Does fetal sex affect pregnancy outcome?

Placental abruption, offspring sex, and birth outcomes in a large cohort of mothers

OBJECTIVE

To investigate stillbirth, neonatal, and perinatal death outcomes in pregnancies complicated by placental abruption, according to fetal sex.

METHODS

We utilized maternally linked cohort data files of singleton live births to mothers diagnosed with placental abruption during the period 1989 through 2005 (n = 10,014). Logistic regression models were employed to generate adjusted odd ratios and their 95% confidence intervals. Male babies served as the referent category.

RESULTS

The sex ratio at birth was 1.18. The overall prevalence of stillbirth, neonatal mortality, and perinatal mortality was 7.2%, 4.5%, and 11.8%, respectively. Placental abruption was less likely to occur in mothers carrying female pregnancies than mothers of male infants (adjusted odds ratio [95% confidence interval] = 0.89 [0.86-0.93]). There were no significant sex differences with regards to stillbirth, neonatal mortality, and perinatal mortality. Similar findings were observed for preterm and term infants.

CONCLUSIONS

Although a preponderance of male infants was discernable among mothers with placental abruption, no sex difference in fetal survival was observed among the offspring of the mothers affected by placental abruption.

Perinatal outcomes associated with low birth weight in a historical cohort

OBJECTIVE

To identify perinatal outcomes associated with low birth weight (LBW).

METHODS

A retrospective cohort study in a tertiary maternity hospital. Analysis of the database on 43,499 liveborn infants delivered between 1986 and 2004 with low (n = 6,477) and normal (n = 37,467) birth weight. Outcomes associated with LBW were identified through crude and adjusted risk ratio (RR) and 95%CI with bivariate and multivariate analysis. The main outcomes were: onset of labor, mode of delivery, indication for cesarean section; amniotic fluid, fetal heart rate pattern, Apgar score, somatic gestational age, gender and congenital malformation.

RESULTS

LBW infants showed more frequently signs of perinatal compromise such as abnormal amniotic fluid volume (especially olygohydramnios), nonreassuring patterns of fetal heart rate, malformation, lower Apgar scores and lower gestational age at birth. They were associated with a greater risk of labor induction and cesarean delivery, but lower risk of forceps.

CONCLUSION

There was a clear association between LBW and unfavorable perinatal outcomes.

INSL3 in the ruminant: a powerful indicator of gender- and genetic-specific feto-maternal dialogue

The hormone Insulin-like peptide 3 (INSL3) is a major secretory product of the Leydig cells from both fetal and adult testes. Consequently, it is a major gender-specific circulating hormone in the male fetus, where it is responsible for the first phase of testicular descent, and in the adult male. In most female mammals, circulating levels are very low, corresponding to only a small production of INSL3 by the mature ovaries. Female ruminants are exceptional in exhibiting high INSL3 gene expression by the thecal cells of antral follicles and by the corpora lutea. We have developed a specific and sensitive immunoassay to measure ruminant INSL3 and show that, corresponding to the high ovarian gene expression, non-pregnant adult female sheep and cows have up to four times the levels observed in other female mammals. Significantly, this level declines during mid-pregnancy in cows carrying a female fetus, in which INSL3 is undetectable. However, in cows carrying a male fetus, circulating maternal INSL3 becomes elevated further, presumably due to the transplacental transfer of fetal INSL3 into the maternal circulation. Within male fetal blood, INSL3 is high in mid-pregnancy (day 153) corresponding to the first transabdominal phase of testicular descent, and shows a marked dependence on paternal genetics, with pure bred or hybrid male fetuses of Bos taurus (Angus) paternal genome having 30% higher INSL3 levels than those of Bos indicus (Brahman) paternity. Thus INSL3 provides the first example of a gender-specific fetal hormone with the potential to influence both placental and maternal physiology.

Placental programming of blood pressure in Indian children

Aim

To determine whether the size and shape of the placental surface predict blood pressure in childhood.

Methods

We studied blood pressure in 471 nine-year-old Indian children whose placental length, breadth and weight were measured in a prospective birth cohort study.

Results

In the daughters of short mothers (<median height), systolic blood pressure (SBP) rose as placental breadth increased (β = 0.69 mmHg/cm, p = 0.05) and as the ratio of placental surface area to birthweight increased (p = 0.0003). In the daughters of tall mothers, SBP rose as the difference between placental length and breadth increased (β = 1.40 mmHg/cm, p = 0.007), that is as the surface became more oval. Among boys, associations with placental size were only statistically significant after adjusting for current BMI and height. After adjustment, SBP rose as placental breadth, area and weight decreased (for breadth β = −0.68 mmHg/cm, p < 0.05 for all three measurements).

Conclusions

The size and shape of the placental surface predict childhood blood pressure. Blood pressure may be programmed by variation in the normal processes of placentation: these include implantation, expansion of the chorionic surface in mid-gestation and compensatory expansion of the chorionic surface in late gestation.

Cognitive function after intrauterine growth restriction and very preterm birth

OBJECTIVE

To evaluate the effects of intrauterine growth restriction (IUGR) with absent or reversed end-diastolic blood flow in the umbilical artery and very preterm birth on cognitive outcome at 5 to 8 years of age.

METHODS

We studied 34 children with IUGR born at a median of 26.9 gestational weeks (GWs) (range: 24-29 GWs) (PT-IUGR), 34 matched preterm appropriate-for-gestational age (PT-AGA) children, and 34 term AGA children (T-AGA) by using the Wechsler Preschool and Primary Scale of Intelligence, Wechsler Intelligence Scale for Children, Strengths and Difficulties Questionnaire, and Brown's attention-deficit disorder (ADD) scales.

