A survey of obstetrical care providers demonstrates practice variation in the management of LPT pregnancies complicated by common co-morbidities. Our results suggest that variation is influenced by provider specialty and level of available newborn services. Variation in management of LPT pregnancies is also influenced by the associated co-morbidity, with negligible variability in the management of chorioamnionitis and significant variability in the management of placenta previa, PPROM, and FGR.
Preterm delivery in the presence of maternal or fetal co-morbidities may be necessary in order to prevent further maternal and/or fetal morbidity and mortality. Estimates of potentially preventable LPT births resulting from elective or non-indicated and “soft call” deliveries range from 6% to 23%. 2,12,20
Variation likely results, in part, from the lack of widespread agreement on best practice and will occur when providers disagree about the “safest” or “best” choice in care. Without strong evidence supporting the optimal timing of delivery of LPT pregnancies complicated by common co-morbidities, providers’ training and specialty, previous experience, and practice environment will likely determine practice.
US birth certificate data show a 5% decrease in LPT births between 2006 and 2009. 1
An increased awareness of LPT neonatal morbidity and subsequent quality improvement initiatives, designed to decrease elective LPT and early term births, likely explain this decline in LPT births. 21–23
It is possible that decreased variation in the management of common co-morbidities affecting LPT pregnancies, if accomplished without compromising maternal outcomes, might further decrease neonatal morbidity by delaying LPT delivery. 12
Morbidity in LPT neonates decreases as gestational age increases, suggesting that delaying LPT delivery might improve neonatal outcomes even if a LPT birth cannot be prevented. 2,7
Our data suggest that the degree of agreement among providers in the management of complicated LPT pregnancies is related to the ability to generate clear and easily applicable evidence-based guidelines. The American College of Obstetricians and Gynecologists (ACOG) and The American Academy of Pediatrics (AAP) recommend delivery of pregnancies complicated by chorioamnionitis at any gestational age. 24
In our study, almost 100% of respondents would proceed with delivery in this scenario. Guidelines for the management of hypertensive conditions provide a threshold of gestational age for delivery. It is recommended that pregnancies complicated by mild preeclampsia be managed expectantly until term, while delivery in the setting of severe preeclampsia is recommended at any gestational age. 24,25
The approach to management of preeclampsia at LPT gestations appears to be consistent across specialties. The majority of our respondents follow recommendations for management of mild preeclampsia; however, 1 out of 6 respondents would proceed with delivery. This variation might result from differences in interpretation of severity of preeclampsia or differences in how physicians balance the risk-benefit of continuing the pregnancy or delivering an LPT newborn. Variation in interpretation of disease severity, if it emerges from a lack of common disease definitions, can itself be a target for improving the quality of obstetrical care. Even though 29% of respondents would expectantly manage an LPT pregnancy complicated by severe preeclampsia, the vast majority of these respondents indicated in their comments a low threshold for proceeding with delivery. As for mild preeclampsia, there might be variability in interpretation of criteria for disease severity.
We found significant variation in the management of PPROM, FGR, and placenta previa. ACOG/AAP guidelines recommend delivery when PPROM occurs at or after 34 weeks’ gestation. 24
Overall 31% of respondents would delay delivery under these circumstances. MFM physicians appeared more consistently to practice according to ACOG/AAP guidelines. This variation highlights the lack of evidence for best practice in the setting of PPROM at LPT gestations. Recommendations are based mostly on studies done prior to the time when latency antibiotics became the standard of care for PPROM. 26
A recent Cochrane review summarized data from 7 RCTs and did not find a difference in outcomes between planned early delivery before 37 weeks and expectant management. 26
For pregnancies complicated by FGR, delivery is not recommended in the setting of normal fetal testing. 11
In our study, the majority of providers would expectantly manage the pregnancy, but 20% of respondents would proceed with delivery. Variation was also noted by specialty, with fewer MFM physicians opting for delivery. ACOG/AAP guidelines for management of pregnancies complicated by placenta previa are less specific as is reflected in the variability in management preferences found in our study. Timing of delivery for LPT pregnancies complicated by placenta previa is guided primarily by expert opinion. 11,27
More recent guidelines recommend delivery at 36 – 37 weeks’ gestation for pregnancies complicated by placenta previa. 25
It appears that for scenarios with the greatest variation in management (PPROM, FGR, and placenta previa) provider specialty plays a significant role. MFM physicians appear to have a lower threshold for delivery of LPT pregnancies complicated by PPROM and placenta previa compared to OB/GYN and FM physicians, and more conservatively manage pregnancies complicated by FGR. MFM physicians are more likely to practice in urban or tertiary academic centers with higher levels of obstetric and newborn services, and care almost exclusively for high-risk pregnancies, both of these factors are likely to influence practice.
Strengths of this study include the use of standardized clinical vignettes to identify practice variation. Clinical vignettes-based studies have been found to provide a valid measure of quality when compared to more standard methods such as chart abstraction and use of standardized patients. 28–30
Clinical vignettes are meant to elicit what providers would do in a given clinical situation, not to test knowledge on current guidelines or recent evidence. 29
A significant advantage of clinical vignettes is that they provide a method of case-mix adjustment, are inexpensive, and less time consuming than other research methods. 28,29
We recruited participants from hospital settings providing different levels of care, rural and urban settings, and from all specialties routinely involved in obstetrical care and delivery decision-making for LPT pregnancies. Our results reflect the practices of respondents who are physicians currently providing or until recently providing obstetrical care.
Our study is limited by a low response rate, particularly among FM physicians. On the other hand, we received responses from over half of the state’s active MFM physicians. Conclusions derived from our results are more applicable to OB/GYN and MFM physicians, who are approximately 85% of active providers of obstetrical care in the state, than they are to FM physicians. Survey responses were anonymous and thus we were unable to compare characteristics of respondents and non-respondents. Given that respondents knew they were being evaluated, inferences about provider practices, based on our results, tell us what physicians say they would do and not necessarily what they actually do. Previous research in clinical vignette methodology, however, has shown strong validity when compared to chart abstraction. These types of validation studies have not been performed in the obstetrical literature, 28,30
and vignette methodology does not help differentiate appropriate versus inappropriate variation. 29
Interpersonal variation in interpretation of both clinical vignettes and disease severity could also contribute to our results.
In conclusion, we identified reported practice variation in the obstetrical management of LPT pregnancies. This variation is a source of potentially modifiable LPT births, particularly in pregnancies complicated by placenta previa, FGR, and PPROM. Future research to improve the quality of obstetrical care and decrease preventable LPT births should generate evidence on best practices for these conditions. It is also necessary to gain a stronger understanding of which factors contributing to practice variation (e.g. practice setting, specialty, level of care) are most amenable to intervention. As new evidence is generated, the community of obstetrical providers must give thought to appropriate and effective dissemination strategies to guarantee the implementation of best practices.