Origin of amniotic fluid alpha-fetoprotein in normal and defective pregnancies.

Alpha-fetoprotein was determined by electroimmunodiffusion and radioimmunoassay in 109 neonatal urine samples and 94 amniotic fluid samples. The samples were obtained from newborns and from pregnancies ranging in gestational age from 20 to 40 weeks. When alpha-fetoprotein values of neonatal urine and amniotic fluid were correspondingly correlated with gestational age, almost identical declining curves could be drawn. Twenty-one cerebrospinal fluid samples from newborns ranging from 25 to 40 weeks of gestation were similarly determined. No correlation between cerebrospinal fluid alpha-fetoprotein and gestational age could be demonstrated. It is concluded that fetal urine is the major source of alpha-fetoprotein in the amniotic fluid of normal pregnancy. In pregnancies associated with neural tube defects, alpha-fetoprotein elevation is probably not due to the leakage of cerebrospinal fluid into the amniotic cavity.     

Outcome of pregnancy in class A1 and A2 gestational diabetic patients delivered beyond 40 weeks' gestation.

The charts of all diabetic women and their infants delivered during the years 1983-1988 in our department were reviewed. The test group included consecutive gestational diabetic women class A1 (n = 65) and class A2 (n = 59), who delivered beyond 40 weeks of gestation. The mean gestational age at delivery was 40.90 weeks (range, 40.0 to 42.57) in class A1 and 40.49 weeks (range, 40.0 to 42.28) in class A2 patients. The first control group matched for age, parity, and presentation included 65 gestational diabetic patients class A1 and 59 A2 who delivered prior to 40 weeks' gestation. The second control group matched for age, parity, and presentation included 124 nondiabetic patients who delivered beyond 40 weeks of gestation (mean, 41.04 +/- 0.83 weeks). By allowing the pregnancies of gestational diabetic patients class A1 and class A2 to proceed beyond 40 weeks of gestation, we did not increase the incidence of perinatal mortality and morbidity rate. The cesarean section rate was low (10.76% in class A1 and 22.03% in class A2). We suggest that not only elective intervention prior to 40 weeks of gestation is to be avoided, but an attempt should be made to allow the gestational diabetics class A1 and class A2 to proceed to spontaneous labor.     

Uteroplacental blood flow velocity waveforms in the second and third trimesters of normal pregnancy as related to the placenta location

The systolic/diastolic ratios (A/B) of uteroplacental blood flow velocity waveforms as related to the placenta location were investigated by continuous-wave Doppler ultrasound in 67 normal pregnancies at 18-21 weeks, in 111 at 31-33 weeks, and in 34 at 40-41 weeks of gestation. Using real-time ultrasound, the placenta was located laterally in 48%, posteriorly in 30% and anteriorly in 22% of the pregnancies. A/B values decreased slightly with advancing gestational age. With lateral placenta location, statistically significant higher A/B values were found in vessels on the nonplacental side at 31-33 weeks of gestation (2.07 +/- 0.43 versus 1.74 +/- 0.27; p less than 0.05). In the other gestational age groups there were no statistically significant differences between A/B values in the vessels on the placental and nonplacental sides. There were also no differences in A/B values between left and right uteroplacental vessels with anterior or posterior placenta locations in any of the gestational age groups.     

Increased level of second trimester maternal serum chorionic gonadotropin in pregnancy with a fetus affected by homozygous alpha-thalassemia 1

With enzyme immunoassay, maternal serum chorionic gonadotropin (MShCG) level was determined in 58 pregnancies affected with fetal homozygous alpha-thalassemia 1. In 40 pregnancies with a gestational age of 10 to 14 weeks, 8 (20%) had an MShCG level above 2.5 multiples of the median (MoM); while in the other 18 pregnancies with a gestational age of 15 to 23 weeks, 14 (78%) had a level above 2.5 MoMs and none had a level below the median. Homozygous alpha-thalassemia 1 of the fetus was associated with an elevated MShCG. Therefore in second-trimester screening for Down's syndrome by measurement of MShCG, homozygous alpha-thalassemia 1 should also be considered if elevated MShCG levels are found. Received: 15 December 1993 / Accepted: 6 April 1994     

