Breastfeeding during pregnancy: A systematic review

Abstract

Background: The consequences of breastfeeding during pregnancy (BDP) have not been clearly established. Available studies have addressed isolated aspects of this issue using different methodologies, often resulting in contradictory results. To our knowledge, no systematic review has assessed and compared these studies, making it difficult to obtain a clear picture of the consequences of BDP.

Aim: To review and summarise all the scientific evidence relating to BDP, and determine whether this evidence is sufficient to establish clear implications for the mother, breastmilk, breastfed child, current pregnancy, and ultimately, the newborn.

Methods: We conducted a systematic review of the English and Spanish literature published between 1990 and 2015 using Cinahl, PubMed, IME, CUIDEN, Cochrane Library, Web of Science and PyscINFO.

Findings: 3278 publications were identified from databases, their titles and abstracts were checked to ensure the studies were related to the subject and met the selection criteria. Only 19 studies met all requirements and were included in the review.

Conclusions and implications: Data suggest that BDP does not affect the way pregnancies end or even birth weights. However, several questions remain unanswered. Specifically, it is unclear how BDP affects maternal nutritional status in developed countries, the growth and health of breastfed siblings, the composition of breastmilk, or the growth of the newborn after delivery. Further studies of BDP are needed with larger samples, adequate methodology and proper control of the main confounders.

Keywords: Birth weight; Breastfeeding; Pregnancy; Premature birth; Spontaneous abortion.