The influence of some perinatal variables on neonatal blood pressure

Adult hypertension has been linked to fetal growth. This study investigates whether this link is evident in the newborn. We measured blood pressure by oscillometry in 248 healthy neonates on day 3/4 of life. Antenatal data and neonatal measurements were obtained from hospital records. Elevated neonatal blood pressure correlated with higher birthweight. There was no correlation between placental weight and blood pressure. Babies born by caesarean section had lower systolic blood pressure. Babies of maternal smokers had higher diastolic blood pressure, but their mothers (45% of this study) had lower blood pressure than non-smokers. Thus, smoking was associated with a significant change in both maternal and neonatal blood pressure, and may be an important influence on the developing cardiovascular system.     

Smoking during pregnancy measured by population cotinine testing

AIM: To establish a baseline cross-sectional prevalence of maternal smoking, measured by antenatal serum cotinine testing, in a population of pregnant women. METHODS: Residual sera from first and second routine antenatal blood samples were collected anonymously over a six-month period for pregnancies within the Canterbury region. Cotinine levels were measured by an ELISA test with a result of > 14 ng/mL indicative of active smoking. Only pregnancies ending in a confirmed live birth were considered in smoking prevalence calculations. There was a total of 1948 eligible residual blood samples. RESULTS: Of the 414 residual blood samples available for the first two months of pregnancy, 146 (35.3%) were found to be positive for cotinine. Smoking prevalence decreased over pregnancy so that by the third trimester 225 (26.8%) of 838 samples were cotinine positive. Infants born from smoking mothers had significantly lower birth weights. CONCLUSIONS: In 1994, a third of women tested in early pregnancy and a quarter of women tested in late pregnancy were identified as being smokers. Repeated objective cross-sectional surveys will allow accurate assessment of the efficacy of smokefree interventions both before and during pregnancy.     

Target position variability throughout prostate radiotherapy

OBJECTIVE: It was our objective to evaluate the association between early maternal weight gain (before 20 weeks), midpregnancy weight gain (20-28 weeks), and late pregnancy weight gain (28 weeks to birth) with fetal growth and birth weight in twins. STUDY DESIGN: This historic cohort study was based on 1564 births of live twins >/=28 weeks' gestation from Baltimore, Maryland, Miami, Florida, Charleston, South Carolina, and Ann Arbor, Michigan. RESULTS: Early fetal growth was affected only by smoking and chorionicity. Factors in models of both mid and late fetal growth included maternal age, pregravid weight, parity, rates of early pregnancy and midpregnancy maternal weight gain, smoking, and pre-eclampsia. Increased midpregnancy fetal growth was associated with early maternal weight gain (10.91 g/wk per pound per week) and midpregnancy maternal weight gain (15.89 g/wk per pound per week). Increased late fetal growth was associated with early maternal weight gain (16.86 g/wk per pound per week) and midpregnancy maternal weight gain (23.88 g/wk per pound per week). Increased birth weight was associated with early (283.02 g per pound per week), mid (163.58 g per pound per week), and late (69.76 g per pound per week) maternal weight gains. CONCLUSIONS: These findings confirm the importance of early maternal weight gain in twin fetal growth and birth weight.     

Sex difference in resistance to dexamethasone-induced apoptosis in NOD mice: treatment with 1,25(OH)2D3 restores defect

The purpose of the study was to evaluate the association between smoking during pregnancy and preterm birth. The overall rate of preterm delivery was 4.3%. Smokers had a 40% higher risk of preterm birth compared to non-smokers. A dose response relationship was found between smoking and risk of preterm birth. Adjustment for women's height, pre-pregnant weight, age of the mother, marital status, education, occupational status, and alcohol intake did not change the results. Among women with an intake of less than 400 mg of caffeine per day no difference in the risk of preterm birth between smokers and non-smokers was found. However, among women with an intake of more than 400 mg of caffeine per day, the risk of preterm birth was increased almost threefold among smokers compared to non-smokers. Furthermore, among women with a high intake of caffeine a dose response relationship was found between smoking and risk of preterm delivery.     

