; polyhydramnios; and neonatal hypoglycemia, hyperbilirubinemia, hypocalcemia, polycythemia, and respiratory distress syndrome
- maternal risks include pre-eclampsia, worsening renal status, and worsening diabetic retinopathy
- manage primarily with insulin rather than oral hypoglycemic agents; goal is fasting less than 95 and 1 hour postprandial less than 140 or 2 hour postprandial less than 120
- use D5 during active labor to maintain a glucose level of 100 mg/dL and monitor for ketonuria
What is postpartum thyroiditis?
an autoimmune inflammation of the thyroid gland that presents as new-onset, painless hypothyroidism, transient thyrotoxicosis, or thyrotoxicosis followed by hypothyroidism within 1 year postpartum
Describe changes in TSH, total T4, free T4, and TBG during pregnancy.
- TSH initially declines as B-hCG levels rise and stimulate thyroid receptors, but then return to normal as B-hCG levels drop around week 10
- total T4 and TBG increase until about week 20 when they plateau; because they both increase, free T4 levels stay relatively constant through pregnancy
What happens to the thyroid gland during pregnancy?
it increases in size due to a decline in plasma iodide levels
How do we screen for thyroid problems during pregnancy?
- routine screening is not recommended
- but for those with evidence to warrant screening, TSH levels are measured since TSH does not cross the placenta and thus is an accurate measure of hormone function during pregnancy
Compare and contrast the use of methimazole and PTU for management of hyperthyroidism during pregnancy.
- methimazole crosses the placental more and causes greater fetal thyroid suppression
- methimazole has thus been associated with reports of aplasia cutis and choanal atresia
- for this reason, methimazole is avoided during the first trimester
- PTU has greater hepatotoxicity and thus isn’t recommended beyond the first trimester
- both are compatible with breastfeeding
When does nausea and vomiting of pregnancy typically begin and resolve?
typically begins before 9 weeks gestation, peaks between 7-12 weeks, and resolves by 16 weeks
Nausea and Vomiting of Pregnancy
- classified as mild (nausea alone), moderate (n/v), and severe (n/v leading to dehydration)
- hyperemesis gravidarum is the most severe form, associated with ketonuria, dehydration, and significant weight loss
- risk factors include multiple gestation, molar pregnancy, and personal or family history of hyperemesis gravidarum
- typically begins before 9 weeks gestation, peaks between 7-12 weeks, and resolves by 16 weeks, in association with changing B-hCG levels
- associated with lower miscarriage rates and the only negative effect is the impact on quality of life
- can often be treated with lifestyle modification but first line medical therapy is vitamin B6 with or without the H1-antagonists doxylamine
What is hyperemesis gravidarum? What are the risks associated with it?
- a severe form of nausea and vomiting of pregnancy, which is associated with ketonuria, dehydration, significant weightless, and biochemical hyperthyroidism
- it is the most common indication for hospital admission in the first half of pregnancy
What are the risk factors for nausea and vomiting of pregnancy?
those associated with elevated hCG like multiple gestation or molar pregnancy as well as either a family or personal history of hyperemesis gravidarum
What is the preferred medical therapy for nausea and vomiting of pregnancy?
vitamin B6 with doxylamine
Intrahepatic Cholestasis of Pregnancy
- a hepatic disorder unique to pregnancy
- risk factors include multiple gestation and chronic hepatitis C
- presents with generalized pruritus and elevated serum bile acid levels, typically in the second half of pregnancy
- maternal risks are low but there is an increased risk of stillbirth and other fetal effects
- diagnosed based on elevated fasting levels of bile acids, serum aminotransferases, and total and direct bilirubin concentrations
- managed with ursodeoxycholic acid, which decreases plasma bile acid concentrations and improves itching
- delivery is recommended at 37 weeks gestation
What labs are consistent with intrahepatic cholestasis of pregnancy?
elevated fasting bile acids, serum aminotransferases, and total and direct bilirubin
How is intrahepatic cholestasis of pregnancy managed?
ursodeoxycholic acid decreases plasma bile acid concentrations to improve itching and delivery is recommended at 37 weeks gestation
Acute Fatty Liver of Pregnancy
- the most common cause of acute liver failure in pregnancy
- may, in some cases, be caused by a recessive mitochondria abnormality of fatty acid oxidation similar to that seen in Reye-like syndromes
- typically presents in the third trimester as persistent nausea and vomiting; other symptoms include hypertension, proteinuria, malaise, anorexia, abdominal pain, edema, and progressive jaundice
- diagnosis is supported by elevated serum aminotransferases, elevated bilirubin, decreased fibrinogen levels, thrombocytopenia, leukocytosis, and liver dysfunction
- liver biopsy, though rare, would show microvesicular steatosis and canalicular cholestasis
- managed with delivery to stop further decline in liver function; recovery may be prolonged
What is the most common cause of acute liver failure in pregnancy?
acute fatty liver of pregnancy
What similarities do pre-eclampsia and acute fatty liver of pregnancy share? How are they best differentiated?
- acute fatty liver may present with some combination of hypertension, proteinuria, and edema
- acute fatty liver can be differentiated, however, because decreased fibrinogen levels, increased bilirubin, and liver dysfunction are rare in pre-eclampsia
How is acute fatty liver of pregnancy managed?
with delivery to halt the progression
What is the most common presentation of acute fatty liver of pregnancy?
persistent nausea and vomiting into the third trimester with declines in liver function
How does asymptomatic bacteriuria differ in pregnancy? Why?
- in pregnancy, it is more likely to lead to cystitis and pyelonephritis
- thought to be because of pregnancy-associated urinary stasis, glucosuria, and increased urine pH secondary to bicarbonate excretion
- urinary stasis is secondary to progesterone-induced decreased ureteral tone and motility, mechanical compression of the ureters at the pelvic brim, and compression of the bladder and ureteral orifices
What three factors contribute to urinary stasis of pregnancy?
- progesterone-induced decreased ureteral tone and motility
- mechanical compression of the ureters at the pelvic brim
- compression of the bladder and ureteral orifices
Urinary Tract Infections of Pregnancy
- asymptomatic bacterium is more likely to lead to cystitis and pyelonephritis during pregnancy
- due to progesterone-induce smooth muscle relaxation, mechanical compression of the ureters at the pelvic brim, compression of the bladder and ureteral orifices, increased bicarbonate excretion, and glucosuria
- screen for asymptomatic bacteria at the onset of prenatal care and treat with ampicillin, cephalexin, or nitrofurantoin
- suppressive antimicrobial therapy is indicated only if there are repetitive UTIs during pregnancy or if there is pyelonephritis during pregnancy
How are urinary tract infections treated during pregnancy?
- we screen for and treat asymptomatic bacteriuria at the onset of prenatal care and treat with ampicillin, cephalexin, or nitrofurantoin
- suppressive antimicrobial therapy is then used for those with repetitive UTIs
- pyelonephritis is treated with cephalosporins or ampicillin and gentamicin followed by suppressive therapy
What symptoms are consistent with cystitis? With pyelonephritis?
- cystitis presents with dysuria, urinary frequency, and urgency
- pyelonephritis patients are more acutely ill with fever, costovertebral tenderness, general malaise, and often dehydration
What are the major complications of pyelonephritis in pregnancy?
- increased uterine activity leading to preterm labor
- septic shock and maternal mortality