Smoking, maternal age, and fetal growth

In a prospective clinical study from an unselected area-based population, the influence on birth weight for gestational age (standardized birth weight) was studied with special respect to risk factors for intrauterine growth retardation. Smoking was the most important risk factor: 16% of the mothers smoked at least ten cigarettes per day, and the influence of smoking on standardized birth weight was highly significant (P less than .001). Maternal age in itself had no effect on standardized birth weight. However, among smokers the reduction in standardized birth weight became more pronounced with increasing maternal age (P less than .001). Longterm smoking has been reported to increase the risk of severe placental complications. This study emphasizes that elderly smokers also must be considered to be at a higher risk than younger smokers for developing fetal growth disturbances.     

The impact of fetal renal pelvic diameter on postnatal outcome

OBJECTIVES: To determine thresholds for the fetal renal pelvic anterior-posterior diameter (APD) predicting postnatal clinically relevant pelvicaliceal dilatation. METHODS: One hundred and forty-eight infants whose prenatal sonography had identified an isolated uni- or bilateral fetal APD of > or = 4 mm before 33 and/or > or = 7 mm after 33 weeks' gestational age were investigated postnatally. On the basis of postnatal ultrasound examination, these infants were grouped according to the Society for Fetal Urology Grading System: no pelvic dilatation (n = 38); only pelvic dilatation (n = 59); pelvicaliceal dilatation (n = 33); pelvicaliceal and ureter dilatation (n = 18). RESULTS: Fetal pyelectasis of 7 mm was 89.3% sensitive and 78.9% specific < 33 weeks, and > or = 33 weeks pyelectasis of 10 mm was 88.4% and 78.6% in predicting subsequent postnatal pelvicaliectasis, respectively. Using a threshold of 4 mm < 33 weeks and 7 mm > or = 33 weeks yielded a sensitivity of 100% and a specificity of 18.7% and 47.8%, respectively. The median APD (range) at > or = 33 weeks was 19 mm (9-36 mm) in patients requiring surgery and 13 mm (7-21 mm) in conservatively treated patients (p = 0.001). Thirteen of fourteen patients with APD > or = 19 mm underwent surgery. CONCLUSION: Women with ultrasonographically detected prenatal fetal pelvic dilatation of > or = 4 mm before 33 weeks and of > or = 7 mm from 33 weeks onwards of gestation should have repeated prenatal ultrasound scans and a detailed postnatal evaluation. The dilatations of an APD > 4 mm before 33 weeks, which have disappeared at the post-33-week scan need no further investigation in the postnatal period.     

Does young maternal age increase the risk of adverse obstetric,fetal and neonatal outcomes: A cohort study

Objective

To determine whether young maternal age is associated with increased risks of adverse obstetric, fetal and perinatal outcomes.

Study design

Register-based study using the data from a computerized database of a University Hospital for the years 1994–2001. The study population included 8514 primiparous women aged less than 31 who delivered a singleton infant. Using maternal age as a continuous variable, crude and adjusted relative risks (RRs) were estimated for each maternal and perinatal outcome.

Results

Crude and adjusted RRs of anaemia during pregnancy and fetal death consistently increased with younger maternal age. After adjustment for confounding factors, RRs (95% confidence interval) of fetal death and anaemia were respectively 1.37 (1.09–1.70) and 1.27 (1.15–1.40) for a 16-year-old compared to a 20-year-old mother. Younger mothers had significantly decreased risks of obstetric complications (preeclampsia, caesarean section, operative vaginal delivery and post-partum haemorrhage). Higher prevalence of prematurity and low birth weight in infants born to teenagers were not attributable to young maternal age after adjustment for confounding factors.

Conclusion

In our population, younger maternal age was significantly and consistently associated to greater risks of fetal death and anaemia and to lower risks of adverse obstetric outcomes.     

Advanced maternal age and fetal growth inhibition in triplets

OBJECTIVE: To determine whether advanced maternal age is associated withfetal growth inhibition in triplets. STUDY DESIGN: We conducted a retrospective cohort study on triplet live births in the United States from 1995 through 1998. The outcomes of fetal growth inhibition measured were low birth weight, very low birth weight, preterm birth, very preterm birth and smallnessfor gestational age. We generated adjusted ORs after taking into account intracluster correlations using the generalized estimating equation framework. RESULTS: As compared to women of younger maternal age (20-29), mature (30-39) and older women (> or =40 years) with triplet gestations tended to have a lower likelihood offetal growth inhibition. Mean birth weight and mean gestational age at delivery increased with increasing maternal age in a dose-dependent pattern (p for trend < 0.0001). As compared to triplets born to younger mothers, those of older women were less likely to have low birth weight (OR=0.51, 95% CI=0.37-0.69) or very low birth weight (OR = 0.58, 95% CI = 0.47-0.72) or to be preterm (OR = 0.39, 95% CI = 0.27-0.56) or very preterm (OR = 0.67, 95% CI = 0.55-0.80). The riskfor small-for-gestational-age infants was comparable. CONCLUSION: Older maternal age is associated with morefavorable triplet fetal growth parameters, although the exact mechanisms of this paradox remain poorly understood.     

