Role of Ultrasonographic Placental Thickness in Prediction of Fetal Outcome: A Prospective Indian Study

Background Information

Placenta is the connecting organ between the mother and the fetus. It supplies oxygen and all the necessary elements for the growth and development of the fetus. In normal pregnancy, the growth of the placenta remains concordant with the growth of the fetus. The sonographic assessment of placenta can give information about the nutritional status of the fetus. It is known that normal placental thickness approximately equals gestational age. It is historically documented that placental weight is one-fifth of the fetal weight and abnormally thin or thick placenta is associated with increased incidence of perinatal morbidity and mortality. However, there are very few studies correlating placental thickness with Neonatal outcome.

Objectives

To correlate ultrasonographic placental thickness at 32 and 36 weeks pregnancy with neonatal outcome. To propose placental thickness as a simple test for prediction of neonatal outcome.

Methods

Placental thickness at 32 and 36 weeks was measured by ultrasound, in 130 pregnant mothers with confirmed dates and uncomplicated singleton pregnancy. Placental thickness was categorized as normal (10th–95th percentile), thin (<10th percentile) and thick (>95th percentile) at each stage and was correlated with birth weight and neonatal outcome.

Results

Neonatal outcome was good in women with normal placental thickness (10th–95th percentile) at 32 and 36 weeks and was compromised in women with thin (<10th percentile) and thick (>95th percentile) placentae.

Conclusion

Placental thickness at 32 and 36 weeks corresponds well with gestational age and is a good prognostic factor in assessing neonatal outcome. Therefore, placental thickness should be measured in addition to biometric parameters in antenatal women undergoing ultrasound.

     

Are placental lakes of any clinical significance?

The aim of this study was to determine prospectively whether an association exists between the finding of placental lakes at the 20 week scan and an increased risk of uteroplacental complications or a poor pregnancy outcome. We studied the placental appearances in 1,198 consecutive second trimester ultrasound scans performed for routine foetal abnormality screening at our institution. The placental thickness was measured at its widest diameter in the sagittal plane and the presence or absence of placental lakes was recorded. The birth weight in each case was plotted against the centile charts in use at the hospital and recorded. Specific outcome measures included foetal growth restriction (IUGR) with a birth weight below the 5th centile, pre-eclampsia, placental abruption, and perinatal deaths. Placental lakes were seen in 17.8 per cent of the scans. There was no significant association with either maternal socio-demographic factors or perinatal mortality (OR 0.94, 95 per cent CI 0.35-2.51). No association was seen with maternal cigarette smoking (OR 1.07, 95 per cent CI 0.75-1.52), a birth weight below the 5th centile (OR 0.68, 95 per cent CI 0.39-1.18), the development of pregnancy induced hypertension (OR 0.68, 95 per cent CI 0.35-1.32), severe pre-eclampsia (OR 0.72, 95 per cent CI 0.21-2.50), or placental abruption (OR 1.79, 95 per cent CI 0.46-6.99). A finding of placental lakes was six times more likely with a thick placenta >3 cm at 20 weeks gestation (OR 6.30, 95 per cent CI 4.39 to 9.05). A finding of placental lakes during the second trimester ultrasound scan does not appear to be associated with uteroplacental complications or an adverse pregnancy outcome. The lesions are more prevalent with increasing placental thickness.     

Vaginal bleeding in the last two trimesters of pregnancy. A clinical and ultrasonic study

Ninety-seven cases of vaginal bleeding during the second and third trimesters of pregnancy are presented with special reference to the follow-up observations and perinatal parameters after the first bleeding and ultrasonic determination of placental site. The perinatal mortality rate was 11 per cent and the rate of premature deliveries 23 per cent. In the cases of recurrent bleeding episodes (N = 33), the corresponding frequencies were 22 and 35 per cent. Placenta previa of some degree was diagnosed by ultrasound during the first episode of bleeding in 36 cases. Although the placenta was observed to "move" upwards from the internal os of cervix in 20 of these patients during the last few weeks of pregnancy, final placenta previa (N = 16) was the most common definite etiological factor behind the bleeding. The high frequency of perinatal complications associated with these pregnancies emphasizes, despite reliable localization of the placenta, the importance of a careful follow-up until delivery.     

