Really important question here.
Absolutely high-yield for the boards and also extremely important for your clerkship rotations.
So let’s jump right in.
You have a 24-year-old primigravida who presents to her physician for regular prenatal care in her 31st week of pregnancy.
She has no complaints and her pregnancy course has been unremarkable.
Her pre-gestational history is only significant for obesity, her BMI is 30.5.
During the pregnancy she has gained 10 kg or 22.4 pounds of weight,
and since her last visit four wks ago, her weight has increased by 2 kg or about 4.5 pounds.
Her vital signs are as follows: blood pressure is 145/90, her heart rate is 87, the respiratory rate is 14, and her temperature is 36.7.
The fetal heart rate is 153.
Physical examination of the mother shows no edema
and is only significant for a two out of six systolic murmur best heard at the apex of the heart.
A 24-hour urine collection is negative for protein.
Which of the following options describes the best management strategy in this case?
Answer choice A: Admission to the hospital for observation;
Answer choice B: Treatment in the outpatient setting with labetalol;
Answer choice C: Observation in the outpatient setting;
Answer choice D: Treatment in the inpatient setting with methyldopa; or
Answer choice E: Treatment in the outpatient setting with nifedipine.
Now take a second to go through these answer choices and come to a conclusion by yourself before we go through it together.
Okay, let’s jump right in. This is an important question.
So let’s first look at our question characteristics. Now, this is an OB-GYN question.
We have a girl coming in, she's pregnant with a baby.
There's baby stuff going on, so definitely fits within OB-GYN.
Now we have a two step question here.
The first thing we have to do is figure out what is going on with the patient?
They're telling us how far along she is in her pregnancy, what her blood pressure is,
they talk about urine protein and a heart murmur so we gotta take all that and put together
and then they want us to say. "Well, what was the next best step in management?"
which is the essential core of all USMLE step two questions, what do I do next?
So two steps one, figure out what's going on; number two, how do you manage it?
And of course the stem here is required complex question, lots of information in the question stem.
We have to kind of sieve through it and find the important pieces.
So let’s begin our walk through.
The first thing we need to do is determine the diagnosis. Now, we have a female pregnant patient,
we're told it’s her first pregnancy cuz it says she’s a primigravida.
Now she's here for a routine prenatal visit in her third trimester of pregnancy and she has no complaints.
You know, it says, she has no complaints and her pregnancy course has been unremarkable.
Now, the only risk factor for a pregnancy complication for her is her obesity, the BMI is 30.5.
Now the physical exam here is very important. You need to pick this up in the question stem.
The first thing you'll notice is that she is hypertensive. We're told her blood pressure is 145/90.
Now again recall, hypertension greater than 140/90 is called hypertension so she is hypertensive.
Now, in addition to her being hypertensive, we're told that she has a systolic heart murmur.
The question stem tells you she has a two out of six systolic murmur best heard at the apex of the heart.
Now, when you think of this, you should know that most systolic murmurs in pregnancy are most likely gonna be benign.
As in 80-90% of pregnant women and even within one to two weeks after delivery, they can have a systolic murmur.
That’s a lot, 80-90% of pregnancy and even after delivery,
and the rationale behind this is that the mechanism is believed to be associated with an alteration in blood viscosity
and the state of the walls of the great vessels in the heart in the condition of pregnancy.
So you should pick up, hey, they're telling me the systolic murmur, is it important or not?
Unlikely, but still something I want you to keep in your mind in addition to having picked up the hypertension.
Now, taking into account the high blood pressure and some of the heart findings,
really are differential diagnosis of what's going on, is preeclampsia and gestational hypertension.
Now, in the question stem, there is really no associated clinical symptoms or proteinuria and that’s important.
They tell you, the physical exam shows no edema and they also tell you a 24-hour urine collection is negative for protein.
So preeclampsia, like by definition presents with proteinuria and typically has some type of systemic edema
and since neither of these are here, it makes that less likely on our differential.
So then, we look back at the question stem, and we see that her blood pressure really is only mildly elevated -
a 145/90 is high but not that high, so then our diagnosis really is mild gestational hypertension, so we did that.
So step two, we have to figure out what's the best next step in management
and I kind of dramatize that word best because that’s the key to getting board questions right.
The question is not what could you do next, well of course, the answer stem is always gonna give you a couple of viable options,
but keep thinking what's the best answer, that’s how you kill step one
and that’s what we're gonna do right now. So what's the best next step in management?
Well, this patient has asymptomatic mild gestational hypertension.
Now, a potential complication of gestational hypertension is preeclampsia,
but this patient has very mild gestational hypertension making the risk of this complication very low.
So really what we wanna do then is have a conservative strategy.
Now, if you look at the answer choices answer choice B, D, and E can all be excluded
cuz they all involved treatment with a medication and since we want to be conservative,
those are not gonna be our choices. And we can also get rid of the answer choice A
because that requires inpatient hospitalization and again, we wanna be conservative so we can get rid of that as well.
So really the answer choice here is Answer choice C which is observation in the outpatient setting
which is the best conservative treatment for a mild gestational asymptomatic hypertension.
Now, let’s go through this answer choices a bit more to say how else you could have figured it out
other than simple process of elimination that I just walked you through.
So, let’s start with the right answer which is Answer choice C, observation in the outpatient setting.
Now, when you look at the patient’s question stem, they tell you, there's no past medical history of hypertension,
so she was previously normotensive and she is now presenting with mild hypertension after the 20th week of gestation
which is how we can call it gestational hypertension, and it’s mild so we can just do conservative management
and we don’t need to give any pharmacological treatments.
