Ob/Gyn Flashcards
Oral contraceptive pill contraindications
smoking history (>15 cigarettes / day) if >35 years old
history of current or past venous thromboembolism (VTE), known thrombophilia
<6 weeks postpartum if breastfeeding
current breast cancer
uncontrolled hypertension (diastolic >100 or systolic >160)
ischemic heart disease, complicated valvular heart disease
history of cerebral vascular accident (CVA) aka stroke
migraine headache with focal neurological symptoms
over age of 35 and migraine without aura
diabetes with end organ involvement
severe cirrhosis, liver tumor, or active viral hepatitis
systemic lupus erythematous (SLE) with positive anti-phospholipid antibody (APLA)
depression, because OCP may cause mood changes
What are routine investigations for an asymptomatic patient at high risk for an STI and how do you complete those investigations
chlamydia and gonorrhoea testing can be by urine or swab
trichomoniasis testing by vaginal swab
What are the mechanisms through which OCP prevents pregnancy
By progesterone:
1) inhibiting ovulation (main mechanism)
2) change cervical mucus which blocks sperm
3) cause pseudo decidualization of endometrium to inhibit implantation
4) inhibit tubal peristalsis to inhibit fertilization
What does estrogen do in OCP
No role in contraception
Prevents breakthrough bleeding
Rare but serious OCP adverse effects
VTE
myocardial infarction (MI)
stroke
increased risk of cervical cancer
Progestin only pill MOA
progestin only pill only have 1 mechanism of action because it is at a very low dose - thickening of cervical mucus to block sperm
Injectable progestin MOA
High dose so 3 mechanisms of action:
inhibit ovulation
thickening of cervical mucus to block sperm
pseudo-decidualization (atophy) of endometrium that inhibit implantation
How often should progestin injectable be given
q3 months (with forgiveness window up to 14 weeks)
Breakthrough bleeding with progestin injectable in the first 3-6 months is normal. How do you manage this?
need to reassure patients
exclude genital tract pathology
treat with estrogen and NSAIDs
can ameliorate by shorter interval of injection
Does IUD increase risk of infection?
Not in the long term
Relative risk of 4 in first 3 weeks after insertion then return to normal baseline
Contraindications for IUD
known or suspected pregnancy
puerperal sepsis (infection and fever post childbirth or miscarriage)
immediate post septic abortion
current pelvic inflammatory disease, purulent cervicitis, chlamydia, gonorrhea (can put in IUD then test and treat STI)
cervical or endometrial cancer
current breast cancer
unexplained vaginal bleeding
distorted uterine cavity anatomy
malignant trophoblastic disease
Abortion timeline
most are done before 12 weeks gestation a women
cannot have an elective abortion past 24 weeks gestation
in general, no doctors and no facilities will perform abortion past 20 weeks gestation, which may be offered in US
Medication abortion options
methotrexate intramuscular injection
misoprostol oral or vaginal delivery
Medication abortion options
up to 7 weeks
Requirements for medication abortion
must have surgical abortion back up option available
folic acid requirements in pregnancy
if average risk patient:
eat food rich in folate
folic acid supplement 0.4-0.8mg (1mg maximum) for at least 1 month before conception and at least 3 months after conception (ideally throughout pregnancy and postpartum)
if high risk patients
(epilepsy or insulin dependent diabetes or obesity BMI>35 or family history of neural tube defect or high risk ethnicity (Sikh)):
increase dietary intake of folate rich foods
folic acid 4mg (5mg maximum) for at least 3 months before conception until 1st trimester, then 1mg maximum throughout pregnancy and in postpartum period
Which vaccines are contraindicated in pregnancy
live vaccines (MMR, rotavirus, chicken pox vaccines)
Durations of trimesters
1st trimester is week 0-12
2nd trimester is week 12-28
3rd trimester is week 28-40/delivery
Prenatal visit schedule
1) 1st prenatal visit in week 6-10
2) visit every 4 weeks from week 0-28
3) visit every 2 weeks from week 28-36
4) visit every 1 week from week 36 to delivery
Uterine location throughout pregnancy
uterus should be palpable above pubic symphysis at 12 weeks; at umbilicus at 20 weeks and then increase 1cm / week until delivery
What does 1st trimester screening include
Integrated Prenatal Screen (IPS) testing
ultrasound
laboratory investigation:
CBC including hemoglobin and MCV for anemia and hemoglobinopathies
blood type: ABO group, Rh, Rh antibody screen can identify women in need of Rhogam treatment
hemoglobin electrophoresis if diagnosed with hemoglobinopathies (e.g. sickle cell, thalassemia), then need special monitoring and management
infection: rubella immunity, HBsAg, VDRL (for syphilis), HIV, urine culture & sensitivity, gonorrhoea, chlamydia
if not immune to rubella, must avoid sick contact during pregnancy and immunize postpartum
if gonorrhoea, chlamydia, bacterial vaginosis or trichomonis, then treat
urine culture & sensitivity can pick up group B streptococcus, which warrant prophylactic antibiotics at delivery
When do you start monitoring fetal heart rate and fundal height?