Alterations of maternal and fetal leptin concentrations in hypertensive disorders of pregnancy

OBJECTIVES: To investigate whether hypertensive disorders of pregnancy alter the maternal and fetal leptin levels. METHODS: Fifty primigravidas between 28 and 34 weeks of gestation were divided into three groups: group A consisted of 17 normal pregnant women with a mean gestational age of 31 weeks, group B consisted of 15 women with gestational hypertension without proteinuria with a mean gestational age of 30 weeks and group C consisted of 18 pre-eclamptic women with a mean gestational age of 31 weeks. RESULTS: The pre-eclamptics had significantly higher serum leptin levels than those in normal pregnancies (p<0.001) but no difference was noted between normal and gestational hypertensive pregnancies. Pre-eclamptic women had significantly higher umbilical vein leptin levels (4.68+/-1.66ng/ml) compared to normal pregnancies (1.92+/-0.71ng/ml) and those with gestational hypertension (2.47+/-0.81ng/ml). CONCLUSIONS: Pre-eclampsia is associated with an increase in maternal plasma leptin levels and fetal of leptin production increases in gestational hypertension and even more in pre-eclampsia.     

Why Do Aboriginal Newborns Weigh Less? Gestational Age at Delivery: Estimation, Distribution and Determinants

Summary: We reviewed birth records pertaining to 1,301 Western Australian singleton Aboriginal pregnancies dated before 24 weeks by ultrasound fetometry using Caucasian standards.
We compared i) ultrasound- and LMP-derived estimates of age at delivery for 323 pregnancies with available last menstrual period (LMP) dates and ii) distributions of ultrasound-estimated age at delivery for full-blood with part-blood Aboriginal neonates and with statutorily collected estimates for Caucasian neonates. We investigated determinants of age at delivery for Aboriginal neonates.
Ultrasound-derived estimates of gestational age for Aboriginal pregnancies were statistically but not clinically significantly shorter than estimates derived from LMP dates claimed to be certain: mean difference = 0.4 weeks (95% 0:0.09-0.71). Aboriginal gestations were shorter than Caucasians' by 2 weeks (median) or 1 week (mode). Some shortening of gestation was accounted for by antepartum haemorrhage, congenital anomaly, history of syphilis, diabetes, hypertensive disease and inductions before 40 weeks without recorded medical complication but not by full-blood (relative to part-blood) Aboriginality.
We conclude that Caucasian fetometry standards gave gestational estimates acceptably close to those derived from certain menstrual dates for dating scan before 24 weeks. Aboriginal gestations tended to be shorter than Caucasian gestations but since factors recorded in the medical record accounted for little of this difference, socioeconomic factors may be partly responsible.     

Forty weeks and beyond: pregnancy outcomes by week of gestation

OBJECTIVE: To assess pregnancy outcomes at 40, 41, and 42 weeks' gestation when labor induction is done routinely at 42 but not 41 weeks. METHODS: We reviewed all singleton pregnancies delivered at 40 or more weeks' gestation between 1988 and 1998 at Parkland Memorial Hospital, Dallas, Texas. We excluded women with hypertension, prior cesarean, diabetes, malformations, breech presentation, and placenta previa. Labor characteristics and neonatal outcomes of pregnancies at 41 and 42 weeks' gestation were compared with pregnancies that ended at 40 weeks. Women with certain dating criteria had induction of labor at 42 weeks. Gestational age was calculated from the last menstrual period (LMP), sonography when available, and clinical examination. If the fundal height between 18 and 30 weeks was within 2 cm of gestational age, the reported LMP was accepted as correct. Sonogram was used to calculate gestational age if a discrepancy was identified. Statistical analysis consisted of chi(2) and analysis of variance. RESULTS: We studied 56,317 pregnancies: 29,136 at 40 weeks, 16,386 at 41 weeks, and 10,795 at 42 weeks. Labor complications increased from 40 to 42 weeks, including oxytocin induction (2% versus 35%, P <.001), length of labor (5.5 +/- 4.9 versus 8.8 +/- 6. 5 hours, P <.001), prolonged second stage of labor (2% versus 4%, P <.001), forceps use (6% versus 9%, P <.001), and cesarean delivery (7% versus 14%, P <.001). Neonatal outcomes were similar in the three groups, including 5-minute Apgar score less than 4, admission to the neonatal intensive care unit (NICU), umbilical artery pH less than 7, seizures, and perinatal mortality. Sepsis was more frequent in the 42-week group than the other groups (0.1 versus 0.3%, P =. 001), as was admission to the NICU (0.4 versus 0.6%, P =.008). CONCLUSION: Routine labor induction at 41 weeks likely increases labor complications and operative delivery without significantly improving neonatal outcomes.     