Maternal food restriction reduces the exchange surface area and increases the barrier thickness of the placenta in the guinea-pig

The extent to which maternal nutrition influences fetal growth through effects on placental functional development is unclear. Poor maternal nutrition is a major cause of poor fetal growth which increases neonatal morbidity and mortality, and may also increase the risk of several adult-onset diseases. We have therefore characterized the ontogeny of structural determinants of function in the placenta in guinea-pigs fed ad libitum or food restricted from before and during pregnancy. Guinea-pigs were killed at days 30 and 60 (term=67 days) of pregnancy. In ad libitum fed animals, the surface density (surface area/g placental labyrinth), which is a measure of the convolution of the exchange surface, doubled, while total surface area increased 18-fold between mid and late gestation. Concomitantly, the arithmetic mean barrier thickness to diffusion across trophoblast decreased by 68 per cent. Late in gestation, food restriction reduced the proportion of the placenta devoted to exchange (labyrinth) by 70 per cent (P< 0.04) and the weight of the placental labyrinth by 45 per cent (P=0.001). Maternal food restriction also reduced the total placental surface area for exchange by 36 per cent at day 30 (P=0.02) and 60 per cent at day 60 (P< 0.0005) of gestation, and the surface density of trophoblast by 36 per cent at day 30 (P=0.01) and 29 per cent at day 60 (P=0.005) of gestation. The arithmetic mean barrier thickness for diffusion was increased by maternal food restriction at both gestational ages (day 30, +37 per cent, P=0.008, and day 60, +40 per cent, P=0.01). These findings suggest that maternal food restriction not only reduces fetal and placental weights, but also induces structural alterations in the placenta that indicate functional impairment beyond what would be expected for the reduction in its weight.     

Histomorphology of the placenta and the placental bed of growth restricted foetuses and correlation with the Doppler velocimetries of the uterine and umbilical arteries

The aim of the present study was to evaluate the histomorphology of the placenta and the placental bed and to correlate this with the Doppler study of the uterine and umbilical arteries of intrauterine growth restricted pregnancies. The study group consisted of 47 women with intrauterine growth restricted foetuses. Twenty-five uneventful pregnancies with appropriate for gestational age foetuses were selected as controls. Doppler studies of umbilical and uterine arteries were performed within the last week before delivery. Placental bed biopsies were obtained at Caesarean section with direct visualization of the placental site. The incidence of pathologic bed biopsies in control, IUGR with normal uterine artery Doppler velocimetry and IUGR with abnormal uterine artery Doppler velocimetry was 0 per cent, 16.6 per cent and 79.3 per cent respectively (P< 0.001). Placentae from IUGR cases with abnormal umbilical artery Doppler velocimetries had a significantly increased number of villous infarcts, cytotrophoblast proliferation and thickening of the villous trophoblastic basal membrane (P=0.001, P=0.038 and P=0.02 respectively). Abnormal placental bed biopsy pathology was significantly associated with abnormal uterine artery velocimetry (OR 33.7, 6.5-173.6; P< 0.001). Abnormal placental pathology was significantly associated with abnormal umbilical artery Doppler velocimetry (OR 21.04, 3.8-115.9;P< 0.001). Women with both abnormal uterine and umbilical artery Doppler velocimetries were delivered earlier and their babies had lower mean birth and placental weight (P< 0.001). In conclusion, placental bed biopsy and placental pathologies are best reflected by abnormal uterine and umbilical artery velocity waveforms, respectively. The most severe clinical outcomes and perinatal mortality are present when both uterine and umbilical districts are altered.     

