Unexplained antepartum fetal deaths: what are the determinants?

Objective The objective was to assess fetal, antenatal, and pregnancy determinants of unexplained antepartum fetal death.Methods This is a hospital-based cohort study of 34,394 births weighing 500 g or more from January 1995 to December 2002. Unexplained fetal deaths were defined as fetal deaths occurring before labor, without evidence of significant fetal, maternal or placental pathology.Results Ninety-eight unexplained antepartum fetal deaths accounted for 27.2% of 360 total fetal deaths. Two-thirds of these deaths occurred after 36 weeks gestation. The following factors are independently associated with unexplained fetal deaths: primiparity (OR 1.74; 95% CI 1.21, 2.86); parity of five or more (OR 1.19; 95% CI 1.26, 3.26); low socioeconomic status (OR 1.22; 95% CI 1.14, 2.86); maternal age 40 years or more (OR 3.62; 95% CI 1.22, 4.52); maternal age of 18 years or less (OR 1.79; 95% CI 0.82, 2.89); maternal prepregnancy weight greater than 70 kg (OR 2.20; 95% CI 1.85, 3.68); fewer than three antenatal visits in women whose fetuses died at 31 weeks or more (OR 1.11; 95% CI 1.08, 2.48); birth weight ratio (defined as ratio of birth weight to mean birth weight for gestational age) between 0.85 and 0.94 (OR 1.77; 95% CI 1.28, 4.18) or over 1.45 (OR 2.92; 95% CI 1.75, 3.21); trimester of first antenatal visit. Previous fetal death, previous abortion, cigarette smoking, fetal sex, low maternal weight, fetal-to-placenta weight, and post date pregnancy were not significantly associated with unexplained fetal deaths.Conclusion Several factors were identified that are associated with an increased risk of unexplained fetal deaths.     

Maternal risk factors associated with fetal death during antenatal care in low-resource tertiary hospitals

BACKGROUND: Data on maternal characteristics that could predict antepartum fetal death in women receiving antenatal care in resource-constrained settings are limited. Aims: To identify maternal sociodemographic and clinical risk factors for antepartum fetal death among women receiving antenatal care in a developing country setting. METHODS: Case-control analyses of risk factors in the occurrence of singleton fetal death before labour at two university hospitals in south-west Nigeria over 4-5 years. A total of 46 cases and 184 controls were compared for 31 sociodemographic and clinical risk factors. Unconditional multivariate logistic regression analysis was applied to determine independent risk factors. Level of significance was set at P < 0.05. RESULTS: The incidence of antepartum fetal death among women receiving antenatal care was 10.8 per 1000 total births during the period. Significant risk factors at univariate level include proteinuria, pregnancy-induced hypertension, pre-existing hypertension, reduced weight gain per week, previous antepartum fetal death, antepartum haemorrhage, previous miscarriage, symphysiofundal height-gestational age disparity = 4 cm and perception of reduced fetal movements. The independent risk factors were proteinuria (adjusted OR 4.23, CI: 1.57-11.42), pregnancy-induced hypertension (adjusted OR 8.24, CI: 3.01-22.51) and perceived reduction in fetal movements (adjusted OR 7.17, CI: 1.57-45.76). CONCLUSIONS: The identified factors should serve as potential targets for antenatal interventions to prevent antepartum fetal death in these institutions. Awareness of these factors should stimulate appropriate risk assessment geared towards the prevention of antepartum fetal deaths by clinicians in these centres and centres in similar setting.     

