Child growth from birth to 18 months old born after assisted reproductive technology--results of a national birth cohort study.
BACKGROUND
Pregnancy conceived by assisted reproductive technology (ART) carries a higher risk of adverse birth outcomes. So far, there have been very few longitudinal studies of the growth of children born after ART.


OBJECTIVE
The purpose of this study was to explore the determinants of growth of children born after ART.


METHODS
Using data of Wave I (6 months old) and II (18 months old) of the Taiwan Birth Cohort Study (TBCS), a national sample of 21,248 pairs of mothers and their children were included for analysis, including 366 pairs resulting from ART (1.7%).


METHODS
Data were collected through field interviews with structured questionnaires, and with references to each child's birth certificate and Passport of Well-baby Care.


RESULTS
Compared to children born with naturally conceived pregnancy, children born after ART had a significantly higher incidences of low birth weight (33.1 vs. 6.9%; p<0.001) and prematurity (42.1 vs. 11.3%; p<0.001). Overall children born after ART had a similar trend of growth in body weight from birth to 18 months old, but did not achieve catch-up of body weight by 18 months old. On the other hand, they had a faster growth and evidence of catch-up in both body height and head circumference from 6 months to 18 months old. Stratified by the birth number, for singleton or twin babies, there was no significant difference in most parameters of growth at birth and up to 18 months old between babies born by ART compared with those born through a natural conception. Analysis using generalized estimating equation modeling showed that multiple pregnancy and breastfeeding as well as having the mother herself as the caregiver in daytime through 18 months old are the negative and positive contributing factors, respectively for both growth and the change of growth with time among children born after ART.


CONCLUSIONS
Though exhibiting a higher incidence of low birth weight as well as prematurity, children born with ART enjoyed a similar or faster rate of growth from birth to 18 months old when compared to those children born through naturally conceived pregnancies. While multiple gestation is always a negative contributing factor, continuous breastfeeding and having the mother herself as the caregiver in daytime are positive contributing factors for the growth and/or change of growth for the children born after ART.
Lee
Shu-Hsin
SH
School of Nursing, Chung Shan Medical University, Taichung, Taiwan.
Lee
Ming-Yung
MY
Chiang
Tung-Liang
TL
Lee
Maw-Sheng
MS
Lee
Meng-Chih
MC
D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D027724:Reproductive Techniques, Assisted; D013624:Taiwan