Our sample comprises 131 mother-infant dyads. We investigated correlations between five neonatal traits (gestational age, birthweight, head, suboccipito-brematic, and abdominal girths), three maternal traits (height, BMI, and uterus height), and three pelvic variables (conjugate, inter-spinous diameters, and sub-pubic angle) using computed tomography pelvimetry.
We found that the five neonatal traits were significantly intercorrelated. BMI was not correlated with neonatal traits while maternal height was correlated with birthweight, suboccipito-brematic, and abdominal girth. In the multiple regression models, gestational age was correlated with birthweight, head, and abdominal girth. Among the neonatal and pelvimetry correlations, conjugate diameter was slightly correlated with suboccipito-bregmatic girth, but inter-spinous and sub-pubic angle were not correlated with neonatal traits. Uterus height predicted all neonatal variables, but it was not correlated with gestational age.
Our results suggest that fetal growth is shaped by maternal phenotype rather than external ecological factors. The association of the inlet size with suboccipito-bregmatic girth reflects the tight fit between the neonatal brain and the maternal pelvis dimensions, an adaptation that would reduce the risk of cephalo-pelvic disproportion, while the absence of tight fit at the midplane and outlet could be due to the effect of the pelvic relaxation. Uterus distention is not the only mechanism involved in the initiation of parturition. Birth and pregnancy are complex processes and we suggest that maternal-neonatal associations are the result of a combination of multiple obstetric tradeoffs.
我们的样本包括131个母婴二叉。我们调查了五个新生儿特征之间的相关性(胎龄,出生体重,头部,Suboccipito-brematic,和腹围),三个母性特征(身高,BMI,和子宫高度),和三个骨盆变量(共轭,棘突间直径,和耻骨下角)使用计算机断层扫描骨盆测量。
我们发现这5个新生儿性状是显著相关的。BMI与新生儿性状不相关,而母亲身高与出生体重相关,Suboccipito-brematic,和腹围。在多元回归模型中,胎龄与出生体重相关,头部,和腹围。在新生儿和骨盆测量的相关性中,共轭直径与节理-bregmatic周长略有相关,但棘突间和耻骨下角与新生儿性状无关。子宫高度预测所有新生儿变量,但与胎龄无关。
我们的结果表明,胎儿的生长是由母体表型而不是外部生态因素决定的。入口大小与腹下腹壁-腹壁围长的关联反映了新生儿大脑与母体骨盆尺寸之间的紧密配合,这将减少头骨盆不相称的风险的适应,而中平面和出口处没有紧密配合可能是由于骨盆松弛的影响。子宫扩张不是分娩开始的唯一机制。出生和怀孕是复杂的过程,我们建议母婴关联是多种产科权衡的结果。