First- and second-trimester ultrasound assessment of gestational age

OBJECTIVE: The purpose of this study was to evaluate and compare the accuracy of first- and second-trimester ultrasound assessment of fetal age. STUDY DESIGN: Differences between ultrasound estimated gestational age and true gestational age were calculated between 11 to 14 weeks of gestation and 18 to 22 weeks of gestation for singleton, twin, and triplet pregnancies that were conceived by in vitro fertilization. RESULTS: One hundred four singleton pregnancies, 81 twin pregnancies, and 33 triplet pregnancies were included. First trimester ultrasound estimates overestimated gestational age by a mean (+/- SEM) of 1.3 +/- 0.2 days (P < .0001) for singleton pregnancies, 1.4 +/- 0.2 days (P < .0001) for twin pregnancies, and 0.8 +/- 0.4 days (P = .027) for triplet pregnancies. Second trimester estimates were underestimated by a mean of -0.1 +/- 0.4 days (P = .87) for singletons, -0.6 +/- 0.3 days (P = .083) for twins, and -0.6 +/- 0.5 days (p = 0.21) for triplets. CONCLUSION: Ultrasound assessment of gestational age is very accurate and is marginally better in the first trimester compared with the second.     

Use of Color Doppler to Study the Breathing Patterns of Fetuses of Mothers with Diabetes

The goal of our study was to assess the breathing patterns of the fetuses of the mothers with well-controlled diabetes utilizing color and spectral Doppler technique.

Fetal breathing-related nasal fluid flow was studied over gestational ages 28–40 weeks in 33 pregnancies complicated by diabetes and 62 uncomplicated pregnancies. Glycemic control was determined by fingerstick glucose value at the time of testing and HgbA1C drawn every 6 weeks. Each ultrasound examination consisted of the combination of gray scale imaging with color-flow and spectral Doppler analysis. In each case, 10 breath cycles were averaged for each of the following parameters: inspiratory peak and duration, expiratory peak and duration, and respiratory rate. A comparison of the study and control groups for each of the parameters was achieved by an analysis of covariance (ANACOVA).

With adjustment for gestational age, no differences between the two groups were measured for any of the five parameters studied. However, there was a positive correlation between expiratory peak and gestational age (r = +0.20, P < 0.042) and between expiratory duration and gestational age (r = +0.24, P < 0.011). Respiratory rate was negatively correlated with gestational age (r = -0.32, P < 0.0006)

Since similar fetal breathing patterns are seen across gestation utilizing color flow and spectral Doppler technique in both pregnancies with and without diabetes, this new modality may prove useful in the assessment of fetal well-being in both groups.     

Increased plasma levels of vasoactive intestinal polypeptide in pre-eclampsia

OBJECTIVE--To investigate the plasma vasoactive peptide (VIP) levels in pregnancies complicated by pre-eclampsia. DESIGN--A prospective clinical study. SETTING--University Department of Obstetrics, Troms?, Norway. SUBJECTS--18 women with untreated gestational proteinuric hypertension between 32 and 40 weeks gestation (13 primigravid) and 8 women with normal pregnancies of similar gestational age. INTERVENTIONS--Fasting blood samples on two occasions, 10 min apart. MAIN OUTCOME MEASURES--Plasma VIP measured by radioimmunoassay. RESULTS--Mean maternal plasma VIP was 13.9 (SEM 1.7) pmol/l in those with pre-eclampsia and 4.4 (SEM 0.5) pmol/l in normal pregnancies (P less than 0.0001). CONCLUSION--The increased levels of VIP in pre-eclampsia may represent a powerful compensatory mechanism to restore vascular perfusion of various organs, including the uterus and placenta.     

