Preterm Labor and PPROM

Today we talk about the routine management of PPROM and PTL. We’ve prepared a little chart that we hope is handy for both teaching and learning! Be sure to also check out ACOB PB 171 and PB 188. For some primary literature, check out the BEAM trial on magnesium sulfate, the most recent Cochrane review on steroid administration, the ALPS trial for Antenatal Late Preterm Steroid administration, and the RCT demonstrating benefit to latency antibiotics in PPROM.

(c) CREOGS over Coffee, 2019

We also use the podcast to highlight a number of controversies, differing practice patterns, or areas of new and active research in these clinical topics (with help from our friends at the ObG Project!)

  • Delivery timing: A 2017 Cochrane review suggested better neonatal outcomes with expectant management of PPROM to 37 weeks, convincing enough to have the Royal College of Obstetrics and Gynecology to change their clinical practice guideline to allow expectant management to 37’0.

  • Administration of Corticosteroids: The ObG Project gives a great summary on when to administer betamethasone. In summary:

    • Between 24-34 weeks in all cases of PPROM and in PTL if delivery is expected within 7 days.

    • A single rescue course should be administered if it has been > 14 days since the last course, and delivery is again expected within the subsequent 7 days.

    • Between 34-36’6 weeks if PPROM or PTL occurs, no prior steroids have been administered, and delivery is expected within the subsequent 7 days.

  • Periviability: The management of periviable PPROM is managed very differently by institution, as resources and optimal management strategies remain to be identified. Protocols and policies should be arranged in accordance with the individual obstetrics and neonatology departments. Ideally, counseling for patients experiencing periviable PTL and PPROM should be performed in an interdisciplinary fashion.

  • Outpatient Management of PPROM: There have a few retrospective studies, the most recent of which came from a large series out of France and received some press attention, suggesting that outpatient management may be appropriate in select candidates. That said, this is definitely NOT the standard of care at this time; inpatient management of PPROM is still the standard set forth by ACOG in the absence of larger, prospective studies.

The Evidence-Based Cesarean Section

Today we go through the steps of cesarean delivery from an evidence basis. We hope this helps everyone from the new interns starting up in just a few weeks to senior residents thinking more about their technique and teaching. The essential article on this from AJOG in 2013 can be found here. However, there have been a number of other articles and talks since, including one regularly given at the ACOG Annual Meeting (check out the 2017 edition by Dr. Strand here), that you all may be aware of and that we encourage you to check out.

One of the more challenging things to relay in the podcast is incisional technique, particularly comparing the traditional Pfannenstiel technique to newer techniques such as Joel-Cohen or Misgav-Ladach. We summarize the differences in those techniques here:

(C) CREOGs Over Coffee (2019)

What’s the difference in these skin incisions?

  • Pfannenstiel: traditionally taught as a curved incision made two finger breadths above the symphysis pubis, with the mid portion of the incision generally within the superior-most aspect of the pubic hair.

  • Joel-Cohen: a straight incision made 3cm below the imaginary line that connects the ASIS on either side. Ultimately this is slightly higher than the Pfannenstiel.

  • Maylard: curved incision made 5-8 cm obove the pubic symphysis. The rectus fascia and muscle are cut transversely, and the inferior epigastric arteries must be ligated.

  • Cherney: using the same skin incision as a Pfannenstiel, but then blunt dissection is used to identify the rectus muscle tendons at their insertion to the public symphysis. They are cut 1-2 cm above their insertion point. On closure, the muscles should be reattached to the anterior rectus sheath, as reattaching to the pubic symphysis may serve as a nidus for osteomyelitis.

Vision Changes in Pregnancy

Today we are joined by Dr. Ben Young. Ben is an ophthalmology resident at Yale New Haven Hospital in Connecticut, and is sharing with us a common complaint that we know very little about - the eye in pregnancy!

Ben also hosts Eyes For Ears, an educational podcast and flashcard reference for ophthalmology residents. If you happen to know any vision sciences students or residents, let them know about it!

