Maternal healthy lifestyle during early pregnancy and offspring birthweight: differences by offspring sex.
OBJECTIVE
Individual maternal lifestyle factors during pregnancy have been associated with offspring birthweight; however, associations of combined lifestyle factors with birthweight and potential differences by offspring sex have not been examined.


METHODS
Participants (N = 2924) were identified from a pregnancy cohort in Washington state. Lifestyle factors during early pregnancy were dichotomized based on Alternate Healthy Eating Index score ≥62, leisure time physical activity (LTPA) ≥ 150 min/week, not smoking during pregnancy and Perceived Stress Scale score ≤3, then combined into a lifestyle score (0-4). Regression models were run overall and stratified by offspring sex, prepregnancy overweight/obese (BMI ≥25 kg/m2) and prepregnancy LTPA.


RESULTS
Overall, 20% of participants had healthy diet, 95% were nonsmokers, 55% had low stress levels, and 66% were physically active. Lifestyle score was not associated with birthweight (β = 3.3 g; 95% CI: -14.5, 21.0); however, associations differed by offspring sex (p = .009). For each unit increase in lifestyle score, there was a suggested 22.4 g higher birthweight (95% CI: -2.7, 47.6) among males and 14.6 g lower birthweight (95% CI: -39.9, 10.7) among females. Prepregnancy BMI and LTPA did not modify associations.


CONCLUSIONS
Healthy lifestyle score in early pregnancy may be associated with greater birthweight among male offspring, but lower birthweight among female offspring.
a Department of Epidemiology , University of Washington , Seattle , WA , USA.
Sylvia E
SE
Badon
b Center for Perinatal Studies , Swedish Medical Center , Seattle , WA , USA.
Raymond S
RS
Miller
b Center for Perinatal Studies , Swedish Medical Center , Seattle , WA , USA.
Chunfang
C
Qiu
b Center for Perinatal Studies , Swedish Medical Center , Seattle , WA , USA.
Tanya K
TK
Sorensen
c Department of Epidemiology , Harvard T.H. Chan School of Public Health , Boston , MA , USA.
Michelle A
MA
Williams
a Department of Epidemiology , University of Washington , Seattle , WA , USA.
Daniel A
DA
Enquobahrie
D000328:Adult; D001724:Birth Weight / Q000502:physiology*; D004032:Diet; D000072001:Diet, Healthy; D015444:Exercise; D005260:Female; D000070497:Healthy Lifestyle / Q000502:physiology*; D006801:Humans; D007899:Leisure Activities; D008297:Male; D000068097:Maternal Health; D011247:Pregnancy; D012737:Sex Factors; D012907:Smoking; D013315:Stress, Psychological / Q000453:epidemiology
Birthweight; diet; lifestyle; physical activity; physiological stress; pregnancy; smoking