Trends in the cause of late fetal death, 1982-2000

BACKGROUND: Progress in reducing late fetal deaths has slowed in recent years, despite changes in intrapartum and antepartum care. OBJECTIVES: To describe recent trends in cause-specific fetal death rates. DESIGN: Retrospective cohort study. SETTING: North of England. POPULATION/SAMPLE: 3,386 late fetal deaths (> or = 28 weeks of gestation and at least 500 g), occuring between 1982 and 2000. METHODS: Data on deaths were obtained from the Northern Perinatal Mortality Survey. Data on live births were obtained from national birth registration statistics. Rate ratios (RR) and 95% confidence intervals (CI) for fetal deaths in 1991-2000 compared with 1982-1990 were calculated. MAIN OUTCOME MEASURES: Cause-specific late fetal death rates per 10,000 total births. RESULTS: Mortality in singletons declined from 51.5 per 10,000 births in 1982-1990 to 42.0 in 1991-2000 (RR 0.82, 95% CI 0.76-0.87). There was a greater decline in multiples, from 197.9 to 128.0 per 10,000 (RR 0.65, 95% CI 0.51-0.83). In singletons, the largest reductions occurred in intrapartum-related deaths, and deaths due to congenital anomalies, antepartum haemorrhage and pre-eclampsia. There was little change in the rate of unexplained antepartum death occurring at term (RR 0.97, 95% CI 0.84-1.11) or preterm (RR 0.94, 95% CI 0.82-1.07), these accounting for about half of all late fetal deaths. Unexplained antepartum deaths declined in multiple births and in singletons of birthweight < 1500 g. CONCLUSIONS: While late fetal mortality due to many specific causes has declined, unexplained antepartum death rates have remained largely unchanged. Improved identification of deaths due to growth restriction and infection, which may otherwise be classified as unexplained, is important. Further investigation of the underlying aetiologies of genuinely unexplained deaths is needed.     

Predictive factors of perinatal mortality in transfused fetuses due to maternal alloimmunization: what really matters?

Introduction: Alloimmunization is the main cause of fetal anemia. There are not many consistent analyses associating antenatal parameters to perinatal mortality in transfused fetuses due to maternal alloimmunization. The study aimed to determine the prognostic variables related to perinatal death. Material and Methods: A cohort study analyzed 128 fetuses treated with intrauterine transfusion (IUT), until the early neonatal period. Perinatal mortality was associated with prognostic conditions related to prematurity, severity of fetal anemia and IUT procedure by univariated logistic regression. Multiple logistic regression was used to compute the odds ratio (OR) for adjusting the hemoglobin deficit at the last IUT, gestational age at birth, complications of IUT, antenatal corticosteroid and hydrops. Results: Perinatal mortality rate found in this study was 18.1%. The hemoglobin deficit at the last IUT (OR: 1.26, 95% CI: 1.04–1.53), gestational age at birth (OR: 0.53, 95% CI: 0.38–0.74) and the presence of transfusional complications (OR: 5.43, 95% CI: 142–20.76) were significant in predicting fetal death. Conclusion: Perinatal mortality prediction in transfused fetuses is not associated only to severity of anemia, but also to the risks of IUT and prematurity.     

Pregnancy-associated cervical cancer: obstetric outcomes.

OBJECTIVE: Describe the obstetric outcomes among women in California with pregnancy associated cervical cancer. METHODS: Cases were identified utilizing computer-linked infant birth/death certificates, discharge records, and cancer registry files, and then assigned to a prenatal or post-partum cancer diagnosis group. Outcomes included cesarean delivery, hospitalizations, birth weight, prematurity, and infant mortality. RESULTS: Among 434 cases identified, those diagnosed prenatally (136 cases) had higher rates of cesarean section (odds ratio 3.7; 95% CI 2.6, 5.2), hospitalization >5 days (maternal: odds ratio 14.1; 95% CI 9.2, 21.5 neonatal: odds ratio 5.2; 95% CI 3.6, 7.5), low birth weight (LBW) (odds ratio 5.5; 95% CI 3.7, 8.1), very LBW (odds ratio 6.9; 95% CI 3.7, 12.8), prematurity (odds ratio 4.7; 95% CI 3.2, 6.7), and fetal deaths (odds ratio 5.5; 95% CI 2.0, 14.8) compared to non-cancer pregnant controls. Very LBW (odds ratio 2.6; 95% CI 1.4, 4.8), prematurity (odds ratio 1.5; 95% CI 1.1, 2.1), and fetal death rates (odds ratio 3.0; 95% CI 1.2, 7.4) remained elevated among those diagnosed post-partum. No neonatal deaths were attributable to elective premature delivery. CONCLUSIONS: We observed higher rates of fetal death and spontaneous prematurity among women with pregnancy-associated cervical cancer.     

