Obstetrics & Gynecology #11

 

HY lecture notes:

Asherman syndrome –> Hx of D&C leading to intrauterine synechiae –> intrauterine fibrous strands –> presents with cyclic abdominal pain + amenorrhea –> will tell you unable to have kids with husband, but he has kids with previous wife (meaning infertility is likely female in etiology).

Lichen sclerosus –> patchy, rough, white-grey lesion(s) on the vulva –> can be idiopathic, but usually due to chronic irritation or scratching –> must do biopsy first to rule out SCC –> if biopsy confirms LS, then topical steroids can be used to Tx. But if the vignette sounds overwhelmingly like LS, remember that you must biopsy first (punch biopsy from side of lesion). If SCC, then excision of course is necessary.

Preeclampsia on the USMLE is simply proteinuria + hypertension after 20 weeks gestation. If proteinuria + hypertension before 20 weeks, think hydatidiform mole. Preeclampsia can also present as HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelet count) –> will see schistocytes on blood smear (what you see on a blood smear in HELP syndrome was asked on my exam).

Preeclampsia is caused by uteroplacental insufficiency –> decreased blood flow to placenta causes cardiovascular system to increase blood pressure in a compensatory attempt to perfuse the placenta. Uteroplacental insufficiency causes intrauterine growth restriction (IUGR) –> decreased abdominal circumference is what the USMLE wants as the fetal parameter most reflective of this (not femur length or biparietal distance, etc.).

Most common cause of abnormal AFP measurement is dating error. Don’t redo AFP. The value coming from the lab was probably accurate. The answer is re-ultrasound to get a better read on the age of the fetus.

Mullerian agenesis vs androgen insensitivity syndrome:

Both will have absent uterus + vagina that ends in blind pouch, but the difference is in AIS, there is scanty or absent pubic/axillary hair. In Mullerian agenesis, there is normal pubic/axillary hair (they’ll often say “coarse” hair in Q to make it clear it’s not AIS). In AIS, karyotype is 46XY (male), whereas MA is 46XX (female). Both have well-developed / normal Tanner stages (i.e., they’ll say a phenotypically female teenager who hasn’t had a period who’s Tanner stage 4). Do karyotype to Dx AIS.

Most effective emergency contraception = copper IUD (not tubal ligation –> if the egg is already fertilized, ligation won’t help + it’s an extreme measure; bottom line is tubal ligation is wrong). If girl doesn’t want copper IUD + prefers a med, give ulipristal (selective progesterone receptor modulator).

Don’t do IUDs in anyone with current STD (sounds obvious, but you’d be surprised by students’ answers).

Contraindications to estrogen-containing contraceptives (OCPs): migraine with aura; smokers age >35; Hx of thrombotic disorder, cardiovascular or cerebrovascular disease, liver disease, malignancy (hypercoagulable state); hypertension (systolic >160 or diastolic >100 mm Hg), or if <6 weeks postpartum. These patients need progesterone-only contraception.

Obgyn NBME forms will describe OCPs as “triphasic oral contraceptives.” They will also refer to the use of an OCP as enabling “synchronization of the endometrium.” For instance, if you get a vignette of PCOS in a high-BMI female who doesn’t want to get pregnant, apart from weight loss, an effective next step is “synchronization of endometrium.” That might sound weird, but I’m just telling you it’s asked.