Maternal asthma during pregnancy and risks of allergy and asthma in progeny: a systematic review protocol

Abstract

Objective: The primary objective of this systematic review is to synthesize the best available evidence on the relationship between in utero exposure to maternal asthma and postnatal allergy. Secondary objectives are to investigate the impact of asthma loss of control, asthma exacerbation, and asthma severity during pregnancy on risks of allergy and asthma in progeny.

Introduction: Maternal asthma is a well-known risk factor for childhood asthma, with recent evidence suggesting that children of asthmatic mothers are also at increased risk of allergic diseases. Importantly, these do not appear to be purely genetic associations, since maternal asthma is more strongly associated with childhood asthma than paternal asthma. In addition, experimentally induced allergic asthma during pregnancy increases allergic responses to sensitization in mice. The strength of the relationships between exposure to maternal asthma or severity of maternal asthma, and progeny asthma and allergy are unknown.

Inclusion criteria: This review will include primary studies that report incidence of physician-diagnosed asthma or allergic disease in human progeny who were exposed in utero to maternal asthma, in comparison to progeny not exposed to maternal asthma.

Methods: Initial search terms include (pregnan∗ OR gestat∗) AND asthma∗ AND allerg∗. We will search the following electronic databases for published and unpublished evidence: PubMed, Embase, MEDLINE (Ovid), Web of Science, Cochrane Library, CINAHL, Scopus, Informit Health, MedNar, ProQuest, and Trove. There will be no restrictions on publication date. Only studies available as a full-text English publication will be considered for inclusion.

Systematic review registration number: PROSPERO CRD42020201538.