RESULTS

The PT-IUGR group had mean (SD) scores on the verbal IQ (VIQ) and full-scale IQ (FSIQ) of 83.8 (17.3) and 78.9 (16.6), respectively, compared with the PT-AGA group, which had scores of 96.0 (14.5) and 90.1 (14.2) (P = .003 and P < .007), and the T-AGA group, which had scores of 101.3 (12) and 102.9 (13.2) (P < .001 and P < 001), respectively. The VIQ difference remained significant after adjustment for parental level of education, gestational age at birth, and neonatal morbidity. Performance IQ (PIQ) did not differ between the PT-IUGR and PT-AGA groups; their mean PIQs were lower than that of the T-AGA group (P < .001). Boys in the PT-IUGR group scored lower than girls in VIQ and FSIQ (P = .005 and .007, respectively). Behavior and ADD scores did not differ between the preterm groups.

CONCLUSIONS

Children born very preterm after IUGR have an increased risk for cognitive impairment at early school age compared with children delivered very preterm for other reasons. Differences in cognitive outcome were restricted to boys who may have been especially vulnerable to the influence of IUGR and very preterm birth.

The association between stillbirth and fetal gender

OBJECTIVE

Stillbirth accounts for approximately 50% of all perinatal deaths. We aimed to characterize the relationship between fetal gender and stillbirths.

METHODS

A retrospective cohort study of all stillbirths cases in a tertiary medical center, between 1995 and 2007. Patient's medical charts were reviewed for demographic information, medical data, and assumed etiology for stillbirth. Stillbirth was defined as fetal death after 20 completed weeks of gestation or birth weight above 500 g, excluding cases of fetal death due to elective termination of pregnancy.

RESULTS

Overall, during the study period there were 77,120 deliveries, of them the stillbirth rate was 0.14% (n = 105). There were 59 females, 39 males (60.2% vs. 48.5%, p = 0.04) and 7 cases of stillbirth with undetermined gender. There were no differences in the demographic and obstetrical characteristics at diagnosis between women carrying a male versus female stillbirth fetuses. The rate of intra uterine fetal death due to placental abruption was significantly higher for male fetuses (OR = 2.1, 95% CI 1.3-4.5) and the rate of stillbirth due to placental insufficiency was significantly higher for female fetuses (OR = 3.7, 95% CI 1.6-5.1).

CONCLUSIONS

Female fetuses are overrepresented in cases of stillbirths compared with male fetuses.

Effects of famine on placental size and efficiency

BACKGROUND

Placental growth responds to maternal influences including diet. We have examined placental size, shape and efficiency among babies born around the time of the 5-month wartime famine in Holland 1944-1945.

METHODS

We examined the birth records of 2414 term singleton babies born in Amsterdam during 1943-1947. The records included the size of the baby and the thickness of the placental surface, together with its length and breadth which we used to calculate its area and volume.

RESULTS

Compared to babies born before the famine babies who were in utero during the famine had smaller placental areas. Babies whose mothers conceived after the famine ended also had smaller placental areas. Famine was associated with a 19 cm(2) decrease in area. Babies who were in mid-late gestation during the famine were 160 g lighter than would have been predicted from their placental area (p < 0.001). Babies who were in early gestation during the famine, or who were conceived after it had ended were 102 g heavier than would have been predicted from their placental area (p < 0.001). These latter babies were either longer or had larger head circumferences depending on when the mother experienced the famine. Among babies who were in early gestation during the famine the reduction in placental area was greater in boys than girls (p for interaction 0.03).

CONCLUSION

Famine impaired the normal processes of placentation, even among babies who were conceived after it had ended. In babies who were in mid-late gestation during the famine, the placenta was less efficient. In babies who were in early gestation during the famine, or who were conceived after it had ended, the placenta was more efficient. The placentas of boys and girls responded differently to famine.

Is fetal cardiac function gender dependent?

INTRODUCTION

An increased nuchal translucency (NT) is more common in males. A delayed diastolic cardiac function maturation has been proposed to explain this and the reported gender-related differences in ductus venosus (DV) flow.

OBJECTIVE

To investigate gender-related differences in fetal cardiac function.

METHODS

One hundred and ninety karyotypically/phenotypically normal fetuses with structurally normal hearts and known NT measurement, (104 > 95th percentile), were prospectively included between 1 October 2003 and 1 April 2009. They had been referred for fetal echocardiography. Three hundred and nine echocardiograms were performed between 11 and 35 weeks' gestation. The atrioventricular valve E- and A-wave peak velocity, E/A-velocity ratio and E/TVI ratio, myocardial performance index, semilunar valves acceleration time (AT) and peak velocity, stroke volume and cardiac output as well as DV pulsatility index for veins at 11-14 weeks' gestation, were measured. A multilevel analysis was performed using the NT (multiples of the median) as a continuous variable.

RESULTS

The male : female ratio was 1.56:1. The tricuspid valve E/TVI was significantly higher and pulmonary valve AT significantly lower in females compared to males. No other significant differences in cardiac function were found.

CONCLUSIONS

Our findings suggest better right ventricular (RV) relaxation and increased RV afterload in female fetuses, independent of NT thickness, between 11 and 35 weeks' gestation.

Nutrition and human health from a sex-gender perspective

Nutrition exerts a life-long impact on human health, and the interaction between nutrition and health has been known for centuries. The recent literature has suggested that nutrition could differently influence the health of male and female individuals. Until the last decade of the 20th century, research on women has been neglected, and the results obtained in men have been directly translated to women in both the medicine and nutrition fields. Consequently, most modern guidelines are based on studies predominantly conducted on men. However, there are many sex-gender differences that are the result of multifactorial inputs, including gene repertoires, sex steroid hormones, and environmental factors (e.g., food components). The effects of these different inputs in male and female physiology will be different in different periods of ontogenetic development as well as during pregnancy and the ovarian cycle in females, which are also age dependent. As a result, different strategies have evolved to maintain male and female body homeostasis, which, in turn, implies that there are important differences in the bioavailability, metabolism, distribution, and elimination of foods and beverages in males and females. This article will review some of these differences underlying the impact of food components on the risk of developing diseases from a sex-gender perspective.