Outcome of dichorionic diamniotic twin pregnancies with spontaneous PPROM before 24 weeks’ gestation

Objective: The objective of this study is to examine the outcome in dichorionic diamniotic twin pregnancies with rupture of membranes (PPROM) before 24 weeks’ gestation.

Material and methods: Retrospective analysis of fetal and neonatal outcomes in women with spontaneous PPROM before 24 weeks’ gestation that were treated at a single tertiary center.

Results: Twenty-nine pregnancies fulfilled the inclusion criteria. Mean gestational age at the time of PPROM was 20.4 weeks. Two women opted for termination. The remaining 27 (93.1%) women elected for expectant management. Ten (37.0%) of these delivered before 24?+?0 weeks’ gestation. The median gestational age at the time of delivery in the remaining 17 (63%) cases was 26.4 weeks. In those patients that did not deliver within the first 5 days of PPROM, the chance of reaching 24?+?0 weeks was 85%. Co-twins that had PPROM compared with those without PPROM suffered more often from several neonatal complications. Overall, about 40% of the fetuses in the PPROM group and 70% of the non-PPROM group survived without major complications.

Conclusion: Dichorionic diamniotic twin pregnancies with PPROM prior to 24?+?0 weeks’ gestation have a 60% chance of delivering at?>24 weeks. Survival rates without major complications in twins with and without PPROM are 40% and 70%, respectively.     

双胎妊娠分娩时机选择的多中心回顾性分析

目的 降低双胎妊娠围产儿不良预后的发生率，探讨合理的双胎终止妊娠时间。方法 对1993年1月到2003年10月十年期间在上海地区六家医院妇产科分娩的655例双胎妊娠进行回顾性分析，分别计算出各孕周大小胎儿出生体重的百分位数、小于孕龄儿（small for gestational age，SGA）和重度窒息的发生率。结果 1．整个孕期双胎妊娠中小胎儿出生体重的第50百分位数均明显落后于单胎胎儿，33周前大胎儿出生体重的第50百分位数与单胎胎儿接近，33周后差别逐渐增大，39周后大小胎儿出生体重与单胎相比差别更为显著。与单胎妊娠不同，双胎妊娠大胎儿在39周、小胎儿40周达最大出生体重（3073g和2670g），在此之后出生体重反而下降，41周时明显降低（2555g和2303g，P〈0．05）。2．双胎妊娠大小胎儿SGA发生率随孕龄的增加呈上升趋势，39周后上升幅度明显增加，41周达到最高（P〈0．05）。3．39周后小胎儿重度窒息的发生率明显增加。结论 39周后双胎妊娠胎儿出生体重呈下降趋势，SGA及小胎儿围产期重度窒息的发生率明显上升，因此双胎妊娠的分娩时间不应超过39周。     

Preeclampsia and birthweight by gestational age in singleton pregnancies in Flanders, Belgium: a prospective study

PURPOSE: Recent studies have questioned the relationship between low birthweight and hypertension in pregnancy, especially in term pregnancies. We aimed to analyse the influence of chronic hypertension, preeclampsia, gestational hypertension and superimposed preeclampsia on birth weight in singleton pregnancies at different gestational ages. METHODS: Between January 1, 2001 and December 31, 2002 data on hypertension (subdivided in chronic hypertension, preeclampsia, gestational hypertension, superimposed preeclampsia and eclampsia) were collected prospectively for all deliveries in the region of Flanders, Belgium. Multiple pregnancies and patients with diabetes were excluded from analysis. Multiple linear regression was performed to construct a model for the prediction of birthweight and to determine the contribution of hypertension. RESULTS: Hypertension was diagnosed in 5,284 of 111,007 (4.8%) singleton pregnancies, and of these 647 had chronic hypertension (0.6% of the total group), 2,253 (2%) gestational hypertension, 2,244 (2%) preeclampsia and 140 (0.1%) superimposed preeclampsia. Birthweight less than 2,500 g was most frequent in the preeclamptic group and less frequent in case of gestational hypertension, but in all hypertensive groups it was statistically more frequent compared to the normotensive pregnancies. Before 26 weeks' gestational age the presence of any kind of hypertension did not influence birthweight. From 26 weeks on preeclampsia contributed to a lower birthweight. Gestational hypertension resulted in a lower birthweight between 28 and 34 weeks, but not before or after this period. Superimposed preeclampsia only had an effect between 32 and 34 weeks and chronic hypertension only marginally contributed to birthweight. A relation with both a high birthweight (> 4000 g) and birthweight < 2500 g was found in term gestational hypertension and preeclampsia. CONCLUSION: At an early gestational age (less then 26 weeks) hypertension is not a significant factor influencing birthweight. Uncomplicated chronic hypertension is not an important factor determining birthweight but preeclampsia is. Gestational hypertension influences birthweight in a limited period between 28 and 34 weeks of gestational age. When hypertensive pregnancies reach term they tend to result both in more babies weighing < 2,500 g and > 4,000 g.     

