Preconception Care Flashcards
Screening for sickle cell trait
Hb electrophoresis and CBC
A patient presents for prenatal testing. Her brother has sickle cell disease, but neither of her parents do. Her partner is from an ethnic group with a 1/10 prevalence of carrier status. What is the probability that their child will have sickle cell disease?
- Probability that the patient is a carrier: 2/3
- Probability that the partner is a carrier: 1/10
- Probability that a child of two carriers is homozygous: 1/4
- Net: 2/3 x 1/10 x 1/4 = 1/60
Patients taking valproic acid during pregnancy will have an increased risk of infants with ___.
Patients taking valproic acid during pregnancy will have an increased risk of infants with neural tube defects, hydrocephalus, and craniofacial malformations.
Patients with uncontrolled diabetes during pregnancy have an increased risk of having infants with ___.
Patients with uncontrolled diabetes during pregnancy have an increased risk of having infants with neural tube defects and congenital heart defects.
As part of preconception care, vaccinations should be offered to all women found to be susceptible to . . .
- Rubella
- Varicella
- Pertussis
- Hepatitis B
While there are a variety of tests for various diseases recommended for women dependent upon their history and background, ___ is recommended for all patients who are planning to become pregnant
While there are a variety of tests for various diseases recommended for women dependent upon their history and background, an HIV test is recommended for all patients who are planning to become pregnant
Choosing a dose of folate for a patient who plans on becoming pregnant
- 0.4 mg for most patients
- 4 mg for patients with a history of NTD pregnancy or are on a medication that interferes with folate metabolism (like topiramate)
Live vaccines and pregnancy
Pregnancy should be avoided within 1 month of receiving a live attenuated strain vaccine
How long does it take before the pregnant uterus becomes apparent on bimanual exam?
- 6 weeks estimated gestational age
Chadwick’s sign
- Genital tract finding of early pregnancy
- Congestion and bluish discoloration of the vagina and cervix
Hegar sign
- Genital tract sign of early pregnancy
- Softening of the cervix on pelvic exam
Quickening
Patient’s initial perception of fetal movement
Not usually seen before 16-18 weeks, often as late as 20 weeks in primigravid individuals.
LH and pregnancy tests
LH and hCG share a common alpha chain
Any pregnancy test that measure this alpha chain cannot discriminate between them, and these can thus yield false positives.
Standard laboratory urine pregnancy tests first become positive. . .
. . . approximately one month following the first day of the LMP.
ie, around when the first period is missed
Test characteristics of home pregnancy tests
Low false positive rate, but high false negative rate
All urine pregnancy tests should be performed upon. . .
. . . early morning urine specimens
Serum pregnancy tests measure. . .
. . . the beta chain
Therefore, they are all quite specific to hCG
With a traditional, nonelectronic, acoustic fetoscope, auscultaton of fetal heart tones first becomes possible at. . .
. . . 20 weeks eGA
This is almost always an indication of a viable pregnancy
eGA and “weeks” uterus
When the uterus grows in size so that it exits the pelvis and is at the level of the umbilicus (16-20 weeks gestation), the fundal height in centimeters represents the gestational age from that time to about 36 weeks.
After 36 weeks, the uterus generally moves downward into the pelvis a bit and the fundal height decreases.
Fundal height
After the uterus reaches the umbilicus (usually ~16-18 wks gestation), uterine size is assessed with use of a tape measure. The uterine fundus is identified and the distance from the pubic symphysis in the midline is taken.
Naegle’s rule
To calculate EDD given LMP
From LMP, add seven days, then subtract three months
___ date for EGA should take preference over ___.
Ultrasound-established date for EGA should take preference over history of LMP