Association between multimorbidity of pregnancy and adverse birth outcomes: A systemic review and meta-analysis

Multimorbidity (>= 2 co-existing conditions) in pregnancy is a significant public health issue with a rising prevalence worldwide. However, the association between pregnancy multimorbidity and adverse birth outcomes is unclear. So, this review assessed the association between pregnancy-multimorbidity and adverse birth outcomes (preterm birth, abnormal birth weight, neonatal mortality, and stillbirth). Relevant peer-reviewed papers in PubMed, Web of Science, Elsevier/ScienceDirect, and Google Scholar were systematically search from January 1990 to March 2023. We used the random-effects model to calculate the multimorbidity pooled odds ratio, quantified heterogeneity using I2 statistics, and performed subgroup and sensitivity analyses in Stata version 17. The review protocol is registered with PROSPERO (CRD42023421336). The meta-analysis included 21 observational studies involving 6,523,741 pregnant women. The overall pooled odds of pregnancy multimorbidity associated with adverse birth outcomes were 3.11(2.14-4.09), 3.76(2.56-4.96) in Europe, 3.38(1.18-5.58) in North America, and 2.94(0.78-5.09) in Asia. Pregnant women with psychological and physical multimorbidity had increased odds of 5.65(1.71-9.59) and 2.75(1.71-9.58), respectively, for adverse birth outcomes. Pregnancy multimorbidity was associated with preterm birth 4.28(2.23-6.34), large gestational age (>90 percentile) 3.33 (1.50-5.17), macrosomia (>= 4000 g) 2.16(0.34-3.98), and small gestational age (<10th percentile) 3.52 (1.54-5.51). There is substantial variance in the odds of pregnancy multimorbidity by type of comorbidity and type of adverse birth outcome, attributed to differences in the healthcare system by geographical location. Therefore, prioritizing pregnant women with multimorbidity is crucial for effective and integrative interventions.