Risk of fetal Down's syndrome based on maternal age and varying combinations of maternal serum markers

Serum samples from 320 women with chromosomally normal fetuses and from 50 women with fetuses affected by Down's syndrome were assayed retrospectively for human chorionic gonadotropin (hCG), pregnancy-specific β ₁ glycoprotein (SP1), alpha fetoprotein (AFP), and unconjugated estriol (uE3) between 14 and 21 weeks of gestation. Nonparametric discriminant analysis was applied to calculate Down syndrome risks on the basis of various combinations of serum parameters. At a risk threshold that falsely identifies 5% of controls as being affected, 46 to 48% of Down syndrome pregnancies were detected by combinations of hCG/AFP, hCG/AFP/uE3, and hCG/AFP/uE3/SP1 respectively. HCG, AFP, and uE3 were assayed in 652 serum samples from women who underwent amniocentesis because of maternal age (≥35 years in this prospective study). 49% of women with euploid fetal karyotype, 8 of 10 pregnancies with Down's syndrome, and 3 pregnancies with sex chromosomal anomalies were identified as being at an increased risk (>1:380). Received: 30 June 1993 / Accepted: 26 January 1994     

Prediction of fetal lung immaturity using gestational age, patient characteristics and fetal lung maturity tests: a probabilistic approach

Objectives  

The lecithin/sphingomyelin (L/S) ratio and the lamellar body count (LBC) can be used to predict respiratory distress syndrome (RDS).     

与高龄妊娠相关的几种胎儿疾病

高龄妊娠是指孕妇年龄在预产期满35周岁的妊娠,对妊娠和围产儿结局产生重要影响。目前已知高龄妊娠显著增加胎儿染色体畸变的发生,高龄妊娠与胎儿非染色体异常畸形、生长受限等胎儿发育异常相关,加强高龄妊娠相关的胎儿疾病筛查、诊断和处理对降低出生缺陷发生率和围产儿死亡率具有重要意义。     

The impact of maternal age on pregnancy and its outcome.

There were 28,600 deliveries of 500 g or more to women at the Rotunda Hospital between January 1st 1985 and December 1st 1989. Of these, 595 were to women aged 40 years and over. Thirty-five variables of clinical significance were analyzed, comparing those of 40 years of age and more with those under 40. The older group had significant increases in gestational diabetes, ante-partum hemorrhage, fetal distress, prematurity, low birth weight and perinatal mortality. Chromosome congenital abnormalities were significantly higher, particularly Down syndrome. There were significantly increased rates of induction and cesarean section in the older women. Some evidence of interaction of age with other factors was found, however these were difficult to separate out in the clinical setting. We therefore recommend it wiser to manage all elderly gravidas in a high risk manner dealing with cases individually within this framework. Intervention should, however, need to be justified in the older as in the younger woman.     

The association between young maternal age and pregnancy outcome

Abstract

Objective: We aimed to determine the association between young maternal age at delivery with adverse pregnancy outcome in a single, tertiary, university-affiliated medical center.

Methods: A retrospective, cohort, matched control study using the first percentile distribution of maternal age at delivery (21 years old, n?=?461) as the study group, and four control groups by maternal age matched by parity in a 2:1 ratio (22–25, 26–30, 31–35 and 36–40 years; n?=?922 each).

Results: Women aged ≤21 years were found to have lower rates of chronic hypertension [compared with women aged 36–40 years old (0.0% versus 1.3%, p?<?0.05)], lower rates of gestational diabetes mellitus (GDM) (1.3% versus 3.7%, p?=?0.007), higher rates of perineal lacerations [compared with women aged 31–35 and 36–40 years old, 41% versus 31.8% and 31.1%, respectively, p?<?0.01)], higher rates of postpartum hemorrhage (4.6% versus 1.5%, p?<?0.0001) and higher rates of low 5-min Apgar score (2.2% versus 0.8%, p?=?0.004). No significant differences were found in terms gestational age at delivery, birth weight, fetal sex, intrapartum or antepartum mortality.

Conclusion: Young maternal age at delivery is associated with increased risk of short-term complications after delivery.     

Smoking, maternal age, fetal growth, and gestational age at delivery

The relationship between smoking and maternal age and their combined effects on birth weight, intrauterine growth retardation, and preterm delivery were studied. Smoking lowers birth weight both by decreasing fetal growth and by lowering gestational age at delivery. However, the effect of smoking on both fetal growth and gestational age is significantly greater as maternal age advances. In a multiple logistic regression model adjusting for race, parity, marital status, maternal weight, weight gain, and alcohol use, smoking was associated with a fivefold increased risk of growth retardation in women older than 35 but less than a twofold increased risk in women younger than 17. Smoking reduced birth weight by 134 gm in young women but 301 gm in women older than 35. Smoking in older women also was associated with more instances of preterm delivery and a lower mean gestational age when compared to women 25 or younger.     

