Psychiatric and substance use disorders as risk factors for low birth weight and preterm delivery

OBJECTIVE: We examined the associations between psychiatric and substance use diagnoses and low birth weight (LBW), very low birth weight (VLBW), and preterm delivery among all women delivering in California hospitals during 1995. METHODS: This population-based retrospective cohort analysis used linked hospital discharge and birth certificate data for 521,490 deliveries. Logistic regression analyses were conducted to assess the associations between maternal psychiatric and substance use hospital discharge diagnoses and LBW, VLBW, and preterm delivery while controlling for maternal demographic and medical characteristics. RESULTS: Women with psychiatric diagnoses had a significantly higher risk of LBW (adjusted odds ratio [OR] 2.0; 95% confidence interval [CI] 1.7, 2.3), VLBW (OR 2.9; 95% CI 2.1, 3.9), and preterm delivery (OR 1.6; 95% CI 1.4, 1.9) compared with women without those diagnoses. Substance use diagnoses were also associated with higher risk of LBW (OR 3.7; 95% CI 3.4, 4.0), VLBW (OR 2.8; 95% CI 2.3, 3.3), and preterm delivery (OR 2.4; 95% CI 2.3, 2.6). CONCLUSION: Maternal psychiatric and substance use diagnoses were independently associated with low birth weight and preterm delivery in the population of women delivering in California in 1995. Identifying pregnant women with current psychiatric disorders and increased monitoring for preterm and low birth weight delivery among this population may be indicated.     

Maternal hypertensive disorders are an independent risk factor for the development of necrotizing enterocolitis in very low birth weight infants

OBJECTIVE: The purpose of this study was to compare complications and outcome of preterm neonates weighing < or =1,500 g who developed necrotizing enterocolitis (NEC) to neonates without NEC. STUDY DESIGN: During January, 1995 to December, 1998, 211 live preterm neonates were born with birth weight < or =1,500 g. A cross sectional prospective study was designed and two groups were defined: 17 neonates who developed NEC and 194 without NEC. Multiple logistic regression analysis was performed to determine independent risk factors for the development of NEC. RESULTS: The prevalence of NEC was 8% (17/211). The following complications were found to be significantly higher among mothers of neonates with NEC: mild pre-eclampsia (11.8 vs. 2.6%, p=0.04); severe pre-eclampsia (35.5 vs. 12.9%, p=0.01); chronic hypertension (29.4 vs. 5.7%, p<0.001) and low birth weight (968 +/- 233 vs. 1,123 +/- 257 g, p=0.02). In contrast, mean maternal age, mean gestational age at delivery and parity were not significantly different between the groups. A multivariate analysis including the following factors: maternal hypertensive disorders, pregestational diabetes mellitus, birth weight and gestational age at delivery, found only maternal hypertensive disorders to be independent risk factors for NEC (OR=5.21, 95% CI 1.64-16.58). CONCLUSIONS: Maternal hypertension is an independent risk factor for the development of NEC in preterm neonates weighing <1,500 g. Thus, maternal vascular disorders may play an important role in the pathophysiology of NEC.     

Pregnancy intention and its relationship to birth and maternal outcomes

OBJECTIVE: To examine whether there are associations between pregnancy intention (intended, unwanted, mistimed, or ambivalent) and negative birth and maternal outcomes: low birth weight (less than 2,500 g), preterm delivery (fewer than 37 weeks), small for gestational age, premature labor, hypertension, and other maternal outcomes. METHODS: We analyzed data from the population-based Pregnancy Risk Assessment Monitoring System, including 87,087 women who gave birth between 1996 and 1999 in 18 states. Information on pregnancy outcomes was derived from birth certificate data and a self-administered questionnaire completed postpartum. We employed SUDAAN (RTI International, Research Triangle Park, NC) for univariable and logistical regression analyses. RESULTS: In analyses controlling for demographic and behavioral factors, women with unwanted pregnancies had an increased likelihood of preterm delivery (adjusted odds ratio [OR] 1.16, 95% confidence interval [CI] 1.01-1.33) and premature rupture of membranes (adjusted OR 1.37, 95% CI 1.01-1.85) compared with women with intended pregnancies. Women who were ambivalent toward their pregnancies had increased odds of delivering a low birth weight infant (adjusted OR 1.15, 95% CI 1.02-1.29); in contrast, women with mistimed pregnancies had a lower likelihood (adjusted OR 0.92, 95% CI 0.86-0.97). CONCLUSION: Pregnancy intention, specifically unwanted and ambivalent, may be an indicator of increased risk for some poor birth and maternal outcomes and should be considered in interventions aimed at improving the health of the mother and child. LEVEL OF EVIDENCE: III.     

