Reference ranges for third-trimester maternal cardiovascular function parameters measured in normotensive pregnant women using a non-invasive cardiac output monitor: A study based on data from the prospective PEACH cohort study.

OBJECTIVE: We defined reference ranges for maternal cardiac output, systemic vascular resistance, and stroke volume measured in the third trimester of pregnancy using the Ultrasound Cardiac Output Monitor 1A. DESIGN: Based on data from the prospective PEACH (PreEclampsia, Angiogenesis, Cardiac dysfunction and Hypertension) cohort study. SETTING: Rigshospitalet and Hvidovre Hospital, Denmark. SAMPLE: Normotensive pregnant women aged 18-45 years with singleton pregnancies, enrolled in the PEACH study in 2016-2018. METHODS: We modelled cardiac output, systemic vascular resistance and stroke volume as a function of gestational age using multilevel linear models with fractional polynomials. MAIN OUTCOME MEASURES: Unconditional and conditional reference ranges for cardiovascular parameters measured in gestational weeks 28-40. RESULTS: Our study cohort included 405 healthy pregnant women who contributed 1210 cardiovascular function measurements for analysis. Maximum cardiac output and stroke volume values were measured in gestational weeks 30-32 and decreased over the third trimester, whereas systemic vascular resistance increased during the same period. We created reference ranges for eight combinations of maternal height, age and parity. We also created a simple calculator to allow for implementation of the reference ranges in clinical practice. CONCLUSIONS: Our reference ranges allow the use of a bedside ultrasound device to non-invasively assess cardiac function in pregnancy and identify women at risk of complications. The unconditional ranges allow clinicians to evaluate isolated measurements and identify women needing follow-up. The conditional ranges incorporate information from previous measurements and improve monitoring over time.

Prognostic value of screening for irregular antibodies late in pregnancy in rhesus positive women.

BACKGROUND: To evaluate the prognostic value of screening for irregular antibodies late in pregnancy (third trimester) in rhesus positive women. Only those cases where irregular antibodies have not previously been demonstrated during routine screening in the first trimester with regard to clinically relevant complications in the newborn, were studied. MATERIALS AND METHODS: All women living in Frederiksborg county and giving birth in 1996 (n = 4216) were assessed for inclusion in the study. This was done by gathering the files at the Hillerød and Hørsholm Hospitals' blood banks for antibody test results. Six hundred women were excluded because of the lack of either the rhesus type or the late antibody test. RESULTS: Of the 3616 women, 3046 were rhesus positive, and 3012 of these had a negative first trimester screen test. Fifteen of the 3012 women later developed irregular antibodies in the third trimester, and were included in the study. This corresponds to only 0.5%, and none of these cases entailed perinatal complications for the mother or the child. CONCLUSION: Routine screening of rhesus positive pregnant women in the third trimester is not rational from a cost-benefit perspective, if the only purpose is to prevent hemolytic disease of the newborn.