Emergency cerclages: a review of 40 consecutive procedures.

This report describes 40 consecutive emergency cerclages on dilated and effaced cervices prior to 26 weeks' gestation. These "emergency" cerclages were associated with a mean extension of gestational age of 12 weeks (range, 3 days to 20.5 weeks). Thirty-one of 40 pregnancies were carried to 28 weeks' gestation and 23 were carried to 34 weeks' gestation or greater. Twelve of 19 women with amniotic membranes bulging into the vagina carried pregnancies to 28 weeks' gestation, with seven of these 19 women carrying the gestation to 34 weeks' or beyond. There was no maternal morbidity. Thirty-four of 41 infants survived (83%). Two pregnancies delivered within 8 days of the procedure. Emergency cerclages should be considered as a management option in women with painless dilation of the cervix and previable gestation.     

Multiple pregnancies. Neonatal morbidity and mortality]

The increase in the number of multiple pregnancies and the high incidence of prematurity in this type of pregnancy justifies a pediatric evaluation. A retrospective study (1985-1989) compared the perinatal and neonatal characteristics of children resulting from 14 multifetal (at least 3 fetuses) pregnancies, with a gestational age of less than 34 weeks, with 27 children resulting from monofetal pregnancies of the same duration. Neonatal morbidity and mortality appeared to be similar in both groups. Thus at this very early time of onset of labour (mean gestational age of 30 weeks), fetal multiplicity expressed itself neither by any particular neonatal pathology nor by malnutrition.     

Prognostic factors for survival of growth-restricted fetuses with absent end-diastolic velocity in the umbilical artery.

OBJECTIVE: The aim of the study was to evaluate the prognostic factors for survival of growth-restricted fetuses with absent end-diastolic velocity in the umbilical artery. STUDY DESIGN: Forty-five intrauterine growth-restricted fetuses with either absent end-diastolic (34 fetuses) or reverse flow (11 fetuses) in the umbilical artery were studied. The clinical characteristics of these pregnancies were determined. Logistic regression analysis was conducted to find the relative value of gestational age at birth, thoracic artery and middle cerebral artery Doppler velocimetry, and short-term variability determined by cardiotochography in the prediction of perinatal mortality. RESULTS: The mean gestational age at birth and birth weight were 30.8+/-2.4 weeks and 972+/-337 g, respectively. The perinatal mortality was 40%. Gestational age at birth was found to have the only significant contribution to the prediction of perinatal deaths. Fetuses with a gestational age at delivery less than 29 weeks died and more than 31 weeks survived. Thoracic artery pulsatility index had the best screening efficiency for predicting perinatal mortality between 29 and 31 weeks gestational age. CONCLUSION: Absent end-diastolic velocity in the umbilical artery is mainly a problem of severe preterm growth-restricted fetuses and is associated with high perinatal mortality. The major and dominant influence on survival is gestational age at birth.     