FHR - 12 weeks
Fundal height - 20 weeks
What does 2nd trimester screening include
morphology ultrasound at 18-20 weeks - anatomical scan to assess fetal anatomy, placental location, detect multiple gestation and date if needed
blood: hemoglobin, ABO, Rh and Rh antibody at 24-28 weeks
hemoglobin for anemia
Rh and Rh antibody screen for need of giving Rhogam
gestational diabetes screening with non-fasting 50g glucose load at 24-28 weeks screen for gestational diabetes mellitus
if positive screening (impaired glucose , need to follow up with further screening (HbA1C)
What does 3rd trimester screening include
group B streptococcus (GBS) vaginal and rectal swab at 35-37 weeks
GBS part of normal vaginal flora in 20% of women
1-2% of babies vaginally delivered by GBS colonized mother can develop infection, resulting in bacteremia, meningitis or pneurmonia
if positive, then intra-partum (i.e. just before delivery) antibiotics to eradicate colonized GBS
What are the possible ultrasounds that can be performed in pregnancy, their purpose and the timeline for each
5-12 weeks: Ultrasound in Early Pregnancy
can measure crown rump length, which is the most accurate estimation of gestational age in 1st trimester after 6 weeks
indication for early ultrasound:
in bleeding and cramping, ultrasound can rule out ectopic pregnancy
in unclear gestational age where menstrual cycle is irregular, last menstrual period is unknown or uterine size do not match, ultrasound can confirm gestational age
prior miscarriage, ultrasound can confirm viability and reassure mother
11-14 weeks: Ultrasound for nuchal translucency
part of Integrated Prenatal Screening (IPS) high nuchal translucency increase risk of neural tube defect and Down’s syndrome as well as congenital heart defect, Turner syndrome and cystic fibrosis (?)
18-20 weeks: morphology ultrasound
only mandatory ultrasound screening
detailed anatomy scan
anatomical scan to assess fetal anatomy, placental location, detect multiple gestation and date
if needed nuchal fold can also be measured, where high nuchal fold carry same risk of defect as high nuchal translucency
can also determine sex of baby
3rd trimester: Biophysical Profile biophysical profile
usually done in high-risk pregnancies in 3rd trimester
biophysical profile is ultrasound evaluation of fetal well-being using Manning’s score system
5 components: 4 from ultrasound (fetal movement, tone, breathing movement, amniotic fluid volume) and 1 from nonstress test (fetal heart rate)
What types of screens are available to screen for birth defects
non-invasive screen include integrated prenatal screen and maternal serum screen
invasive screen include chorionic villous sampling and amniocentesis
What does the integrated prenatal screen include
IPS is the integrated results from 2 series of tests to screen for Down syndrome, Edward’s syndrome and neural tube defect
1) nuchal translucency on ultrasound and PAPP-A at 11-14 weeks
both nuchal translucency and PAPP-A evaluate for Down Syndrome
2) maternal serum screening (free beta-hCG, AFP, uE3) at 15-21 weeks, ideally at 15+3 weeks
free beta-hCG in Down syndrome
AFP (alpha fetoprotein) in neural tube defects
uE3 (unconjugated estriol) low in Down syndrome and Edward’s syndrome
What are the indications for invasive prenatal screening and what types of invasive prenatal screening are offered
invasive screening can test for other genetic and birth defects outside the Down syndrome, Edward’s syndrome and neural tube defect
indication for invasive screening:
positive prior screening test (IPS or maternal serum screening)
family history of genetic disease
maternal age >40
specific ultrasound finding that need to be followed up
invasive screening include chorionic villous sampling at 11-13 weeks or amniocentesis at 15-22 weeks
How many feeds and wet diapers should newborn have per day
8-12 feeds per day
6-8 wet diapers per day
