Number Of Male Fetuses Research Articles

Prenatal Study of Testes Growth and Histological Development 2-Fetal Goat

This study was conducted on 53 samples of female local Kurdi goats uterus contained one or two fetuses .These samples were collected from Sulaimani slaughter house, A total of 53genitlia were consisted of 36 (67.92%)single and 17(32.08%)twin fetuses ,with a total of 70 fetus,of them 33(47.14%) and 37(52. 86%) were located in the right and left horns, respectively. The number of fetuses with macroscopically clear external sex organ was 55, the total number of male fetuses was 34(48.57%) while the female was 21(30%).The fetuses whose external organ could not be diagnosed were 15(21.42%). The weight of the fetal testes and the length of scrotum were increased steadily with an increasing in the fetal Crown Rump Length(CRL). When the CRL is 2.5-5cm testes location is close to the kidney, while testes are located in the inguinal ring and/or scrotum at about20-23 and 28cm.Histological sections of testes showed the density of fibroblast layer and connective tissue capsules as well as the appearance of seminiferous tubles containing a few spermatogonia cells and small leydig cells at early stages of CRL=8cm. With an increasing in CRL , the seminiferous tubules filled with different types of spermatogonia cells, spermatocytes cells ,increasing in number and size of sertoli and leydig cells. Different Types of spermatid were also present in sections of more than 20cm CRL. The study indicated that the fetal testes secreted testosterone hormone which is essential for testes development and descending

The number of male pups within a litter of NMRI mice is associated with the dam’s food preferences late in pregnancy

Pregnancy related differences in food preferences and food intake are well recognized in animals and humans.Changes in maternal hormonal profiles are supposed to be implicated in such a phenomenon. Since fetal sex hormones are excreted in their dams’ bloodstream, they can affect the behaviour of mothers during gestation. We investigated whether there was a relationship between the number of male pups within the litter and food preferences in pregnant mice. In the first experiment we found that, parcelling out the effect of litter size, the number of male fetuses was positively correlated to maternal testosterone levels on pregnancy day (PD)18. In the second experiment we showed an association between the number of males and the consumption of a 0.25% saccharin solution on PD18, controlling for litter size and baseline (before pregnancy) saccharin intake. In the third experiment, mice on PD18 were placed in a test cage and underwent a 1-h binary choice test between two unknown unpalatable diets, a high fat diet (HFD) and a sweet mesh diet (HSD). Results revealed that the number of males was negatively associated with the preference for the HFD at birth. These results are consistent with the hypothesis that the behavioural profile of dams can be associated with fetal gender composition.

Twin birth weight discordance and risk of preterm birth

Objectives: Our purpose was to determine whether birth weight discordance is a risk factor for preterm birth of twins, and to further characterize the relationships involved. Study Design: Maternally linked 1978-1990 Missouri birth certificates were used to analyze gestations resulting in live twins. We used contingency tables and multiple logistic regression. Results: The degree of discordance correlated strongly with risk for live preterm birth but only for discordances >30% and preterm birth at <32 weeks’ gestation. Among 9479 pregnancies with discordance <30%, 9.5% ended in birth at <32 weeks’ gestation, versus 13.7% of 326 with discordance of 30% to 40% (P =.03) and versus 34.1% of 126 with discordance ≥40% (P <.001). There were 42 preterm twin births at <32 weeks’ gestation with discordances ≥40%. Of these, 51% were attributable to fetal growth restriction and 16% to large size for gestational age in one infant; in 72% the smaller twin was the second born, and in 86% the twins were like sex. The relative association between ≥40% discordance and preterm birth at <32 weeks’ gestation was strengthened (final odds ratio, 9.54; P <.0001) in a multivariate model containing other risk factors for delivery at <32 weeks’ gestation: black race, either twin small for gestational age, unmarried, teenage mother, number of male fetuses, like fetal sex, education <12 years, nulliparity, and cigarette smoking. Conclusions: Twin birth weight discordance has now clearly been demonstrated to be a risk factor for preterm birth. The effect was found particularly with discordances ≥40% before 32 weeks’ gestation. Discordance was usually attributable to fetal growth restriction, most often in the second-born twin. (Am J Obstet Gynecol 2000;183:63-7.)

