Maternal risk factors for preterm birth and low birthweight in Cape Verde

BACKGROUND: Fifteen years after the implementation of an antenatal risk screening program in Cape Verde, the first assessment of an association between maternal obstetric characteristics and preterm birth or low birthweight (LBW) infants was undertaken. METHODS: A cohort of 353 systematically selected antenatal clinic attenders in the county of Praia, Cape Verde, was studied prospectively during the period October 1991 through December 1992. The cohort was followed past the perinatal period and information was obtained according to a pretested structured questionnaire. In the analysis of preterm birth and LBW, multiple logistic regression was listed to estimate the relative risks of ll background variables. RESULTS: The prevalence of preterm birth (<37 gestational weeks) was 12%, and the prevalence of LBW infants was 8%. Low birthweight (<2500 grams) was significantly associated with low maternal age (< or = 19 years, RR=3.7); nulliparity (RR=5.2) and obstetric history of previous LBW infant (RR-6.5). The risk of preterm birth was significantly increased if the woman had an obstetric history of hypertension or convulsions (RR=2.6). CONCLUSIONS: In the setting studied, teenage women and women with previous pregnancy hypertension should be given selective attention in antenatal care to achieve improved pregnancy outcome. Primary prevention is needed to lower the prevalence of teenage pregnancies.     

Family planning: an essential component of prenatal care

This nation's traditional approach to improving maternal and infant health has been prenatal care. But evidence is mounting that additional progress in reducing maternal and infant morbidity and mortality will depend, at least in part, on the care that a woman receives before she conceives. The studies reviewed in this paper indicate that increasing the interval between deliveries and preventing or delaying pregnancies among women at high risk could lower the rate of low birthweight (LBW). Since reducing the rate of unintended pregnancies would also reduce the number of pregnancies in women at high risk of LBW because of race, age, late or no prenatal care, and unhealthy behaviors, the prevention of unintended pregnancies would also reduce LBW. Unfortunately, prenatal care, as experienced by many women, devotes little attention to these family planning issues. Many women do not realize the importance of family planning to their own health and that of their children. Prenatal care providers should include instruction about the importance of pregnancy planning and encourage women to continue receiving health care between pregnancies. If the health of women and infants is to be improved, society must be willing to provide health services to women of reproductive age even when they are not pregnant.     

Determinants of stillbirth mortality in Greece

A population-based case-control study of the determinants of stillbirths was conducted in Greece from 1989 to 1991. All reported stillbirths after 28 weeks of pregnancy (N = 2,006) during the three year study period comprised the case group. The control group derived from random sampling of 10% of all livebirths in Greece, during the same period (N = 30,705). The data were analysed by modelling through multiple logistic regression. The adjusted relative risk of stillbirth was significantly higher for males compared to females. A statistically significant monotonic increase in relative risk was observed with shorter gestational age, low maternal education, and older maternal age. Birthweight and parity showed a statistically significant U-shaped association with stillbirth risk, with a higher risk being observed among both low and high birthweight deliveries, as well as among primiparous or multiparous (4+) mothers. Positive associations of stillbirth with multiple births, out-of-wedlock marriage and non-Greek-orthodox maternal religion were noted in crude analyses, but these associations almost disappeared in logistic regression model. Maternal urban or rural residence showed no relation to risk. Overall, the prospective risk of stillbirth after the 24th week of gestation in Greece has been estimated to be higher than that in Japan (a more developed country) with more than 40% of stillbirths occurring after the 36th week of pregnancy.     

Introduction to microscopic research of silver halides and related dispersed systems

> Objective: To establish whether uterine artery flow velocity waveforms in the second trimester are associated with adverse pregnancy outcome in women with a poor obstetric history. Methods: We reviewed the obstetric case notes of 50 women with a poor obstetric history in previous pregnancies in whom uterine artery flow velocity waveforms had been obtained at 18 weeks gestation. Results: In this population 40% had an adverse pregnancy outcome (preeclampsia, pregnancy-induced hypertension, preterm delivery, birthweight <10th percentile or perinatal death). Preeclampsia, perinatal death, and preterm delivery were all significantly associated with abnormal uterine artery waveforms at 18 weeks. Conclusions: Assessment of uterine artery flow velocity waveforms at 18 weeks gestation shows promise as a screening test in the high risk obstetric population. The technique requires formal evaluation in a prospective, double blinded study.     