Large babies and unplanned Caesarean delivery

OBJECTIVE: The relationship between birth weight > or =4000 g and unplanned Caesarean delivery was examined. DESIGN: A retrospective cohort study. SETTING: A district general hospital. Population: Two thousand three hundred and ninety-three women who delivered babies weighing > or =2500 g. METHODS: The mode of delivery of babies who weighed > or =4000 g was compared with those who weighed between 2500 and 4000 g. Comparative analysis of data was followed by regression analysis of explanatory variables. The effect of increasing birth weight on unplanned Caesarean delivery was determined. RESULTS: Women who had an unplanned Caesarean were delivered at an earlier gestation (OR = 0.89, 95% CI 0.81-0.97; P = 0.007), and were more likely to be primiparous (OR 5.4, 95% CI 4.1-7.1; P = 0.0001). Further, women who had an unplanned Caesarean were more likely to have babies weighing > or =4000 g (OR = 2.24, 95% CI 1.61-3.12; P = 0.003). The odds of having an unplanned Caesarean were increased 16.9-fold with a previous Caesarean (95% CI 9.24-30.8; P = 0.001). When a previous Caesarean was combined with a baby weighing > or =4000 g, the odds of having an unplanned Caesarean increased 37.8 times (95% CI 18.8-75.8), compared to a woman who previously had a normal vaginal birth and a baby weighing between 2500 and 4000 g. CONCLUSION: Birth weight > or =4000 g is associated with more than a two-fold increased risk of an unplanned Caesarean delivery. The risk increased further (37.8 x) when a previous Caesarean delivery was combined with a birth weight > or =4000 g.     

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.     

Progestational agents to prevent preterm birth: a meta-analysis of randomized controlled trials

OBJECTIVE: To perform an updated systematic review with meta-analysis to further elucidate the efficacy of progestational agents for the prevention of preterm births in patients at elevated risk. DATA SOURCES: Computerized databases, references in published studies, and textbook chapters in all languages were used to identify randomized controlled trials (RCTs) evaluating the use of progestational agents for the prevention of preterm births in women at elevated risk. METHODS OF STUDY SELECTION: We identified RCTs that compared progestational agents with placebo for patients at risk for preterm birth and evaluated at least one of the following: delivery before 37 weeks of gestation, birth weight less than 2,500 g, threatened preterm labor, respiratory distress syndrome, and perinatal mortality. The primary outcomes assessed were preterm delivery and perinatal mortality. TABULATION, INTEGRATION, AND RESULTS: Ten studies met inclusion criteria for this review. For each study with binary outcomes, an odds ratio (OR) with 95% confidence intervals (CIs) was calculated for selected outcomes. Homogeneity was tested across the studies. Compared with women allocated to receive placebo, those who received progestational agents had lower rates of preterm delivery (26.2% versus 35.9%; OR 0.45, 95% CI 0.25-0.80). Similar results were noted when comparing patients who were specifically treated with 17alpha-hydroxyprogesterone caproate (29.3% versus 40.9%; OR 0.45, 95% CI 0.22-0.93). Additionally, subjects allocated to receive 17alpha-hydroxyprogesterone caproate had lower rates of birth weights less than 2,500 g (OR 0.50, 95% CI 0.36-0.71). No differences in rates of hospital admissions for threatened preterm labor or perinatal mortality were noted for subjects receiving progestational agents in general or for those receiving only 17alpha-hydroxyprogesterone caproate specifically. CONCLUSION: The use of progestational agents and 17alpha-hydroxyprogesterone caproate reduced the incidence of preterm birth and low birth weight newborns.     

