Monthly Archives: November 2014

Review of Three-Tier Fetal Heart Rate Interpretation System

Category I : Normal.
The fetal heart rate tracing shows ALL of the following:

Baseline FHR 110-160 BPM, moderate FHR variability, accelerations may be present or absent, no late or variable decelerations, may have early decelerations.

Strongly predictive of normal acid-base status at the time of observation. Routine care.

Category II : Indeterminate.

The fetal heart rate tracing shows ANY of the following:

Tachycardia, bradycardia without absent variability, minimal variability, absent variability without recurrent decelerations, marked variability, absence of accelerations after stimulation, recurrent variable decelerations with minimal or moderate variability, prolonged deceleration > 2minute but less than 10 minutes, recurrent late decelerations with moderate variability, variable decelerations with other characteristics such as slow return to baseline, and “overshoot”.

Not predictive of abnormal fetal acid-base status, but requires continued surveillance and reevaluation.

Category III: Abnormal.

The fetal heart rate tracing shows EITHER of the following:

Sinusoidal pattern OR absent variability with recurrent late decelerations, recurrent variable decelerations, or bradycardia.

Predictive of abnormal fetal-acid base status at the time of observation. Depending on the clinical situation, efforts to expeditiously resolve the underlying cause of the abnormal fetal heart rate pattern should be made.

Case 1
G1P0 . Induction for preeclampsia at 37 weeks.

Click the image to view the entire tracing

Case 2

G2P1. Arrived in active labor at 40 weeks

Click the image to view the entire tracing


G1, P0, 34 weeks gestation admitted to Labor and Delivery with SROM with moderate amount of pink tinged fluid.

Click the image to view the entire tracing

Macones GA et al., The 2008 National Institute of Child Health and Human Development Workshop Report on Electronic Fetal MonitoringUpdate on Definitions, Interpretation, and Research Guidelines Obstetrics & Gynecology 2008;112:661-666 PMID:18757666

Home Fetal Monitors- May Give a False Sense of Security

Expectant mothers perceiving a sudden decrease in fetal movements should not rely on fetal heart monitors at home to reassure themselves of their baby’s well-being according to Dr. Abhijoy Chakladar of Princess Royal Hospital in West Sussex, England.

Dr. Chakladar reports a case where a mother at 38 weeks, noticed a decrease in her baby’s movements, but was reassured by an apparent fetal heartbeat from her monitor. However, the device may have been detecting the mother’s heartbeat. A few days later, unable to hear the baby’s heartbeat, she went to the hospital where the fetus was discovered to be stillborn.

Abhijoy Chakladar and Hazel Adams Dangers of listening to the fetal heart at home BMJ 2009;339:b4308, doi: 10.1136/bmj.b4308 (Published 5 November 2009)

Joint panel, NICHD, SMFM, ACOG, ACR, SPR and SR, issues an executive summary on fetal imaging

In an executive summary a panel of experts recommended Elimination of the terms partial and marginal previa and retaining  only the terms placenta previa and low-lying placenta

  • If the placental edge is less than 2 cm from the internal os but not covering the internal os, the placenta should be labeled as low-lying, and follow-up ultrasonography is recommended at 32 weeks of gestation.
  • “If the placental edge covers the internal cervical os, the placenta should be labeled as placenta previa, and follow-up ultrasonography is recommended at 32 weeks of gestation. “

The panel also issued opinions on soft markers used to evaluate the risk for Down syndrome in fetuses.

  • Isolated soft markers that are of no importance in the absence of an elevated a priori risk for fetal aneuploidy are choroid plexus cyst and echogenic intracardiac foci.

There is no need for ultrasonographic follow-up in fetuses with isolated choroid plexus cysts, because the cysts almost always resolve.

  • When mild pyelectasis is identified, a targeted ultrasound study to rule out other structural abnormalities and correlation with aneuploidy screening results should be done. Follow-up ultrasonography at 32 weeks of gestation to rule out persistent pyelectasis should be performed. If the renal pelvis measures 7 mm or greater at the 32-week examination, postnatal follow-up is suggested because of correlation with postnatal renal disease.