The Diabetes in Early Pregnancy Study: beta-hydroxybutyrate levels in type 1 diabetic pregnancy compared with normal pregnancy. NICHD-Diabetes in Early Pregnancy Study Group (DIEP). National Institute of Child Health and Development

OBJECTIVE: The objective was to assess relationships between beta-hydroxybutyrate (beta-OHB) level and pregnancy outcome in human pregnancy in light of the fact that high levels of beta-OHB cause malformations and growth retardation in in vitro studies. RESEARCH DESIGN AND METHODS: We analyzed beta-OHB in prospectively collected specimens from the National Institute of Child Health and Human Development-Diabetes in Early Pregnancy Study, in gestational weeks 6-12 in diabetic (n = 204-239) and nondiabetic (n = 316-332) pregnant women. RESULTS: Levels of beta-OHB in diabetic women were 2.5-fold higher than in nondiabetic pregnant women at 6 weeks' gestation and declined to 1.6-fold above nondiabetic women by 12 weeks' gestation (P < 0.0001 at all times). beta-OHB was positively correlated with glucose levels (P < 0.0001) in diabetic mothers, probably reflecting degree of diabetic control. beta-OHB correlated inversely with glucose (P < 0.0003) (gestational week 6 only) in nondiabetic mothers, possibly reflecting caloric intake. beta-OHB tended to be lower (not higher) in diabetic and nondiabetic mothers with malformed infants or pregnancy losses, but the difference was not statistically significant. beta-OHB in diabetic mothers at 8, 10, and 12 weeks correlated inversely with birth weight (P = 0.004-0.02), even after adjusting for maternal glucose levels. beta-OHB levels were also generally lower in diabetic mothers of macrosomic infants, and week 12 ultrasound crown-rump measurements were inversely related to beta-OHB levels. CONCLUSIONS: The lst trimester beta-OHB is significantly higher in diabetic than nondiabetic pregnant women. In both groups, beta-OHB tended to be lower, not higher, in mothers who had a malformed infant or pregnancy loss. beta-OHB was inversely related to crown-rump length and birth weight. The modest beta-OHB elevation in the 1st trimester of reasonably well-controlled diabetic pregnancy is not associated with malformations, probably because beta-OHB levels causing malformations in embryo culture models are 20- to 40-fold higher. The mechanism of the beta-OHB association with impaired fetal growth is unknown.     

Determinants of poor pregnancy outcomes among teenagers in Sweden

OBJECTIVE: To study pregnancy outcomes among teenagers and to determine whether age-related increases in risk are due to differences in socioeconomic conditions, maternal smoking, or anthropometric status. METHODS: All single births during 1990-1991 to mothers aged less than 25 years recorded in the Swedish Medical Birth Registry were studied (n = 62,433). The pregnancy outcomes analyzed were late fetal death, infant mortality, preterm birth, low birth weight, small for gestational age, and low Apgar scores. Information on maternal age, parity, family situation, maternal smoking, maternal height, and weight gain during pregnancy was recorded in the Medical Birth Registry. Information on socioeconomic characteristics was obtained from the Population Census. Logistic regression analysis was used to define the determinants of the adverse outcomes among teenagers. RESULTS: Compared with women aged 20-24 years, girls of 17 years or less were at higher risk for preterm birth (odds ratio [OR] 1.6), and this increased risk remained essentially unchanged after controlling for major confounding factors (OR 1.5). Teenagers also had a crude 50% higher risk of late fetal death and infant mortality, but this risk was reduced after controlling for the effect of socioeconomic characteristics (adjusted OR 1.2). CONCLUSIONS: The increase in risk of late fetal death and infant mortality associated with low maternal age is substantially an effect of teenagers' poorer socioeconomic situation. However, the increase in preterm birth among younger teenagers suggests that young maternal age may be a biologic risk factor for preterm birth.     