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.     

The cortical reactions during sensory and motor activities in healthy children and adults and in depression patients

We recruited 111 patients who were considered to be at significantly increased risk of preeclampsia on the basis of previous obstetric history or preexisting medical disorders. All patients were treated with low dose aspirin (75 mg/day) from the first occasion the patient attended the antenatal clinic, regardless of gestational age. If the maternal mean platelet volume (MPV) increased significantly (by > 0.8 fl) from the baseline, antiplatelet treatment was increased. Five pregnancies were lost during the second trimester and 106 of the treated patients had live infants. The incidence of neonatal death (3/106 infants) was much lower than in the previous pregnancies in these patients (32/134 infants). Patients who were treated from the first trimester of pregnancy (group A, 89 patients) did substantially better than those treated from the second trimester (group B, 17 patients) as assessed by the incidence of pre-eclampsia or intrauterine growth restriction (IUGR), gestational age and birthweight at delivery. These data suggest that longitudinal monitoring of the MPV may identify the women who could benefit from increased antiplatelet treatment, and that antiplatelet treatment may be more effective when initiated in the first trimester rather than later in pregnancy.     

Perinatal outcome of pregnancies after assisted reproduction: a case-control study

PURPOSE: A matched case-control study of all pregnancies obtained after either IVF or ICSI was conducted to investigate the perinatal outcome. METHODS: Three hundred eleven singleton and 115 twin pregnancies obtained after assisted reproduction were studied. Controls were selected from a regional register and were matched for maternal age, parity, singleton or twin pregnancy, and date of delivery. RESULTS: No significant difference was observed for gestational age at delivery, birth weight, incidence of congenital anomalies, and incidence of perinatal mortality between ART (singleton and twin) pregnancies and spontaneous controls. ART twin pregnancies showed a higher incidence of preterm deliveries than control pregnancies (52 vs 42%; P < 0.05) and needed more neonatal intensive care (47 vs 26%; P < 0.05). CONCLUSIONS: From this case-control study it is concluded that the perinatal outcome of ART singleton pregnancies is not different from that in matched controls. ART twin pregnancies showed a higher incidence of preterm deliveries than control pregnancies and needed more neonatal intensive care.     

Risk factors for aboriginal low birthweight, intrauterine growth retardation and preterm birth in the Darwin Health Region

Risk factors for Aboriginal low birthweight (< 2500 g), preterm birth (< 37 weeks' gestation) and intrauterine growth retardation (under the tenth percentile of Australian birthweights for gestational age) were examined in 503 live-born singletons recorded as born to an Aboriginal mother and routinely delivered at the Royal Darwin Hospital between January 1987 and March 1990. Infants born to mothers with body mass index less than 18.5 kg/m2 had five times the risk of having low birthweight and 2.5 times the risk of intrauterine growth retardation. Population-attributable risk percentages suggest that 28 per cent of low birthweight and 15 per cent of growth retardation could be attributed to maternal malnutrition. Risk percentages for maternal smoking of more than half a packet of cigarettes a day were 18 per cent for low birthweight and 10 per cent for growth retardation. For growth retardation, 18 per cent could be attributed to a maternal age under 20 years. Risk factors for preterm birth were predominantly obstetric: the population-attributable risk percentage for pregnancy-induced hypertension was 26 per cent and for other obstetric conditions was 16 per cent. For Aboriginal births in the Darwin Health Region, maternal malnutrition and smoking are key elements in the prevention of low birthweight and intrauterine growth retardation. Teenage pregnancy is an important risk for intrauterine growth retardation, and pregnancy-induced hypertension is a risk for preterm birth.     