How well are infant and young child World Health Organization (WHO) feeding indicators associated with growth outcomes? An example from Cambodia

We assessed eight World Health Organization (WHO) core child feeding indicators for their association with stunting and underweight in Cambodia in 2000 and 2005. We compared the feeding data from the Cambodian Demographic and Health Surveys for 2000 with 2005 for 0-24 months children using the WHO feeding indicators, with stunting and underweight as outcomes. Prevalence of stunting and underweight was significantly less in 2005 than in 2000 among children aged 0-5 and 6-11 months, but stunting among children 18-23 months remained >50%. Prevalence of compliance with seven of the eight core healthy feeding indicators was higher in 2005. Exclusive breastfeeding among 0-5 months infants increased more than fivefold; among 6-11 and 12-17 months children, prevalence of feeding diversity and meeting a minimally acceptable diet, while improved, remained ≈25%. Modelling showed compliance with breastfeeding indicators was associated with reduced risk of underweight in 0-5 months infants, no association between compliance with feeding indicators and growth outcomes in other ages, and a significant association of higher relative wealth with growth outcomes overall. Between 2000 and 2005, Cambodia stabilized and focused resources on infant feeding. Prevalence of meeting the WHO feeding indicators improved, but modelling indicated that, in general, relative wealth, not feeding practices, was associated with improved growth outcomes. Yet, over 50% of children 18-23 months were stunted in 2005. Similar to the success with breastfeeding, focus on complementary feeding of 6-23 months children may reduce the risk of stunting in Cambodia.

Macrosomia, top of the iceberg: the charm of underlying factors

BACKGROUND

Macrosomia is associated with childhood obesity. Gestational diabetes mellitus (GDM) is a risk factor for macrosomia. The aim of this large-scale investigation was to determine the incidence, risk factors, characteristic features, and perinatal outcome of macrosomic infants.

METHODS

This prospective study was carried out on 6385 newborns. Demographic data included maternal age, paternal age, type of delivery, sex, parity and gestational age at delivery. Anthropometric measurements were recorded. ABO/Rh typing was performed and GDM was diagnosed.

RESULTS

Out of 6385 term deliveries, 477 infants (7.47%) were macrosomic. Incidence of GDM was 0.6% and 4.8% in the control group and in macrosomic births, respectively. Incidence of GDM(+) cases was 4% among macrosomic infants weighing 4000-4500 g. GDM(+) cases were densely populated (11%) in macrosomic infants weighing ≥ 4500 g (P ≤ 0.05). Male/female ratio was significantly higher in macrosomic infants weighing ≥ 4500 g than those weighing 4000-4500 g (P ≤ 0.05). High parental age was the risk factor for GDM. Blood group A was the most frequently observed type among mothers with macrosomic infants, however, blood group O was dominant in cases with GDM. In multivariate logistic regression analysis, the male infant was the most striking infant characteristic and GDM was the most striking maternal characteristic that were significantly associated with increased odds of macrosomic birth.

CONCLUSIONS

This research reports the association between blood group system and macrosomia as well as parental age and GDM simultaneously. Our study reports a prevalence of GDM in both infants with normal birth weight and macrosomic newborns at the same time.

Fetal and maternal factors associated with infant mortality in vervet monkeys

BACKGROUND

Causes of infant death remain unknown in significant proportions of human and non-human primate pregnancies.

METHODS

A closed breeding colony with high rates of infant mortality had pregnancies assessed (n=153) by fetal measurements and maternal characteristics. Infant outcome was classified as neonatal death (stillborn or died <48 hours from birth), postnatal death (died 2-30 days) or surviving (alive after 30 days).

RESULTS

Fetal size did not predict outcome. Poor maternal glycemic control and low social ranking increased odds for adverse outcome (OR=3.72, P=0.01 and 2.27, P=0.04, respectively). Male sex was over-represented in stillbirths (P=0.04), and many were macrosomic, but size did not associate with maternal glycemic control measured as glycated hemoglobin A1c. Postnatally dead infants were smaller (P<0.01), which associated with behavioral factors and glycemic control.

CONCLUSIONS

Fetal growth estimates predicted gestational age but not fetal outcome. Maternal social status and metabolic health, particularly glycemic control, increased risks of adverse pregnancy outcome.

Does fetal sex influence the risk of preterm delivery in dichorionic twin pregnancies after spontaneous conception?

OBJECTIVE

The incidence of preterm delivery has been increasing, and our aim was to estimate the influence of fetal sex on the risk of preterm delivery in dichorionic twins after spontaneous conception.

METHODS

125 spontaneously conceived dichorionic twin gestations, with viable fetuses, born after 24 weeks and delivered spontaneously before 37 weeks, were enrolled. The impact of fetal sex, previous preterm delivery, maternal age, body-mass-index, smoking, and parity on gestational age at birth were evaluated.

RESULTS

Despite similar baseline characteristics in all three groups, women with one or two male fetuses delivered significantly more often before 34 weeks than patients with two female fetuses, 48% (23/48) and 43% (19/44) vs 21% (7/33), p = .04. Regression analyses, including fetal sex, maternal age, maternal body-mass-index, smoking, previous preterm delivery and parity, revealed that only fetal sex was significantly associated with spontaneous preterm delivery (p = .03).

CONCLUSION

Fetal sex appears to be a risk factor for preterm delivery in spontaneously conceived dichorionic twin gestations. Twin pregnancies with one or two male fetuses seem to be at higher risk for spontaneous preterm delivery than those with only females.

