Having an OB gyn rotation cheat sheet can make all the difference in your success.
This article/guide will walk you through all the finer details that you should know in order to succeed on your OB gyn rotation.
Truth is, whether you want to pursue practicing OB/GYN or not, you have to go through the rotation in order to graduate from medical school.
Every school has an OB/Gyn rotation during either your 3rd or 4th year.
We will be going over everything from fetal strip review to staffing with your attending.
Bookmark this web page on your phone so you can reference it easily throughout the rotation, because there are a lot of useful resources on it.
Hopefully this article will be the “cheat sheet” you need to absolutely own your OB Gyn Rotation.
You can also download a PDF version of this article by filling out the form below.
If you are interested in Picmonic for your OB Gyn rotation (it rocks) then get 20% off with this link
Things to Know
Gravida and Para of a patient
These are the “G’s and P’s” of a patient.
Gravida is how many total pregnancies the patient has had, and the Para is how many past pregnancies the patient has had.
With Gravida there is only one number, it is the total pregnancies the patient has had. Whether the baby lived or not, it is included in the “g” number.
The parity is split into 4 numbers.
There is full term, pre-term, terminations, and living kids
For Example: G4P2103
This could also just be read as G4P3.
Pap Smear Results and what they mean
Screening guidelines: >21 y/o, women need to have screening every 3 years with pap smear and HPV
>30 y/o screening can be done every 3 years without HPV testing, or it can be done every 5 years with HPV and Pap smear testing.
No Abnormalities seen: Obviously this is a good result, return to regular screening.
Negative Pap smear, +HPV: Guidelines vary on this, so be sure to look it up. Some say repeat in one year, some say do coloposcopy.
ASCUS: Same as above, some resources say to repeat in a year, some say do colposcopy.
CIN1/2/3: Make sure to check your book and UpToDate for the latest material on what to do. This typically involves a combination of colposcopy vs LEEP, since they are cancer just at varying depths invasion.
Cardinal movements of Labor
- Internal Rotation
- External Rotation
Remember them in the order listed above, that is how the babies head moves as it comes through the birth canal and out of the pelvis.
Instead of going over this in text form, this video goes over all the important aspects of OB anatomy and is something you should watch for sure.
Basic Interventions During Labor
Post Partum Hemmorhage or PPH
What you need to remember here is the meds involved in managing this.
Oxytocin should be given, when it is given varies. I personally like to give it after the baby delivers, but before the placenta.
Some argue that doing this leads to harder placenta deliveries, but I have yet to experience that.
Metergine is contraindicated in patients that have a history of HTN, but is great in all other patients.
Prostaglandin is contraindicated in pateints with a history of asthma, but is good in all others.
And oxytocin and misoprostol are good to use in all.
You will absolutely get pimped on the contraindications to the above medications. So, know them.
Know the signs and then the common methods of treatment for a shoulder dystocia.
This is one of the things that makes this ob gyn rotation cheat sheet so valuable, little tid bits like this.
Things to know, and then a quick summary of them.
Signs of a shoulder dystocia: Failure to progress, turtle head sign.
The turtle head sign is when the head comes out and then retracts back in, almost as if the shoulders are being shrugged or a turtle head is going back into the shell.
If you see that, then you should be suspecting a shoulder dystocia.
This wouldn’t be an ob gyn rotation cheat sheet without a mnemonic or two right?
There is a helpful mnemonic for shoulder dystocia, it is HELPERR
- H: Call for Help
- E: Evaluate for Episiotomy
- L: Legs, Mcroberts Manuever
- P: Suprapubic Pressure
- E: Enter rotational manuevers
- R: Remove the posterior arm
- R: Roll the patient onto their hands and knees
If you can remember the details for post partum hemorrhage and shoulder dystocias, then you will for sure impress a few attendings and get more points on exams.
Understand Cervical Dilation, effacement, and station
The cervix is what keeps the baby in the uterus and prevents it from just falling out.
Initially it is long (3-5 cm) and closed (the opening is tight), and firm (as opposed to soft).
As the baby gets further along its head begins to put pressure on the cervix and it will begin to dilate from 0 up to 10 cm. When it gets to 10 cm that is when it is considered complete.
Effacement is essentially the thinness of the cervix. This is reported as a percentage. For example, you will commonly see it reported as 50% effaced. Once it gets to 100% effaced then you know baby is getting closer to coming out since the cervix ranges from 0% effaced to 100% effaced.
I won’t begin to go over these with you and the finer details of each one.
I am by no means an expert, but know the basics here.
First look for the baseline heart rate.
Then look for accelerations, you want to make sure there are atleast 2 accelerations that last 15 seconds and that the heart rate increases by 15 beats per minute in a 20 minute period.
