Antenatal blood pressure for prediction of pre-eclampsia, preterm birth, and small for gestational age babies: development and validation in two general population cohorts.
Can routine antenatal blood pressure measurements between 20 and 36 weeks' gestation contribute to the prediction of pre-eclampsia and its associated adverse outcomes?
This study used repeated antenatal measurements of blood pressure from 12 996 women in the Avon Longitudinal Study of Parents and Children (ALSPAC) to develop prediction models and validated these in 3005 women from the Southampton Women's Survey (SWS). A model based on maternal early pregnancy characteristics only (BMI, height, age, parity, smoking, existing and previous gestational hypertension and diabetes, and ethnicity) plus initial mean arterial pressure was compared with a model additionally including current mean arterial pressure, a model including the deviation of current mean arterial pressure from a stratified normogram, and a model including both at different gestational ages from 20-36 weeks.
The addition of blood pressure measurements from 28 weeks onwards improved prediction models compared with use of early pregnancy risk factors alone, but they contributed little to the prediction of preterm birth or small for gestational age. Though multiple imputation of missing data was used to increase the sample size and minimise selection bias, the validation sample might have been slightly underpowered as the number of cases of pre-eclampsia was just below the recommended 100. Several risk factors were self reported, potentially introducing measurement error, but this reflects how information would be obtained in clinical practice.
The addition of routinely collected blood pressure measurements from 28 weeks onwards improves predictive models for pre-eclampsia based on blood pressure in early pregnancy and other characteristics, facilitating a reduction in scheduled antenatal care.
UK Wellcome Trust, US National Institutes of Health, and UK Medical Research Council. Other funding sources for authors are detailed in the full online paper. With the exceptions of CM-W, HMI, and KMG there were no competing interests.
Macdonald-Wallis C
,Silverwood RJ
,de Stavola BL
,Inskip H
,Cooper C
,Godfrey KM
,Crozier S
,Fraser A
,Nelson SM
,Lawlor DA
,Tilling K
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《BMJ-British Medical Journal》
Association of maternal polycystic ovary syndrome and diabetes with preterm birth and offspring birth size: a population-based cohort study.
Is the presence of polycystic ovary syndrome (PCOS) associated with more adverse infant outcomes in mothers with different types of diabetes?
The presence of PCOS implies higher risks of total (medically indicated and spontaneously combined) and spontaneous preterm birth in mothers with non-insulin-treated type 2 diabetes and gestational diabetes mellitus (GDM), and lower risk of offspring being large for gestational age (LGA) in mothers with insulin-treated diabetes.
PCOS is suggested to be an independent risk factor for adverse infant outcomes, and it is highly prevalent in mothers with diabetes. However, the impact of PCOS on the associations of different types of maternal diabetes with preterm birth and offspring birth sizes has not been reported.
This is a population-based cohort study including all live births between 1996 and 2014 in Finland. Children with concurrent maternal diagnoses that could cause signs and symptoms similar to PCOS were excluded. A total of 1 097 753 children were included.
National registries were linked to identify births with maternal PCOS (n = 24 682), stratified by diabetes types. Logistic regression was used to examine the association of maternal PCOS and comorbid insulin-treated diabetes, non-insulin-treated type 2 diabetes or GDM with offspring LGA and small for gestational age (SGA). Generalized estimating equation was used to assess the risk of preterm birth in relation to maternal PCOS and diabetes. Potential interaction between PCOS and diabetes was evaluated on both additive and multiplicative scales.
Using mothers with no PCOS and no diabetes as the reference and adjusting for maternal and birth factors, there were higher risks of total (odds ratio (OR) 2.84, 95% CI 2.21 - 3.66 vs. OR 1.91, 95% CI 1.77 - 2.07, P = 0.01) and spontaneous (OR 4.02, 95% CI 2.94 - 5.50 vs. OR 2.35, 95% CI 2.13 - 2.59, P = 0.001) preterm birth for those with PCOS in mothers with non-insulin-treated type 2 diabetes and higher risks of total (OR 1.42, 95% CI 1.27-1.58 vs. OR 0.89, 95% CI 0.86-0.91, P = 0.0001) and spontaneous (OR 1.80, 95% CI 1.59-2.05 vs. OR 1.01, 95% CI 0.98-1.05, P = 0.0001) preterm birth for those with PCOS in mothers with GDM. Among mothers with type 2 diabetes, further adjusting for maternal BMI eliminated the difference in preterm birth risks between those with and those without PCOS, and adjustment for infertility treatment and pre-eclampsia also reduced the preterm risks associated with PCOS significantly. For mothers with GDM, however, the risks of total and spontaneous preterm birth remained higher for those with PCOS following these aforementioned adjustments or stratified analysis. The risk of offspring being LGA was lower for those with PCOS than those without PCOS among mothers with insulin-treated diabetes (OR 18.90, 95% CI 14.21-25.14 vs. OR 32.04, 95% CI 29.79-34.46, P = 0.0001), showing departure from additivity (relative excess risk due to interaction -11.74, 95% CI -16.17 to -7.31, P < 0.001) and multiplicativity (P < 0.001). PCOS did not alter the risk estimate of preterm birth in mothers with insulin-treated diabetes or offspring LGA and SGA in mothers with type 2 diabetes or GDM.
The register-based diagnoses used in this study captured only women with PCOS seeking medical care and having live births. Including female infertility associated with anovulation as PCOS exposure was a risk for misclassification. Sample sizes for pregestational diabetes were small. Insulin purchase during pregnancy in those without a diabetes diagnosis was not accounted for in the analysis. For patients treated with insulin or other medications, we were unable to assess how they complied with such prescriptions. Also, maternal BMI was recorded only once in early pregnancy, thus the potential influence of gestational weight gain on birth outcomes could not be examined. Data on the causes for preterm birth were not available from the registers.
The presence of PCOS implied higher risks of total and spontaneous preterm birth in mothers with type 2 diabetes or GDM, and lower risk of offspring being LGA in mothers with insulin-treated diabetes. The higher risks of preterm birth added by PCOS could be explained by prepregnancy BMI or in part by infertility treatment and pre-eclampsia in maternal non-insulin-treated type 2 diabetes, but not in maternal GDM. The differential effects of PCOS on the associations of different types of maternal diabetes with infant outcomes have implications for preventative strategies and clinical counseling for affected pregnancies.
This study was supported by Shandong Provincial Natural Science Foundation, China (ZR2020MH064 to X.C.), Shandong Province Medical and Health Technology Development Plan (2018WS338 to X.C.), the joint research funding of Shandong University and Karolinska Institute (SDU-KI-2019-08 to X.C. and C.L.), the Finnish National Institute for Health and Welfare: Drug and pregnancy project (M.G.), the Swedish Research Council (2014-10171 to C.L.), the regional agreement on medical training and clinical research (ALF) between Stockholm County Council and Karolinska Institute Stockholm County Council (SLL20170292 and SLL20190589 to C.L.), the Swedish Brain Foundation (FO2019-0201 and FO2020-0305 to C.L.). X.C. received grants from the China Scholarship Council at the beginning of the study. The authors have no competing interests to disclose.
N/A.
Chen X
,Gissler M
,Lavebratt C
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