Changes in glucose and thyroid in preg Flashcards
What % of pregnancy has insulin resistance?
50%
- women must increase insulin secretion (in liver) by 2-3x to maintain euglycemia
80% of the energy needs of fetus comes from what?
Glucose
Women are insulin ______ in 1st trimester
sensitive
- dont feel low glucose
- women at risk for severe nocturnal hypoglycemia in 1st trimester and wont wake up
Women are insulin _____ in late 2nd and 3rd trimester
resistant
- with increase hPL, hPGH, TNFa
Prolonged fasting in preg women –>?
Starvation ketosis
(accelerated starvation of pregnancy)
- high risk of DKA in pregnancy
- decreased buffering capacity
fasting blood glucose (FBG) in preg women
lower FBG but slightly higher postprandial (after lunch/dinner) glucoses and hyperinsulinemia
Gestational diabetes (GDM)
glucose intolerance recognized for the first time during preg.
- occurs LATER in pregnancy 24 weeks
- vast majority are overweight and insulin resistant
caused by:
- Insulin resistance
- Impaired insulin secretion
- Increased hepatic glucose production
*50% of pts with GBM will be declared as having T2D in the next 10 yrs
IGT (prediabetes)
diagnosed before 24 weeks and at very high risk for developing T2D post partum
thin pt with “gestational diabetes”
latent autoimmune diabetes
LANA or MODY (mature onset diabetes of the young)
Why is GDM a burden to mom?
- More doctor stuff
- Higher risk of infxn
- C Section
- Preeclampsia
- ~50% MATERNAL RISK OF DEVELOPING T2D in 5-10 yrs
- target for primary prevention
Does breastfeeding increase or decrease risk of T2D ?
Decreases risk
Infant of woman with diabetes
- fatter baby (abdominal) - get stuck in birth canal –> C section or shoulder dystocia
- Macrosomia
- infant respiratory distress syndrome
- neonatal hypoglycemia
- Hyperbilirubinemia
GLucose vs insulin in the placenta
GLucose crosses placenta, insulin doesnt
*baby sees too much glucose –> dev. High insulin –> pancreatic hyperplasia –>
after birth and moms glucose goes away –> baby bcomes hypoglycemic
Insulin fx in babies
insulin is a growth hormone causing excess fat deposition
hyperinsulinemia –> pancreatic hyperplasia
Long term implications of GDM
- T1D, T2D, GDM –>
- increased fetal insulin and leptin
- neonatal adiposity
- enlargement of pancreas + heart - Appetite regulation –> neonatal obesity and impaired glucose tolerance in childhood
- Higher risk of devel diabetes in offspring
TBG in pregnancy
Increase due to estrogen
- so mom needs to make more TH (T4 to maintain nl free T4)
(which requires more iodine, plasma vol, and GFR).
fetal brain has what transporters?
T4
DO NOT USE T3 IN PREGNANCY
Maternal and fetal iodine deficiency –> ?
Cretinism
*recommendation is for preggos to take 250 ug/day
Maternal hypothyroidism
most cases due to hashimotos
T4 needed for trophoblast fxn
Most women require 25% increase in thyroid hormone supplements early in gestation
Hypothyroidism can do what to the placenta?
- neurodev. delay
- preg loss
- preterm delivery
*remember that T4 needed for trophoblast fxn
Causes of hyperthyroidism in pregnancy
- Graves disease ~85%
- hCG induced
- Toxic multinodular goiter
- Toxic adenoma
Post partum thyroiditis
2 phases:
- hyperthyroid phase : 2-4 mo postpartum
- destruction of thyroid gland –> release thyroid hormone - Continued destruction 4-8 mo: hypothyroid
The placenta has which hormone, that hydrolyzes maternal TG to FFAs for utilization?
Lipoprotein lipase
- FFAs important for fetal fat accretion/neonatal adiposity
What id diagnostic for GDM?
at 24-28 weeks:
Give 50 gram oral glucose load
if abnl (>140): give 3 hour 100gm OGTT
- fasting glucose >92
- 1 hr glucose >180
- in T2D: fasting glucose > 95, and 1 hr glucose is >180
- women at higher risk should be screen at first prenatal visit
