Unexpected complications of low-risk pregnancies in the United States

Abstract

OBJECTIVE Determining appropriate sites of care for any type of medical issue assumes successful matching of patient risks to facility capabilities and resources. In obstetrics, predicting patients who will have a need for additional resources beyond routine obstetric and neonatal care is difficult. Women without prenatal risk factors and their newborns may experience unexpected complications during delivery or postpartum. In this study, we report the risk of unexpected maternal and newborn complications among pregnancies without identified prenatal risk factors. STUDY DESIGN We conducted a cross-sectional investigation utilizing US natality data to analyze 10 million birth certificate records from 2011 through 2013. We categorized pregnancies as low risk (no prenatal risk factors) or high risk (at least 1 prenatal risk factor) according to 19 demographic, medical, and pregnancy characteristics. We evaluated 21 individual unexpected or adverse intrapartum and postpartum outcomes in addition to a composite indicator of any adverse outcome. RESULTS Among 10,458,616 pregnancies, 38% were identified as low risk and 62% were identified as high risk for unexpected complications. At least 1 unexpected complication was indicated on the birth certificate for 46% of all pregnancies, 29% of low-risk pregnancies, and 57% of high-risk pregnancies. While the risk for unexpected or adverse outcomes was greatly reduced for the low-risk group compared to the high-risk group overall and for several of the individual outcomes, low-risk pregnancies had higher risks of vacuum delivery, forceps delivery, meconium staining, and chorioamnionitis compared to high-risk pregnancies. CONCLUSION Of births, 29% identified to be low risk had an unexpected complication that would require nonroutine obstetric or neonatal care. Additionally, for select outcomes, risks were higher in the low-risk group compared to the group with identified risk factors. This information is important for planning location of birth and evaluating birthing centers and hospitals for necessary resources to ensure quality care and patient safety.

Authors' reply re: BJOG Debate ‘Home birth is unsafe’

“…benefits for the fetus and no increased risk of maternal death.' 3 Another reference misquoted by Ms Cohain 4 reports that, contrary to her assertion that low risk pregnancies are uncomplicated, a high percentage of low risk pregnancies had unexpected complications. Recommendations to support home births in 'low risk' pregnancies are therefore questionable.…”

“…This is false. Many other pregnancy emergencies, such as a ruptured uterus, abruptio placentae, cord entanglement, shoulder dystocia, and chorioamnionitis, can occur in 'low risk' pregnancies 4 and will benefit from hospital birth, proximity to an OR and well trained personnel. It is false that placental abruptio and uterine rupture 'happen at high risk births only' as Ms Cohain claims.…”

“…Recommendations to support home births in 'low risk' pregnancies are therefore questionable. 4 Ms Cohain claims that cord prolapse is 'the only event with better outcomes in a hospital'. This is false.…”

“…It is false that placental abruptio and uterine rupture 'happen at high risk births only' as Ms Cohain claims. 4 Her claim that hospital births in 'healthy, term mothers in labour . .…”

Authors' reply re: Magnesium sulphate, chorioamnionitis, and neurodevelopment after preterm birth

“…So the effects of magnesium, sulphate may be underestimated and this needs to be considered when considering the overall effect. 4 It is clear that there remain gaps in our knowledge on preterm labour, neurodevelopmental impairments and the effects of magnesium sulphate. However, the study by Kamyar et Authors' reply Sir, We are grateful for Dr Marasinghe's interest in our study.…”