Secondary recurrent miscarriage is associated with previous male birth

Secondary recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses after delivery of a viable infant. Previous reports suggest that a firstborn male child is associated with less favourable subsequent reproductive potential, possibly due to maternal immunisation against male-specific minor histocompatibility antigens. In a retrospective cohort study of 85 cases of secondary RM we aimed to determine if secondary RM was associated with (i) gender of previous child, maternal age, or duration of miscarriage history, and (ii) increased risk of pregnancy complications. Fifty-three women (62.0%; 53/85) gave birth to a male child prior to RM compared to 32 (38.0%; 32/85) who gave birth to a female child (p=0.002). The majority (91.7%; 78/85) had uncomplicated, term deliveries and normal birth weight neonates, with one quarter of the women previously delivered by Caesarean section. All had routine RM investigations and 19.0% (16/85) had an abnormal result. Fifty-seven women conceived again and 33.3% (19/57) miscarried, but there was no significant difference in failure rates between those with a previous male or female child (13/32 vs. 6/25, p=0.2). When patients with abnormal results were excluded, or when women with only one previous child were considered, there was still no difference in these rates. A previous male birth may be associated with an increased risk of secondary RM but numbers preclude concluding whether this increases recurrence risk. The suggested association with previous male birth provides a basis for further investigations at a molecular level.

Boys live dangerously in the womb

The growth of every human fetus is constrained by the limited capacity of the mother and placenta to deliver nutrients to it. At birth, boys tend to be longer than girls at any placental weight. Boy's placentas may therefore be more efficient than girls, but may have less reserve capacity. In the womb boys grow faster than girls and are therefore at greater risk of becoming undernourished. Fetal undernutrition leads to small size at birth and cardiovascular disorders, including hypertension, in later life. We studied 2003 men and women aged around 62 years who were born in Helsinki, Finland, of whom 644 had hypertension: we examined their body and placental size at birth. In both sexes, hypertension was associated with low birth weight. In men, hypertension was also associated with a long minor diameter of the placental surface. The dangerous growth strategy of boys may be compounded by the costs of compensatory placental enlargement in late gestation. In women, hypertension was associated with a small placental area, which may reduce nutrient delivery to the fetus. In men, hypertension was linked to the mothers' socioeconomic status, an indicator of their diets: in women it was linked to the mothers' heights, an indicator of their protein metabolism. Boys' greater dependence on their mothers' diets may enable them to capitalize on an improving food supply, but it makes them vulnerable to food shortages. The ultimate manifestation of their dangerous strategies may be that men have higher blood pressures and shorter lives than women.

Infant male sex as a risk factor for shoulder dystocia but not for cephalopelvic disproportion: an independent or confounded effect?

BACKGROUND

Shoulder dystocia (ShD) and cephalopelvic disproportion (CPD) share some common risk factors. Whether infant male sex is an independent risk factor for ShD, or if the risk is confounded by other known factors, is uncertain.

OBJECTIVE

The aim of this study was to explore the unconfounded effect of infant male sex on the risk for ShD and its interaction with other risk factors compared with CPD.

METHODS

A retrospective data analysis was conducted of deliveries in Lamphun Hospital, Lamphun, Thailand. All vaginal deliveries complicated by ShD were collected as ShD cases. All labors terminated by cesarean delivery (CD) due to CPD were collected as CD/CPD cases. Vaginal deliveries that took place immediately before or after the index ShD cases were collected as controls. Multivariable adjusted odds ratios (AORs) for infant male sex and its 95% CI in cases of ShD and CD/CPD were computed by multichotomous logistic regression controlling for other obstetric risks. The effects of maternal height, gestational age, and birth weight on the risk for ShD or CD/CPD among male or female infants was also explored. Stability of the effect of the risk between male and female infants was tested with Chow tests.

RESULTS

Thirty-five ShD cases and 199 CD/CPD cases were collected, as were 586 controls. Infant male sex was a significant independent risk factor for ShD (AOR = 5.00; 95% CI, 1.83-13.61; P = 0.002), but not for CD/CPD (AOR = 1.09; 95% CI, 0.75-1.59; P = NS). For CD/CPD, the effects of maternal height, gestational age, and birth weight were similar for male and female infants, but the corresponding effect on ShD was more pronounced in male than in female infants (P < 0.001 for all comparisons).

CONCLUSIONS

Infant male sex is a risk factor for ShD independent of other known risks. Male sex also amplified the existing effects of short maternal height, extended gestational age, and greater birth weight. If infant sex is known to be male before delivery, the obstetrician may consider avoiding vaginal delivery in mothers who have other strong risks for ShD.

Increased risk of adverse pregnancy outcomes among women affected by herpangina

OBJECTIVE

This population-based study aimed to assess the relation between herpangina and adverse pregnancy outcomes: low birthweight (LBW), small for gestational age (SGA), and preterm delivery.

STUDY DESIGN

A total of 242 pregnant women who had singleton births and who visited ambulatory care centers for the treatment of herpangina were assessed, together with 1936 matched women as a comparison group. Conditional logistic regression analyses were performed to examine the risk of LBW, preterm birth, and SGA for mothers with herpangina and unaffected mothers.

RESULTS

Compared with pregnant women without herpangina, herpangina was associated with a 2.29- (95% confidence interval [CI], 1.42-3.69), 1.67- (95% CI, 1.04-2.68), and 1.63-fold (95% CI, 1.14-2.33) increased risk of having LBW, preterm, and SGA infants, respectively, after adjusting for family income and maternal and infant characteristics.

CONCLUSION

Our findings highlight a significant potential risk posed by herpangina, a usually mild disease, among pregnant women.

Fetal gender and pregnancy outcome

OBJECTIVE

To assess the effect of fetal gender on pregnancy outcome.

METHODS

Retrospective study of all singleton pregnancies at a tertiary hospital during 1995-2006.