The impact of advanced maternal age on the outcome of twin pregnancies

Purpose

To assess the effect of advanced maternal age on the obstetrics and neonatal outcome of twin pregnancies.

Methods

A retrospective study of 716 dichorionic–diamniotic twin pregnancies delivered at our institute. The study population was divided into two groups: women aged 35–39 years (group A, n = 142) and women aged ≥ 40 years (Group B, n = 48). The control group consisted of women younger than 35 years (group C, n = 516).

Results

The rate of cesarean section (CS) was significantly higher among women older than 35 years compared to the control group (A 76.8% and B 87.5% vs C 65.7%, P = 0.001). Women older than 35 years were also at higher risk for developing hypertensive disorders (A 7.0%, B 14.6%, vs C 5.4%, P = 0.04). On multivariate regression analysis, maternal age was found to be independently associated with a higher rate of CS (odds ratio vs reference group C: group A 1.6, 95% CI 1.08–2.6; group B 3.2, 95% CI 1.3–7.8). There was no difference between the groups in the rate of neonatal complications.

Conclusion

Women with twin pregnancy, older than 35 years, have a significantly higher rate of CS and hypertensive disorder. This rate increases with maternal age, with no increased rate of neonatal complications.

     

Influence of young maternal age and parity on term and preterm low birthweight

Data on 4496 singleton births to young women (19 years or less) are reported by maternal age and parity with birthweight and gestation cross-classified to yield rates of preterm and term low birthweight. After adjustment, the risk of preterm low birthweight was increased with very young maternity (15 years or less); preterm low birthweight and term low birthweight were each increased with young multiparity. These data suggest that the identification of factors associated with preterm birth and their incorporation into the prenatal care regimen may be important in improving pregnancy outcome in young women.     

Effect of young maternal age and skeletal growth on placental growth and development

Objectives

Teenagers are susceptible to delivering small-for-gestational-age infants. Previous studies implicate continued skeletal growth as a contributory factor, and impaired placental development was the primary cause of fetal growth restriction in growing adolescent sheep. The aims of this study were to examine the impact of young maternal age and growth on placental development.

Study design

Placentas were collected from 31 teenagers, of which 12 were growing and 17 non-growing based on knee height measurements. An adult control group (n = 12) was included.

Main outcome measures

Placental weight and morphometric measurements of villous, syncytiotrophoblast, fibrin and vessel areas, as well as indices of proliferation and apoptosis, were analysed in relation to maternal growth and age.

Results

Growing teenagers had a higher birthweight:placental weight ratio than non-growing teenagers (p < 0.05). Villous area, syncytial area, fibrin content, vascularisation and cell turnover did not differ between growing and non-growing teenagers. There were no differences in placental weight or morphometry between adult and teenage pregnancies. Maternal smoking, a potential confounding factor, did not exert a major influence on the placental parameters examined, except for a stimulatory effect on placental proliferation (p < 0.05) and syncytial knot formation (p < 0.05).

Conclusions

We were unable to detect any major differences in placental size or composition between growing and non-growing teenagers. Birthweight:placental weight ratio was higher in growing compared to non-growing teenagers. This suggests that maternal growth may affect placental function rather than development, and is consistent with our recent observations that maternal growth was not detrimental to fetal growth.     

Influence of age and parity on various parameters of maternal morbidity and on fetal morbimortality

Results are presented of a study of 19,853 deliveries prospectively studied from January 1969-May 1970 in a teaching hospital maternity ward in Chile to determine relationships between age, parity, and maternal and fetal mortality. The frequency of toxemia of pregnancy remained more or less constant from 15 years to 29 years but above 29 years it progressively increased, until by age 40 it was twice the level found in women under 30. Highest levels were found in nulliparas and multiparas with 7 or more births. Lowest incidences were found in parities 1-2. The incidence of hypertensive syndrome increased in relation to age in all parity groups when age and parity were jointly analyzed but the influence of parity was not similary consistent. There was a clear tendency to increased incidence of breech births with age, with lowest frequency in the 15-19 age group and almost 7 times the frequency among those 35 and above. The incidence of breech births also increased with parity. Postpartum hemorrhage due to uterine inertia was almost constant from 15-29 years, doubled in the group from 30-39 years, and was 3 times higher in the group 40 years and above. Postpartum hemorrhage was least common in nulliparous women and increased steadily before reaching its maximum among women of parity 7 or more. The incidence of placental hemorrhage remained almost constant through 29 years and thereafter increased but not progressively. The frequencey of placental hemorrhage was lowest in parity 1 and 2, moderately higher in parities 0, 3, and 5, and highest in parities 5 and above. The highest incidence of fetal malformation was among mothers aged 40 or above. Between 14-34 the incidence did not vary. The rate doubled for mothers under 15 and in those aged 35-39, and quadrupled among in mothers also higher among women over 40. No correlation was observed between parity and neonatal mortality. Late fetal mortality remained almost constant through 34 years and almost doubled for the group 35-39. The highest incidence was among mothers over 40. Late fetal mortality declined from parity 0 to parity 1-2, and thereafter increased steadily with parity.