Sunday, December 15, 2013

New Terminology for Term Pregnancies

In November, 2013, ACOG released Committee Opinion 579: Definition of Term Pregnancy. The new guideline suggests using the following terms:

  • Preterm: Before 37 0/7 weeks gestation
  • Early term: 37 0/7 - 38 6/7 weeks gestation
  • Full term: 39 0/7 - 40 6/7 weeks gestation
  • Late term: 41 0/7 - 41 6/7 weeks gestation
  • Post-term: Greater than 42 0/7 weeks gestation
The Opinion recommends against referring to all deliveries between 37 and 42 weeks as Term. The new nomenclature emphasizes the primacy of neonatal outcomes between 39 and 41 weeks gestation. 

New Preeclampsia Guidelines

In November 2013, ACOG released a new publication, Hypertension in Pregnancy, which significantly changes a few things about the diagnosis and treatment of hypertension in pregnancy.

The Guideline recognizes four categories of hypertension in pregnancy:
  1. Preeclampsia-eclampsia
  2. Chronic hypertension
  3. Chronic hypertension with superimposed preeclampsia
  4. Gestational hypertension
One of the most fundamental changes is removing the necessity of proteinuria from the diagnosis of preeclampsia. Going forward, preeclampsia is diagnosed when there is:
  • New onset hypertension after 20 weeks greater than 140/90 on two occasions at least four hours apart;
  • Proteinuria of at least 300 mg/24 hours (or this amount extrapolated out from a shorter interval). 
If proteinuria is not present, then the diagnosis can still be made if hypertension plus any of the following are present: 
  • Thrombocytopenia (platelets less than 100,000);
  • Renal insufficiency (serum creatinine greater than 1.1 or a recent doubling of the creatinine in the absence of other renal disease);
  • Impaired liver function (elevation of the transaminases to double normal);
  • Pulmonary edema;
  • Cerebral or visual symptoms. 
Of note, the term mild preeclampsia should give way simply to preeclampsia. 

The diagnosis of preeclampsia with severe features (replacing the term severe preeclampsia) is no longer dependent upon the amount of proteinuria (removing the previous 5g/24 hour criteria). The guideline instead focuses on signs and symptoms of end-organ damage. The following features are used to diagnosis preeclampsia with severe features: 
  • BPs greater than 160/110 on two separate occasions four hours apart;
  • Thrombocytopenia (platelets less than 100,000);
  • Progressive renal insufficiency (serum creatinine greater than 1.1 or a recent doubling of the creatinine in the absence of other renal disease);
  • Impaired liver function (elevation of the transaminases to double normal), severe progressive RUQ or epigastric pain unrelieved by medication and not otherwise explained, or both;
  • Pulmonary edema;
  • New onset cerebral or visual symptoms. 
Of note, growth restriction is no longer used as a criterion for preeclampsia with severe features, and the management of severe growth restriction or abnormal umbilical artery dopplers is the same whether the patient has hypertension or not. 

Gestational hypertension is simply new onset hypertension after 20 weeks without proteinuria or any of the above symptoms. 

The Task Force did not recommend any screening for the prediction of preeclampsia beyond history and physical (such as ultrasounds or biochemical markers). They did recommend starting a low-dose aspirin in women who have had preeclampsia in more than one prior pregnancy or in women who have previously been delivered at or before 34 weeks due to preeclampsia in any pregnancy. Vitamins C and E, bed rest, and salt restriction were not recommended. 

Delivery of women with preeclampsia without severe features is recommended at 37 0/7 weeks. Use of NSAIDs should be avoided if hypertension persists greater than 1 day after delivery due to the effect of nonsteroidals on blood pressure. 

For women with preeclampsia with severe features, delivery should continue at 34 weeks or sooner if any of the following is present:
  • Uncontrolled severe hypertension
  • Eclampsia
  • Pulmonary edema
  • Abruptio placentae
  • DIC
  • Nonreassuring fetal status
  • IUFD
Women with Chronic Hypertension should not be delivered before 38 weeks. For women with chronic hypertension with superimposed preeclampsia, delivery is at 37 weeks or earlier if severe features are present. 

All 99 pages are worth reading and there are many more specific recommendations, but these are the most fundamental changes to what has been standard of care for the last few years.