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.

Management of an Early Unlocated Pregnancy

Today we’re bringing back Dr. Erin Cleary one more time before she transitions to her new role as an MFM fellow at the Ohio State University! Dr. Cleary today talks with us on early pregnancy of unknown location - a common problem in the office or the emergency department/triage.

Women presenting to the ED with first trimester bleeding, pain, or both, have had a demonstrated prevalence rate of ectopic pregnancy up to 18% in some studies. Ruptured ectopic is a leading cause of pregnancy-related mortality in the first trimester, accounting for 2.7% of pregnancy-related deaths overall in 2011-2013. Proper identification and management of early, unlocated pregnancy is life-saving!

Dr. Cleary was kind enough to put together her high points from this episode for our blog post today:

H&P:

  • Any patient with an unlocated pregnancy should be considered to have a potential ectopic pregnancy.

    • Women with prior ectopic, regardless of method of treatment, are at risk for ectopic in a subsequent pregnancy (three- to eightfold higher compared with other pregnant women).

    • If pregnancy is present while IUD is in place, risk of ectopic is 1 in 2 pregnancies for the levonorgestrel IUD and 1 in 16 pregnancies for the copper IUD.

    • Women with a history of PID have an approximately threefold increased risk of ectopic pregnancy

  • Pelvic exam. THIS MUST BE DONE.

Beta-HCG

  • The threshold for a positive qualitative β-hcg test is 20-50 milli-int units, depending on test. For quantitative serum tests, the threshold is 5-10 milli-int units, and 1-2 milli-int units, for ultrasensitive tests.

  • The β-hcg concentration doubles every 29 to 53 hours during the first 30 days after implantation of a viable, intrauterine pregnancy.

  • When ectopic pregnancy is on the differential, a qualitative test is not sufficient. A serum quantitative value is essential to:

    • 1. Interpret imaging (“discriminatory zone”)

    • 2. Have a baseline in the event the β-hcg must be trended

The Discriminatory Zone

  • Definition: A concept that there is a quantitative β-hcg level above which the landmarks of a normal intrauterine pregnancy (yolk sac and embryo) should be visible on ultrasound.

    • Therefore, the absence of a gestational sac when β-hcg level is above the DZ is strongly suggestive of nonviable pregnancy, with 50-70% being ectopic.

  • Pelvic ultrasound is the gold standard first line imaging modality in early pregnancy and for evaluation of suspected ectopic pregnancy

  • Imaging results will fall into 1 of 5 main categories

    • IUP with normal adnexa. Normal pregnancy!

    • IUP with abnormal adnexa. Although rare, must evaluate for heterotopic pregnancy, or presence of both an intra and extra-uterine pregnancy.

    • No IUP, extra-uterine mass with YS/FP. Confirms ectopic pregnancy.

    • No IUP, adnexal mass without YS/FP. Suspicious for ectopic pregnancy

    • No IUP, normal adnexa. Differential includes normal but early IUP, failed IUP, or unidentified ectopic.

  • A patient with a confirmed ectopic requires evaluation and counseling by an OBGYN to evaluate candidacy for medical or surgical evaluation.

Management:

  • Expectant management: serial quantitative β-hcg level assessment ~q 48 hours, only for stable patients.

    • Scenario A: The β-hcg level rises appropriately (doubles approximately every 2 days).

    • Scenario B: The β-hcg level falls precipitously.

    • Scenario C: The β-hcg level neither rises appropriately nor drops precipitously. Now we should be MORE concerned about ectopic pregnancy, but abnormal IUP is also on the differential.

  • Repeat pelvic imaging is very helpful

  • Every patient who is stable and an appropriate candidate to trend β-hcg levels will eventually declare herself, with either a located IUP, a failed IUP/SAB, or a confirmed or presumed ectopic pregnancy.

We will cover ectopics for surgical and medical management in a future episode, so stay tuned!