RESULTS

Of the 66,387 women studied, 34,367 (51.8%) delivered male and 32,020 (48.2%) delivered female neonates. The rate of preterm delivery (as early as 29 weeks) was higher for male fetuses and was attributed to an increased incidence of spontaneous preterm labor and preterm premature rupture of membranes. Women carrying male fetuses were at increased risk for operative vaginal delivery (OVD) for non-reassuring fetal heart rate, failed OVD and cesarean delivery. Female fetuses were more likely to experience fetal growth restriction (FGR).

CONCLUSION

Fetal gender is independently associated with adverse pregnancy outcome. Although the added risk is relatively small, further investigation of the mechanisms underlying this association may contribute to our understanding of the pathophysiology of pregnancy complications such as preterm delivery and FGR.

Maternal and neonatal outcomes of pregnancies complicated by asthma in an Australian population

OBJECTIVE

To determine if there are sex differences in risk and incidence of stillbirth, preterm delivery and small-for-gestational age (SGA) in pregnancies complicated by maternal asthma relative to a non-asthmatic population.

STUDY DESIGN

Univariant and multiple regression analysis of the incidence of preterm delivery, SGA and stillbirth in singleton pregnancies complicated by asthma in Newcastle, NSW, Australia, from 1995 to 1999.

RESULTS

Asthma complicated 12% of all singleton pregnancies. The incidence of preterm delivery was not significantly different between asthmatic (13%) and non-asthmatic (11%) pregnancies. Male fetuses (53%) were more likely to deliver preterm than female fetuses (47%) in both asthmatic and non-asthmatic populations. There were significantly more male neonates of pregnancies complicated by asthma that were SGA at term relative to those of the non-asthmatic population. There were significantly more preterm female neonates that were SGA in pregnancies complicated by asthma relative to those of the non-asthmatic population. Male fetuses were more likely to be associated with a stillbirth in pregnancies complicated by asthma than female fetuses.

CONCLUSION

The presence of maternal asthma during pregnancy increases the risk of stillbirth for the male fetus and is associated with changes in fetal growth, but does not increase the incidence of a preterm delivery.

Effects of sex and estrogen on chicken ductus arteriosus reactivity

Sex hormones have an important influence on cardiovascular physiology and pathophysiology and sex differences in vascular reactivity have been widely demonstrated. In the present study we hypothesized 1) the presence of sexual dimorphism in chicken ductus arteriosus (DA) responsiveness to contractile and relaxant stimuli and 2) that estrogens are vasoactive in the chicken DA. In vitro contractions (assessed with a wire myograph) induced by normoxia, KCl, 4-aminopyridine, norepinephrine, phenylephrine, U46619, or endothelin-1, as well as relaxations induced by ACh, sodium nitroprusside, BAY 41-2272, PGE(2), isoproterenol, forskolin,Y-27632, and hydroxyfasudil were not significantly different between males and females. The estrogen 17beta-estradiol elicited concentration-dependent relaxation of KCl-, phenylephrine-, and oxygen-induced active tone in male and female chicken DA. The stereoisomer 17alpha-estradiol showed lesser relaxant effects, and the selective estrogen receptor (ER) agonists 4,4',4''-(4-propyl-[(1)H]pyrazole-1,3,5-triyl)tris-phenol (ERalpha) and 2,3-bis(4-hydroxyphenyl)-propionitrile (ERbeta) did not show any effect. There were no sex differences in the responses to estrogen. Endothelium removal or the presence of the soluble guanylate cyclase inhibitor ODQ, the K(+) channel blockers tetraethylammonium, glibenclamide, and charybdotoxin, or the ER antagonist fulvestrant did not modify 17beta-estradiol-induced relaxation. CaCl(2) (30 muM-10 mM) induced concentration-dependent contraction in DA rings depolarized by 62.5 mM KCl or stimulated with 21% O(2) in Ca(2+)-free medium. Preincubation with 17beta-estradiol or the L-type Ca(2+) channel blocker nifedipine produced an inhibition of CaCl(2)-induced contractions. In conclusion, there are no sex-related differences in chicken DA reactivity. The estrogen 17beta-estradiol induces an endothelium-independent relaxation of chicken DA that is not mediated by ER activation. This relaxant effect is, at least partially, due to inhibition of Ca(2+) entry from extracellular space.

Ulcerative colitis and pregnancy outcomes in an Asian population

OBJECTIVES

As the prevalence of ulcerative colitis (UC) is much higher in Western countries than in Asian countries, previous investigations of pregnancy outcomes for women with UC were limited to people of European descent. This study was aimed at examining the risk of adverse pregnancy outcomes (low birth weight (LBW), preterm birth, small for gestational age (SGA), and cesarean section (CS)) among Asian women with UC.

METHODS

Using a 3-year nationwide population-based database, we identified a total of 196 women who gave birth from 2001 to 2003, who were diagnosed with UC within 2 years before their index deliveries. A total of 1,568 unaffected pregnant women matched these cases according to age and year of delivery. Conditional logistic regression analyses were performed to estimate risk.

RESULTS

There were significant differences between women with and without UC in terms of LBW (12.76% vs. 5.55, P<0.001) and preterm births (11.73% vs. 6.25%, P=0.004). After adjusting for infant gender, parity, maternal age, highest maternal educational level, parental age difference, maternal marital status, hypertension, diabetes, anemia, family monthly income, as well as conditioning on maternal age and year of delivery, the odds of LBW and preterm births for women with UC were 2.36 (95% confidence interval (CI)=1.45-3.82) and 1.90 (95% CI=1.16-3.11) times, respectively, those for unaffected women.

CONCLUSIONS

Although UC often follows a milder disease course in Asians than in people of European descent, we demonstrated that Asian women suffering from UC were still at risk of having preterm and LBW babies, compared with unaffected mothers.

Effect of maternal asthma, inhaled glucocorticoids and cigarette use during pregnancy on the newborn insulin-like growth factor axis

BACKGROUND

Fetal growth varies in a sex-specific manner in response to maternal asthma during pregnancy, but the mechanisms are unclear.