We start out talking about the “ocular vital signs,” which are:
- Visual Acuity
- Pupils (“swinging light test”)
- Intraocular pressure
- Visual Fields
- Extra-ocular movements

Image copyright of FOAMCast

The most common reasons for ophthalmology issues in pregnancy relate to either 1) vision changes requiring a new prescription, or 2) dry eye. However, don’t forget some key pearls:

- Monocular (single eye) double vision — dry eye. Binocular (both eye) double vision — badness!
- A Snellen chart and a flashlight are the best tools you have to help out a consultant.
- Check out this video on how to perform a swinging flashlight test.

Further reading from the OBG Project:
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Is Cataract Surgery in Women Associated with Decreased Mortality?

Fetal Growth Restriction

On today’s episode, we tackle the new ACOG PB 204 on fetal growth restriction. There’s quite a bit to cover, so you’ll see today’s episode is a bit longer. We’ve enlisted the help of Chris Nau, MD, an MFM fellow at Brown, to help us through all the recommendations.

FGR, as Chris explains, results from a process where there is mismatch between fetal demands and placental supply of oxygen and nutrients. Symmetric growth restriction arises earlier, and asymmetric growth restriction arises later, with the differentiating factor being asymmetric growth restriction resulting in a larger head circumference : abdominal circumference ratio. The PB 204 goes into many of the common causes, but the list is long!

ACOG PB 204

ACOG and SMFM state that a sonographic estimated fetal weight less than the 10th percentile is the measurement definition of fetal growth restriction, though as Chris explains, there are a number of limitations to this definition.

Screening is performed using a fundal height at prenatal visits, and if the height is < 2cm discrepant from the gestational age, an ultrasound should be performed. Alternatively ultrasounds can be used primarily, especially with known maternal conditions that might predispose someone to FGR, or if fundal height assessments are difficult.

Once a growth-restricted infant is identified, you should check the due date calculation and make sure it is right! (Check out our previous episode on dating!) Next, re-review the mother’s medical history and pregnancy history, including aneuploidy screening, to date. A level 2 ultrasound may help identify anatomic abnormalities that point to an etiology. And identifying modifiable risk factors, including optimizing medical conditions or smoking cessation, may be worthwhile.

With respect to management, there are variable institutional protocols with respect to monitoring. Umbilical artery velocimetry reduces risk of perinatal death when added to other antenatal testing (i.e., modified BPP). Normal or elevated systolic : diastolic flow ratio does not carry increased risk to the fetus; however absent or reversed end-diastolic flow increases risk for perinatal mortality. Chris reviews our protocol at Brown in the podcast.

Timing of delivery is a tricky one — there is not great evidence, and the newest guidance from PB 204 states that reassuring fetal testing should deliver between 38w0d - 39w6d. If there is FGR plus concerning maternal or fetal findings, delivery should be considered between 32w0d to 37w6d.

When counseling about future pregnancies, there is about a 20% risk of recurrence. At this time, ACOG/SMFM do not recommend baby aspirin for prevention of FGR in the absence of other risk factors for preeclampsia.

Further reading from the OBGProject:
Fetal Growth Restriction: Diagnosis, Evaluation, and Management
Aspirin Treatment - ACOG and USPSTF Recommendations

Interpreting Cardiotocography/EFM Part I: Definitions

Today we take a break from STIs to jump back into obstetrics, and are joined by two very special guests: Liz Kettyle and Linda Steinhardt, both of whom are certified nurse midwives (CNMs) and clinical educators at the Warren Alpert Brown School of Medicine.

ACOG PB 106 (membership required) forms the basis for this episode and in a future episode, we will discuss management of cardiotocography (CTG). Also, for a recent article surrounding the naming of CTG vs. EFM vs. all the other names for this technology, check out a recent AJOG article on its now 50-year history.

We also are using some special sound effects for these episodes! As you listen to the various sounds for different types of decelerations, keep in mind that the higher-pitched sound represents a contraction pattern, and the lower-pitched sound represents the fetal heart rate response.