Predictors of pregnancy and postpartum haemoglobin concentrations in low-income women.
OBJECTIVE
Pregnancy and postpartum iron status is of great public health importance, yet few studies have examined predictors of haemoglobin (Hb) concentration during this time. We identified predictors of Hb from 24 weeks' gestation until delivery and from 4 to 25 weeks postpartum.


METHODS
Blood was drawn as many as four times during care: at the initial visit, at 24-29 weeks' gestation, at delivery and postpartum. A longitudinal, multivariable linear regression model was used to predict Hb concentration.


METHODS
A public health clinic in Raleigh, North Carolina.


METHODS
n=520 women who participated in the Iron Supplementation Study.


RESULTS
Hb concentration at the previous blood draw, short stature, non-Hispanic white ethnicity/race, >12 years of education and smoking were positive predictors of pregnancy and postpartum Hb concentrations. Iron supplement use was a positive predictor, while inadequate weight gain and severe nausea/vomiting were negative predictors of gestational Hb. A high infant birth weight and postpartum haemorrhage were negative predictors of postpartum Hb. Pre-pregnancy body mass index had a slight positive relationship with gestational Hb, but had a strong negative relationship with postpartum Hb. The longitudinal model also confirmed the typical pattern of gestational Hb concentration. As the number of weeks between the initial visit and the 24- to 29-week visit increased, Hb at 24-29 weeks' gestation decreased. As gestational age increased from 24 weeks until delivery, Hb concentration increased as well.


CONCLUSIONS
The predictors identified here could be used in clinical settings to target high-risk women for intervention.
Bodnar
Lisa M
LM
Department of Maternal and Child Health, University of North Carolina School of Public Health, Chapel Hill, NC, USA.
Siega-Riz
Anna Maria
AM
Arab
Lenore
L
Chantala
Kim
K
McDonald
Thad
T
D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000453:epidemiology / Q000209:etiology; D001721:Birth Intervals; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D019266:Iron, Dietary / Q000008:administration & dosage*; D008137:Longitudinal Studies; D009657:North Carolina / Q000453:epidemiology; D049590:Postpartum Period; D011203:Poverty; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D011263:Pregnancy Trimester, Third; D011644:Puerperal Disorders / Q000097:blood / Q000453:epidemiology / Q000209:etiology; D016032:Randomized Controlled Trials as Topic; D012044:Regression Analysis
D006454:Hemoglobins; D019266:Iron, Dietary