Then check for variability, or the changes in heart rate in general. If the heart rate is consistently one number then this is minimal variability, and there can be moderate or marked variability.
Then look for decelerations.
There are early, variable, and late decelerations.
Early are expected, late are troublesome.
Variables if they are repetitive or don’t bounce back quick to baseline then they become a problem.
The AAFP has a great article here that describes this process.
Below is a video to help out as well
Here are the basic procedures that you should be familiar with how they are done before you begin your ob gyn rotation, and after you are done should be able to do no problem.
Instead of describing how to do each one of these, I will instead provide you with a good list of quality resources to read about them.
This website is overall a great resource, for all things OB/GYN, and their description of how to perform the speculum exam is great and easy to follow with.
Check it out here: https://teachmeobgyn.com/history-taking-examinations/examinations/speculum/
As always you should check UpToDate or other medical references, but as far as websites go this one is great at describing the process. https://www.peacehealth.org/medical-topics/id/zx3441
The image below goes over how to know the dilation and effacement. It is tough to know what it actually is dilated to, but with time and practice you get better at knowing this.
Essentially, do a speculum exam as mentioned above and then you use a brush to get a sample of the transition zone.
Here is a great article from the May Clinic on how to perform this exam https://www.mayoclinic.org/tests-procedures/pap-smear/about/pac-20394841#:~:text=Pap%20test-,Pap%20test,spatula%20(1%20and%202).
Two handed Ties
When it comes to OB/GYN, knowing how to do two handed ties will benefit you greatly. For most OB/GYN procedures that you will do during your rotation, two handed ties will be preferred to one handed ties.
The video below walks you through how to do these.
Make sure you practice so you can be proficient in it before your rotation starts.
Books to Study
As far as a great book for COMAT/Shelf and Step/COMLEX prep goes, Case Files is usually not one you think of.
For OB/GYN it is amazing though.
It goes into detail on 60 different common things seen in practice as well as common scenarios that you will see on your exams.
It really does a great job of walking you through the steps and processes needed in OB/GYN.
This is a great book if you plan on doing some OB in residency.
If you want more details that practice questions, case files, or your general prep for the OB COMAT doesn’t answer, then be sure to get this book.
It is short and to the point, and honestly makes a good quick read in-between deliveries.
Prep for the COMAT/Shelf
When it comes to prepping for the COMAT (I am a DO, so I discuss this more) or the shelf exam practice questions are key.
Make sure you do 15-20 every single day, and if you can swing it do more of them on the weekend.
Plan on making UWorld a centerpiece to your prep.
For Osteopathic Students and the OB COMAT, you should also plan on using COMQUEST. It does a great job and should be the second Q-Bank you do behind UWorld.
Get 15% off of COMQUEST by using the code “SEAN15” at checkout.
Other than questions, do some reading from the Case files book mentioned above.
Online Med Ed does a decent job with this material, but the educator is an internist and has limited post med school experience with OB, so the videos tend to be rather superficial.
Case Files would be more then adequate to cover the anticipated topics.
- COMQUEST (15% off with code “SEAN15”)
- And Case Files
Common “pimping” questions
Alright, we will cover these very superficially, and you can do more research in UpToDate or other resources to get more good info.
What is the difference between placenta previa and abruptio placentae?
Placenta previa is when the placenta covers the internal os of the cervix.
Whereas, placental abruption is where the placenta prematurely begins to separate from the uterus.
Abruption is typically painful, whereas previa is typically not painful.
What are the diagnostic criteria for pre-eclampsia?
Protein in the Urine
It is important to diagnose pre-eclampsia before it turns into eclampsia or even HELLP syndrome.
What are the diagnostic criteria for gestational diabetes?
You do a 1 hour glucose tolerance test, and if their glucose is >135 ish (depending on the lab) then you order a 3 hour glucose tolerance test.
That is the basics of testing for gestational diabetes. Be sure to review the latest information on cut off values for diagnostic purposes of both the 1 hour and 3 hour tests.
Presentation and S/S for different kinds of vaginitis?
Trichomoniasis: Green discharge, treatment is flagyl. Check out the latest guidelines and diagnostic criteria on UpToDate though. Be sure to watch the sketchy videos of this.
Bacterial Vaginosis: Fishy odor, clue cells, grey/white discharge, treatment is with Flagyl.
Yeast infection: White clumpy discharge, recent abx use, diabetic, OCP usage, treatment is with Diflucan (an -azole).
Then be sure to know the different kinds of STI’s and how they present.
OB Gyn Rotation Cheat Sheet: Final thoughts
All of the information above is the basics of what you need to know. This article should make you stand out and get better test scores overall.
That is the point of CPM and all the articles on it, to help you succeed.
Good luck and deliver many babies (if that’s your thing).
Thanks for reading
Sean Kiesel, DO, MBA