Maternal hemoglobin drop in multiple pregnancy is associated with higher gestational age at birth and birthweight.

Introduction: This retrospective study investigated the hypothesis that maternal hemoglobin (Hb) levels in twin pregnancy fall between the first and second trimesters and that higher falls are associated with higher gestational age at birth and higher birthweight (BW).

Material And Methods: The study population was defined as pregnant women with twin pregnancies delivering two live, phenotypically normal neonates, after 24 weeks of gestation, between October 2009 and September 2021 at an inner London maternity unit. Maternal Hb and mean corpuscular volume (MCV), at ≤14 weeks of gestation (Hb1) and again at 20-30 weeks gestation (Hb2) were recorded from the Hospital's perinatal database.