Risk of preterm delivery in relation to vaginal bleeding in early pregnancy

OBJECTIVE: To examine the relationship between vaginal bleeding during early pregnancy and preterm delivery. METHODS: Study subjects (N=2678) provided information regarding socio-demographic, biomedical, and lifestyle characteristics. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS: Any vaginal bleeding in early pregnancy was associated with a 1.57-fold increased risk of preterm delivery (95% CI: 1.16-2.11). Vaginal bleeding was most strongly related with spontaneous preterm labor (OR=2.10) and weakly associated with preterm premature rupture of membrane (OR=1.36) and medically induced preterm delivery (OR=1.32). As compared to women with no bleeding, those who bled during the first and second trimesters had a 6.24-fold increased risk of spontaneous preterm labor; and 2-3-fold increased risk of medically induced preterm delivery and preterm premature rupture of membrane, respectively. CONCLUSION: Vaginal bleeding, particularly bleeding that persists across the first two trimesters, is associated with an increased risk of preterm delivery.     

Maternal serum ferritin concentration in patients with preterm labor and intact membranes.

OBJECTIVE: To determine the relationship between maternal serum ferritin concentrations in the second trimester and the risk of preterm delivery (PTD). METHODS: A prospective observational study was conducted. Fifty consecutive women with singleton pregnancies, who were admitted to the Maternal Fetal Medicine Unit due to preterm labor in the second trimester, were included. Maternal serum samples for determination of ferritin concentrations were obtained. Multiple logistic regression analysis was performed to control for confounders. RESULTS: Out of fifty patients enrolled in the study, 38% (19/50) delivered prematurely. Eight women (16%) had maternal serum ferritin concentrations above 30 ng/ml in the second trimester. Among them, 75% (n = 6) subsequently presented with preterm delivery (odds ratio (OR) = 6.7 with 95% confidence interval (CI) 1.1-56.2, p = 0.04). Only two patients with increased maternal ferritin concentrations delivered at term. However, 13 patients with second trimester ferritin concentrations below 30 ng/ml had preterm delivery. No significant differences in mean maternal ferritin concentrations were found between patients who delivered preterm and those that delivered at term, 31.9 +/- 50.6 vs. 13.6 +/- 15.2, respectively (p = 0.064). Using a multivariable analysis, controlling for anemia, leucocytosis and maternal age, increased serum ferritin concentrations were found to be an independent risk factor for PTD (OR = 8.6; 95% CI 1.4-52.5; p < 0.019). No significant correlation was found between serum ferritin concentrations and gestational age at birth (Pearson correlation coefficient r = -0.093; p = 0.522). CONCLUSIONS: Maternal ferritin concentrations above 30 ng/ml in the second trimester can serve as a marker for preterm delivery. However, since no correlation was found between serum ferritin concentrations and gestational age at birth, the routine use of serum ferritin as a marker for preterm delivery warrants further investigation.     

Chronic hypertension is an independent risk factor for preeclampsia and preterm delivery in women with rheumatologic diseases: a population-based study

OBJECTIVE: The objective was to determine the prevalence of maternal and perinatal complications among patients with rheumatologic diseases (RD) and to investigate the maternal risk factors for preeclampsia and preterm delivery among RD patients. STUDY DESIGN: A retrospective population-based cohort study was conducted. The study group comprised women with RD; the control group comprised patients without RD. The obstetric and neonatal outcomes of the groups were compared, and the data were obtained from a computerized database. RESULTS: During the study period, there were 179 deliveries by 125 women with RD. The prevalence of severe preeclampsia, chronic hypertension, pregestational diabetes, oligohydramnios, preterm deliveries and cesarean sections was significantly higher in the RD group than in the control group. Mean birth weight was significantly lower in the study group compared with the general population. Maternal RD was found to be an independent risk factor for preterm delivery and severe preeclampsia (OR 3.59; 95% CI: 2.52-5.11; OR 3.05; 95% CI: 1.44-6.45, respectively). The presence of chronic hypertension in patients with RD was found to be an independent risk factor for severe preeclampsia and preterm delivery (OR 12.2; 95% CI: 2.1-69.8; OR 3.8; 95% CI: 1.1-12.7, respectively). CONCLUSION: Chronic hypertension is an independent risk factor for preterm delivery and severe preeclampsia among RD patients.     