OBJECTIVE

We examined the influence of maternal asthma severity and associated exposures, inhaled glucocorticoid treatment, maternal cigarette use, and fetal sex on fetal growth and placental function during pregnancy and on the newborn insulin-like growth factor (IGF) axis. STUDY SUBJECTS AND DESIGN: Fetal growth was assessed in a prospective cohort of asthmatic and non-asthmatic women (n=145). At delivery, umbilical vein plasma was collected from male (n=61, controls n=16 and asthmatic n=45) or female (n=84, controls n=22 and asthmatic n=62) fetuses. Cord plasma insulin-like growth factor (IGF) binding protein (BP)-1, IGFBP-3, IGF-1 and IGF-2 were measured by radioimmunoassay and ELISA.

RESULTS

Cord plasma IGF-1 was the main component of the neonatal IGF axis altered by asthma and cigarette use. IGF-1 was increased in the presence of mild asthma and a male fetus and decreased in the presence of a female fetus and maternal asthma with cigarette use. IGFBP-3 was also decreased in the female fetuses of pregnancies complicated by asthma and cigarette use. Inhaled glucocorticoid use for the treatment of asthma did not affect the IGF axis. The strongest overall predictor of female birth weight after accounting for asthma severity, inhaled glucocorticoid treatment and cigarette use was IGF-1. For males, the strongest predictor of birth weight was IGFBP-3.

CONCLUSION

The data suggest male and female fetuses institute different strategies in response to adverse pregnancy conditions such as asthma and cigarette use.

Sex-specific responses to stroke

Stroke is a sexually dimorphic disease, with differences between males and females observed both clinically and in the laboratory. While males have a higher incidence of stroke throughout much of the lifespan, aged females have a higher burden of stroke. Sex differences in stroke result from a combination of factors, including elements intrinsic to the sex chromosomes as well as the effects of sex hormone exposure throughout the lifespan. Research investigating the sexual dimorphism of stroke is only in the beginning stages, but early findings suggest that different cell death pathways are activated in males and females after ischemic stroke. A greater understanding of the mechanisms underlying sex differences in stroke will lead to more appropriate treatment strategies for patients of both sexes.

Mitochondrial manganese superoxide dismutase mRNA expression in human chorioamniotic membranes and its association with labor, inflammation, and infection

OBJECTIVE

Human parturition is characterized by the activation of genes involved in acute inflammatory responses in the fetal membranes. Manganese superoxide dismutase (Mn SOD) is a mitochondrial enzyme that scavenges reactive oxygen species (ROS). Mn SOD is up-regulated in sites of inflammation and has an important role in the down-regulation of acute inflammatory processes. Therefore, the aim of this study was to determine the differences in Mn SOD mRNA expression in the fetal membranes in patients with term and preterm labor (PTL) as well as in acute chorioamnionitis.

STUDY DESIGN

Fetal membranes were obtained from patients in the following groups: (1) term not in labor (n = 29); (2) term in labor (n = 29); (3) spontaneous PTL with intact mebranes (n = 16); (4) PTL with histological chorioamnionitis (n = 12); (5) preterm prelabor rupture of the membranes (PPROM; n = 17); and (6) PPROM with histological chorioamnionitis (n = 21). Mn SOD mRNA expression in the membranes was determined by quantitative real-time reverse transcription-polymerase chain reaction.

RESULTS

(1) Mn SOD mRNA expression was higher in the fetal membranes of patients at term in labor than those not in labor (2.4-fold; p = 0.02); (2) the amount of Mn SOD mRNA in the fetal membranes was higher in PTL than in term labor or in PPROM (7.2-fold, p = 0.03; 3.2-fold, p = 0.03, respectively); (3) Mn SOD mRNA expression was higher when histological chorioamnionitis was present both among patients with PPROM (3.8-fold, p = 0.02) and with PTL (5.4-fold, p = 0.02) than in patients with these conditions without histological chorioamnionitis; (4) expression of Mn SOD mRNA was higher in PTL with chorioamnionitis than in PPROM with chorioamnionitis (4.3-fold, p = 0.03).

CONCLUSION

The increase in Mn SOD mRNA expression by fetal membranes in term labor and in histological chorioamnionitis in PTL and PPROM suggests that the fetus deploys anti-oxidant mechanisms to constrain the inflammatory processes in the chorioamniotic membranes.

Fetal sex determines the impact of maternal PROGINS progesterone receptor polymorphism on maternal physiology during pregnancy

BACKGROUND

Recent evidence from very rare human diseases suggests that variation in the fetal genome can modify maternal physiology during pregnancy. Here, we tested the hypothesis that fetal sex as a major genetic variant of the fetal genome may affect maternal physiology during pregnancy in genetically susceptible pregnant women.

METHODS

We analyzed the impact of fetal sex on maternal physiology during pregnancy in relationship with the maternal PROGINS progesterone receptor gene polymorphism. Two thousand and eighty-nine (2089) Caucasian women without preexisting diabetes and preexisting hypertension with singleton pregnancies delivering consecutively at the Charité obstetrics department participated in this study.

RESULTS

The maternal PROGINS progesterone receptor polymorphism on its own had no effect on blood pressure, new onset of proteinuria, and total glycated hemoglobin at delivery. However, by considering the offspring's sex, the AA variant of the PROGINS progesterone receptor polymorphism was associated with profound cardiovascular/metabolic effects; mothers carrying both A alleles (AA genotype) delivering a boy had significantly lower systolic blood pressure during the first trimester of pregnancy versus AA mothers delivering girls (107.9+/-10.2 vs. 116.6+/-15.1 mmHg, P = 0.044). Diastolic blood pressure was similarly lower during the first trimester of pregnant AA women delivering boys in comparison with AA women delivering girls (63.4+/-5.7 vs. 68.2+/-10.9 mmHg, P = 0.032). Total glycated hemoglobin at delivery was significantly (P = 0.002) higher in AA mothers delivering boys (6.6+/-0.7%) versus AA mothers delivering girls (5.9+/-0.6%).

