Pre- and Perinatal Characteristics Associated with Apgar Scores in a Review and in a New Study of Dutch Twins

Abstract

A literature review was carried out to identify pre and perinatal characteristics associated with variation in Apgar scores in population-based studies. The parameters identified in the literature search were included in the classical twin design study to estimate effects of pre and perinatal factors shared and nonshared by twins and to test for a contribution of genetic factors in 1- and 5-min Apgar scores in a large sample of Dutch monozygotic (MZ) and dizygotic (DZ) twins. The sample included MZ and DZ twins (N = 5181 pairs) recruited by the Netherlands Twin Register shortly after birth, with data on prenatal characteristics and Apgar scores at first and/or fifth minutes. The ordinal regression and structural equation modeling were used to analyze the effects of characteristics identified in the literature review and to estimate genetic and nongenetic variance components. The literature review identified 63 papers. Consistent with the review, we observed statistically significant effects of birth order, zygosity and gestational age (GA) for 1- and 5-min Apgar scores of both twins. Apgar scores are higher in first-born versus second-born twins and DZ first-born versus MZ first-born twins. Birth weight had an effect on the 5-min Apgar of the first born. Fetal presentation and mode of delivery had different effects on Apgar scores of first- and second-born twins. Parental characteristics and chorionicity did not have significant main effects on Apgar scores. The MZ twins’ Apgar correlations equaled the DZ Apgar correlations. Our analyses suggest that individual differences in 1- and 5-min Apgar scores are attributable to shared and nonshared pre and perinatal factors, but not to genotypic factors of the newborns. The main predictors of Apgar scores are birth order, zygosity, GA, birth weight, mode of delivery and fetal presentation.

Pregnancy outcomes in women affected by fetal alpha-thalassemia: a case control study

“…Consistent with the previous study 29 , we herein found a significant negative association between gestational age and low Apgar scores among thalassemic women. However, we noted that predicting low Apgar scores based on gestational age alone was less accurate using a ROC curve.…”

Twin-Singleton Comparisons Across Multiple Domains of Life

“…The second-born twin generally faces the greatest risks as obstetric complications, such 4 as placental separation, cord prolapse, uterine atony, prolonged intertwin delivery time, and cervical spasm, may occur after delivery of the first-born twin [88] and can cause fetal distress, low Apgar scores, and neonatal morbidity [41,75].…”

Accuracy and Interrater Agreement of Registered Nurses’ Assignment of Apgar Scores to Standardized Clinical Vignettes

“…Catlin et al (1986) demonstrated that respiratory effort, muscle tone, and reflex irritability are affected by the neonate's estimated gestational age meaning that otherwise healthy neonates born small or premature will receive lower Apgar scores compared to their appropriate for gestational age, term counterparts. Other researchers have supported these findings (Cnattingius et al, 2020;Odintsova et al, 2019). Finally, per NRP (Weiner, 2021), any intervention for a neonate requiring resuscitation should begin well before the 1-min Apgar score is assigned.…”