Effects of smoking on the urine excretion of oral 51Cr EDTA in ulcerative colitis

BACKGROUND: Smokers have a reduced risk and ex-smokers an increased risk of ulcerative colitis (UC). Stopping smoking often precedes onset and relapses. Smoking reduces the 24 hour urine excretion of oral chromium-51 labelled EDTA in healthy individuals. AIMS: To estimate the effects of smoking on the urine excretion of oral 51Cr EDTA in well characterised patients with UC. SUBJECTS: Sixteen smoking and 16 non-smoking patients with UC in remission were studied. The non-smokers had never smoked. Most were taking 5-aminosalicylic acid. No patient took steroids or immunosuppressants. The control group comprised 25 smoking healthy volunteers and 25 who had never smoked. The median cigarette consumption was equal in the patients and volunteers. METHODS: The 24 hour urine excretion of oral 51Cr EDTA was measured and the results were correlated with smoking habits, number of cigarettes, and disease extent. RESULTS: Patients with UC had significantly higher 24 hour urine recoveries than healthy controls (p = 0.04). This difference was more pronounced when patients who smoked were compared with healthy smokers (p = 0.005) No significant differences were found when comparing non-smoking patients with non-smoking controls or when comparing smoking and non-smoking patients. Urine recoveries did not correlate with number of cigarettes or disease extent. Smoking was more prevalent in patients with a more limited disease extent (p = 0.033). CONCLUSIONS: Effects of smoking on the urine excretion of 51Cr EDTA in health were abolished by the presence of UC. The protective effects of smoking in established UC are not due to a moderating effect of smoking on intestinal permeability.     

Differential effects of maternal heroin and methadone use on birthweight

An analysis of birthweights of 337 neonates in relation to history of maternal narcotic usage was undertaken. Mean birthweight of infants born to mothers abusing heroin during the pregnancy was 2,490 gm, an effect primarily of intrauterine growth retardation. Low mean birthweight (2,615 gm) was also seen in infants born to mothers who had abused heroin only prior to this pregnancy, and mothers who had used both heroin and methadone during the pregnancy (2,535 gm). Infants born to mothers on methadone maintenance during the pregnancy had significantly higher mean birthweights (2.961 gm), but lower than the control group (3,176 gm). A highly significant relationship was observed between maternal methadone dosage in the first trimester and birthweight, i.e., the higher the dosage, the larger the infant. Heroin causes fetal growth retardation, an effect which may persist beyond the period of addiction. Methadone may promote fetal growth in a dose-related fashion after maternal use of heroin.     

The influence of maternal passive and light active smoking on intrauterine growth and body composition of the newborn

OBJECTIVE: To assess the influence of passive and light active smoking on the reduction of intrauterine growth of the foetus and on modifications in the body composition of the newborn. DESIGN: Random. SETTING: Full term newborn infants at the Department of the Pediatric and Gynaecological Divisions of the City Major Hospital, Chair of Paediatrics, Verona University. SUBJECTS: One hundred and twelve mothers selected after having completed a questionnaire on smoking habits during pregnancy. One hundred and twelve newborn infants were divided into three groups: Group 1: non-smoking and non-exposed mothers; Group 2: non-smoking but exposed mothers; Group 3: light smoking mothers (under 10 cigarettes/d, whether or not also exposed to passive smoking). Examination within 24 h of birth established the anthropometric measurements and estimates of body composition through indices or equations. RESULTS: Newborns of groups 2 and 3 had a statistically significant reduction of fat mass and most anthropometric measurements: fat mass according to Dauncey (P < 0.001), birth-weight (P < 0.013), crownheel length (P < 0.000), upper- and lower-arm length (P < 0.000) and circumference (P < 0.002), triceps skinfold and sum of all skinfolds (P < 0.004). Student t-test, between groups 2 and 3, did not evidence intergroup differences. CONCLUSIONS: Exposure of the foetus to passive and/or light active smoking involves a reduction of most auxiological parameters and not only weight. As regards body composition, smoking appears to reduce fat mass. The prevention of smoking during pregnancy is therefore extremely important, as intrauterine growth seems to be negatively influenced not only by active smoking, but also by passive and light active smoking.     

