Neonatal morbidity and mortality associated with maternal haemolysis elevated liver enzymes and low platelets syndrome

To compare the impact of maternal haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome, uncomplicated hypertension in pregnancy (HIP), and no hypertension (controls) on neonatal morbidity and mortality, 108 infants were matched with respect to gestational age, date of birth, and gender. The HELLP group infants had more grade 3 and 4 respiratory distress syndromes (36%) than the HIP group (19%) or controls (11%). Cardiovascular instability (arterial hypotension, volume resuscitation) was significantly more common in HELLP neonates (20% and 31%) than in HIP infants (9% and 6%) or controls (3% and 9%). Both, HELLP and HIP infants showed a higher incidence of growth retardation than the controls. After 32 weeks of gestation the incidence of severe neonatal morbidity was not different. Conclusion Before 32 weeks of gestation both respir-atory and cardiovascular morbidity and intra-uterine growth retardation associated with HIP is further aggravated by a maternal HELLP syndrome. Received: 31 May 1996 / Received in revised form and accepted: 3 October 1996     

Neonatal morbidity and mortality associated with maternal HELLP syndrome

The syndrome of hemolysis, elevated liver enzymes and low platelet count (HELLP syndrome) is a severe form of preeclampsia and eclampsia. To compare the impact of HELLP syndrome and hypertension in pregnancy (HIP) on neonatal morbidity and mortality, 11 infants born to mothers with HELLP syndrome were recruited between 1993 and 1997 from neonatal records. They were compared to 11 infants born to mothers with HIP and 11 control infants born to healthy mothers matched for gestational age, postnatal age and gender. Cesarean section rate was higher in the HELLP group than in the controls (p < 0.05). HELLP group infants had lower Apgar scores (54.5% < 1 at 5th min), than controls (9.1%) (p < 0.05). Both HELLP and HIP group infants showed a higher incidence of intrauterine growth retardation (63.6% and 54.5%, respectively) than the controls (9.1%) (p < 0.05). The incidence of respiratory distress syndrome (RDS) was similar in HELLP and HIP groups and was greater than that in controls (p = NS). Additionally, the neonatal death rate was the highest in the HELLP group (p = NS).     

Maternal haemolysis, elevated liver enzymes and low platelets syndrome: perinatal and neurodevelopmental neonatal outcomes for infants weighing less than 1250 g

OBJECTIVES: To study mortality and short-term morbidity of infants born to women with HELLP (haemolysis, elevated liver enzymes, and low platelets) syndrome and to compare the long-term neurodevelopmental morbidity of a subgroup with birth weight (BWT) less than 1250 g (study group) with weight matched controls. METHODS: Retrospective chart review and prospective neurodevelopmental follow-up through a Perinatal Follow-up clinic. Analysis of perinatal and neonatal data for women diagnosed with HELLP from 1993 to 1996. Neurodevelopmental outcome for the study group was compared to a group of weight matched controls. RESULTS: A total of 109 infants (mean gestational age 32.6 weeks, mean BWT 1766 g) were born to 104 women with HELLP syndrome. There was a significant decrease in mortality (P = 0.002) and morbidity (P < 0.05) with increasing gestational age and birthweight. No significant differences in neonatal mortality and morbidity were present between the infants weighing less than 1250 g study and weight matched control group. However, at 3 years, the study group had fewer children with cerebral palsy (P = 0.024) and mental disability (P trend = 0.07). Mean cognitive index was 99 versus 91 in the controls (P = 0.101). CONCLUSION: Improved health outcomes occur with increased gestational age. Infants with BWT less than 1250 g born to women with HELLP syndrome were not at risk of increased neurodevelopmental disability compared to controls.     

Transient proteinuria in an infant born to a mother with HELLP syndrome

The syndrome of haemolysis, elevated liver enzymes and low platelet count (HELLP syndrome) is a severe form of pre-eclampsia and eclampsia associated with poor maternal and neonatal outcome. We report here the case of an infant born to a mother with HELLP syndrome. The infant was initially diagnosed as having nephrotic syndrome but after a follow-up period of 25 days proteinuria and oedema had disappeared. CONCLUSION: to our knowledge, transient proteinuria with maternal HELLP syndrome has not been previously described in the literature.     

Lung maturation in small for gestational age fetuses from pregnancies complicated by placental insufficiency or maternal hypertension

BACKGROUND: Clinical studies suggest that respiratory outcome of infants born preterm may be influenced by placental insufficiency and hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome. If so, one could expect to see differences in lung maturation indices (lecithin/sphingomyelin (L/S) ratio and lamellar body count (LBC)) in the amniotic fluid. The present study investigates lung maturation indices of preterm small for gestational age (SGA) fetuses with or without abnormal Doppler ultrasound examination and with or without maternal hypertension/HELLP syndrome. STUDY DESIGN: Retrospective cohort study of 76 neonates born in our center between 1997 and 2003 with gestational age (GA) <34 weeks, birth weight 相似文献   

Outcome of hospital deliveries of women living at high altitude: a study from Lhasa in Tibet