Obstetric history and the risk of placenta previa

OBJECTIVE: To evaluate secular trends in the occurrence of placenta previa and whether placenta previa is associated with the outcome of previous pregnancies, cesarean section, and sociodemographic factors. DESIGN: A cohort study based on the Medical Birth Registry of Norway. Placenta previa in the second pregnancy was investigated for associations with outcomes in the first pregnancy and sociodemographic factors. RESULTS: In birth orders 1 and 2 the occurrence of placenta previa was 1.2 and 2.2 per 1,000, respectively, with no secular trend. The occurrence increased with maternal age and was lowest in women aged 20-29 years. The recurrence rate was 23 per 1,000 (adjusted odds ratio (OR) of recurrence=9.7). In women with prior delivery at < or =25 gestational weeks the risk of placenta previa was 6.7 per 1,000 (adjusted OR=3.0). In women with prior placental abruption the risk was 5.8 per 1,000 (OR=2.6). In women with prior perinatal death the risk was 4.4 per 1,000 (adjusted OR= 1.8). No independent relationship emerged with socio-economic factors, previous birthweight, and a history of pregnancy induced hypertension. Cesarean section was associated with subsequent development of placenta previa (adjusted OR= 1.3). CONCLUSIONS: We found no secular trends in the occurrence of placenta previa. Placenta previa is associated with previously described risk factors for placental abruption. The increased risk of placenta previa subsequent to placental abruption supports the theory of a shared etiologic factor. However, placenta previa and placental abruption do not share a common etiology in relation to a history of pregnancy induced hypertension, fetal growth retardation, and socio-economic factors.     

Obstetrics and perinatal outcome of pregnancies after the age of 45.

We set out to describe the maternal and perinatal outcome of pregnancies in women >/= 45 years old at the time of delivery. A retrospective review of hospital deliveries after 28 weeks of pregnancy was performed at the Princess Badeea Teaching Hospital (PBTH) in North Jordan for patients delivered between 1 April 1994 and 31 December 1997. During the study period, there were 114 women aged >/= 45 years at delivery at the PBTH. The incidence was 3.3 per 1000 births. The median maternal age was 45 years. The majority of women (81.6%) were 45-46 years old. Maternal ages were 45 (n =64), 46 (n =29), 47 (n =9), 48 (n =8), 49 (n =2) and 50 (n =2) years. Median gravidity was 10, median parity was seven. Forty-four (38.6%) patients had obstetric complications. The most frequent complication was diabetes mellitus (9.6%), followed by hypertension (4.4%). Caesarean section was performed in 32.5%. There were nine stillbirths and four early neonatal deaths, the perinatal mortality rate was 114/1000 births. We conclude that women >/= 45 years old at delivery have high perinatal mortality rate and we also noted a higher incidence of placental abruption, placenta praevia and caesarean delivery, compared with a younger group of women.     

The epidemiology of placental infarction at term

The incidence and associations of placental infarction at term were investigated as part of a population based case-control study of small for gestational age (SGA) infants. 509 placentas from women delivering SGA infants (SGAP) and 529 placentas from women delivering infants with birthweights appropriate for gestational age (AGAP) were examined using fixed protocols for macroscopic identification and microscopic confirmation of infarction. Other information was obtained by maternal interview and from an obstetric database.Infarcts were found in 17.3 per cent of SGAP and 11.7 per cent of AGAP. This difference was in placentas with multiple infarcts not involving the placental margin and was significant in multivariate analysis (OR 1.66; 95 per cent CI 1.12,2.47). Multivariate analysis showed significant associations between the presence of any infarct and maternal hypertension in both SGAP (OR=4.00; 95 per cent CI 1.96,8.16) and AGAP (OR 2.99; 95 per cent CI 1.23,7.32); maternal smoking, associated with a lesser risk in SGAP only (OR=0.31; 95 per cent CI 0.13,0.73); maternal age at first pregnancy in a linear relationship with AGAP only (beta co-efficient 0.09, P=0.0034); and between some ethnic groups. We conclude that at least five factors have independent associations with the incidence of placental infarction and these associations differ by site and age of infarcts.     

Obstetric characteristics and perinatal outcome of pregnancies with uterine leiomyomas