Now, how do you diagnose gestational hypertension?
Well, this is important so like really pay attention to this numbers -- it’s the same as in anyone else.
So you have to have a blood pressure greater than 140/90 which is what you would say in any person with hypertension
but it has to be after the 20th week of pregnancy and that’s how you can call it gestational hypertension.
Also, you have to make sure there is no accompanied proteinuria because if there was,
we would then call that preeclampsia, and really it’s proteinuria or/and organ damage.
Now, the proteinuria, that’s defined as having protein in a 24-hour urine collection greater than 0.3 grams
or a protein to creatinine ratio greater to or equal to 0.3 on a random urine sample
if you can't get a 24-hour collection or more than 1+ on a dipstick test in the clinic
when you can't do a proper urine or urine collection test or you had evidence of and/or organ damage
and that can be having altered mental status, that’ll be cerebral symptoms or visual symptoms,
headache, blurred vision, pulmonary edema or obviously any kind of kidney or liver failure.
All of these can be a sign of preeclampsia
and that would move you out of the diagnosis of gestational hypertension into preeclampsia.
Now, what's important to understand is that gestational hypertension is a part of pregnancy associated hypertensive disorders.
Now it’s important to distinguish gestational hypertension from preeclampsia with or without severe features
and really the absence of proteinuria or/and organ damage is a key factor
that differentiates gestational hypertension and preeclampsia, that’s very important that you understand.
Now, gestational hypertension is asymptomatic in this patient and it’s not accompanied by any laboratory abnormalities.
We also don’t see any clinical symptoms; no edema, no headache, no change in vision, no right upper quadrant pain -
that’ll be liver, no shortness of breath, no crackles in the lung -
that’ll be pulmonary symptoms, and also no laboratory abnormalities.
We don’t see thrombocytopenia, they don’t mention it.
They don’t tell us anything about a increase creatinine or increase transaminitis.
There’s no change in any other symptoms.
And also, preeclampsia here, we don’t suggest at all because there’s no comment of proteinuria.
Now, mild gestational hypertension with the blood pressure that’s less than 160/110,
we can actually manage in the outpatient setting without pharmacological intervention.
So if it’s between 140 and 160, we call that mild, and we can manage it in the outpatient setting.
Now there is a possibility of conversion into preeclampsia with mild gestational hypertension
and reports have said the rate of this convertion is between 10 - 50% so monitoring is really quite important in this condition
and the way we would do it is in in-office outpatient blood pressure management in measuring once or twice a week
and we would look at her urine to make sure there's no proteinuria,
we would look at labs to make sure that there is no thrombocytopenia,
and we would also check the liver enzymes to make sure that there is no liver damage.
And here we do not need to do bed rest because she has no significant co-morbidities.
Now, if the systolic blood pressure was greater than 160 and diastolic greater than 110,
then we would have to give a antihypertensive and we could use labetalol, nifedipine, methyldopa
or you could even do a pregnancy delivery if the pregnancy was greater than thirty four weeks gestation -
so that’s why the correct answer is outpatient because it is mild, the systolic blood pressure is greater than 140
and less that 160, there is no evidence of preeclampsia so we can simply monitor in the outpatient setting.
Now, let’s go through the other answer choices and see why they are incorrect.
Now, answer choice A is admission to the hospital.
You don’t have to admit, it is not an emergency -- we can measure in the outpatient.
Answer choice B is outpatient use of labetalol.
Again, systolic is less than 160, we don’t need to give medications.
Labetalol is perfectly applicable in pregnancy but not viable in this case.
Answer choice D would be inpatient treatment with methyldopa.
Now methyldopa can be used but only for severe gestational hypertension,
so put that on the top shelf of scary things you wanna use for severe gestational hypertension,
but again, in this case we have mild, we don’t need to use an agent.
Answer choice E nifedipine in the outpatient setting.
Again, a very viable treatment when you need to give pharmacological agents in pregnancy,
but again, not applicable in this case.
Now, let’s go over some high-yield facts for this case.
So here we’re talking about pregnancy associated hypertensive disorders.
Now, blood pressure greater than 140/90 in a pregnant woman is how we diagnose a hypertensive pregnancy associated disorder.
Now, this is actually quite common between 5 - 10% of pregnancy,
women will have pregnancy associated hypertension and this is thought to be due to placental circulation changes
and overall resistance in the mother’s blood circulations affecting blood pressure.
Now, there are different causes to this and there's really three I want you to look at your diagram here of our flow chart to make sense of it.
Now, chronic hypertension can be a cause, that is the mother came in hypertensive,
she now has a baby so of course she's going to be hypertensive.
So that’s a pre-pregnancy hypertension. Now the other cause can be a gestational hypertension
which is you know after 20 weeks you have a baby and you get high blood pressure,
you didn’t have high blood pressure before and you do not have proteinuria,
so that can be another cause or preeclampsia of course in which you have proteinuria
or/and organ damage in the setting of hypertension.
And you can see that here on our flow chart as proteinuria is really present in both cases of where we diagnose preeclampsia.
Now, the diagnosis here is based on a combination of blood pressure measurement and clinical history.
If you look at our flow chart we see the before 20 weeks and after 20 weeks categories and then we see treatment based on that.
So if you look at our flow sheet we see that treatment is indicated at preventing preeclampsia.
We can either observe or give blood pressure medications.
We don’t want blood pressure to go so high where we’re getting proteinuria or/and organ damage.
And of course, if preeclampsia is already present, we want to treat it or if applicable try to deliver the baby and the placenta.