Second-trimester growth velocities in twin and singleton pregnancies

OBJECTIVE

Previous small studies used individualized growth assessment (IGA) to characterize prenatal growth velocities of singletons and twins. We aimed to compare second-trimester growth velocities of individual anatomical parameters between monochorionic diamniotic (MCDA) twins, dichorionic diamniotic (DCDA) twins and singleton fetuses in a larger study.

METHODS

This was a study of a novel cohort of 222 MCDA twins and previously published cohorts of 40 DCDA twins and 118 singletons with serial ultrasound data. Fetal biometric measurements of biparietal diameter, head circumference, abdominal circumference and femur diaphysis length from prenatal ultrasound examinations were used to calculate second-trimester growth velocities using direct calculation or linear regression analysis. Linear fit was assessed based on the coefficient of determination (R² ). Mean growth velocities and variances were compared among the three groups.

RESULTS

The majority of cases underwent three second-trimester ultrasound examinations with fetal biometry available. All fetuses had linear growth, with R² > 99% for all parameters. Only 1-2% of all MCDA and DCDA anatomical parameters had abnormal growth velocity scores outside the 95% reference range for singletons. There were no significant differences in mean growth velocity for any parameter between MCDA twins and singletons. Femur diaphysis length growth velocity was significantly lower in DCDA twins than in both MCDA twins and singletons. There were no other significant differences among the groups.

CONCLUSIONS

Expanding on prior work using IGA, we found that second-trimester growth velocity of the four major anatomical parameters overall was similar between twins and singletons and between MCDA and DCDA twins, supporting the use of singleton-derived growth standards for IGA in twins. Twin growth potential appears to be similar to that of singletons in the second trimester, suggesting that subsequent growth divergence may be due to third-trimester physiological or pathological changes in twin pregnancies. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Factors associated with early childhood stunted growth in a 2012-2015 birth cohort monitored in the rural Msambweni area of coastal Kenya: a cross-sectional study

BACKGROUND

Chronic malnutrition, often measured as stunted growth, is an understudied global health problem. Though poor nutritional intake has been linked to stunted growth, there is evidence suggesting environmental exposures may have a significant role in its occurrence. Here, we characterize the non-nutritional prenatal and postnatal factors that contribute to early childhood stunted growth in rural coastal Kenya.

METHODS

Overall, 232 women and 244 children from a 2012-2015 maternal-child cohort in Msambweni, Kenya were included. Women were tested for parasitic infections during the prenatal period and at the time of delivery. Children were tested for parasitic infections and assessed for stunted growth using height-for-age Z-scores (HAZ) at 6-month intervals after birth. Socioeconomic status (SES) was evaluated using both a simplified water, asset, maternal education, and income (WAMI) index and a principal component analysis (PCA) asset score. Multivariate logistic regression analysis was used to determine the relative influence of prenatal and postnatal factors on the occurrence of stunted growth.

RESULTS

Of the 244 children (ages 6-37 months), 60 (25%) were stunted at the study endpoint. 179 mothers (77%) had at least one parasitic infection during pregnancy and 94 children (38%) had at least one parasitic infection during the study period. There was no significant association between maternal parasitic infection and child stunted growth (p = 1.00). SES as determined using the WAMI index was not associated with HAZ in linear regression analysis (p = 0.307), however, the PCA asset score was (p = 0.048). Multivariate logistic regression analysis identified low birth weight (AOR: 3.24, 95% CI: [1.38, 7.57]) and child parasitic infectious disease burden (AOR: 1.41, 95% CI: [1.05, 1.95]) as independent predictors of stunted growth, though no significant association was identified with PCA asset score (AOR: 0.98, 95% CI: [0.88, 1.10]).

CONCLUSIONS

Stunted growth remains highly prevalent in rural Kenya, with low birth weight and child parasitic infectious disease burden demonstrated to be significantly associated with this indicator of chronic malnutrition. These results emphasize the multifaceted nature of stunted growth and the need to address both the prenatal and postnatal environmental factors that contribute to this problem.