OBJECTIVE: To determine the rate, obstetric characteristics and perinatal outcome of pregnancies with uterine leiomyomas. STUDY DESIGN: A population-based study comparing all singleton deliveries between the years 1988 and 1999 in women with and without uterine leiomyomas was performed. Patients lacking prenatal care were excluded from the analysis. Multivariable analysis, adjusting for possible confounders, such as maternal age, parity and gestational age, was performed to investigate associations between uterine leiomyomas and selected outcomes. RESULTS: There were 105,909 singleton deliveries with 690 (0.65%) complicated by uterine leiomyomas during the study period. Using a multivariable analysis, the following conditions were significantly associated with uterine leiomyomas: nulliparity (odds ratio [OR]=4.0, 95% confidence interval [CI] 3.3-4.7, P<.001), chronic hypertension (OR=1.9, 95% CI 1.6-2.4, P<.001), hydramnios (OR=1.5, 95% CI 1.2-2.0, P<.001), diabetes mellitus (OR=1.4, 95% CI 1.1-1.7, P=.001) and advanced maternal age (OR=1.2, 95% CI 1.1-1.2, P<.001). Higher rates of perinatal mortality (2.2% vs. 1.2%, OR=1.8, 95% CI 1.1-3.2, P<.001) were found in the uterine leiomyoma group as compared to the control group. While adjusting for maternal age, parity, gestational age and malpresentation, pregnancies with uterine leiomyomas had higher rates of cesarean deliveries (OR=6.7, 95% CI 5.5-8.1, P<.001), placental abruption (OR=2.6, 95% CI 1.6-4.2, P<.001) and preterm deliveries (<36 weeks' gestation, OR=1.4, 95% CI 1.1-1.7, P=.009) as compared to pregnancies without uterine leiomyomas. Conversely, no significant differences were noted regarding perinatal mortality (OR=1.4, 95% CI 0.7-2.8, P=.351) after controlling for maternal age, parity and gestational age using a multivariable analysis. CONCLUSION: Uterine leiomyomas increase the risk of adverse pregnancy outcomes, thus emphasizing the importance of appropriate intrapartum management of these high-risk pregnancies.     

Maternal and perinatal outcome of pregnancies after the age of 45

OBJECTIVE: To describe the maternal and perinatal outcome of pregnancies in women aged 45 years or more at the time of delivery and to compare them with pregnancies in women aged between 20 and 29 years. METHODS: A retrospective review of hospital deliveries after 28 weeks gestation was performed at the Princess Badeea Teaching Hospital in North Jordan for patients delivered between 1st April 1994 and 31st December 1997. We compared the maternal and perinatal outcome of pregnancies in women aged of 45 years or more (study group, n = 114) with women aged between 20-29 years (control group, n = 121) delivered at the same hospital during the same period. RESULTS: The incidence of pregnant women aged 45 years or more was 3.3 per 1,000 births. The median maternal age was 45 years. The majority of women (81.6%) were 45 to 46 years old. Gravidity and parity was significantly higher in the study group (p < 0.0001), also antenatal and medical complications as pre-eclampsia and diabetes mellitus were higher in the study group. Caesarean section rate, incidences of placental abruption and placenta previa were more common in older patients compared with young patients (32.4 vs 10.7%, 6.1 vs 0.8% and 4.4 vs 1.6%, respectively). There were no differences in the incidences of neonatal deaths, lethal malformations and fetal weight between the 2 groups. CONCLUSION: Women aged 45 years or more at delivery may expect a good pregnancy outcome but should expect a higher incidences of placental abruption, placenta previa, preeclampsia and caesarean delivery.     

精子来源与数量对单精子卵胞浆内注射术妊娠结局的影响

目的:分析不同精子来源和数量对单精子卵胞浆内注射术(ICSI)妊娠结局的影响。方法:2000年1月至2003年6月在本中心进行ICSI治疗而妊娠的271例,据精子来源与数量分为精液正常组(39例)、少弱精组(144例)与手术取精组(88例)。比较精液正常组、少弱精组、手术取精组的临床妊娠率、流产率、分娩率、妊娠并发症、分娩孕周、新生儿出生体重、畸形、围生儿死亡率等组间差异。结果:精液正常组、少弱精组与手术取精组患者的临床妊娠率、流产率、分娩率、双胎率、妊娠期高血压疾病发生率、前置胎盘发生率、早产率、分娩孕周、新生儿出生体重、先天性畸形发生率(4.5%、6.3%、4.0%)、围生儿死亡率差异均无显著性(P>0.05)。结论:精液正常组、少弱精组与手术取精组ICSI治疗后临床妊娠率、流产率、妊娠期并发症、新生儿出生体重、先天性畸形发生率、围生儿死亡率相似,不同精子来源与数量不影响ICSI治疗后的妊娠和围生儿结局。     