Other important recommendations given by the panel may be found in the article available at:

REFERENCE: Reddy UM, etr al. Fetal imaging: Executive Summary of a joint Eunice Kennedy Shriver National institute of child health and human development,  society for maternal-fetal medicine, american institute of ultrasound in medicine, american college of obstetricians and gynecologists, american college of radiology, society for pediatric radiology, and society of radiologists in ultrasound fetal imaging workshop. J Ultrasound Med. 2014 May;33(5):745-57.  PMID:24764329

Pregnant women at risk for developing preeclampsia should take low-dose aspirin

Pregnant women  at risk for developing preeclampsia should take low-dose aspirin daily to reduce their chance of developing the disorder according to new recommendations by the U.S. Preventive Services Task Force (USPSTF).

The USPSTF recommends low-dose aspirin (81 mg/day) preventive medication after 12 weeks’ gestation in women who are at high risk for preeclampsia.

Women at high risk include:

  • Prior preeclampsia, especially when accompanied by an adverse outcome
  • Multiple gestation pregnancy
  • Chronic hypertension
  • Type 1 or 2 diabetes
  • Renal disease
  • Autoimmune disease (i.e., systemic lupus erythematous, antiphospholipid syndrome)

In addition The U.S. Preventive Services Task Force (USPSTF)  recommends women with more than one moderate risk factor for pre-eclampsia should to take 81 mg of aspirin daily after 12 weeks of gestation

Moderate risk factors include:

  • Nulliparity (first pregnancy)
  • Obesity (i.e., body mass index >30 kg/m2)
  • Family history of preeclampsia (i.e., mother, sister)
  • Sociodemographic characteristics (i.e., African American race, low socioeconomic status)
  • Age ≥35 years
  • Personal history factors (e.g., low birth weight or small for gestational age, previous adverse pregnancy outcome, >10-year pregnancy interval)

The USPSTF recommendations are similar to recommendation given by the National Institute for Health and Clinical Excellence (NICE) in previous years.

The USPSTF Draft Recommendation Statement is available at:

Safe Prevention of the Primary Cesarean Delivery

In response to concerns that cesarean delivery may be overused.

The American College of Obstetricians and Gynecologists (the College) and the Society for Maternal-Fetal Medicine has Published Guidelines

First stage of labor

  • Cervical dilation of 6 cm should be considered the threshold for the active phase of most women in labor. Thus, before 6 cm of dilation is achieved, standards of active phase progress should not be applied.
  • Cesarean delivery for active phase arrest in the first stage of labor should be reserved for women at or beyond 6 cm of dilation with ruptured membranes who fail to progress despite 4 hours of adequate uterine activity, or at least 6 hours of oxytocin administration with inadequate uterine activity and no cervical change.

Second stage of labor

Before diagnosing arrest of labor in the second stage, if the maternal and fetal conditions permit, allow for the following:

  • At least 2 hours of pushing in multiparous women
  • At least 3 hours of pushing in nulliparous women

Longer durations may be appropriate on an individualized basis (eg, with the use of epidural analgesia or with fetal malposition) as long as progress is being documented.


US Cesarean Section Rate

Guidelines Diagnosis and Treatment of Fetal Cardiac Disease

A greater than 1 % absolute risk for having a child with congenital heart disease or a fetal arrhythmia are Indications for referral for fetal echocardiogram according to the  guidelines by the American Heart Association .

The guidelines also outline the elements of the fetal echocardiographic examination, and provide guidance on In utero management of bradycardias and tachycardias .

Donofrio MT, et. al., Diagnosis and treatment of fetal cardiac disease: a scientific statement from the American Heart Association.Circulation. 2014 May 27;129(21):2183-242. PMID: 24763516

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Antepartum Testing

The guidelines proposed by the National Institute of Child Health and Human Development (NICHD) for the interpretation of fetal heart rate tracings are generally applicable to antepartum testing. However, as of this posting, they do not define reactivity.

A non stress test (NST) is considered reactive when two or more fetal heart rate accelerations peak (but do not necessarily remain) at least 15 beats per minute above the baseline and last 15 seconds from baseline to baseline within a 20 minute period with or without fetal movement discernible by the woman.

The following presentation discusses the NICHD guidelines and antepartum testing:

Antepartum Testing (Powerpoint)

Case 1

Case 2

Case 3


The normal range for the single deepest pocket in twin gestation appears to be 2.2 cm to 7.5 cm [1]

1. Magann EF,et al The ultrasound estimation of amniotic fluid volume in diamniotic twin pregnancies and prediction of peripartum outcomes. Am J Obstet Gynecol. 2007;196(6):570. PMID: 17547899