Objective
Chronic kidney disease (CKD) has been linked with adverse pregnancy outcomes, but few studies have examined the influence of cause and severity. The aim of this meta-analysis was to synthesize the evidence on CKD and adverse pregnancy outcome, by cause and severity of CKD where reported.
Data sources
We searched PubMed, Embase, and Web of Science from inception to May 2021. Study selection and Data Extraction: Studies reporting associations between CKD and adverse pregnancy outcomes were included according to pre-defined eligibility criteria (PROSPERO protocol registration: CRD42020211925). Two reviewers independently screened titles, abstracts, and full-text articles and performed data extraction. The certainty of the evidence was assessed using the GRADE approach.
Main Outcomes and Measures: We used random-effects meta-analyses to calculate pooled estimates. Primary outcomes included pre-eclampsia, Caesarean section (CS), preterm birth (PTB <37 wk.) and small for gestational age (SGA).
Results
In total, 31 studies were included. The certainty of the evidence was deemed to be ‘very low' for all outcomes using the GRADE approach as expected given the observational study design. Pre-pregnancy CKD was associated with pre-eclampsia [pooled adjusted odds ratio (aOR)=2.58 (1.33-5.01)], CS [aOR=1.65 (1.21-2.25)], PTB [aOR=1.73 (1.31-2.27)] and SGA [aOR= 1.93 (1.06-3.52)]. Subgroup analyses suggested that different causes of CKD had differing risks for adverse pregnancy outcomes, and later stages of CKD, compared to earlier stages, were associated with higher odds of pre-eclampsia [crude OR = 2.77 (1.73-4.44)], PTB [4.21 (2.99-5.92)], and SGA [2.43 (1.33-4.46)].
Conclusions
CKD was associated with a higher risk of adverse pregnancy outcomes, and the degree of risk varied by cause and severity. These findings highlight the need for further studies of a more robust quality evaluating the effects of cause and severity of kidney disease on adverse pregnancy outcomes.
Key messages
Pre-pregnancy CKD was associated with higher risk of adverse pregnancy outcomes. The risk of adverse pregnancy outcomes varied by CKD cause and severity.
Background: Existing studies have established an association between pregnancy, birth complications, and mental health in the first few weeks postpartum. However, there is no clear understanding of whether pregnancy and birth complications increase the risk of adverse maternal mental outcomes in the longer term. Research on maternal adverse mental health outcomes following pregnancy and birth complications beyond 12 months postpartum is scarce, and findings are inconsistent. Objective: This systematic review and meta-analysis will examine the available evidence on the association between pregnancy and birth complications and long-term adverse maternal mental health outcomes. Methods and analysis: We will include cohort, cross-sectional, and case-control studies in which a diagnosis of pregnancy and/or birth complication (preeclampsia, pregnancy loss, caesarean section, preterm birth, perineal laceration, neonatal intensive care unit admission, major obstetric haemorrhage, and birth injury/trauma) was reported and maternal mental disorders (depression, anxiety disorders, bipolar disorders, psychosis, and schizophrenia) after 12 months postpartum were the outcomes. A systematic search of PubMed, Embase, CINAHL, PsycINFO, and Web of Science will be conducted following a detailed search strategy until August 2022. Three authors will independently review titles and abstracts of all eligible studies, extract data using pre-defined standardised data extraction and assess the quality of each study using the Newcastle-Ottawa Scale. We will use random-effects meta-analysis for each exposure and outcome variable to calculate overall pooled estimates using the generic inverse variance method. This systematic review will follow the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Ethical consideration: The proposed systematic review and meta-analysis is based on published data; ethics approval is not required. The results will be presented at scientific meetings and publish in a peer-reviewed journal. PROSPERO registration: CRD42022359017
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