Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Maternal Age”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1993

Patterns of birth weight in relation to gestational age, maternal age, parity, and prenatal care in Texas' triethnic population, 1984 through 1986.

This study investigated the distribution of birth weights in Texas' triethnic populations for the years 1984 through 1986 (more than 900,000 births) with regard to gestational age, maternal age, parity, and visits for prenatal care. African-American infants had a systematic tendency to be born earlier and smaller than Anglo and Hispanic infants. Among the maternal age categories, mothers younger than 18 years had the highest rates of preterm birth (less than 37 completed weeks), very low birth weight (less than 1500 g), and low birth weight (less than 2500 g). High multiparity and inadequate visits for prenatal care were associated with increased rates for the same adverse pregnancy outcomes, and the risks were always much higher in African-American than in Anglo and Hispanic women of the same age, parity, and prenatal care categories. The predictive values of these associations for individual pregnancies were limited, but their recognition may improve the planning of prenatal care for Texas women and of the anticipatory care for their infants.

Adolescent↗
PubMed1979

Anencephaly in Japan: paternal age, maternal age and birth order.

The statistical association between incidence of anencephaly and paternal age, maternal age and birth order was analysed in 1815 cases of foetal deaths with anencephaly reported during 1975--6. The birth order association was confirmed with an extremely high degree of statistical significance.

Adolescent↗
PubMed1978

Down syndrome, paternal age, maternal age and birth order.

Recent cytogenetic evidence has shown that trisomy 21 can arise, perphaps even in substantial proportion, from paternal nondisjunction. The statistical association between Down syndrome incidence and maternal age, paternal age and birth order has been studied in a sample of over 4000 cases. The size of this sample made it possible to control for the effect of maternal age by single years of age during the search for a paternal age effect and vice versa, and the importance of such stringent control is emphasized. The maternal age association was confirmed with an extremely high degree of statistical significance while no independent effect of paternal age was found; indeed, the rates at paternal ages over 45 years appear to be nearly constant. After adjusting for the effects of parental age, a significant inverse association of birth order with incidence was noted. It also appears that the incidence among very young mothers may be high: for maternal ages 15 years and less the rates seem to be equivalent to those found at 30 or 35 years. In order to help answer the question of whether the maternal age association is the result of increasing rates of nondisjunction or of some other mechanism (for example, an age related defect in a spontaneous abortion screening mechanism), the proportion of cases due to maternal and paternal nondisjunction at different parental ages must be determined.

Adolescent↗
PubMed1979

The secondary sex ratio, paternal age, maternal age and birth order in Japan.

The simultaneous effects of several variables on the secondary sex ratio have been examined using data from over 3.7 million births which occurred in Japan during 1975--6. A weak and negative association between sex ratio and birth order was observed but it was not significant in the statistical sense. A negative effect of paternal age--birth order interaction was obtained when maternal age was controlled. The quadratic model is much more powerful than the linear model in explaining the sex ratio variability.

Adolescent↗
PubMed1998

Epidemiology of neonatal acute respiratory disorders. A multicenter study on incidence and fatality rates of neonatal acute respiratory disorders according to gestational age, maternal age, pregnancy complications and type of delivery. Italian Group of Neonatal Pneumology.

A prospective 3-month survey of neonatal respiratory disorders in 17,192 Italian infants born in 65 hospitals, located in 17 Italian regions representative of northern, central and southern Italy, was performed to evaluate the incidence of neonatal acute respiratory disorders and their risk factors. The prematurity rate was 7.3%, while the extremely low birth weight (< 1,000 g) and very low birth weight (< 1,500 g) rates were 0.58% and 0.99%, respectively. Four hundred and ninety-one infants (2.8%) developed respiratory signs. Lethality or specific fatality rate (SFR) for acute respiratory disorders with regard to the overall study population was 0.45%. The male/female ratio of affected infants was 1.3:1. Among affected newborns the case fatality rate (CFR) for respiratory disorders was 15.88% (78/491) and was higher in males than in females (2:1), in infants with a gestational age of < or = 28 weeks (60%) and birth weights of < 1,000 g (50%). Moreover, the SFR was higher (p < 0.05) in the infants of mothers older than 34 years. SFR was 3.0% in intrauterine growth-retarded infants, 3.6% in the first twin and 3.2% in the second twin. An Apgar score of < or = 3 at 5 min was strongly related to the incidence of respiratory disorders (47.1%). The antenatal prevention of neonatal respiratory distress syndrome with maternal corticosteroid treatment was performed in 84% of newborns (< 32 weeks) with respiratory problems in northern Italy, and about 25% and 38% in central and southern Italy, respectively. The CFR was double in southern Italy as compared with northern and central Italy. Prematurity, low birth weight and a low Apgar score (< or = 3) at 1 and 5 min as well as a maternal age of > 34 years are risk factors for acute respiratory disorders.