Restricted fetal growth in sudden intrauterine unexplained death

BACKGROUND: Unexplained antepartum stillbirth is a common cause of perinatal death, and identifying the fetus at risk is a challenge for obstetric practice. Intrauterine growth restriction (IUGR) is associated with a variety of adverse perinatal outcomes, but reports on its impact on unexplained stillbirths by population-based birthweight standards have been varying, including both unexplained and unexplored stillbirths. AIM: We have studied IUGR, assessed by individually adjusted fetal weight standards, in antepartum deaths that remained unexplained despite thorough postmortem investigations. METHODS: Antenatal health cards from a complete population-based 10-year material of 76 validated sudden intrauterine unexplained deaths were compared to those of 582 randomly selected liveborn controls. Birthweight <10th percentile of the individualized standard adjusted for gestational age, maternal height, weight, parity, ethnicity, and fetal gender was defined as growth restriction. RESULTS: 52% of unexplained stillbirths were growth restricted, with a mean gestational age at death of 35.1 weeks. Suboptimal growth was the most important fetal determinant for sudden intrauterine unexplained death (odds ratio 7.0, 95% confidence interval 3.3-15.1). Concurrent maternal overweight or obesity, high age, and low education further increase the risk. Overweight and obesity increase the risk irrespective of fetal growth, and while high maternal age increases the risk of the normal weight fetus, it is not associated to growth restriction as a precursor of sudden intrauterine unexplained death. CONCLUSIONS: IUGR is an important risk factor of sudden intrauterine unexplained death, and this should be excluded in pregnancies with any other risk factor for sudden intrauterine unexplained death.     

Interaction between risk factors for fetal growth retardation associated with abnormal umbilical artery Doppler studies

BACKGROUND: The role of antenatal risk factors associated with the occurrence of fetal growth restriction complicated by abnormal umbilical artery Doppler studies has not yet been studied extensively. We evaluated the role and the interactions of antenatal antecedents of fetal growth restriction complicated by abnormal umbilical artery end-diastolic velocities. METHODS: We compared antenatal variables in 183 pregnancies complicated by fetal growth retardation and abnormal umbilical artery Doppler studies and 549 appropriately grown fetuses with normal end-diastolic velocity waveform in the umbilical artery. Logistic regression was used to evaluate the association between antenatal variables and fetal growth retardation and to test for interaction. RESULTS: In logistic models, increasing maternal age [odds ratio (OR) 1.06, 95% confidence interval (CI) 1.01-1.11], nulliparity (OR 2.2, 95% CI 1.37-3.5), smoking during pregnancy (OR 2.56, 95% CI 1.56-4.22), preeclampsia (OR 27.5, 95% CI 15.1-49.9), first-trimester hemorrhage (OR 2.25, 95% CI 1.32-3.82) and low (< 0.2 kg/week) weight gain in pregnancy (OR 3.48, 95% CI 1.71-3.05) were significantly associated with an increased risk of fetal growth restriction complicated by abnormal Doppler studies. These risk factors were also significantly correlated with the occurrence of absent/reversed end-diastolic blood flow in the umbilical artery. Maternal smoking during pregnancy interacted negatively with preeclampsia but positively with a low weight gain in pregnancy. CONCLUSIONS: The results of this study have shown that antenatal risk factors for intrauterine growth retardation (IUGR) complicated by abnormal Doppler studies are similar to those associated with the birth of a small-for-gestational-age infant. Preeclampsia, maternal smoking and low weight gain in pregnancy play a significant causal role in the origin of fetal growth restriction associated with abnormal uteroplacental blood flow.     

Pregnancy-associated cervical cancer: Obstetric outcomes

Objective.?Describe the obstetric outcomes among women in California with pregnancy associated cervical cancer.

Methods.?Cases were identified utilizing computer-linked infant birth/death certificates, discharge records, and cancer registry files, and then assigned to a prenatal or post-partum cancer diagnosis group. Outcomes included cesarean delivery, hospitalizations, birth weight, prematurity, and infant mortality.

Results.?Among 434 cases identified, those diagnosed prenatally (136 cases) had higher rates of cesarean section (odds ratio 3.7; 95% CI 2.6, 5.2), hospitalization >?5 days (maternal: odds ratio 14.1; 95% CI 9.2, 21.5 neonatal: odds ratio 5.2; 95% CI 3.6, 7.5), low birth weight (LBW) (odds ratio 5.5; 95% CI 3.7, 8.1), very LBW (odds ratio 6.9; 95% CI 3.7, 12.8), prematurity (odds ratio 4.7; 95% CI 3.2, 6.7), and fetal deaths (odds ratio 5.5; 95% CI 2.0, 14.8) compared to non-cancer pregnant controls. Very LBW (odds ratio 2.6; 95% CI 1.4, 4.8), prematurity (odds ratio 1.5; 95% CI 1.1, 2.1), and fetal death rates (odds ratio 3.0; 95% CI 1.2, 7.4) remained elevated among those diagnosed post-partum. No neonatal deaths were attributable to elective premature delivery.

