Length of gestation and birthweight in dizygotic twins

doi:10.1016/S0140-6736(01)05716-6

The Lancet

Volume 358, Issue 9281, 18 August 2001, Pages 560-561

https://doi.org/10.1016/S0140-6736(01)05716-6 Get rights and content

Summary

Despite the longer gestation of girls, their birthweight is less than that of boys. Because unlike-sex twins provide a natural situation in which to investigate the influence of sex on gestation, we compared birthweight and gestation of 1929 same-sex and unlike-sex dizygotic pairs. Length of gestation in unllke-sex pairs was similar to that of female same-sex pairs, and significantly (0·4 weeks; p=0·02) longer than that of male same-sex pairs. Birthweight of girls from unlike-sex pairs was similar to that of girls from same-sex pairs, but boys from unlike-sex pairs weighed 78 g more than boys from same-sex pairs (p=0·001). These data show that in unlike-sex pairs it is the girl that prolongs gestation for her brother, resulting in a higher birthweight than that of same-sex boys.

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Cited by (84)

Sons and parental cognition in mid-life and older adulthood
2022, Journal of Psychiatric Research
Prior research suggests a relationship between number of sons and maternal long-term health outcomes, including dementia. We assessed the relationship between having sons and parental cognitive aging. Specifically, we investigated the relationship between having at least 1 son and parental baseline cognition level and rate of cognitive decline, accounting for life course sociodemographic characteristics in a cohort of 13 222 adults aged ≥50 years from the US Health and Retirement Study. We included only participants with at least one child. We further explored whether this relationship varies by parental sex and whether the magnitude of the relationship increases with each additional son. Cognition was assessed biennially for a maximum of nine times as a sum of scores from immediate and delayed 10-noun free recall tests, a serial 7s subtraction test, and a backwards counting test. Associations were evaluated using linear mixed-effects models, stepwise adjusting for sociodemographic and health-related factors. In our analytic sample of parents, a total of 82.3% of respondents had at least 1 son and 61.6% of respondents were female. Parents of at least 1 son had a faster rate of cognitive decline in comparison to parents without any son. Our results also suggest that cognitive decline was faster among parents of multiple sons, compared to parents with only daughters. Thus, the results support the theory that having sons might have a long-term negative effect on parental cognition.
Effect of Co-twin Fetal Sex on Fetal Anthropometry and Birth Time in Twin Pregnancies
2021, Journal of Obstetrics and Gynaecology Canada
Citation Excerpt :
As in singleton pregnancies, male newborns of multiple pregnancies have a higher birth weight than female newborns.15–17 However, whether birth weight in twins is affected not only by the infant's sex but also by the sex of the co-twin remains controversial.7,18–23 Therefore, the effects of fetal sex and opposite fetal sex on birth weight and other anthropometric factors in twins were examined in the present study.
This study of twin deliveries aimed to examine the effect of fetal sex and fetal sex of the co-twin on fetal anthropometry and length of gestation.
Pregnancies were grouped as male/male, male/female, and female/female. Birth weight, head circumference, body length and delivery time of newborns were compared between unlike-sex and like-sex twin pregnancies.
A total of 1028 pregnant women who met the inclusion criteria were enrolled in the study. Of these pregnancies, 32.6% (n = 335) were male/male, 33.4% (n = 343) were male/female, and 34.0% (n = 350) were female/female. The discordant (male/female) newborns had a higher total birth weight than concordant twins (P = 0.015). Compared with male newborns from male/female twin pregnancies, male newborns from male/male pregnancies were found to be 129 grams heavier, 0.7 cm longer, and had a 0.4 cm larger head circumference (P<0.001, P=0.023, and P = 0.039, respectively). Pregnancies with male/female fetuses had statistically significantly longer gestations than pregnancies with male/male and female/female fetuses (P = 0.003 and P = 0.004, respectively). The shortest mean gestation was observed in the male/male group. Male/male pregnancies had a 1.53 times higher risk of preterm delivery than male/female pregnancies and a 1.51 times higher risk than female/female pregnancies (OR 1.53; 95% CI 1.07–2.19 and OR 1.51; 95% CI 1.06–2.16, respectively).