Significance of idiopathic preterm birth in relation to previous and future pregnancies

This registry-based cohort study aimed to describe the relationship between pregnancy complications in the first and second pregnancy, focussing on idiopathic and indicated preterm birth of singleton infants in either pregnancy. The cohort consisted of all women living in Denmark with a first singleton birth in 1982 and a second in the period 1982-1987 (13,967 women). The risk of a second preterm birth was not significantly different between women who had an idiopathic or an indicated first preterm birth (15.2 and 12.8% respectively). Adjustment by logistic regression analysis for other risk factors for preterm birth did not influence the relative risk (6.0 before 32 weeks and 4.8 between 32 and 36 weeks) of a second preterm birth subsequent to a first one. Women with idiopathic preterm delivery in their first or second pregnancies give birth to infants with lower birth weight in previous or subsequent pregnancies. Emergency cesarean section in a first term pregnancy was a risk factor for subsequent idiopathic preterm birth.     

Metastatic dermatofibrosarcoma protuberans mimicking meningioma

Relationships between body mass index (BMI) and weight gain with perinatal outcome and birthweight were examined. BMI was calculated on 582 consecutive pregnant women who delivered at or >37 weeks gestational age. Statistical analysis was done using Chi-square tests, analysis of variance, and multiple logistic regression. Of those studied, 13% were underweight, 39% normal, 13% overweight, and 35% obese. Obesity was associated with increasing age (P < .01), multiparity (P < .01), previous cesarean delivery (P < .01), previous macrosomia (P = .01), previous fetal death (P = .03), hypertensive disorders (P < .01), gestational diabetes (P = .02), cesarean delivery (P = .03), and neonatal intensive care unit admission (NICU) (P = .01). The underweight group had the most low birthweight (LBW) infants and the lowest mean birthweight. Ideal weight gain occurred in 31%, inadequate weight gain in 34%, and excessive weight gain in 35%. Inadequate weight gain had increased asthma (P < .05), and hyperemesis (P = .03). Women with ideal weight gain had less smokers (P < .01), fetal distress (P < .05), cesarean delivery (P = .02), and preeclampsia (P < .001). The mean birthweight was highest in the excessive weight gain (P < .01). With multivariate analysis, previous LBW, BMI, and tobacco use were significant predictors of LBW. Normal BMI and ideal weight gain in pregnancy is associated with decreased perinatal complications and an optimum birthweight.     

Influence of the cytochrome P4502D6*4 allele on the pharmacokinetics of controlled-release metoprolol

Unexplained elevations of maternal serum alpha-fetoprotein exist in approximately 1% of the obstetric population. A consensus has been reached that these women face an increased risk of adverse pregnancy outcome. Whether their overall risk can be altered by the currently available surveillance modalities, however, remains controversial. Current research has focused on identifying those pregnancies with the highest risks of either fetal growth restriction, pre-eclampsia, preterm delivery or intrauterine fetal demise. Markedly increased maternal serum alpha-fetoprotein (over 4.0 multiples of the median), elevations of other serum markers such as human chorionic gonadotropin and abnormal umbilical Doppler flow are associated with the greatest risk of poor pregnancy outcome. When initiating surveillance of the pregnancy with unexplained elevated maternal serum alpha-fetoprotein consideration of these factors is receiving increased attention.     

Is there an independent association between parity and maternal weight gain?

The independent associations between parity and maternal body mass index (BMI), and between parity and maternal weight gain, were investigated using a combination of cross-sectional and longitudinal analyses based on a retrospective, repeat-pregnancy study that examined the change in maternal body weight from the beginning of one pregnancy to the beginning of the next. A group of 523 multiparous women who had been weighed regularly during pregnancy, and none of whom had fallen pregnant less than 12 months after the birth of their previous child, were examined. Sociodemographic, behavioural, medical, obstetric and perinatal data, together with antenatal measurements of maternal body weight and height, were abstracted from each mother's obstetric notes. Parity was found to be independently associated with maternal BMI (p < 0.001), gestational weight gain (p < 0.001) and interpregnancy weight gain (p = 0.032). Women of different parities were found to be at differential risk of long-term weight gain for two reasons. First, primiparous women are at risk of long-term weight gain because they gain the most weight during pregnancy, and high gestational weight gain is in itself a risk factor for long-term weight gain. Second, women of higher parity (4+) are at risk of long-term weight gain because they gain more weight in association with pregnancy, irrespective of the amount of weight they gain during their pregnancies. For women of parity 3 or less, the association between maternal body weight and parity appears to be the result of cumulative weight gained during successive pregnancies. For women of greater parity, the association between maternal body weight and parity is partly the result of cumulative excess gestational weight gained during successive pregnancies, and partly the result of gaining more weight from the beginning of one pregnancy to the next at later pregnancies.     