Conclusions.?We observed higher rates of fetal death and spontaneous prematurity among women with pregnancy-associated cervical cancer.     

First Birth Cesarean and Risk of Antepartum Fetal Death in a Subsequent Pregnancy

Introduction: To examine the relationship between first birth by cesarean and antepartum fetal death in a subsequent pregnancy in a large, hospital‐based population. Methods : Data for this retrospective cohort study were taken from a database of all women who gave birth at Brigham and Women's Hospital during 4 waves of data collection beginning in 1994 and ending in 2002. We calculated the risk of antepartum fetal death in the subsequent pregnancy for women whose first birth was by cesarean compared to women with a vaginal first birth. Survival analysis was used to examine the influence of gestational age at birth. Results: Of 10,996 women who met inclusion criteria, 22% (n = 2450) had first births by cesarean, and 78% (n = 8546) had vaginal first births. The risk of antepartum fetal death in the subsequent pregnancy for women whose first birth was by cesarean was significantly greater than the risk for women whose first birth was vaginal (odds ratio 2.6; 95% confidence interval, 1.1‐6.2). The relationship between first birth cesarean and antepartum fetal death in a subsequent pregnancy differed by gestational age at birth, with no excess risk among women with a previous cesarean birth who gave birth before 34 weeks’ gestation but with a substantially increased risk for women who gave birth at 34 or more weeks’ gestation (unadjusted hazard ratio = 5.6; 95% confidence interval, 1.6‐19.8). Hazard ratio estimates for the association remained significant in bivariate models when adjusted for maternal height, weight, age, hypertension, and diabetes. Discussion: In these data, first birth by cesarean was associated with an increased risk of antepartum fetal death in a subsequent pregnancy. Our findings suggest that antepartum fetal deaths in subsequent pregnancies might be prevented by avoiding primary cesarean birth.     

Socio-economic, demographic and obstetric risk factors for late fetal death of unknown etiology in Lithuania: a case--referent study

BACKGROUND: The purpose of this study was to evaluate the association between third trimester unexplained prelabor fetal deaths and various socio-economic, demographic and obstetric factors in Lithuania. METHODS: A case-referent study on 58 women with third trimester fetal death and 116 women with live fetus at term was carried out. Inclusion criteria for women in the first group (cases) were: prelabor fetal death of unknown etiology, singleton pregnancy >26 weeks of gestation and intact fetal membranes. For each case two referent women were recruited, admitted during the same period in active phase of labor at term (>37 weeks of gestation) with intact fetal membranes and fetus alive. Data were obtained by interview, anthropometry and by reviewing the medical records. Several potential socio-economic, demographic and obstetrical risk factors for unexplained fetal death were investigated. RESULTS: Univariate analyses determined several factors that were associated with fetal death of unknown etiology: low educational level, single marital status, low income, etc. After secondary logistic regression analysis only three independent variables remained significantly associated with otherwise unexplained stillbirth: small for gestational age fetus (OR 29.6; 95% CI 6.2-141.6), low income (OR 7.4; 95% CI 3.1-17.6), and maternal white blood cell count more than 16,000/mm3 (OR 5.4; 95% CI 1.4-21.6). Body mass index, smoking, occupation of women and other evaluated parameters were not confirmed to be significant risk factors. CONCLUSION: Small for gestational age fetus, low income and elevated maternal white blood cell count are factors significantly associated with late prelabor fetal death in Lithuania.     