This study suggests that, in twin pregnancies, birth weight, head circumference, and body length are affected by the sex of the co-twin. Male sex is associated with shorter gestation and male/male twin pregnancies are at higher risk for preterm labour.
Cette étude sur les grossesses gémellaires visait à examiner l'incidence du sexe fœtal des jumeaux sur l'anthropométrie fœtale et la durée de la gestation.
Les grossesses ont été réparties en 3 groupes de sexe fœtal : masculin/masculin, masculin/féminin et féminin/féminin. Le poids à la naissance, le périmètre crânien, la taille et la durée de l'accouchement des nouveau-nés ont été comparés entre les grossesses de jumeaux de sexes différents et les grossesses de jumeaux de même sexe.
Au total, 1 028 femmes enceintes répondant aux critères d'inclusion ont participé à l’étude. De ces grossesses, 32,6 % (n = 335) étaient du groupe de sexe fœtal masculin/masculin; 33,4 % (n = 343), masculin/féminin; et 34,0 % (n = 350), féminin/féminin. Le poids total à la naissance était plus élevé chez les jumeaux de sexes différents (masculin/féminin) que chez les jumeaux de même sexe (P = 0,015). Comparativement aux nouveau-nés masculins issus d'une grossesse gémellaire masculin/féminin, ceux issus d'une grossesse gémellaire masculin/masculin étaient 129 g plus lourds, étaient 0,7 cm plus longs et avaient un périmètre crânien 0,4 cm plus grand (P < 0,001, P = 0,023 et P = 0,039, respectivement). Une augmentation statistiquement significative de la durée de gestation a été observée pour les grossesses de type masculin/féminin par rapport à celles de types masculin/masculin et féminin/féminin (P = 0,003 et P = 0,004, respectivement). La durée de gestation moyenne la plus courte a été observée dans le groupe masculin/masculin. Le risque d'accouchement prématuré des grossesses masculin/masculin est 1,53 et 1,51 fois plus élevé par comparaison aux grossesses masculin/féminin et féminin/féminin, respectivement (RC : 1,53; IC à 95 % : 1,07–2,19 et RC : 1,51; IC à 95 % : 1,06–2,16, respectivement).
Cette étude indique que, en cas de grossesse gémellaire, le poids à la naissance, le périmètre crânien et la taille sont influencés par le sexe des jumeaux. Le sexe masculin est associé à une gestation plus courte, et le risque d'accouchement prématuré est le plus élevé en cas de grossesse gémellaire masculin/masculin.
Association between single nucleotide polymorphism in ovine Calpain gene and growth performance in three Egyptian sheep breeds
2016, Journal of Genetic Engineering and Biotechnology
Citation Excerpt :
Sex of animal influenced significantly birth weight. Superiority in growth performance of males compared to females in various sheep breeds was reported by De Zegher et al. [24], Loos et al. [25] and Cruickshank et al. [26]. Esenbuga and Dayıoğlu [27] reported that sex had highly significant effect on BW of Awassi and Red-Karman lambs.
The aim of the present study was to assess the association of single nucleotide polymorphisms (SNPs) of Calpain (CAPN) gene with birth weight (BW), final weight (FW) and average daily gain (ADG) in three Egyptian sheep breeds: Barki, Rahmani and Ossimi. Blood samples were collected from 108 animals representing the three breeds. DNA was isolated using salting out procedure and then the quality and quantity of DNA extracted were measured. A 190 bp of CAPN was amplified by PCR using specific primers. The allele and genotype frequencies for all the identified SNPs were calculated. The PCR products corresponding to each genotype were sequenced to identify SNPs associated with the traits in question. Two SNPs (C→T) were detected in the nucleotides 44 and 154. For each SNP, the two mentioned alleles were named C and T, respectively. The sequenced CAPN segments were subjected to nucleotide blast at NCBI, which revealed 99% identity with that reported for sheep in Genbank. The TT was the least common genotype, whereas frequencies of CT and CC genotypes were fluctuated in the three sheep breeds under study. Animal carrier TT genotype had higher BW, FW and ADG than those with CT genotype, while the lowest values were associated with CC genotype. For the three traits under study, Rahmani had the highest estimates followed by Ossimi and Barki. Males exhibited heavier BW and FW as well as higher ADG compared with females. The results generated provide preliminary indication of the functional diversity present in Barki, Rahmani and Ossimi sheep and the possibility of using this polymorphism in Egyptian sheep genetic improvement.