Advanced maternal age and adverse perinatal outcomes in an Asian population

Objective

To investigate (1) whether there is an increasing trend in the mean maternal age at the birth of the first child and in the group of women giving birth at age 35 or older, and (2) the association between advanced maternal age and adverse perinatal outcomes in an Asian population.

Study design

We conducted a retrospective cohort study involving 39,763 Taiwanese women who delivered after 24 weeks of gestation between July 1990 and December 2003. Multivariable logistic regression was used to adjust for potential confounding variables.

Results

During the study period, the mean maternal age at the birth of the first child increased from 28.0 to 29.7 years, and the proportion of women giving birth at age 35 or older increased from 11.4% to 19.1%. Compared to women aged 20–34 years, women giving birth at age 35 or older carried a nearly 1.5-fold increased risk for pregnancy complications and a 1.6–2.6-fold increased risk for adverse perinatal outcomes. After adjusting for the confounding effects of maternal characteristics and coexisting pregnancy complications, women aged 35–39 years were at increased risk for operative vaginal delivery (adjusted odds ratio [OR] 1.5, 95% confidence interval [CI] 1.2–1.7) and cesarean delivery (adjusted OR 1.6, 95% CI 1.5–1.7), while women aged 40 years and older were at increased risk for preterm delivery (before 37 weeks of gestation) (adjusted OR 1.7, 95% CI 1.3–2.2), operative vaginal delivery (adjusted OR 3.1, 95% CI 2.0–4.6), and cesarean delivery (adjusted OR 2.6, 95% CI 2.2–3.1). In those women who had a completely uncomplicated pregnancy and a normal vaginal delivery, advanced maternal age was still significantly associated with early preterm delivery (before 34 weeks of gestation), a birth weight <1500 g, low Apgar scores, fetal demise, and neonatal death.

Conclusion

In this population of Taiwanese women, there is an increasing trend in the mean maternal age at the birth of the first child. Furthermore, advanced maternal age is independently associated with specific adverse perinatal outcomes.     

Placental weight and efficiency in relation to maternal body mass index and the risk of pregnancy complications in women delivering singleton babies

Herein we report placental weight and efficiency in relation to maternal BMI and the risk of pregnancy complications in 55,105 pregnancies. Adjusted placental weight increased with increasing BMI through underweight, normal, overweight, obese and morbidly obese categories and accordingly underweight women were more likely to experience placental growth restriction [OR 1.69 (95% CI 1.46-1.95)], while placental hypertrophy was more common in overweight, obese and morbidly obese groups [OR 1.59 (95% CI 1.50-1.69), OR 1.97 (95% CI 1.81-2.15) and OR 2.34 (95% CI 2.08-2.63), respectively]. In contrast the ratio of fetal to placental weight (a proxy for placental efficiency) was lower (P < 0.001) in overweight, obese and morbidly obese than in both normal and underweight women which were equivalent. Relative to the middle tertile reference group (mean 622 g), placental weight in the lower tertile (mean 484 g) was associated with a higher risk of pre-eclampsia, induced labour, spontaneous preterm delivery, stillbirth and low birth weight (P < 0.001). Conversely placental weight in the upper tertile (mean 788 g) was associated with a higher risk of caesarean section, post-term delivery and high birth weight (P < 0.001). With respect to assumed placental efficiency a ratio in the lower tertile was associated with an increased risk of pre-eclampsia, induced labour, caesarean section and spontaneous preterm delivery (P < 0.001) and a ratio in both the lower and higher tertiles was associated with an increased risk of low birth weight (P < 0.001). Placental efficiency was not related to the risk of stillbirth or high birth weight. No interactions between maternal BMI and placental weight tertile were detected suggesting that both abnormal BMI and placental growth are independent risk factors for a range of pregnancy complications.     