Risk Factors of Maternal Death in Mexico

ABSTRACT: Background: One of the United Nations’ Millennium Development Goals for 2015 is to reduce the maternal mortality ratio by three fourths. Ninety‐nine percent of maternal deaths occur in developing countries, and the World Health Organization encourages investigations in these settings to determine the risk factors of maternal deaths. Our aim was to identify these risk factors in a hospital‐based study in Mexico. Methods: The study was conducted at the Hospital of Obstetrics and Gynecology at the Mexican Institute of Social Security in Leon, Guanajuato, Mexico, from January 1, 1992, to March 31, 2004. Women were divided into groups of 110 individuals who had died during pregnancy, delivery, or postpartum, and 440 women who survived the postpartum period. We used a logistic regression analysis to find the significant risk factors for maternal deaths. Odds ratios with 95% t confidence intervals were estimated. Results: The maternal mortality ratio was 47.3 per 100,000 live births. The main causes of death were hemorrhage (30.9%), preeclampsia/eclampsia (28.2%), and septic shock (10.9%). Six factors were significantly associated with maternal death: age (OR = 1.09, 95% CI = 1.00–1.18), marital status (OR = 16.2, 95% CI = 1.3–196.1), number of antenatal visits (OR = 1.3, 95% CI = 1.0–1.6), preexisting medical conditions (OR = 23.3, 95% CI = 6.6–81.6), obstetric complications in previous pregnancies (OR = 28.3, 95% CI = 4.9–163.0), and mode of delivery (OR = 1.6, 95% CI = 1.0–2.4). Conclusions: Socioeconomic, medical, and obstetric risk factors are associated with maternal deaths in Mexico. (BIRTH 34:1 March 2007)     

Multivariate analysis of risk factors for stillbirth in Leon, Mexico

BACKGROUND: To identify sociodemographic and clinical risk factors for antenatal fetal death in a developing country setting. METHODS: A case-control study was carried out, including 753 women: 251 had a stillbirth (cases) and 502 had a healthy live birth (controls). Stillbirths were considered as antenatal fetal death after 21 weeks of gestation. Seventeen sociodemographic and clinical risk factors for stillbirth were analyzed. Statistical analysis. Student's t-test or the Mann-Whitney U-test for continuous data and the chi2-test or Fisher's exact test for categorical variables were used. Logistic regression analysis was used to find significant predictors for stillbirth. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. RESULTS: Three risk factors were significant in the logistic regression model: maternal age (OR 1.04, 95% CI 1.00-1.08), antenatal care (OR 0.1, 95% CI 0.0-0.2) and umbilical cord complication (OR 5.8, 95% CI 3.2-10.2). The whole model had a determination coefficient of 0.280, with a chi2-value of 246.2 (p < 0.001). CONCLUSIONS: In our setting antenatal care should be considered as the cornerstone in the prevention of stillbirth. With adequate antenatal care both women with advanced maternal age and umbilical cord complication could be identified. This finding could be useful for developing as well as developed country settings to avoid the occurrence of stillbirth.     

A case-control study of unexplained antepartum stillbirths.

OBJECTIVE: To ascertain factors that will identify women who are at increased risk of unexplained antepartum stillbirth. DESIGN: Matched case-control study. The cases and controls were initially analysed as a whole group and again after dichotomizing into those of low birthweight (< 2500 g) and those of normal birthweight (> or = 2500 g). SETTING: Western Australia 1980-1983. SUBJECTS: Unexplained antepartum stillbirths of > or = 1000 g birthweight (cases) and liveborn infants individually matched for year of birth, plurality, sex and birthweight of infant and race of mother (controls). RESULTS: The case pregnancies had more polyhydramnios (OR 10.83, 95% CI 2.41-48.69) and cord problems (OR 6.57 95% CI 1.36-31.75) than the controls but, paradoxically, other obstetric and medical complications were less common in the cases. The association with polyhydramnios persisted when the analysis was confined to those with low birthweight. With normal birthweight fetal distress was more frequent in the cases (OR 3.65 95% CI 1.36-9.80) but there were few other differences. CONCLUSIONS: The clinical and diagnostic systems currently in use are unable to identify many fetuses at risk of death. Decreases in the rate of unexplained antepartum stillbirths await the discovery of new preventable causes, or of innovations in clinical or laboratory aspects of obstetric care.     

