This population-based cohort study by Mantel et al. «Mantel Ä, Hirschberg AL, Stephansson O. Associatio...»1 included all singleton births included in the Swedish Medical Birth Register from January 1, 2003, to December 31, 2014. A total of 7542 women with eating disorders were compared with 1 225 321 women without eating disorders. Statistical analysis was performed from January 1, 2018, to April 30, 2019. Via linkage with the national patient register, women with eating disorders were identified and compared with women free of any eating disorder. Eating disorders were further stratified into active or previous disease based on last time of diagnosis.
The risk of adverse pregnancy outcomes (hyperemesis, anemia, preeclampsia, and antepartum hemorrhage), the mode of delivery (cesarean delivery, vaginal delivery, or instrumental vaginal delivery), and the neonatal outcomes (preterm birth, small and large sizes for gestational age, Apgar score <7 at 5 minutes, and microcephaly) were calculated using Poisson regression analysis to estimate risk ratios (RRs). Models were adjusted for age, parity, smoking status, and birth year. The results on pregnancy and neonatal complications were stratified into active and preexisting eating disorders.
There were 2769 women with anorexia nervosa (mean [SD] age, 29.4 [5.3] years), out of which 279 had active or recent AN and 2490 had previous AN, 1378 women with bulimia nervosa (mean [SD] age, 30.2 [4.9] years), out of which 239 had active or recent BN and 1139 had previous BN and 3395 women with an eating disorder not otherwise specified (EDNOS; mean [SD] age, 28.9 [5.3] years), out of which 618 had active or recent EDNOS and 2777 had previous EDNOS. They were analyzed and compared with 1 225 321 women without eating disorders (mean [SD] age, 30.3 [5.2] years).
In general, the RRs for most outcomes were more pronounced for women with active disease vs those with preexisting disease. For instance, the risk of bleeding complications during pregnancy appeared more pronounced for women with active anorexia nervosa (doubled) compared with those with previous anorexia nervosa (1.5-fold). The risk of anemia was doubled for women with active anorexia nervosa (RR, 2.1 [95 % CI, 1.3-3.2]) and for women with EDNOS (RR, 2.1 [95 % CI, 1.5-2.8]), but the risk was not present for those with previous disease.
Similarly, RRs for neonatal outcomes were consequently more pronounced for women with active disease (especially anorexia nervosa), but most RRs for neonatal outcomes also remained significantly increased in women with previous disease. The risk of preterm birth was 2-fold in active anorexia nervosa and 1.5-fold in previous anorexia nervosa (RR, 2.0 [95 % CI, 1.4-2.9], and RR, 1.5 [95 % CI, 1.3-1.8], respectively). The risk of SGA was 2-fold in active anorexia nervosa and 1.3-fold in previous anorexia nervosa (RR, 2.1 [95 % CI, 1.3-3.6], and RR, 1.3 [95 % CI, 1.0-1.7], respectively). The risk of microcephaly was 3-fold in active anorexia nervosa and 2-fold in previous anorexia nervosa (RR, 2.8 [95 % CI, 1.5-5.0], and RR, 1.8 [95 % CI, 1.4-2.3], respectively).
This study by Micali et al. «Micali N, Stemann Larsen P, Strandberg-Larsen K, y...»2 attempted to investigate whether eating disorders are associated with lower size at birth, symmetric growth restriction, and preterm birth; and whether pregnancy smoking explains the association between anorexia nervosa and fetal growth.
The longitudinal population-based cohort study looked at a female study population from the Danish National Birth Cohort (n = 83 826). Women with anorexia nervosa (n = 1609), bulimia nervosa (n = 1693) and both (anorexia + bulimia nervosa, n = 634) were compared with unexposed women (n = 76 724) (women with exposure data and singletons n = 80 660) using crude and adjusted linear and logistic regression models.
The study used data on self-reported pre-pregnancy BMI and recency of onset to determine whether maternal AN was active or past: given that underweight is a diagnostic criterion of AN, all women who self-reported having suffered from AN lifetime and who had a BMI < 18.5 were classified as having active AN (n = 174, 0.23 %), women with lifetime AN who had a BMI > 18.5 pre-pregnancy (n = 1415, 1.84 %), were classified as past AN. Women with active AN reported onset of the disorder closer to enrolment.
Main outcome measures were size at birth (birthweight, length, head and abdominal circumference and placental weight); gestational age; small- and large-for-gestational-age (SGA, LGA); ponderal index, abdominal/head circumference.
Babies of women with active AN had worse size at birth outcomes compared to babies of women with past AN for all outcomes except abdominal/head circumference ratio. Babies of women with past AN also had worse oucomes compared to babies of unexposed women, although the magnitude of effects was lower than in women with active AN. The prevalence of preterm birth in women with recent AN was almost double that of women with past AN (respectively 7.51 % versus 4.11 %). The mean birth weight of babies of women with active AN was 3213.1 g (SD 553.4) and 3522.9 g (SD 521.3) with past AN. The findings were in line with this finding with regard to length, ponderal index, head circumference, and abdominal circumference. Placental mean weight was 579.2 g (SD 135.4) in women with active AN and 654.4 g (SD 146.9) in women with past AN. The risk of SGA was 2.4-fold in active AN versus 1.3-fold in past AN (24.03 % of the babies being SGA in active AN, OR=2.37, 95 % CI 1.61-3.51 in the fully adjusted model versus 14.42 % of babies being SGA in past AN, OR=1.31, 95 % CI 1.11-1.55).
The study concludes that maternal anorexia nervosa (both active and past) is associated with lower size at birth and symmetric growth restriction, with evidence of worse outcomes in women with active disorder. Women with anorexia nervosa should be advised about achieving full recovery before conceiving. Similarly, targeting smoking in pregnancy might improve fetal outcomes.
The study by Ante et al. «Ante Z, Luu TM, Healy-Profitós J, ym. Pregnancy ou...»3 attempted to estimate whether maternal hospitalization for anorexia nervosa before or during pregnancy is associated with an elevated risk of adverse maternal and infant birth outcomes.
The researchers performed a retrospective cohort study of 2,134,945 pregnancies in Quebec, Canada, from 1989 to 2016. The main exposure measure was anorexia nervosa requiring hospital treatment before or during pregnancy. The women with anorexia nervosa had 1910 births. Outcome measures included stillbirth, preterm birth, low birth weight, small-for-gestational age birth, preeclampsia, gestational diabetes, cesarean delivery, and other pregnancy disorders.
Women with more recent hopitalizations for anorexia nervosa were at greatest risk of adverse infant outcomes. Relative to no admissions, anorexia nervosa admissions within 2 years of delivery were associated with 1.92 times the risk of preterm birth (95 % CI 1.32-2.80), whereas admissions within 2-4 years of delivery were associated with 1.37 times the risk (95 % CI 0.92-2.02) and admissions ≥5 years prior were associated with 1.21 times the risk (95 % CI 0.98-1.47). Findings were generally similas for low birth weight and small-for-gestational-age birth. Anorexia nervosa was associated with all three outcomes regardless of the total number of admissions.
The risks of adverse outcomes were declining over time since hospitalization for anorexia nervosa, but remained elevated.