Perinatal events associated with maternal smoking during pregnancy

To identify components of smoking-related increased perinatal mortality, detailed analyses of data from the Ontario Perinatal Mortality Study (50,000 births, 1,300 deaths, 1960-1961) measured the relationship of maternal smoking to birth weight, gestation, placental complications, and perinatal mortality. Cross-tabulations with other factors and multiple adjustment showed increases with amount smoked of birth weights less than 2500 gm, gestations less than 38 weeks, placenta previa, abruptio placentae, and perinatal mortality. These significant, smoking-related increases were independent of mother's height, weight, hospital status, age-parity group, birthplace, previous pregnancy history, weight gain, time of registration, and sex of child. Maternal smoking had the strongest effect on birthweight in the 8 factor regression, and birth less than 2500 gm increased directly with smoking level from 20% to 340% in 37 data subgroups. Births less than 38 weeks increased 20% and 50% and perinatal mortality increased 20% and 35% for less than 1 pack and 1 + pack smokers, respectively, adjusted for 7 other factors. Placental complications increased consistently with smoking level in all of 37 subgroups except for primiparous less than 1 pack smokers. Adjusted rates increased 25% and 92% for placenta previa, 23% and 86% for abruptions among smokers of less than 1 pack and 1 + packs, respectively. These complications carry high perinatal mortality risk, and account for one-third to one-half of the perinatal deaths attributable to maternal smoking.     

The effects of smoking outside workplaces on non-regular smokers

The introduction of workplace smoking bans has resulted in smokers smoking outside their workplaces (exiled smoking). Social identity theory postulates that this may cause antagonism between smokers and non-smokers, or where non-smokers were friends with smokers, pressure on non-smokers to smoke. This study examines perceptions and beliefs about exiled smoking in 166 non-smoking workers. They saw smokers as having a work benefit not available to them, but otherwise they were generally not drawn to the activity. Half had joined smokers outside for breaks, but of these only one-third had ever smoked. Those would smoked reported that they did not have a regular pattern of joining the same group of smokers. Although it may provide a conduit for susceptible non-smokers to take up smoking, exiled smoking does not appear to influence those who are not otherwise vulnerable.     

The effect of smoking cessation during pregnancy on preterm delivery and low birthweight

BACKGROUND: Evidence exists that maternal cigarette smoking is associated with preterm birth. Our purpose was to investigate the relation between maternal smoking cessation at different points during pregnancy and the preterm delivery rate and low birthweight. METHODS: Data from the 1988 National Health Interview Survey were analyzed. The study included women who gave birth to children within 6 years of the 1988 interview date (N = 4876). Preterm delivery and infant low birthweight were the main outcome measures. These measures were compared with maternal smoking status during pregnancy. Logistic regression models were computed to control for maternal age at the time of birth, parity, race, and total family income. RESULTS: Women who did not smoke cigarettes during pregnancy were less likely to give birth prematurely (5.9% vs 8.2%, P = .003) or give birth to a low-birthweight baby (5.5% vs 8.9%, P < .001) than women who smoked at some time during the year before giving birth. A significant association existed between maternal smoking status and both preterm delivery and low birthweight. Compared with those who smoked beyond the first trimester, those who quit smoking within the first trimester had reductions in the proportion of preterm deliveries (6.7% vs 9.1%) and low birthweight infants (7.9% vs 9.6%). CONCLUSIONS: Low birthweight and preterm delivery are reduced in women who stop smoking in the first trimester of pregnancy.     