Fetal and neonatal mortality among twin gestations in the United States: the role of intrapair birth weight discordance

OBJECTIVE: To examine the association of intrapair birth weight discordance with fetal and neonatal mortality. METHODS: We used the United States (1995-1997) Matched Multiple Birth File (n = 297,155). RESULTS: Among twin live births and stillborn fetuses, 29.9% had less than 5% birth weight discordance, 24.2% had 5-9%, 29.6% had 10-19%, 11.1% had 20-29%, 3.4% had 30-39%, and 1.8% had 40% or more. The stillborn fetus rate increased progressively with increasing birth weight discordance for smaller and larger twins of the same sex. Compared with the less than 5% birth weight discordance category, the adjusted odds ratios (OR) (95% confidence intervals [CIs]) for stillborn fetus associated with 5-9%, 10-19%, 20-29%, 30-39%, and 40% or more birth weight discordance, respectively, were 0.81 (95% CI 0.58, 1.11), 1.41 (95% CI 1.07, 1.84), 1.74 (95% CI 1.28, 2.35), 3.06 (95% CI 2.21, 4.24), and 4.29 (95% CI 3.05, 6.04) for smaller twins. The corresponding ORs (95% CIs) for larger twins were 0.78 (95% CI 0.57, 1.08), 1.26 (95% CI 0.96, 1.66), 1.77 (95% CI 1.27, 2.46), 3.38 (95% CI 2.33, 4.92), and 2.91 (95% CI 1.89, 4.47). Similar associations were observed among smaller but not larger twins of opposite sex. Among larger but not smaller twins of the same sex, increasing birth weight discordance was associated with overall neonatal deaths. This association was not apparent among smaller and larger twins of opposite sex. However, increasing birth weight discordance was associated with neonatal deaths related to congenital malformations among smaller and larger twins. CONCLUSION: The results provide evidence that increased twin birth weight discordance was associated with increased risk of intrauterine death and malformation-related neonatal deaths.     

Maternal and neonatal outcomes of assaults during pregnancy

OBJECTIVE: To assess perinatal outcomes of women hospitalized for assault during pregnancy as a function of timing of delivery. METHODS: A retrospective population-based study analyzing maternal discharge records linked to birth/death certificates in California from 1991 to 1999 was performed. International Classifications of Disease, Ninth Clinical Modification (ICD-9-CM) codes were used to identify injury types and outcomes. External causation codes identified assaults as the mechanism of the injuries. Injury Severity Scores were assessed. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated, and multivariate logistic regression was used for analysis of outcomes. RESULTS: A total of 2,070 women were hospitalized during pregnancy after sustaining an assault. Assaulted women were younger, multiparous, and with delayed prenatal care compared with unassaulted controls. Women delivering at the assault hospitalization had high rates of prematurity: 24%, OR 2.4 (95% CI 1.8-3.3), maternal death: 0.71%, OR 19 (95% CI 2.7-144.7), fetal death: 9.3%, OR 8 (95% CI 4.6-14.3), uterine rupture: 0.71%, OR 46 (95% CI 6.5-337.8), and other adverse outcomes compared with unassaulted women. Women discharged after an assault, delivering at a subsequent hospitalization, had increased risks of abruption: 2%, OR 1.8 (95% CI 1.3-2.5), hemorrhage: 3.2%, OR 1.8 (95% CI 1.4-2.5), prematurity: 15%, OR 1.3 (95% CI 1.2-1.5), and low birth weight: 13.4%, OR 1.7 (95% CI 1.5-1.9) at delivery. CONCLUSION: Women sustaining an assault during pregnancy experience both immediate (uterine rupture, increased fetal and maternal mortality) and long-term sequelae (prematurity and low birth weight infants), which have significant negative effects on pregnancy outcome. LEVEL OF EVIDENCE: III.     

Perinatal outcomes in singletons following in vitro fertilization: a meta-analysis

