Pregnancy Planning and Special Considerations

Human chorionic gonadotropin hCG

Tells your body to thicken uterine lining to help fetal development by signaling

Produced by placenta to help maintain the corpus luteum

Progesterone

Maintain uterine lining and prepare the breast for milk production

Estrogen

Promote growth of uterus and development of mammary glands

Changes in hormone levels in pregnancy

All hormones rise

First trimester weight increase

1-5 pounds or no weight at all

Second and third trimester weight increase

1/2-1 pound/week

Thyroid levels in pregnancy

Increase

Changes in insulin sensitivity

Affect glucose metabolism

Increase in blood volume does what to drug concentration

Dilute drug concentration

Folic acid supplementation

400-1000 mcg at least one month BEFORE conception

Why is folic acid supplementation needed

To reduce the risk of neural tube defects

Drugs that affect male fertility

Cimetidine, sulfalazine, and nitrofuratoin

Steroids

Chemotherapy and radiation

Effect on GFR in pregnancy

Increase by 50% in first trimester and rises until final week

Contraindicated drugs in pregnancy due to teratogenic effects

Isotretinoin, warfarin, valproic acid, methotrexate, semaglutide, tirzepatide, liraglutide, empagliflozin, dapagliflozin

Drugs with risk of teratogenicity

Lithium, carbamazepine, ondansetron

Hypertension in pregnancy

>140/90 measured twice at least 4 hours apart

Severe hypertension

>160/110 measured twice

What is elevated systolic BP associated with

Increased risk of preterm delivery and infants who are small for gestational age and have low birth weight

Chronic hypertension

Pre-existing HTN before pregnancy or that develops before 20 weeks of gestation

Gestational hypertension

>140/90 develops after 20 weeks of gestation without proteinuria or other signs of preeclampsia

Preeclampsia

HTN with proteinuria with gestational HTN or end organ damage

Proteinuria

>/=300mg/24hr urine collection

Protein creatinine ratio

0.3 mg/dL

Ecclampsia

Preeclampsia + seizures

Treatment for severe HTN and/or preeclampsia

Magnesium sulfate 4-6g IV over 15-20 minutes

Magnesium sulfate MOA

Block calcium channels => more relaxation => prevents seizures

HELLP syndrome

Severe form of preeclampsia which could destroy RBCs and interfere with clotting

Prophylaxis of HELLP

Aspirin 81-162mg once daily started between 12-28 weeks of gestation if they have 1+ high risk factor or 2+ moderate risk factor

First line agents for HDP

Labetalol, nifedipine (ER), methyldopa

First line agents for urgent treatment of severe HTN

Labetalol IV, nifedipine IR oral, hydralazine IV

Anti-HTN drugs to avoid in pregnancy

ACE-I, ARBS, atenolol, mineralocorticoid receptor antagonists, nitroprusside