Offspring birth weights after maternal intrauterine undernutrition: a comparison within sibships

The authors examined the effects of maternal intrauterine undernutrition on offspring birth weights in a cohort of women born between August 1944 and April 1946 in Amsterdam, The Netherlands. This period included the Dutch Hunger Winter, a war-induced famine. Undernutrition was defined separately for each trimester of pregnancy as an average supply of less than 1,000 calories per day from government food rations. For maximum control of potential maternal confounding factors related to offspring birth weight, the authors performed a within-family analysis, including 437 families with two siblings and 107 families with three siblings born between 1960 and 1985. As in other studies of the famine, maternal birth weight itself was decreased after third trimester intrauterine exposure but not after first trimester exposure. The expected increase in offspring birth weights with increasing birth order was not seen after maternal intrauterine exposure in the first trimester of pregnancy. In this group, second born infants weighed, on average, 252 g less at birth than their firstborn siblings (95% confidence interval (CI) -419 to -85), and thirdborn infants weighed 419 g less (95% CI -926 to 87), even after adjustment for trimester of maternal intrauterine exposure, maternal birth weight, smoking during pregnancy, and sex of infants in the sibling pairs. Additional adjustment for the birth weight of the elder sibling did not materially change this abnormal pattern. There were no abnormal patterns in offspring birth weights after maternal intrauterine exposure in the second or third trimester of pregnancy. The study outcomes could not be explained by other selected determinants of birth weight, by lack of control for socioeconomic status, or by loss to follow-up of the 1944-1946 birth cohort. This study suggests that there may be long-term biologic effects, even into the next generation, of maternal intrauterine undernutrition which do not correspond to the effects on the mothers' own birth weights.     

A comparison of two different systems for CD34+ selection of autologous or allogeneic PBSC collections

Narghile smoking, a common habit among women in many non-Western societies, is assumed by the public to be minimally harmful. This study aims at identifying the effect of smoking narghiles during pregnancy on the weight of the newborn and other pregnancy outcomes. Three groups of pregnant women were interviewed in several hospitals in Lebanon between 1993 and 1995: 106 who smoked narghiles during their pregnancy, 277 who smoked cigarettes, and 512 who did not smoke. The adjusted mean birth weight of babies born to women who smoked one or more narghiles a day during pregnancy and to women who started smoking in the first trimester was more than 100 g less than that of babies born to nonsmokers (p < 0.1). The adjusted odds ratio of having babies with low birth weight (<2,500 g) among the narghile smokers was 1.89 (95% confidence interval (CI) 0.67-5.38). The risk increased to 2.62 (95% CI 0.90-7.66) among those who started smoking narghiles in the first trimester. A stronger association and a dose-response relation were found among cigarette smokers. The association between narghile smoking and other pregnancy outcomes, especially Apgar score and respiratory distress, was also noticeable. Further research and a policy action to fight the misperception that narghile smoking is safe are both recommended.     

Objectively measured tobacco exposure during pregnancy: neonatal effects and relation to maternal smoking

OBJECTIVES: To measure quantitatively and objectively the maternal and fetal tobacco exposure during pregnancy and its neonatal effects. DESIGN: Tobacco exposure was assessed from maternal serum samples, obtained during the first half of pregnancy and from umbilical serum samples obtained at delivery, by measuring the concentration of nicotine metabolite, cotinine. Data on the respective pregnancies and neonates were collected from the Finnish Medical Birth Registry. SETTING: Finland. SUBJECTS: One thousand two hundred and thirty-seven pregnancies and newborns, representing all pregnancies resulting in a liveborn infant during one week in one country. MAIN OUTCOME MEASURES: Gestational age, birthweight and crown-heel length of newborns. RESULTS: Cotinine (> 6 micrograms/l) was detected in either maternal or umbilical serum in 300 pregnancies, and these mothers and newborns were classified as exposed. Important differences occurred between measured exposure and reported smoking behaviour. Of the exposed mothers, 38% were nonsmokers and 3.4% of the nonexposed mothers were smokers. Tobacco exposure was associated with shorter gestational age, reduced birthweight and shorter crown-heel length of the newborns. After correction for parity, gender, and gestational age, the exposed newborns were on average 188 g (95% confidence interval (CI) 123-253 g) lighter and 10 mm (95% CI 7-13 mm) shorter than the nonexposed newborns. One micrograms/ml of cotinine in maternal serum resulted in a mean decrease of 1.29 g (95% CI 0.55-2.02 g) in birthweight and in a mean decrease of 0.059 mm (95% CI 0.035-0.083 mm) in birth length. Maternal cotinine concentrations better explained the neonatal findings than the reported smoking habits. CONCLUSIONS: There is a quantitative dose and effect relation between tobacco exposure and a decrease in the gestational age at birth and size of the neonate. The smoking habit reported by mothers themselves is not an accurate measure of fetal tobacco exposure.     