OBJECTIVE: To estimate whether singleton pregnancies following in vitro fertilization (IVF) are at higher risk of perinatal mortality, preterm delivery, small for gestational age, and low or very low birth weight compared with spontaneous conceptions in studies that adjusted for age and parity. DATA SOURCES: We searched MEDLINE, BIOSIS, Doctoral Dissertations On-Line, bibliographies, and conference proceedings for studies from 1978-2002 using the terms "in vitro fertilization," "female infertility therapy," and "reproductive techniques" combined with "fetal death," "mortality," "fetal growth restriction," "small for gestational age," "birth weight," "premature labor," "pre-term delivery," "infant," "obstetric," "perinatal," and "neonatal." METHODS OF STUDY SELECTION: Inclusion criteria were singleton pregnancies following IVF compared with spontaneous conceptions, control for maternal age and parity; 1 of the above outcomes; and risk ratios or data to determine them. Study selection and data abstraction were performed in duplicate after removing identifying information. TABULATION, INTEGRATION, AND RESULTS: Fifteen studies comprising 12,283 IVF and 1.9 million spontaneously conceived singletons were identified. Random-effects meta-analysis was performed. Compared with spontaneous conceptions, IVF singleton pregnancies were associated with significantly higher odds of each of the perinatal outcomes examined: perinatal mortality (odds ratio [OR] 2.2; 95% confidence interval [CI] 1.6, 3.0), preterm delivery (OR 2.0; 95% CI 1.7, 2.2), low birth weight (OR 1.8; 95% CI 1.4, 2.2), very low birth weight (OR 2.7; 95% CI 2.3, 3.1), and small for gestational age (OR 1.6; 95% CI 1.3, 2.0). Statistical heterogeneity was noted only for preterm delivery and low birth weight. Sensitivity analyses revealed no significant changes in results. Early preterm delivery, spontaneous preterm delivery, placenta previa, gestational diabetes, preeclampsia, and neonatal intensive care admission were also significantly more prevalent in the IVF group. CONCLUSION: In vitro fertilization patients should be advised of the increased risk for adverse perinatal outcomes. Obstetricians should not only manage these pregnancies as high risk but also avoid iatrogenic harm caused by elective preterm labor induction or cesarean.     

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.     

The risk of unexplained antepartum stillbirth in second pregnancies following caesarean section in the first pregnancy

Objective  To determine if a previous caesarean section increases the risk of unexplained antepartum stillbirth in second pregnancies.
Study design  Retrospective cohort study.
Setting  Large Canadian perinatal database.
Population  158 502 second births.
Methods  Data were obtained from a large perinatal database, which supplied data on demographics, pregnancy complications, maternal medical conditions, previous caesarean section and pregnancy outcomes.
Main outcome measures  Total and unexplained stillbirth.
Results  The antepartum stillbirth rate was 3.0/1000 in the previous caesarean section group compared with 2.7/1000 in the previous vaginal delivery group ( P = 0.46). Multivariate logistic regression modelling, including terms for maternal age (polynomial), weight >91 kg, smoking during pregnancy, pre-pregnancy hypertension and diabetes, did not document an association between previous caesarean section and unexplained antepartum stillbirth (OR 1.27, 95% CI 0.92–1.77).
Conclusion  Caesarean section in the first birth does not increase the risk of unexplained antepartum stillbirth in second pregnancies.     

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.     

The impact of prenatal care on neonatal deaths in the presence and absence of antenatal high-risk conditions

OBJECTIVE: The purpose of this study was to determine the association between prenatal care in the United States and the neonatal death rate in the presence and absence of antenatal high-risk conditions. STUDY DESIGN: Data were derived from the national perinatal mortality data sets for the years 1995 through 1997, which were provided by the National Center for Health Statistics. Analyses were restricted to singleton live births that occurred after 23 completed weeks of gestation. Multivariable logistic regression analyses were used to adjust for the presence or absence of various antenatal high-risk conditions, maternal age, gestational age at delivery, and birth weight. RESULTS: Of 10,530,608 singleton live births, 18,339 (1.7/1000 births) resulted in neonatal death. Neonatal death rates (per 1000 live births) were higher for African American infants compared with white infants in the presence (2.7 vs 1.5, respectively) and absence (10.7 vs 7.9, respectively) of prenatal care. Lack of prenatal care was associated with an increase in neonatal deaths, which was greater for infants born at > or =36 weeks of gestation (relative risk, 2.1; 95% CI, 1.8, 2.4). Lack of prenatal care was also associated with increased neonatal death rates in the presence of preterm premature rupture of the membranes (relative risk, 1.3; 95% CI, 1.1, 1.5), placenta previa (relative risk, 1.9; 95% CI, 1.2, 2.9), fetal growth restriction (relative risk, 1.7; 95% CI, 1.2, 1.6), and postterm pregnancy (relative risk, 1.4; 95% CI, 1.0, 2.9). CONCLUSION: In the United States, prenatal care is associated with fewer neonatal deaths in black and white infants. This beneficial effect was more pronounced for births that occurred at > or =36 weeks of gestation and in the presence of preterm premature rupture of the membranes, placenta previa, fetal growth restriction, and postterm pregnancy.