Acute Disease↗
PubMed1988

Schizophrenia, season of birth, and maternal age.

Maternal age is a neglected variable, with obvious implications for aetiology, in psychiatric research. In samples of schizophrenic patients, the distributions by month of birth and maternal age at birth show remarkable anomalies. These phenomena may be connected, because the seasonal distribution of births varies with maternal age, probably as a result of the age-dependent changes of fertility. Preliminary attempts to describe the seasonal effect in schizophrenia as a function of the shift in mean maternal age are not wholly successful at the quantitative level. Southern-hemisphere findings do not seem to fit the predicted pattern. Examples from other areas of research are discussed (sudden unexpected death in infants, congenital dislocation of the hip, and handedness) in which the seasonal distributions of births, and the findings on maternal age, conform to different varieties of the expected relationship.

Adult↗
PubMed1999

[Combined use of nuchal translucency, gestational age and maternal age for evaluation of the risk of trisomy 21].

PURPOSE: Despite the definition of new screening policies for fetal trisomies, based on nuchal translucency thickness (NT) or maternal serum, the prevalence of trisomy 21 remains high. We propose a strategy based on a combination of maternal age, gestational age and NT, measured at the first trimester ultrasound examination, for the assessment of risk. METHODS: We present, in this paper, a characterisation of the physiological increase of fetal NT between the 10th and the 14th week of gestation, in a preliminary study of 266 echographic examinations. Next we propose a calculation of the simultaneous risk of trisomy 21 based on marginal risks for maternal age and increased NT values available in the literature. RESULTS AND CONCLUSION: We propose to define a high-risk group associated to the NT marker by using a cut-off risk of 1/250 for the simultaneous risk. This criteria may, as well, be expressed by a pathological threshold of NT varying with maternal age and gestational age. Without questioning that women aged of 38 years or older are a high-risk group, this approach should allow an improvement of the prenatal screening for trisomy 21.

Adult↗
PubMedDate not supplied

Maternal age as a factor in determining the reproductive and behavioral outcome of rats prenatally exposed to ethanol.

Nulliparous Long-Evans rats were bred at one of four different ages and assigned to one of three treatment groups within each age condition. Maternal ages were 9, 18, 32, and 36 weeks. Treatment groups were ethanol (E), administered by gavage as 8 g/kg in two divided doses on days 10-14 of gestation, pair-fed (PF) controls, administered as an isocaloric sucrose solution by gavage on days 10-14 of gestation, and ad lib fed controls (C). All offspring were surrogate fostered shortly after delivery to untreated recently parturient dams. Litter sizes were standardized to 8 on the day of birth. Offspring were assessed longitudinally for growth, mortality, and behavior (olfaction, locomotor activity, maze learning, avoidance acquisition and startle). Approximately 85% of the 36 week old dams did not produce viable litters. In the remaining maternal age conditions, ethanol delayed offspring olfactory orientation and increased locomotor activity, the latter dissipating after 50-60 days of age. These ethanol-related effects occurred independent of maternal age condition. Maternal age, independent of ethanol, was a factor which reduced litter size and offspring weight up to 50 days, but produced few effects on behavior. The combination of maternal age and prenatal ethanol interacted to increase pregnancy loss (oldest maternal age), reduce offspring weight up to day 99 (oldest and middle maternal age), alter olfactory orientation performance (oldest and middle maternal age), reverse the typical ethanol-induced increase in activity for males in the figure-8 test (oldest maternal age group), shift the pattern of open-field activity, and change errors in a complex water maze. Not all of these interactions turned out to be specific to the ethanol X old maternal age condition. Several of the interactions occurred in both the old and middle maternal age conditions. The only effect of old maternal age that interacted strongly with ethanol was in their combined effects on reproduction. Here the combination of the two factors increased maternal mortality, the number of early pregnancy losses, and the number of litters where all members were dead or resorbed. It was concluded that short-term prenatal ethanol combined with advanced maternal age produces additive interactions on pregnancy success without affecting longer-term outcomes, while young maternal age showed no clear detrimental effects compared to the middle maternal age reference group.