Etiology and perinatal medical significance of prematurity below 1,500 g

305 preterm babies with birthweight below 1500 g were delivered at our centre between 1991 and 1994. Classification according to etiology shows that more than half (52.7%) of these deliveries had to be induced secondary to underlying fetal or maternal pathology. A more efficient tocolysis could have prevented up to one third of these deliveries (31.4%). The main cause of each preterm delivery was defined according to Whitfield's etiological classification. In decreasing order of frequency we found hypertensive disorders of pregnancy, multiple pregnancy, preterm premature rupture of membranes, preterm labour and vaginal bleeding in the third trimester. The majority of these deliveries (88.6%) were prenatal referrals, reflecting widespread regionalization of obstetric services in Switzerland. Nevertheless, 64 women (24.2%) with threatening preterm labour before the 32nd week of gestation had to be denied admission to our hospital because of shortage of neonatal intensive care beds, or had to be transferred from our hospital to another offering perinatal facilities during the study period (1991-1994). Acute lack of neonatal intensive care unit beds in Switzerland requires closer attention in the future.     

Recent advances in the large scale fermentation of Neisseria meningitidis group B for the production of an outer membrane protein complex

BACKGROUND: As women with cystic fibrosis are living longer, pregnancy is becoming increasingly common. The combined experience of pregnancies in women with cystic fibrosis from adult centres in the Midlands and North of England has been examined. METHODS: A retrospective study of the case notes of 22 pregnancies in 20 patients with cystic fibrosis examined changes in lung function, body weight, and microbiological status during the course of pregnancy. Duration of pregnancy, birth weight, and maternal survival were amongst other variables studied. The relation between values before pregnancy and important outcome measures were examined. RESULTS: Eighteen of 22 pregnancies were completed producing healthy, non-cystic fibrosis infants (12 female). Mothers lost 13% of FEV1 and 11% of FVC during pregnancy, most of which was regained. Body weight changes were variable, but most mothers gained weight (mean weight gain 5.7 kg). Microbiological status remained unchanged. Six infants were preterm and two were light for dates. Four mothers died up to 3.2 years following delivery. Of the prepregnancy parameters examined, %FEV1 showed the best correlation with maternal weight gain, gestation, birth weight, and maternal survival. CONCLUSIONS: Pregnancy was well tolerated by most mothers with cystic fibrosis although those with moderate to severe lung disease (%FEV1 < 60%) before pregnancy fared worse, producing preterm infants and suffering increased loss of lung function and mortality compared with mildly affected mothers. Prepregnancy %FEV1 appears to be the most useful predictor of important outcome measures in pregnancies in women with cystic fibrosis.     

Maternal risk factors in infants with very low birth weight

To determine whether maternal risk factors associated with the delivery of very low birth weight infants under 1501 g are different from those associated with low birth weight infants of 1501 to 2500 g, prenatal data on 12,247 deliveries were evaluated. The sample contained 302 very low birth weight infants. Maternal race, age, height, weight, gravidity, parity, past pregnancy performance, and pregnancy complications were analyzed. Factors related to very low birth weight but not to low birth weight infants were previous abortions, previous fetal deaths, and hypertensive vascular disease. Race, maternal height, and prepregnancy weight were not related to very low birth weight but were associated with an increase in low birth weight. There was no significant difference in the rate of very low birth weight or low birth weight by maternal age from 14 to 40 years. These results contradict the concept of a uniform set of predisposing factors for birth of all infants weighing 2500 g or less.     