Outcomes of trial of labor following previous cesarean delivery among women with fetuses weighing >4000 g

OBJECTIVE: To compare outcomes at term of a trial of labor in women with previous cesarean delivery who delivered neonates weighing > 4000 g versus women with those weighing < or = 4000 g. STUDY DESIGN: We reviewed medical records for all women undergoing a trial of labor after prior cesarean delivery during a 12-year period. The current analysis was limited to women at term with one prior cesarean and no other deliveries. The rates of cesarean delivery and symptomatic uterine rupture for women with infants weighing > 4000 g were compared to the rates for women with infants weighing < or = 4000 g. Logistic regression was used to control for the potential confounding by use of epidural, maternal age, labor induction, labor augmentation, indication for previous cesarean, type of uterine hysterotomy, year of delivery, receiving public assistance, and maternal race. Adjusted odds ratios and 95% confidence intervals were calculated. RESULTS: Of 2749 women, 13% (365) had infants with birth weights > 4000 g. Cesarean delivery rate associated with birth weights < or = 4000 g was 29% versus 40% for those with birth weights > 4000 g (P = .001). With use of logistic regression, we found that birth weight > 4000 g was associated with a 1.7-fold increase in risk of cesarean delivery (95% CI, 1.3-2.2). The rate of uterine rupture for women with infants weighing < or = 4000 g was 1.0% versus a 1.6% rate for those with infants weighing > 4000 g (P = .24). Although the logistic regression analysis revealed a somewhat higher rate of uterine rupture associated with birth weights of > 4000 g (adjusted OR, 1.6; 95% CI, 0.7-4.1), this difference was not statistically significant. The rate of uterine rupture was 2.4% for women with infants weighing > 4250 g, but this rate did not differ significantly from the rate of uterine rupture associated with birth weights < or = 4250 g (P = .1). CONCLUSION: A trial of labor after previous cesarean delivery may be a reasonable clinical option for pregnant women with suspected birth weights of > 4000 g, given that the rate of uterine rupture associated with these weights does not appear to be substantially increased when compared to lower birth weights. However, some caution may apply when considering a trial of labor in women with infants weighing > 4250 g. In these women with infants weighing > 4000 g, the likelihood of successful vaginal delivery, although lower than for neonates weighing < or = 4000 g, is still 60%.     

Is grandmultiparity an independent risk factor for adverse perinatal outcomes?

OBJECTIVE: To compare maternal and neonatal outcomes among grandmultiparous women to those of multiparous women 30 years or older. METHODS: A database of the vast majority of maternal and newborn hospital discharge records linked to birth/death certificates was queried to obtain information on all multiparous women with a singleton delivery in the state of California from January 1, 1997 through December 31, 1998. Maternal and neonatal pregnancy outcomes of grandmultiparous women were compared to multiparous women who were 30 years or older at the time of their last birth. RESULTS: The study population included 25,512 grandmultiparous and 265,060 multiparous women 30 years or older as controls. Grandmultiparous women were predominantly Hispanic (56%). After controlling for potential confounding factors, grandmultiparous women were at significantly higher risk for abruptio placentae (odds ratio OR: 1.3; 95% confidence intervals CI: 1.2-1.5), preterm delivery (OR: 1.3; 95% CI: 1.2-1.4), fetal macrosomia (OR: 1.5; 95% CI: 1.4-1.6), neonatal death (OR: 1.5; 95% CI: 1.3-1.8), postpartum hemorrhage (OR: 1.2; 95% CI: 1.1-1.3) and blood transfusion (OR: 1.5; 95% CI: 1.3-1.8). CONCLUSION: Grandmultiparous women had increased maternal and neonatal morbidity, and neonatal mortality even after controlling for confounders, suggesting a need for closer observation than regular multiparous patients during labor and delivery.     

