TY - JOUR
T1 - Gestation-Specific Vital Sign Reference Ranges in Pregnancy
AU - Green, Lauren J.
AU - Mackillop, Lucy H.
AU - Salvi, Dario
AU - Pullon, Rebecca
AU - Loerup, Lise
AU - Tarassenko, Lionel
AU - Mossop, Jude
AU - Edwards, Clare
AU - Gerry, Stephen
AU - Birks, Jacqueline
AU - Gauntlett, Rupert
AU - Harding, Kate
AU - Chappell, Lucy C.
AU - Watkinson, Peter J.
PY - 2020/3/1
Y1 - 2020/3/1
N2 - OBJECTIVE: To estimate normal ranges for maternal vital signs throughout pregnancy, which have not been well defined in a large contemporary population. METHODS: We conducted a three-center, prospective, longitudinal cohort study in the United Kingdom from August 2012 to September 2017. We recruited women at less than 20 weeks of gestation without significant comorbidities with accurately dated singleton pregnancies. We measured participants' blood pressure (BP), heart rate, respiratory rate, oxygen saturation and temperature following standardized operating procedures at 4-6 weekly intervals throughout pregnancy. RESULTS: We screened 4,279 pregnant women, 1,041 met eligibility criteria and chose to take part. Systolic and diastolic BP decreased slightly from 12 weeks of gestation: median or 50th centile (3rd-97th centile) 114 (95-138); 70 (56-87) mm Hg to reach minimums of 113 (95-136); 69 (55-86) mm Hg at 18.6 and 19.2 weeks of gestation, respectively, a change (95% CI) of -1.0 (-2 to 0); -1 (-2 to -1) mm Hg. Systolic and diastolic BP then rose to a maximum median (3rd-97th centile) of 121 (102-144); 78 (62-95) mm Hg at 40 weeks of gestation, a difference (95% CI) of 7 (6-9) and9 (8-10) mm Hg, respectively. The median (3rd-97th centile) heart rate was lowest at 12 weeks of gestation: 82 (63-105) beats per minute (bpm), rising progressively to a maximum of 91 (68-115) bpm at 34.1 weeks. SpO2 decreased from 12 weeks of gestation: median (3-97 centile) 98% (94-99%) to 97% (93-99%) at 40 weeks. The median (3-97 centile) respiratory rate at 12 weeks of gestation was 15 (9-22), which did not change with gestation. The median (3-97 centile) temperature at 12 weeks of gestation was 36.7 (35.6-37.5)°C, decreasing to a minimum of 36.5 (35.3-37.3)°C at 33.4 weeks. CONCLUSION: We present widely relevant, gestation-specific reference ranges for detecting abnormal BP, heart rate, respiratory rate, oxygen saturation and temperature during pregnancy. Our findings refute the existence of a clinically significant BP drop from 12 weeks of gestation. CLINICAL TRIAL REGISTRATION: ISRCTN, ISRCTN10838017.
AB - OBJECTIVE: To estimate normal ranges for maternal vital signs throughout pregnancy, which have not been well defined in a large contemporary population. METHODS: We conducted a three-center, prospective, longitudinal cohort study in the United Kingdom from August 2012 to September 2017. We recruited women at less than 20 weeks of gestation without significant comorbidities with accurately dated singleton pregnancies. We measured participants' blood pressure (BP), heart rate, respiratory rate, oxygen saturation and temperature following standardized operating procedures at 4-6 weekly intervals throughout pregnancy. RESULTS: We screened 4,279 pregnant women, 1,041 met eligibility criteria and chose to take part. Systolic and diastolic BP decreased slightly from 12 weeks of gestation: median or 50th centile (3rd-97th centile) 114 (95-138); 70 (56-87) mm Hg to reach minimums of 113 (95-136); 69 (55-86) mm Hg at 18.6 and 19.2 weeks of gestation, respectively, a change (95% CI) of -1.0 (-2 to 0); -1 (-2 to -1) mm Hg. Systolic and diastolic BP then rose to a maximum median (3rd-97th centile) of 121 (102-144); 78 (62-95) mm Hg at 40 weeks of gestation, a difference (95% CI) of 7 (6-9) and9 (8-10) mm Hg, respectively. The median (3rd-97th centile) heart rate was lowest at 12 weeks of gestation: 82 (63-105) beats per minute (bpm), rising progressively to a maximum of 91 (68-115) bpm at 34.1 weeks. SpO2 decreased from 12 weeks of gestation: median (3-97 centile) 98% (94-99%) to 97% (93-99%) at 40 weeks. The median (3-97 centile) respiratory rate at 12 weeks of gestation was 15 (9-22), which did not change with gestation. The median (3-97 centile) temperature at 12 weeks of gestation was 36.7 (35.6-37.5)°C, decreasing to a minimum of 36.5 (35.3-37.3)°C at 33.4 weeks. CONCLUSION: We present widely relevant, gestation-specific reference ranges for detecting abnormal BP, heart rate, respiratory rate, oxygen saturation and temperature during pregnancy. Our findings refute the existence of a clinically significant BP drop from 12 weeks of gestation. CLINICAL TRIAL REGISTRATION: ISRCTN, ISRCTN10838017.
UR - http://www.scopus.com/inward/record.url?scp=85081142169&partnerID=8YFLogxK
U2 - 10.1097/AOG.0000000000003721
DO - 10.1097/AOG.0000000000003721
M3 - Article
C2 - 32028507
SN - 0029-7844
VL - 135
SP - 653
EP - 664
JO - Obstetrics and Gynecology
JF - Obstetrics and Gynecology
IS - 3
ER -