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.     

Obstetric outcome of teenage pregnancies

A retrospective cohort study was performed in a tertiary centre to determine if teenage nulliparas (aged alpha19 years, study group) had higher incidences of instrumental and Caesarean deliveries compared with nulliparas aged 20-34 years (control group) selected from the first women in the birth registry who delivered after each study case and satisfying the criteria for controls. The hospital records of the study and control cases were retrieved for review. Comparison was made in the maternal demographics, major antenatal complications, outcome of labour, mode of delivery, and perinatal outcome. In the study group, maternal height was similar but the body mass index was lower. Although the mean birthweight was lower and the incidences of preterm labour and small-for-gestational-age infants higher, there were also increased incidences of large-for-gestational-age and macrosomic infants. While there was no difference in the types of labour, there were fewer Caesarean and instrumental deliveries, a finding that persisted even after excluding the preterm deliveries. Lastly, teenage mothers aged <17 years had similar outcomes to those aged 17-19 years. These results indicated that teenage mothers had better obstetric outcomes, despite the higher incidence of preterm labour, and that young adolescents (<17 years) performed as well as their older peers.     

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.     

Maternal shunt dependency: implications for obstetric care, neurosurgical management, and pregnancy outcomes and a review of selected literature

OBJECTIVE: Because more women with cerebrospinal fluid shunts are surviving to child-bearing age, neurosurgeons, obstetricians, and other health care professionals require information about the care of these patients, especially during pregnancy and delivery. The purpose of this study was to gather comprehensive data from women with shunts regarding their clinical histories during and immediately after pregnancy. The following questions were addressed. 1) How does maternal shunt dependency influence the course of pregnancies and pregnancy outcomes? 2) What neurosurgical complications characterize this population of patients? 3) What complications of shunt dependency influence obstetric management, including prenatal testing and delivery? METHODS: A total of 37 respondents (age, 18-41 yr), accounting for 77 pregnancies, completed a questionnaire providing information on maternal background and medical history, shunt performance during pregnancy, management of delivery, pregnancy outcomes, and unusual complications. RESULTS: Fifty-six pregnancies resulted in live births; of these, 47 occurred in women with ventriculoperitoneal shunts. Three women underwent therapeutic abortions, 1 experienced preterm delivery, and 8 experienced 17 miscarriages. Four women experienced seizures during pregnancy, five reported third-trimester headaches, and eight described abdominal pains during the first and third trimesters. Four babies were diagnosed as having congenital defects. Shunt malfunctions and revisions occurred 10 times in 7 women, either during pregnancy or within 6 months after delivery. No acute malfunctions occurred during delivery. Forty-seven cases, representing 84% of all pregnancies, exhibited no shunt malfunctions or revisions. CONCLUSION: This study extends previous observations to a larger population of shunt-dependent mothers. The results suggest that maternal shunt dependency entails a relatively high incidence of complications but that proper care of these patients can lead to normal pregnancies and deliveries.     

Epidemiologic aspects of pre-eclampsia in Saudi Arabia

Pre-eclampsia is pregnancy induced hypertension of unknown aetiology. There is a paucity of maternal data on the disease from this region and this study was undertaken to identify maternal and possible aetiologic factors associated with the disease in the north western region of Saudi Arabia. Seven hundred and five consecutive maternities which delivered from October 1990 till January 1991 at the Armed Forces Hospital were analysed. 2.8% of women in this community study developed pre-eclampsia. Women at extremes of maternal age, the nulliparous and high parity women; women with high body mass index, blood group O and those with no antenatal care or late booking in this study were at greater risk of developing pre-eclampsia when compared with controls who delivered in the same period. Of the babies born to mothers with pre-eclampsia, 46.7% were of low birthweight (< 2500g) while only 10.4% of controls were low birthweight. It is concluded that mothers with pre-eclampsia have to be identified early. Potential modifiable factors include reducing pregnancies at extremes of maternal age, among high parity women and encouraging early booking as well as regular attendance at the antenatal clinic.