Heightened risk of preterm birth and growth restriction after a first-born son
2015, Annals of Epidemiology
In Scandinavia, delivery of a first-born son elevates the risk of preterm delivery and intrauterine growth restriction of the next-born infant. External validity of these results remains unclear. We test this hypothesis for preterm delivery and growth restriction using the linked California birth cohort file. We examined the hypothesis separately by race and/or ethnicity.
We retrieved data on 2,852,976 births to 1,426,488 mothers with at least two live births. Our within-mother tests applied Cox proportional hazards (preterm delivery, defined as less than 37 weeks gestation) and linear regression models (birth weight for gestational age percentiles).
For non-Hispanic whites, Hispanics, Asians, and American Indian and/or Alaska Natives, analyses indicate heightened risk of preterm delivery and growth restriction after a first-born male. The race-specific hazard ratios for preterm delivery range from 1.07 to 1.18. Regression coefficients for birth weight for gestational age percentile range from −0.73 to −1.49. The 95% confidence intervals for all these estimates do not contain the null. By contrast, we could not reject the null for non-Hispanic black mothers.
Whereas California findings generally support those from Scandinavia, the null results among non-Hispanic black mothers suggest that we do not detect adverse outcomes after a first-born male in all racial and/or ethnic groups.
Disgust in pregnancy and fetus sex-Longitudinal study
2015, Physiology and Behavior
Citation Excerpt :
What is more, gestation when carrying a boy is likely to be a greater energetic burden to a mother, than gestation when carrying a girl. Males are heavier and larger at birth [25,26], with the difference emerging as early as the 8th pregnancy week [27]; thus they require more energy during fetal development [28]. As disgust sensitivity is thought to vary across pregnancy, in a manner that compensates for changes in the vulnerability to disease and risk to the mother and a fetus, trading-off the profit and cost [8], one may expect that fetus sex may also moderate maternal disgust sensitivity during pregnancy.
Disgust, an emotion triggering behavioral avoidance of pathogens, serves as a first line of defense against infections. Since behavior related to disgust involves some cost, the aversive reaction should be adjusted to the level of an individual's immunocompetence, and raise only when immunological function is lower (e.g. during pregnancy). We studied changes in disgust sensitivity in pregnant women, and tested if disgust sensitivity is related to a fetus's sex. 92 women participated in a three-stage research, answering the Disgust Scale-Revised questionnaire at each trimester of pregnancy. The result showed that total disgust and disgust sensitivity in the Core Domain were the highest in the first trimester (when maternal immunosuppression is also the highest), and decreased during pregnancy in women bearing daughters. Women bearing sons had relatively high disgust sensitivity persisting in the first and in the second trimester. The elevation in disgust sensitivity during the second trimester for mothers bearing male fetus can be explained by the necessity to protect for a longer time, a more ecologically sensitive fetus, and also herself when bearing a more energetically costly sex. The proximate mechanism may involve the differences in maternal testosterone and cortisol concentrations in the second trimester of pregnancy.
A 10-Year Observational Study on Twin Pregnancy: Role of Fetal Sex Pairing on Obstetric Outcome
2023, Twin Research and Human Genetics

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Research LettersLength of gestation and birthweight in dizygotic twins

Summary

Causes of prematurity. III. Influence of race and sex on duration of gestation and weight at birth

Am J Dis Child

Fetal growth: boys before girls

Hormone Res

Research Letters
Length of gestation and birthweight in dizygotic twins