The smoking addiction of pregnant women and the consequences on their offspring's intellectual development

Many scientists have studied the effects of smoking by pregnant women on intrauterine development. Because nicotine and other toxic substances in cigarette smoke are not stopped by the placental barrier, there is a risk that the development of the child could be hindered. It has been shown, for instance, that babies whose mothers smoked during pregnancy have lower size and weight at birth. Few authors have studied the consequences a mother's pre-natal smoking may have on the intellectual development of her child. We compared two samples of children, aged 4 to 5, and aged 6 to 7 (40 children in total), whose mothers had smoked during pregnancy, with two samples of 40 children of the same ages whose mothers had not smoked. We tested them on the Wechsler scale. The social and cultural levels were equivalent. We found a difference of more than 15 IQ points in favor of the children of nonsmoking mothers. These results permit us to suppose that smoking during pregnancy hinders the intellectual development of the child.     

Preterm delivery: effects of socioeconomic factors, psychological stress, smoking, alcohol, and caffeine

OBJECTIVE: To examine the relation between preterm birth and socioeconomic and psychological factors, smoking, and alcohol, and caffeine consumption. DESIGN: Prospective study of outcome of pregnancy. SETTING: District general hospital in inner London. PARTICIPANTS: 1860 consecutive white women booking for delivery; 1513 women studied after exclusion because of multiple pregnancy and diabetes, refusals, and loss to follow up. MEASUREMENTS: Gestational age was determined from ultrasound and maternal dates; preterm birth was defined as less than 37 completed weeks. Independent variables included smoking, alcohol and caffeine consumption, and a range of indicators of socioeconomic status and psychological stress. MAIN RESULTS: Unifactorial analyses showed that lower social class, less education, single marital status, low income, trouble with "nerves" and depression, help from professional agencies, and little contact with neighbours were all significantly associated with an increased risk of preterm birth. There were no apparent effects of smoking, alcohol, or caffeine on the length of gestation overall, although there was an association between smoking and delivery before 32 weeks. Cluster analysis indicated three subgroups of women delivering preterm: two predominantly of low social status and a third of older women with higher social status who did not smoke. Mean gestational age was highest in the third group. CONCLUSIONS: Adverse social circumstances are associated with preterm birth but smoking is not, apart from an association with very early births. This runs counter to findings for fetal growth (birth weight for gestational age) in this study, where a strong effect of smoking on fetal growth was observed but there was no evidence for any association with psychosocial factors.     

Review of Smoking for two: Cigarettes and pregnancy.

Reviews the book, Smoking for Two: Cigarettes and Pregnancy by Peter A. Fried and Harry Oxorn (1980). In Smoking for Two. Peter Fried, a Professor of Psychology at Carleton University, and Harry Oxorn, a Professor of Obstetrics and Gynecology at the University of Ottawa, document what is known and not known about the consequences of smoking during pregnancy. Topics which are discussed include: 1) epidemiology of smoking, particularly among women of reproductive age, 2) involuntary smoking, 3) constituents of smoke and effects on mother and fetus, 4) smoking and maternal weight gain, 5) smoking and the function of the placenta, 6) smoking and complications during pregnancy, 7) smoking and infant birth weight, 8) smoking and the newborn, 9) smoking and nursing, 10) long-term effects of smoking during pregnancy, and 11) suggestions for pregnant women who are trying to quit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maternal corticotropin-releasing hormone levels in the early third trimester predict length of gestation in human pregnancy