CONCLUSION

Our study indicates that fetal sex may substantially affect maternal blood pressure as well as glycemic control during pregnancy in genetically susceptible mothers.

Male gender as a favorable prognostic factor in pregnancies with enlarged nuchal translucency

OBJECTIVE

The aim of this study was to investigate the influence of fetal gender on pregnancy outcome in fetuses with enlarged nuchal translucency (NT).

METHODS

Pregnancy outcomes of all women who underwent an NT measurement at our institution between January 2000 and November 2007 were retrospectively reviewed. Separate analyses were performed for fetuses with normal and with enlarged (>or= 95(th) percentile) NT.

RESULTS

A normal NT was measured in 3637 males (51.4%) and 3435 females (48.6%). Of the fetuses with enlarged NT 365 were males (57.4%) and 271 females (42.6%) (P = 0.001). In this group a normal pregnancy outcome-of those pregnancies for which the outcome was known-was registered for 187/332 (56.3%) of the male fetuses and 98/249 (39.4%) of the female fetuses (P < 0.001; relative risk (RR) for adverse outcome for male gender, 0.72). Eighty percent of the chromosomally normal male fetuses with an enlarged NT had an uneventful pregnancy outcome; this increased to 90% when only the male fetuses with NT measurements >or= 95(th) percentile and < 99(th) percentile and normal karyotype were considered (RR for adverse outcome for male gender, 0.47).

CONCLUSION

In a population of fetuses with enlarged NT there are significantly more males. Male fetuses with enlarged NT and normal chromosomes have an almost two-fold greater chance of a favorable outcome than females. We believe that a minimal degree of NT enlargement in male fetuses without genetic or structural anomalies may be interpreted as a feature of accelerated growth or, alternatively, as a maturational delay of the cardiovascular system more common in males, leading to moderately increased nuchal fluid accumulation.

Influence of prematurity and growth restriction on the adipokine profile, IGF1, and ghrelin levels in cord blood: relationship with glucose metabolism

OBJECTIVE

To determine the influence of gestational age and fetal growth restriction on the cord blood adipokine profile, IGF1, and ghrelin levels, and their relationship with glucose metabolism.

STUDY DESIGN

One hundred and ninety newborns (99 preterm and 91 full term) were studied and, according to their anthropometry at birth, classified as small (SGA) or adequate for gestational age (AGA).

METHODS

Venous cord blood serum levels of IGF1, IGF binding protein 3 (IGFBP-3), adiponectin, resistin, leptin, soluble leptin receptor (sOB-R), tumoral necrosis factor-alpha, interleukin 6 (IL-6), total ghrelin, and acylated ghrelin were determined and compared between preterm and full-term, as well as between SGA and AGA, newborns. Correlations with newborn weight, gestational age, and homeostatic model assessment (HOMA) index, as an index of insulin resistance, were determined.

RESULTS

Preterm newborns had higher HOMA, sOB-R, resistin, and IL-6 and lower IGF1, IGFBP-3, leptin, and adiponectin levels than full-term newborns. SGA had lower IGF1, IGFBP-3, leptin, IL-6, and adiponectin and higher sOB-R and total ghrelin than AGA newborns. Adiponectin and HOMA showed independent positive and negative correlations with gestational age respectively, but not with neonatal weight. Birth weight was correlated positively with IGF1 and leptin levels and negatively with total ghrelin ones.

CONCLUSIONS

Our findings suggest that the lack of proper acquisition of adipose tissue by the fetus either due to prematurity or to fetal growth restriction is associated with changes in the cord blood adipokine profile that may contribute to the impairment of glucose metabolism.

Male predominance of congenital malformations in infants of women with type 1 diabetes

OBJECTIVE

To investigate sex-related differences in maternal, perinatal, and neonatal outcome in type 1 diabetic pregnancies in the Netherlands.

RESEARCH DESIGN AND METHODS

This was a nationwide prospective cohort-based study. Logistic regression analysis was used to identify sex-specific risk factors for adverse pregnancy outcome.

RESULTS

A total of 323 type 1 diabetic pregnancies were included; 314 were ongoing after 24 weeks of gestation. There were eight twin pregnancies and one triplet, resulting in 324 infants born after 24 weeks of gestation. Multiple logistic regression analysis showed that the occurrence of congenital malformations was independently associated with male newborns (OR 3.5 [95% CI 1.3-10.0]; P = 0.02).

CONCLUSIONS

The higher incidence of congenital malformations in infants of women with type 1 diabetes appears to be restricted to male infants only.

Male sex and pre-existing diabetes are independent risk factors for stillbirth

AIM

To determine whether the risk of stillbirth is associated with male fetal sex, fetal growth and maternal factors in an Australian population.

METHODS

A retrospective secondary data analysis of 16 445 singleton births was performed using a tertiary referral centre obstetric database (1995-1999). Univariate and multiple logistic regression analyses were performed.

RESULTS

Stillbirth complicated 1% of the pregnancies in the study population, and 59% of stillbirths were associated with a male fetus. Significant characteristics associated with stillbirth were intrauterine growth restriction (IUGR), birth defects, gestational age, Aboriginal ethnicity, previous stillbirth, parity greater than three and placental abruption. Male stillbirths were more likely to occur at a later gestation (median gestation 30.5 weeks, range 20-43 weeks) compared to females (median 25 weeks, range 20-40 weeks), P = 0.01. Sixty per cent of IUGR fetuses were female (P < 0.001). Male sex (odds ratio (OR) 1.5, confidence interval (CI) 1.01, 2.17, P = 0.04) and maternal type 1 diabetes (OR 4.7, CI 1.58, 14.19, P = 0.006) were independently associated with stillbirth.