Aging↗
PubMed1980

Rates of Down's syndrome at the upper extreme of maternal age--absence of a "leveling" effect and evidence for artifacts resulting from analyses of rates by five-year maternal age intervals.

A "leveling" in the first order exponential increase of the rate of Down's syndrome with maternal age over 40 years of age has been suggested by others in review of data reported by five-year maternal age interval. In contrast, data reviewed here analyzed by one-year interval reveal no evidence for such an effect when the observed rates (O) at each maternal age in the 40--49-year age range and in the 45--49-year age range are compared with those predicted (P) from first order exponential equations derived from data in the 33--44-year age range. The sign of O -- P is not predominantly negative as would be expected if there were a "leveling" effect. Part of the evidence for leveling in previous studies may derive from the fact that rates have been plotted at the midpoints of the intervals rather than at the true mean maternal ages of mothers having births in these five-year intervals. It is shown that in the three data sources considered here, the difference between the quin-quennial mean maternal age and the interval midpoint is greater at older ages than at younger ages. Thus, plotting rates at the midpoint of five-year intervals results in significant graphic underestimate of the rates, and may result in a slight leveling effect. It is suggested that selective underascertainment of births to those in the older maternal ages in previous studies may also have contributed to the leveling effect observed earlier.

Adult↗
PubMed1994

[Relation of gestational age, maternal body weight and age or serum alpha-fetoprotein and human chorionic gonadotropin at second-trimester].

Serum levels of alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) were measured in serum samples of 1,964 pregnant Japanese women whose gestational age and singleton pregnancy were confirmed by ultrasound examination during the first trimester of pregnancy. Statistical analysis of log-linear regression to calculate multiples of the median (MoM) was accomplished by the SAS statistical method. The levels of the two analytes noticeably decreased as maternal body weight increased. However, maternal age did not have a significant effect on either of them. The MoM formulae were as follows: MSAFPMoM = AFP/exp(0.861 + 0.0685 x gestational age(weeks) - 0.00572 x body weight(kg)). MShCGMoM = hCG/exp(6.12 - 0.787 x gestational age(weeks) - 0.00613 x body weight(kg)). Gestational age and maternal body weight should be considered as regression functions for the adjustment of serum levels in risk estimation of fetal anomalies and fetal demise in Japan.

Adult↗
PubMed1991

Neonatal outcome and its relationship with maternal age.

The relationship between maternal age and neonatal outcome was examined in 22,689 pregnancies using various determinants of neonatal well-being which included evidence of fetal distress, birth-weight, Apgar scores, the necessity for admission to the neonatal unit and other indicators of neonatal morbidity. Differences in the incidence of congenital malformations and perinatal mortality were also studied. There was a trend towards more frequent fetal heart monitoring, lower birth-weight and a higher rate of neonatal unit admission for infants delivered by younger women. There was also a significant increase in the Caesarean section rate with advancing maternal age. Maternal age had no effect, however, on the incidence of fetal distress, Apgar score, the development of respiratory disease, the need for intubation and ventilation nor on subsequent neonatal central nervous system complications. There was also no association between maternal age and either perinatal mortality or the incidence of congenital malformations. The favourable outcome in teenagers in this study may have been influenced by the extremely low pregnancy rate amongst young adolescents in Hong Kong, but a similar outcome in the mature age women was likely to have reflected the recognition of risk and its appropriate management.