Adverse perinatal outcomes among interracial couples in the United States

OBJECTIVE: We examined the association between parental race and stillbirth and adverse perinatal and infant outcomes. METHODS: We conducted a retrospective cohort analysis using the 1995-2001 linked birth and infant death files that are composed of live births and fetal and infant deaths in the United States. The study included singleton births delivered at 20 or more weeks of gestation with a fetus weighing 500 g or more (N = 21,005,786). Parental race was categorized as mother white-father white, mother white-father black, mother black-father white, and mother black-father black. Multivariable logistic regression analysis was performed to examine the association between parental race and risks of stillbirth (at > or = 20 weeks), small for gestational age (defined as birth weight < 5th and < 10th percentile for gestational age), and early neonatal (< 7 days), late neonatal (7-27 days), and postneonatal (28-364 days) mortality. All analyses were adjusted for the confounding effects of maternal age, education, trimester at which prenatal care began, parity, marital status, and smoking during pregnancy. RESULTS: Although risks varied across parental race categories, stillbirth was associated with a higher-than-expected risk for interracial couples: mother white-father black, relative risk (RR) 1.17 (95% confidence interval [CI] 1.10-1.26) and mother black-father white, RR 1.37 (95% CI 1.21-1.54) compared with mother white-father white parents. The RR for stillbirth was even higher among mother black-father black parents (RR 1.67, 95% CI 1.62-1.72). The overall patterns of association for small for gestational age births (< 5th and < 10th percentile) and early neonatal mortality were similar to those seen for stillbirth. CONCLUSION: There is an increased risk of adverse perinatal outcomes for interracial couples, including stillbirth, small for gestational age infants, and neonatal mortality. LEVEL OF EVIDENCE: II-2.     

Leptin secretion to both the maternal and fetal circulation in the ex vivo perfused human term placenta

The contribution of placental leptin, if any, to both the fetal and maternal circulation and its role in pregnancy remains to be determined. In an experiment to investigate this, 27 placentae from term pregnancies were perfused ex vivo (gestational age=39.5 s.d. 1.2; range=38-42 weeks: fetal weight=3285 s.d. 482; range=2480-4420; birthweight centile range=4th to the 98th) at both the maternal and fetal interface. Placental leptin was exported into both the maternal and fetal circulations. The log leptin production by the maternal side of the placenta was significantly greater (P=0.001) than that for the fetal side (5.193 s.d.1.049 versus 4.387 s.d. 0.768 ng/placenta/min). There was no significant relationship between maternal and fetal log leptin production and maternal body mass index, birthweight, birthweight centile, ponderal index or gestational age or with cord blood pO(2), pCO(2) and pH. There was however, a significant increase in the maternal log leptin production with increasing fetal to placental weight ratio (P=0.017; r(2)=20.7 per cent) but no corresponding relationship for fetal leptin production. It is proposed that such a mechanism would allow the placenta to modulate fat supply to the fetus in response to the fetal demand relative to placental supply.     

Reverse flow in fetal vessels and perinatal events

BACKGROUND/PATIENTS: A reverse flow in the umbilical artery and/or fetal aorta is associated with a higher perinatal and neonatal mortality. 30 fetuses showed a reverse flow using pulsed wave Doppler sonography (group I). A matched-pair control group including 30 fetuses with the same gestational age as well as a normal Doppler flow pattern in the umbilical artery and/or fetal aorta was taken for comparison (group II). RESULTS: In the group with reverse flow the rates of pregnancies with pre-eclampsia (n = 19/30, p < 0.0001), intrauterine growth retardation (n = 25/30, p < 0.0001), oligohydramnios (n = 21/30, p < 0.0001) and nicotine abuse (n = 15/30, p < 0.01) were significantly higher compared to the control group. Postnatal data showed significantly lower pH values in group I (p < 0.01). 40 % of the fetuses with reverse flow died in utero whereas in 67 % the reverse flow was accompanied by an insufficiency of the placenta (IUGR, oligohydramnios, histopathological abnormalities of the placenta). None of the fetuses in the control group died in utero. The incidence of IUGR (< 5ht percentile) was 83 % in group I but only 3 % in group II. The perinatal and overall mortality (including neonatal mortality 7 - 28 days after birth) amounted to 27 % and 53 % in group I, respectively, compared to 3 % and 0 % in the control group (p < 0.001). In addition cerebral anomalies could be found by ultrasound in 50 % of the neonates who presented a reverse flow prenatally. In 28 % of the surviving newborns an intracerebral hemorrhage (ICH) could be detected. None of the newborns of group II developed an ICH. CONCLUSIONS: Pregnancies with a reverse flow in the umbilical artery and/or fetal aorta have to be considered as a high risk group with a poor prognosis. The reverse flow is mainly caused by chronic placental insufficiency with IUGR. With respect to the further neuromotor development the incidence and severity of cerebral lesions in affected fetuses should be considered when discussing the perinatal situation with the parents.     