Twin birth weight discordance and risk of preterm birth

Objectives: Our purpose was to determine whether birth weight discordance is a risk factor for preterm birth of twins, and to further characterize the relationships involved. Study Design: Maternally linked 1978-1990 Missouri birth certificates were used to analyze gestations resulting in live twins. We used contingency tables and multiple logistic regression. Results: The degree of discordance correlated strongly with risk for live preterm birth but only for discordances >30% and preterm birth at <32 weeks’ gestation. Among 9479 pregnancies with discordance <30%, 9.5% ended in birth at <32 weeks’ gestation, versus 13.7% of 326 with discordance of 30% to 40% (P =.03) and versus 34.1% of 126 with discordance ≥40% (P <.001). There were 42 preterm twin births at <32 weeks’ gestation with discordances ≥40%. Of these, 51% were attributable to fetal growth restriction and 16% to large size for gestational age in one infant; in 72% the smaller twin was the second born, and in 86% the twins were like sex. The relative association between ≥40% discordance and preterm birth at <32 weeks’ gestation was strengthened (final odds ratio, 9.54; P <.0001) in a multivariate model containing other risk factors for delivery at <32 weeks’ gestation: black race, either twin small for gestational age, unmarried, teenage mother, number of male fetuses, like fetal sex, education <12 years, nulliparity, and cigarette smoking. Conclusions: Twin birth weight discordance has now clearly been demonstrated to be a risk factor for preterm birth. The effect was found particularly with discordances ≥40% before 32 weeks’ gestation. Discordance was usually attributable to fetal growth restriction, most often in the second-born twin. (Am J Obstet Gynecol 2000;183:63-7.)

Effects of fetal sex and race on risk of very preterm birth in twins

OBJECTIVE: Our purpose was to determine whether the risk of twin preterm birth correlates with the number of male fetuses. STUDY DESIGN: Among 8109 white and 1884 black twin pregnancies in the Missouri Successive Pregnancy Birth/Death Data Set, 1978 through 1990, risk for preterm birth at various gestational ages was determined with 0, 1, or 2 male infants. RESULTS: Studied as individuals, white preterm twins <35 weeks’ gestation demonstrated a 9.2% excess of male fetuses ( P < .001). Adjusted for monozygosity, risk for preterm birth <35 weeks’ gestation was 15.7% in white female-female pairs, 17.9% in unlike-sex white fetuses, and 20.2% in white male-male pairs ( r = .999, P = .01). The effect was absent in black pregnancies and was unrelated to birth order, cesarean delivery, parity, twins’ weight differential, year, or season. CONCLUSIONS: In white twin gestations the observed linear relationship between the number of male fetuses and the likelihood of preterm birth <35 weeks’ gestation suggests a fetal mechanism for preterm birth <35 weeks’ gestation linked to fetal sex. Studies of mechanisms for preterm birth must stratify by fetal sex and race. (Am J Obstet Gynecol 1998;179:762-5.)

A surprising effect of paternal alcohol treatment on rat fetuses

Male rats were intubated with either 5, 2.5, or 0 g/kg alcohol. Animals in the latter two groups were pairfed to those in the 5 g/kg group. A fourth group of males was not treated and was fed ad lib. Males were bred once after 3 weeks of intubation and twice after 9 weeks of intubation. Females in the first two breedings were sacrificed prior to delivery, whereas females in the last breeding were allowed to deliver their litters. There were no significant decreases in male fertility or litter size, but fecundity was reduced in females bred to alcohol-treated males when all breedings were pooled. Newborn weights (third breeding) were not significantly affected by paternal alcohol treatment, but fetal weights in the first two breedings were significantly increased in association with paternal alcohol treatment. There was also an alcohol-related increase in the number of male fetuses in breeding one, and an increase in placental weights in breeding two; the placental index (placental weight/fetal weight) was also decreased by paternal alcohol treatment for fetuses in the second breeding. These results suggest paternal alcohol treatment can have effects on offspring body weights, which are not observable once females have given birth.

The Relationship of Conceptus Number and Fetal Sex to Maternal Serum Testosterone Concentration in the Rat

On Day 8 of pregnancy, the number of implantation sites in pregnant rats was adjusted to 1, 2, 4, 6, or greater than 10. Blood was collected on Days 11, 12, 15, 18, and 20 for the determination of serum testosterone, progesterone, and androstenedione. Serum testosterone levels exhibited a direct linear relationship with implantation number, increasing from 1 through greater than 10 implants. This linear relationship was particularly evident at Days 12, 15, and 18 of pregnancy. Serum progesterone levels increased from one to four conceptuses and plateaued above this number. There was no apparent relationship between the number of conceptuses and serum androstenedione levels, which may reflect the multiple origins of this steroid in the pregnant rat. In a separate group of rats in which the number of conceptuses was adjusted to three on Day 8 of pregnancy, blood was collected on Days 11, 12, 15, 18, and 20. Fetal sex was determined between the last bleeding and the day of parturition. Serum testosterone was determined and results were examined with regard to the number of male/female fetuses in the litter of three. There was no relationship between maternal serum testosterone levels and the number of male fetuses, indicating that the fetal testis does not make a significant contribution to circulating maternal testosterone levels.