Adolescent↗
PubMed1980

A search for evidence for a paternal age effect independent of a maternal age effect in birth certificate reports of Down's syndrome in New York state.

The discovery that in 20% to 30% of Down's syndrome cases the extra chromosome is of paternal origin, and the recent independent report of two groups that maternal age-specific rates are two-fold greater for livebirths to couples in which the father is aged 55 years and over prompted this investigation. Analyses were of coded birth certificate reports of Down's syndrome in Upstate New York residents in the years 1963-1974. The expected numbers of cases, on the assumption of no paternal age effect, were determined at each paternal age interval (and at each paternal age minus maternal age interval) adjusting for an effect of maternal age; these were compared with observed values. There was a slightly lower number of observed than expected cases for fathers aged 55 years and over (ratio = 0.76), and the results exclude with 95% confidence an increase of 1.5-fold or greater in rates in this group after correction for maternal age. There was, moreover, no overall evidence for any trend to increasing rates with paternal age. Regression analyses in which the data were first fit to functions of maternal age and subsequently terms involving paternal age were introduced also revealed no evidence that paternal age made a significant independent contribution to the observed rates in contrast to the conclusion of earlier positive reports.

Adolescent↗
PubMed1997

Maternal age modifies the effect of maternal smoking on intrauterine growth retardation but not on late fetal death and placental abruption.

To investigate whether the effect modification of smoking by maternal age previously reported for small for gestational age births was also obtained for late fetal death and placental abruption, the author analyzed single births in Sweden (n = 1,057,711) from 1983 to 1992. An effect modification of smoking by maternal age was obtained only with regard to fetal growth: Compared with nonsmokers aged 40-44 years, the risk of small for gestational age births among women smoking at east 10 cigarettes per day in the same age group was 4.5, whereas the corresponding risk increase among teenagers was only 2.0. The present results support the hypothesis that smoking actually influences fetal growth more among older smokers.

Abruptio Placentae↗
PubMed1984

Maternal age and breast cancer risk.

Maternal age at time of birth was investigated as a risk factor for breast cancer in a study of 1,176 matched case-control pairs. There was no pattern of increasing adjusted relative risk of breast cancer with increasing maternal age, nor was the mean maternal age of cases older than that of controls. Similar negative results were found among the subset of subjects up to 35 years old, a group previously found to show marked maternal age effects. Thus previous reports of an association between breast cancer and advanced maternal age may have been due to chance, extraneous factors, or a misleading reliance on unadjusted mean maternal ages, rather than on relative risks.

Adult↗
PubMed1992

Cytogenetic evidence for enhanced selective miscarriage of trisomy 21 pregnancies with advancing maternal age.

The effect of advancing maternal age on the risk of death of fetuses with certain chromosome abnormalities has been tested by comparing their frequency at the time of chorionic villus sampling (CVS) with that at amniocentesis. The frequency of chromosome abnormalities among women whose sole risk factor for a chromosome abnormality was advanced maternal age (> or = 35 years old) was determined in a pooled group of 15,147 CVS cases, of whom > 1/3 were from the initial 7,500 CVS cases at the University of California, San Francisco, and compared with a pooled group of 74,851 amniocentesis cases collected from the literature. The frequency of trisomy 21 not only increased with advancing maternal age as expected, but the slope of the increase was about 25% greater in the CVS group than in the amniocentesis group (P = 0.08 for the difference in slopes by a logistic statistical model and P = 0.04 by a normit model). Similar patterns were seen for trisomies 18 and 13, but the P values for the differences in slopes were much higher. These results suggest that the miscarriage rate of trisomy 21 during the gestational interval studied is selectively greater with advancing maternal age. The basis for the enhanced selective loss of trisomy 21 with maternal age may be a reduced ability of the ageing "maternal compartment" to compensate for abnormal conceptuses.

Abortion, Spontaneous↗