Placenta accreta--summary of 10 years: a survey of 310 cases

The objective was to study the incidence, risk factors, and outcome of pregnancies complicated by placenta accreta in our population. Retrospective analysis of all deliveries between the years 1990-2000, and identification of all cases of placenta accreta, defined by clinical or histological criteria. For comparison purposes we defined two sub-groups: (i) all cases that ended with severe outcome and (ii) all patients who had a previous event of placenta accreta in one or more of their previous deliveries. We evaluated the potential risk factors leading to these conditions. The SPSS software package was used for statistical analysis. Univariate and multivariate analyses were performed by stepwise logistic regression. The study covered 34 450 deliveries from which 310 cases of placenta accreta were diagnosed (0.9 per cent). The risk factors associated with placenta accreta were previous cesarean delivery (12 per cent), advanced maternal age, high gravidity, multiparity, previous curettage and placenta previa (10 per cent). Hysterectomy was performed in 11 patients (3.5 per cent) with one case of maternal death, whereas 21 per cent of the patients required postpartum blood products transfusion. Antenatal diagnosis of placenta accreta or percreta by ultrasound or MRI, was achieved only in eight of the cases. In the sub-group of 15 patients (4.8 per cent) with severe outcome, the only significant risk factors were increased parity (O.R.=1.29, 95 per cent CI 1.056-1.585), anteriorly low placenta (O.R.=6.1, 95 per cent CI 1.4-25.3) and repeated cases of caesarean sections (O.R.=3.3, 95 per cent CI 0.9-12.5), whereas in the 49 (16 per cent) patients with repeated cases of placenta accreta the only significant risk factor was the number of deliveries (O.R.=1.5, 95 per cent CI 1.0-2.2). Repeated cesarean delivery, high parity, and anteriorly low placental location are associated with severe outcome in case of placenta accreta. Women with repeated events of placenta accreta may have better outcome and a genetic factor may serve as a cause for this condition.     

The outcome of pregnancies complicated by bleeding during the second trimester

Vaginal bleeding during the second trimester has historically been associated with high perinatal mortality rates (33 to 82 per cent). Because this topic has not been specifically studied since the advent of obstetric ultrasound and electronic fetal heart rate monitoring, we reviewed the experience at the University of Utah with second trimester vaginal bleeding from 1 January 1983 through 15 June 1989. The cause of the bleeding was found to fit into four general categories. These are placenta previa, abruption, both previa and abruption, and other or unknown. Midtrimester bleeding is still associated with a high perinatal mortality rate (22.3 per cent), being highest when associated with placental abruption (36.6 per cent) and lowest with placenta previa (7.4 per cent). For the entire series, pregnancies maintained into the third trimester were associated with a much lower perinatal mortality rate than those in which delivery occurred during the second trimester (7.1 versus 54.5 per cent). These relatively improved outcomes suggest that aggressive obstetric management is warranted in most instances.     

Doppler velocimetry and placental disease

Quantitative placental examinations were performed on 47 women who had Doppler flow velocity studies of the umbilical artery during their pregnancy. The systolic-diastolic ratio of the umbilical artery was used as the measurement parameter to divide the study population into two groups. Group 1 consisted of women with normal systolic-diastolic ratios (systolic-diastolic less than 3), and group 2 consisted of women with an elevated systolic-diastolic ratio (systolic-diastolic greater than or equal to 3). The group with an increase in systolic-diastolic ratio had more perinatal complications as demonstrated by two stillbirths, a higher incidence of cesarean deliveries for fetal distress, and more admissions to the neonatal intensive care unit. Significant differences were found when gestational age at delivery, placental weight, birth weight, and the number of small muscular arteries in the placenta were compared. Since gestational age may have accounted for the difference in placental findings, patients were matched for gestational age. The placental weights were comparable, but there were fewer small muscular arteries in those patients with an increase in systolic-diastolic ratio (p less than 0.001). In addition, when these findings were examined to determine the influence of diminished uterine flow velocity, none was found.     