Maternal anemia during pregnancy is an independent risk factor for low birthweight and preterm delivery

OBJECTIVE: The present study was designed to investigate the outcome of pregnancy and delivery in patients with anemia. METHODS: A retrospective population-based study comparing all singleton pregnancies of patients with and without anemia was performed. Deliveries occurred during the years 1988-2002 in the Soroka University Medical Center. Maternal anemia was defined as hemoglobin concentration lower than 10 g/dl during pregnancy. Patients with hemoglobinopathies such as thalassemia were excluded from the analysis. Multiple logistic regression models were performed to control for confounders. RESULTS: During the study period there were 153,396 deliveries, of which 13,204 (8.6%) occurred in patients with anemia. In a multivariable analysis, the following conditions were significantly associated with maternal anemia: placental abruption, placenta previa, labor induction, previous cesarean section (CS), non-vertex presentation and Bedouin ethnicity. Higher rates of preterm deliveries (<37 weeks gestation) and low birthweight (<2500 g) were found among patients with anemia as compared to the non-anemic women (10.7% versus 9.0%, p < 0.001 and 10.5% versus 9.4%, p < 0.001; respectively). Higher rates of CS were found among anemic women (20.4% versus 10.3%; p < 0.001). The significant association between anemia and low birthweight persisted after adjusting for gender, ethnicity and gestational age, using a multivariable analysis (OR = 1.1; 95% CI 1.0-1.2, p = 0.02). Two multivariable logistic regression models, with preterm delivery (<37 weeks gestation) and low birthweight (<2500 g) as the outcome variables, were constructed in order to control for possible confounders such as ethnicity, maternal age, placental problems, mode of delivery and non-vertex presentation. Maternal anemia was an independent risk factor for both, preterm delivery (OR = 1.2; 95% CI 1.1-1.2, p < 0.001) and low birthweight (OR = 1.1; 95% CI 1.1-1.2, p = 0.001). CONCLUSION: Maternal anemia influences birthweight and preterm delivery, but in our population, is not associated with adverse perinatal outcome.     

Relationship among placenta previa, fetal growth restriction, and preterm delivery: a population-based study

OBJECTIVE: To examine the independent contributions of prematurity and fetal growth restriction to low birth weight among women with placenta previa. METHODS: A population-based, retrospective cohort study of singleton live births in New Jersey (1989-93) was performed. Mother-infant pairs (n = 544,734) were identified from linked birth certificate and maternal and infant hospital discharge summary data. Women diagnosed with previa were included only if they were delivered by cesarean. Fetal growth, defined as gestational age-specific observed-to-expected mean birth weight, and preterm delivery (before 37 completed weeks) were examined in relation to previa. Severe and moderate categories of fetal smallness and large for gestational age were defined as observed-to-expected birth weight ratios below 0.75, 0.75-0.85, and over 1.15, respectively, all of which were compared with appropriately grown infants (observed-to-expected birth weight ratio 0.86-1.15). RESULTS: Placenta previa was recorded in 5.0 per 1000 pregnancies (n = 2744). After controlling for maternal age, education, parity, smoking, alcohol and illicit drug use, adequacy of prenatal care, maternal race, as well as obstetric complications, previa was associated with severe (odds ratio [OR] 1.37, 95% confidence interval [CI] 1.25, 1.50) and moderate fetal smallness (OR 1.24, 95% CI 1.17, 1.32) births. Preterm delivery was also more common among women with previa. Adjusted OR of delivery between 20-23 weeks was 1.81 (95% CI 1.24, 2.63), and 2.90 (95% CI 2.46, 3.42) for delivery between 24-27 weeks. OR for delivery by each week between 28 and 36 weeks ranged between 2.7 and 4.0. Approximately 12% of preterm delivery and 3.7% of growth restriction were attributable to placenta previa. CONCLUSION: The association between low birth weight and placenta previa is chiefly due to preterm delivery and to a lesser extent with fetal growth restriction. The risk of fetal smallness is increased slightly among women with previa, but this association may be of little clinical significance.     