CONCLUSION

Male fetal sex and pre-existing diabetes are independent risk factors for stillbirth. Diabetes remains a significant risk for stillbirth even with contemporary monitoring and clinical management. Those diabetic pregnancies where the fetus is male require appropriate monitoring and timely interventions to achieve an optimal outcome.

Trial of labor after one cesarean: role of the order and number of prior vaginal births on the risk of emergency cesarean delivery and neonatal admission

OBJECTIVE

To evaluate the influences of mode of immediate preceding delivery and number of prior vaginal births on the risk of repeat cesarean and neonatal admission at attempted vaginal birth after cesarean.

MATERIALS AND METHODS

We performed a retrospective study of the risk factors for emergency repeat cesarean delivery and neonatal admission in a trial of labor after prior cesarean section. The study comprised 342 women at term with at least one prior vaginal delivery in addition to one previous lower transverse cesarean. Clinical variables with crude p < 0.2 on Fisher's exact test for the defined primary outcomes of repeat cesarean and neonatal admission were included in the model for multivariable logistic regression analysis.

RESULTS

Cesarean as the immediate preceding mode of delivery (adjusted odds ratio, 5.3; 95% confidence interval, 2.5-10.8) was an independent predictor of emergency repeat cesarean delivery but not of neonatal admission. Higher parity of two or more previous vaginal deliveries compared with only one prior vaginal delivery was not associated with repeat cesarean or neonatal admission.

CONCLUSION

In women who have had prior vaginal birth attempting a trial of labor after cesarean, a vaginal delivery before cesarean delivery is an independent risk factor for repeat cesarean. Women with two or more prior vaginal births have a similar risk for repeat cesarean and neonatal admission to women with only one prior vaginal birth.

Sex ratio patterns according to Asian ethnicity in Québec, 1981-2004

Elevated ratios of male to female births are emerging in Asian countries due to selective abortion of female foetuses. Little research has evaluated the possibility of sex selection among Asians in the West. We evaluated patterns in the secondary sex ratio (SSR, number of male per 100 female births) according to ethnicity in Québec, Canada. We performed a population-based retrospective analysis of live and still births in urban Québec, 1981-2004 (N = 1,612,614 live births). Outcomes included: (1) first and second order SSR over four consecutive 6-year intervals analysed according to parental mother tongue, parental birth region, and mothers still speaking her mother tongue at home, (2) adjusted relative risk (RR) of female birth by parental ethnicity, and (3) estimated number of unborn females. For the period 1987-1992, first order SSRs were elevated (range 118-121) for Indo-Pakistani parental mother tongue and mothers currently speaking Indo-Pakistani at home. Second order SSRs were not elevated. For Indo-Pakistani mother tongues, the RR of female birth was lower than French/English in the same period (adjusted RR 0.96, 95% CI 0.92-0.99). SSRs were not imbalanced in the late 1990s among Indo-Pakistani parents, or among Chinese ethnicity in any study period. The SSR in Québec was elevated in the 1980s and early 1990s among firstborn relative to subsequent born infants of Indo-Pakistani descent. The reason for this imbalance is unclear. Further research in other Western settings is necessary to evaluate the possibility of sex selection.

[Obstetric anaesthesia for instrumental vaginal delivery]

The aim of the anaesthesia for instrumental delivery is to provide optimal operation conditions for the obstetrician, appropriate maternal comfort, altogether with safety for the mother and her foetus. The type and location for this intervention are chosen individually for each case according to the indication, the risk of caesarean section and the local specificities. The general safety recommendations for obstetric anaesthesia apply in every case. Since an epidural analgesia is often already working, this type of anaesthesia is the most frequently used for the extractions. A spinal anaesthesia is a logical choice where an epidural in sot yet working. The pudendal block is a second line choice and the general anaesthesia remains as the last alternative in acute emergencies, in cases of failed regional anaesthesia or when the mother refuses any other anaesthesia despite proper information or proves unable to cooperate.

The sex ratio of singleton offspring in assisted-conception pregnancies

OBJECTIVE

To evaluate the effect of intracytoplasmic sperm injection (ICSI) and male factor infertility on the sex ratio in births from assisted reproductive technology.

DESIGN

Historic cohort study.

SETTING

Clinic-based data.

PATIENT(S)

The study population included 15,164 singleton live births in the Society for Assisted Reproductive Technology national database for 2005 from cycles using ejaculated sperm, categorized by the use of insemination or ICSI and the absence or presence of male factor infertility, and cleavage- versus blastocyst-stage embryo transfers (ETs).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The probability of a male infant with and without the use of ICSI and in the presence or absence of male factor infertility.

RESULT(S)

The sex ratio for all U.S. live births in 2005 was 52.5%, versus 48.9% for cleavage-stage and 51.6% for blastocyst-stage embryos. With blastocyst-stage embryos, the sex ratios were 49.6% and 54.9% with and without ICSI and 52.6% and 50.0% with and without male factor infertility, respectively. With cleavage-stage embryos, the sex ratio was not significantly affected by ICSI or male factor infertility, singly or in combination.

CONCLUSION(S)

The use of ICSI, particularly with blastocyst-stage embryos, is associated with a decrease in the sex ratio of male infants.

Sex differences in stroke

Increasing evidence suggests that sex differences exist in the etiology, presentation, treatment, and outcome from stroke. The reasons for these sex disparities are becoming increasingly explored, but large gaps still exist in our knowledge. Experimental studies over the past several years have demonstrated intrinsic sex differences both in vivo and in animal models which may have relevance to our understanding of stroke in clinical populations. A greater understanding of the differences and similarities between males and females with respect to the risk factors, pathophysiology, and response to stroke will facilitate the design of future clinical trials and enhance the development of treatment strategies to improve stroke care in both sexes. This article reviews the current literature on sex differences in stroke with an emphasis on the clinical data, incorporating an analysis of bench research as it pertains to the bedside.