Parental,fetal, and environmental factors in perinatal mortality

The parental, fetal, and environmental factors associated with 279 perinatal deaths and 398 controls have been examined. From the data it is quite evident that socioeconomic factors are of primary importance in perinatal mortality.The difference in perinatal mortality between the white and non-white groups disappeared when adjusted for socioeconomic factors.The father's occupation and the mother's education showed significant differences in relation to perinatal mortality even when adjusted for race, age, and parity. The father's occupation and mother's education were considered as indices of the socioeconomic status of the family.The mother's age was found to be a highly significant factor in perinatal mortality even when adjusted for race, age, and parity.The technique used in obtaining the data for the present study did not yield reliable information in regard to the nutritional status of the mother.Birth interval, parity, previous obstetric complications, and previous perinatal mortality did not appear to be significant in relation to perinatal mortality when adjusted for race, age, and parity.No correlation was noted between the level of the maternal hemoglobin and perinatal mortality.Certain complications of pregnancy such as toxemia, premature separation of the placenta, placenta previa, and other antepartum bleeding were associated with extremely high perinatal mortality rates.In this study the type of delivery appeared to have no relationship to perinatal mortality when other variables were considered.     

Uteroplacental blood flow measurement using radioisotopes in small placentas

In 25 pregnant females with a placental weight below the 20th percentile uteroplacental blood flow measurements using 113mIn-transferrin were performed in the 3rd trimester of pregnancy. Twelve patients with pregnancy-induced hypertension (PIH) were compared to 13 females with normal blood pressures. The results of uteroplacental blood flow measurements showed normal flow patterns in only 6 of the 25 subjects and were significantly worse in the group with PIH. Babies of patients with PIH had a mean birth weight of 1,100 g at a mean gestational age of 34.2 weeks versus 1,752 g and 37.4 weeks for newborns without PIH. Perinatal mortality was significantly higher in the PIH group. In combination with a small placenta PIH compounds the fetal risk.     

The postmature baby

Of the 4,106 firstborn infants, 832 were white and 3,274 Negro. The incidence of postmaturity in the white group was 9 per cent and in the Negro group, 6 per cent.The perinatal mortality rate in the mature white group was 1.4 per cent; in the postmature white group, 1.3 per cent.The perinatal mortality rate in the mature Negro group was 2.3 per cent; in the postmature Negro group, 3.1 per cent.Two small babies died of malnutrition and anoxia during labor. The placenta of each showed changes which might have been attributed to aging.There were 5 per cent fewer small babies (2,500 grams) in the postmature white group than in the mature white group.There were 6 per cent fewer small babies in the postmature Negro group than in the mature Negro group.In the mature white group the largest number of babies fell into the 3,200 gram division. This was also the largest division in the postmature white group. There was a 1 per cent increase in 3,200 gram babies and a 10 per cent increase in babies weighing 3,700 grams and over in the postmature white group over the mature white group.In the mature Negro group the largest number of babies fell into the 2,700 gram division, while in the postmature Negro group the largest number fell into the 3,200 gram division. There was a 13 per cent increase in 3,200 gram babies and a 3 per cent increase in babies who weighted 3,700 grams and over in the postmature Negro group over the mature Negro group.From a study of “The Larger Babies Born at the Chicago Maternity Center,” the incidence of postmaturity for large babies (4,500 grams and over) born of mothers of all races and parities is 7 per cent greater than for averagesized babies (3,200 grams). The same increase in the incidence of postmaturity is found for large firstborn babies over average-sized firstborn children.Twenty-seven per cent of white premature babies classified by weight fall into the mature group when classified by gestational age.Twenty-eight per cent of mature babies classified by weight fall into the premature group when classified by gestational age.