Effect of chronic intrauterine stress on the disappearance of tunica vasculosa lentis of the fetal eye: a neonatal observation

We performed ophthalmologic examinations on 180 neonates (27 to 34 weeks gestational age) shortly after birth, and disappearance of the anterior capsule of the lens vessels was used to estimate gestational age. Three groups of patients were studied: I: chronic hypertension (n = 80); II: preeclampsia (n = 60); III: normal pregnancies (n = 40). The gestational age was also determined by a reliable menstrual history or early ultrasound examination, or both, and Ballard's scoring and compared with that assessed by grading of the anterior vascular capsule of the lens. We found a significant acceleration of gestational age in vascular capsule of the lens when maternal chronic hypertension existed. This study shows that chronic intrauterine stress results in the disappearance of the tunica vasculosa lentis of the fetal eye and therefore suggesting accelerated maturation of this vascular compartment.     

Delayed interval delivery in multiple pregnancies. Is optimism justified?

OBJECTIVE: Evaluation of the success of delayed interval delivery in multiple pregnancies. METHOD: Retrospective analyses of all multiple pregnancies with the birth of one child at a gestational age of 16-31 weeks (n=80). Three groups were defined: group I, unsuccessful attempt to temporize delivery, group II, interval between the first child and the other child or children 3 hours or more, with delivery of the remaining children before 28 weeks and group III, prolongation of pregnancy beyond 28 weeks. RESULTS: In 15 multiple pregnancies (ten sets of twins, five sets of triplets), the aim was to postpone the delivery of the second (and third) child. The mean gestational age at admittance was 25 weeks. Delay of the delivery of the second child was achieved in ten cases, five in group II and five in group III. In groups II and III, the mean interval of delivery was 12 days; the gestational age at the delivery of the remaining children in these ten patients was 27 5/7 weeks. No relation could be found between the reason for admittance and the interval in delivery between the first and the other children. The only severe maternal complication was blood loss exceeding 2 liters. In the neonatal outcome of first and second children (with a gestational age of 28 weeks or more) no striking differences were observed. CONCLUSION: Delayed delivery in multiple pregnancies after the birth of the first child is only successful in a minority of patients and should be considered prior to the birth of the first child.     

Weight adjustment of serum markers in early first-trimester prenatal screening for Down syndrome

OBJECTIVE: To assess whether existing weight correction formulas for PAPP-A and free-beta-hCG developed for weeks 11 to 14 can be applied to pregnancies in weeks 8 to 10. METHODS: Development of formulas based on limited data sets of 8- to 10-week pregnancies and comparison with existing formulas. Calculation of median MoMs adjusted with different formulas for weight correction. RESULTS: Weight correction formulas for the gestational age of 11 to 14 weeks were not appropriate in the 8- to 10-week gestational age interval for PAPP-A, whereas existing weight correction formulas could be applied to free-beta-hCG, independent of gestational age interval. CONCLUSION: If PAPP-A is used in different gestational age intervals, weight corrections should be developed for the interval.     

Effect of spontaneous pregnancy reduction on obstetric outcome

OBJECTIVE: To determine if obstetric outcome is compromised in pregnancies in which a spontaneous pregnancy reduction (SPR) occurred in the first trimester. STUDY DESIGN: Case-control study. RESULTS: First-trimester SPR was diagnosed in 29 (27.8%) of 104 twin pregnancies, 14 (28.6%) of 49 triplet pregnancies and 10 (28.6%) of 35 quadruplet pregnancies. Of these 53 patients, 15 were excluded from the analysis. In the remaining 38 women with SPR, vaginal bleeding occurred in 2 (5.3%) as compared to 7 (8.3%) of the controls. Pregnancy-induced hypertension occurred in 4 (10.5%) of SPR pregnancies as compared to 9 (10.7%) of control pregnancies. When compared to respective controls, there were no significant differences in the birth weights or gestational age at delivery of pregnancies spontaneously reduced to singletons (SPR, 38.5 weeks; controls, 38.2 weeks), twins (SPR, 36.2 weeks; controls, 34.4 weeks) or triplets (SPR, 31.0 weeks; controls, 32.0 weeks). CONCLUSION: SPR can be recognized in >25% of multiple pregnancies diagnosed in the early first trimester. Our data suggests that SPR is not associated with decreased gestational age at delivery, reduced birth weight or increased incidence of pregnancy-induced hypertension.