Maternal low birth weight and gestational hyperglycemia.

We aimed to investigate whether birth weight could predict the subsequent risk of gestational diabetes and impaired glucose tolerance. Consecutive women with a singleton pregnancy and gestational diabetes (n = 50), impaired glucose tolerance (n = 50) and normoglycemia (n = 200) were included in the study. Birth data were collected from original hospital records of the women. Women with gestational hyperglycemia were significantly older and heavier than those with normoglycemia. Maternal birth weights significantly declined for each class of glucose tolerance (3389 +/- 644; 3184 +/- 583 and 3077 +/- 661, respectively for women with normoglycemia, impaired glucose tolerance and gestational diabetes). After adjustment for age, gestational age and weight gain, maternal diabetes, and pre-pregnancy body mass index, maternal birth weight was negatively related to impaired glucose tolerance (OR 0.88, 95% CI 0.81-0.97) and to gestational diabetes (OR 0.82, 95% CI 0.74-0.91) in a multiple logistic regression model. These findings suggest that women with low birth weight constitute a group at increased risk for both gestational impaired glucose tolerance and diabetes.     

Low first-trimester hemoglobin and low birth weight, preterm birth and small for gestational age newborns.

OBJECTIVE: To examine the relationship between first-trimester hemoglobin (Hb) concentration and risk of low birth weight (LBW), preterm birth and small for gestational age (SGA). METHODS: Data were obtained from a population-based prenatal care program in China. A total of 88,149 women who delivered during 1995-2000 and had their Hb measured in the first trimester were selected as study subjects. RESULTS: The prevalence of anemia (Hb<110 g/L) was 22.1% in the first trimester. The risk of LBW, preterm birth and SGA was increased steadily with the decrease of first-trimester Hb concentration. After controlling for confounding factors, women with Hb 80-99 g/L had significantly higher risk for LBW (OR=1.44, 95% CI 1.17-1.78), preterm birth (OR=1.34, 95% CI 1.16-1.55) and SGA (OR=1.13, 95% CI 0.98-1.31) than women with Hb 100-119 g/L. No elevated risk was noted for women with Hb> or =120 g/L. CONCLUSION: Low first-trimester Hb concentration increases the risk of LBW, preterm birth and SGA.     

Prepregnancy body mass index and adverse pregnancy outcomes

OBJECTIVE: The aim of this study was to evaluate the association between prepregnancy BMI, and adverse maternal and neonatal outcomes. METHOD: In this retrospective cohort study 916 consecutive singleton gestations were included who gave birth between 1 January 2006 and 31 August 2006 at the Department of Obstetrics and Gynecology, University of Udine, Italy. Statistical analysis was performed using univaried logistic regression and measured by odds ratio. RESULTS: The obese patients had a statistically, significantly increased incidence of Caesarean section (OR = 2.17, p = 0.009). Women with overweight (OR = 2.43, p = 0.002) and obese weight (OR = 4.86, p < 0.0001) were at increased risk for preterm deliveries. The pre-eclampsia and the fetal macrosomia (> or =4,000 g) were increased in obese women (OR = 5.68, p < 0.0001; OR = 2.58, p = 0.033, respectively). CONCLUSION: Maternal prepregnancy obesity is significantly associated with increased risk of Caesarean section, preterm delivery, pre-eclampsia and macrosomia.     

Low maternal weight, failure to thrive in pregnancy, and adverse pregnancy outcomes