OBJECTIVE: Corticotropin releasing hormone, a hypothalamic neuropeptide, plays a major role in regulating pituitary-adrenal function and the physiologic response to stress. During pregnancy corticotropin-releasing hormone is synthesized in large amounts by the placenta and released into the maternal and fetal circulations. Various endocrine, autocrine, and paracrine roles have been suggested for placental corticotropin-releasing hormone. The aim of this study was to prospectively assess the relationship between maternal plasma concentrations of corticotropin-releasing hormone in the early third trimester of pregnancy and the length of gestation in two groups of deliveries, with and without spontaneous labor. STUDY DESIGN: In a sample of 63 women with singleton intrauterine pregnancies, maternal plasma samples were collected between 28 and 30 weeks' gestation and corticotropin-releasing hormone concentrations were determined by radioimmunoassay. Each pregnancy was dated on the basis of last menstrual period and early ultrasonography. Parity, antepartum risk conditions, presence or absence of spontaneous labor, and birth outcomes were abstracted from the medical record. RESULTS: Maternal corticotropin-releasing hormone levels between 28 and 30 weeks' gestation significantly and negatively predicted gestational length (P < .01) after adjustment for antepartum risk. Moreover, subjects who were delivered preterm had significantly higher corticotropin-releasing hormone levels in the early third trimester (P < .01) than did those who were delivered at term. In deliveries preceded by spontaneous onset of labor, maternal third-trimester corticotropin-releasing hormone levels significantly and independently predicted earlier onset of labor (P < .01) and preterm labor (P < .05), whereas in deliveries effected by induction of labor or cesarean delivery, maternal corticotropin-releasing hormone levels were a marker of antepartum risk but not a statistically independent predictor of gestational length. CONCLUSION: These findings support the premise that placental corticotropin-releasing hormone is potentially implicated in the timing of human delivery in at least two ways. First, placental corticotropin-releasing hormone may play a role in the physiology of parturition. Premature or accelerated activation of the placental corticotropin-releasing hormone system, as reflected by precocious elevation of maternal corticotropin-releasing hormone levels, may therefore be associated with earlier onset of spontaneous labor and resultant delivery. Second, placental corticotropin-releasing hormone may be a marker of antepartum risk for preterm delivery and therefore an indirect predictor of earlier delivery. The implications of these findings are discussed in the context of the neuroendocrinology of placental corticotropin-releasing hormone and human parturition. Furthermore, the role of corticotropin-releasing hormone as a possible effector of prenatal stress in producing alterations in the timing of normal delivery is detailed.     

1988 National Maternal and Infant Health Survey: methods and response characteristics

OBJECTIVES: The 1988 National Maternal and Infant Health Survey (NMIHS) was conducted by the National Center for Health Statistics to study factors related to poor pregnancy outcome, such as adequacy of prenatal care; inadequate and excessive weight gain during pregnancy; maternal smoking, drinking, and drug use; and pregnancy and delivery complications. METHODS: The NMIHS is a nationally representative sample of 11,000 women who had live births, 4,000 who had late fetal deaths, and 6,000 who had infant deaths in 1988. Questionnaires were mailed to mothers based on information from certificates of live birth, reports of fetal death, and certificates of infant death. Information supplied by the mother, prenatal care providers, and hospitals of delivery was linked with the vital records to expand knowledge of maternal and infant health in the United States. RESULTS: The response rates in all three components of the NMIHS differed according to the mothers' characteristics. Mothers were more likely to respond if they were 20-39 years of age, were white, were married, had fewer than four children, entered prenatal care early, had more prenatal visits, had more years of education, or resided in the Midwest Region. The percent of respondents was lower for teenage mothers, mothers of races other than white, and mothers with four or more children, little prenatal care, or fewer years of education. Mothers whose infants weighed less than 2,500 grams were less likely to respond in the live-birth and infant-death components than mothers whose infants weighed 2,500 grams or more. CONCLUSIONS: The NMIHS will provide an invaluable tool for researchers and practitioners seeking solutions to perinatal and obstetric problems.