OBJECTIVE: The purpose of this study was to correlate low maternal pregravid weight, delivery weight, and poor gestational weight gain with perinatal outcomes. STUDY DESIGN: Maternal and perinatal data from January 1997 to June 2001 were obtained from a perinatal database at MetroHealth Medical Center. Low maternal weight (LMW) was defined as pregravid or delivery weight <100 pounds or body mass index (BMI) < or =19.8 kg/m(2). Low maternal weight gain was defined as <0.27 kg per week. Perinatal complication rates in these subjects were compared with those with weights of 100 to 200 pounds, normal BMI (>19.8, <26 kg/m(2)), and normal gestational weight gain (0.27-0.52 kg/wk). Chi-square and t tests were used where appropriate. P<.05 was significant. RESULTS: A percentage (2.6%) of 15,196 subjects began pregnancy weighing < or =100 pounds; 0.15% weighed <100 pounds at delivery and 13.2% had a pregravid BMI < or =19.8 kg/m(2). Pregravid LMW was highly correlated with ethnicity (Asians, 8.6%; Hispanics, 4.3%; Caucasians, 2.5%; African Americans, 1.9%; P<.001). Subjects with pregravid LMW were at increased risk for intrauterine growth restriction (IUGR) (relative risk [RR], 2.3, 95% CI, 1.3-4.05), and perineal tears (3rd-degree lacerations; RR, 1.8, 95% CI, 1.1-2.9), and low birth weight ([LBW] <2500 g; RR, 1.8, 95% CI, 1.1-2.9). They had a lower risk of cesarean section (RR, 0.72, 95% CI, 0.56-0.92) and preterm delivery (PTD) (RR, 1.1, 95% CI, 0.97-1.06). Pregravid BMI <19.8 kg/m(2) was associated with preterm labor (PTL) (RR, 1.22, 95% CI, 1.02-1.46), IUGR (RR, 1.67, 95% CI, 1.2-2.39), and LBW (<2500 g; RR, 1.13, 95% CI, 1.0-1.27) and was protective against cesarean delivery (RR, 0.8, 95% CI, 0.71-0.91). Delivery LMW was associated with LBW (<2500 g; RR, 2.81, 95% CI, 1.62-4.84), active-phase arrest (RR, 5.07, 95% CI, 1.85-13.9), PTL and PTD (RR, 2.5, 95% CI, 1.02-6.33, and RR, 2.45, 95% CI, 1.4-4.4, respectively), a lower gestational age at delivery (36.8 vs 38.3 wks, P<.05), and mediolateral episiotomy (RR, 9.6, 95% CI, 1.9-48.0). A percentage (0.8%) of subjects had BMI <19.8 kg/m(2) at delivery. Low delivery BMI was associated with birth weight <2500 g (RR, 1.74, 95% CI, 1.3-2.32), PTL (RR, 2.16, 95% CI, 1.45-3.19), and PTD (RR, 1.57, 95% CI, 1.18-2.11). Failure to thrive in pregnancy (weight gain <0.27 kg/wk) was associated with LBW (<1500 g; RR, 1.23, 95% CI, 1.03-1.45), <2500 g; RR, 1.22, 95% CI, 1.13-1.33), and PTL and PTD (RR, 1.2, 95% CI, 1.05-1.37, and RR, 1.11, 95% CI, 1.02-1.2, respectively). CONCLUSION: Low weight and BMI at conception or delivery, as well as poor weight gain during pregnancy, are associated with LBW, prematurity, and maternal delivery complications.     

Pregnancy outcome in primiparae of advanced maternal age

OBJECTIVE: To investigate the impact of maternal age on singleton pregnancy outcome, taking into account intermediate and confounding factors. STUDY DESIGN: In this population-based retrospective cohort study, perinatal data of primiparous women aged 35 years or more (n = 2970), giving birth to a singleton child of at least 500 g, were compared to data of primiparous women aged 25-29 years old (n = 23,921). Univariate analysis was used to assess the effect of maternal age on pregnancy outcomes. The effects of intermediate (hypertension, diabetes and assisted conception) and confounding factors (level of education) were assessed through multivariable logistic regression analysis. RESULTS: Older maternal age correlated, independently of confounding and intermediate factors, with very preterm birth (gestational age <32 weeks) [adjusted odds ratio (AOR) 1.51, 95% confidence intervals (CI) 1.04-2.19], low birth weight (birth weight <2500 g) (AOR 1.69, 95% CI 1.47-1.94) and perinatal death (AOR 1.68, 95% CI 1.06-2.65). CONCLUSION: Maternal age is an important and independent risk factor for adverse pregnancy outcome.