AIM: To describe rates of neonatal mortality, low birthweight (LBW), preterm birth and small for gestational age (SGA), and relate outcome to ethnicity and perinatal risk factors of liveborn infants of hospital deliveries in Lhasa. The differences in these variables between ethnic Tibetans and non-Tibetans were also studied. METHODS: Data were prospectively collected on the outcome of all liveborn infants born in four hospitals in the urban area of Lhasa, Tibet, in 2005. RESULT: A total of 2540 liveborn infants were recorded. The rates of LBW, preterm birth and SGA were 13.6%, 5.7% and 22.2%, respectively. Neonatal mortality rate was 42/1000 for the infants born alive in the hospitals. Lower GA, vaginal delivery, foetal distress and lack of prenatal care, but not ethnicity, were associated with increased risk of death in multivariate logistic regression. Tibetans had higher BW and lower rates of LBW, SGA, need of oxygen supplementation and maternal hypertension, but higher rates of foetal distress, caesarean section, multiple births and low Apgar scores. CONCLUSION: This study provided a profile of perinatal-neonatal care of hospital newborn infants in Lhasa, Tibet. The rates of neonatal mortality, LBW and SGA were high. The findings suggest ethnic differences in perinatal-neonatal adaptation to high altitude.     

Infants of mothers with HELLP syndrome compensate intrauterine growth retardation faster than unaffected premature infants: does HELLP change fetal programming?

OBJECT: To investigate the influence of HELLP (hemolysis, elevated liver enzymes and low platelet count) pregnancies on the postpartal course and further development of the neonate. METHODS: The postnatal course and further development up to 4 years of age of 43 infants after pregnancies complicated by HELLP syndrome were evaluated. 43 unexposed infants matched for gestational age and gender served as controls. RESULTS: Small-for-gestational age (SGA) neonates exhibiting hypoglycemia and hypoproteinemia during the first 4 weeks after birth were significantly more commonly observed in the HELLP group (p < 0.5). No other differences in the postpartal course or clinical outcome were detected. At the age of 4 years the gains in weight and length were significantly increased in the HELLP group (p < 0.01). CONCLUSION: The postnatal course of newborns after HELLP pregnancies is influenced by low energy stores. Fetal programming toward a more efficacious GH-IGF-1 pathway may explain the faster postnatal catch-up growth of premature SGA infants born to mothers with HELLP syndrome.     

The Pediatric Investigators Collaborative Network on Infections in Canada (PICNIC) study of neonatal group B streptococcal infections in Canada

OBJECTIVES:

To determine the presentation and medical outcomes of neonatal group B streptococcus (GBS) disease in Canada, and describe maternal and obstetrical risk factors.

DESIGN:

Retrospective review of health records and laboratory databases using standardized data collection forms.

SETTING:

All neonates diagnosed with GBS infections in 1992 at 13 Canadian paediatric centres.

RESULTS:

A total of 105 infants meeting the criteria for neonatal GBS disease were identified. The majority of cases (78 or 74.3%) had early-onset disease (EOD); 78.9% (60 of 76) of these cases presented within 24 h of delivery. Rates of EOD (less than seven days) varied from 0.44/1000 live births to 2.1/1000 live births, with an overall rate of 1.2/1000 live births. Pneumonia was the most common clinical illness (43.8%), followed by bacteremia without focus (23.8%) and meningitis (16.2%). At least one maternal risk factor for neonatal GBS disease was noted in 46 of 78 (59%) infants with EOD. A median of one dose (range one to 23 doses) of intrapartum antibiotics was given in 18 of 75 (24%) of the pregnancies. Overall, the mean gestational age at birth was 36.2±4.7 weeks, with 38 of 96 (39.6%) infants having a gestational age at birth younger than 37 weeks (31 of 73 [42.5%] EOD cases were born with a gestational age younger than 37 weeks). The median birth weight was 3099 g (range 610 g to 4830 g). Thirty of 94 (31.9%) infants had a birth weight less than 2500 g. Seventeen (16.2%) infants died.

CONCLUSIONS:

In 1992, neonatal GBS disease was a significant cause of morbidity and mortality in Canadian infants. More than half of the cases identified in this study could have been potentially preventable by the use of intrapartum antibiotics for women with known risk factors. There is a need for prospective studies to better define risk factors and preventative measures for neonatal GBS infections in Canada.     

Complicaciones neonatales del síndrome HELLP

IntroductionHELLP syndrome is a variant of pregnancy-induced hypertension that is associated with significant maternal and perinatal morbidity and mortality. The aim of our study was to investigate the neonatal complications associated to this syndrome.Patients and methodA retrospective observational study was carried out on all newborns of mothers with HELLP syndrome in Virgen del Rocio hospital from 1995 to 2005. There were 120 newborns of 99 mothers with HELLP syndrome. Gestational age, birth weight, length, skull perimeter, number of hospital admissions and mortality were analyzed. The birth weight, length and skull perimeter were compared with a healthy population of the same gestational age using Lubchenco charts. The statistical relationships were determined between the mothers’ platelet counts and the birth weight and perinatal mortality.ResultsA total of 80% of pregnancies were preterm delivery with a mean gestational age of 33 weeks. Mean birth weight was 1,834 g, length 41 cm and skull perimeter 29 cm. A third of newborns had fetal growth restriction. 61% of newborns needed admitting to hospital due to prematurity and low birth weight. There were 24 perinatal deaths. We did not find any correlation between the number of platelets of the mother and birth weight or perinatal mortality.ConclusionsHELLP syndrome is an uncommon but potentially serious complication of pregnancy which is associated with an increased risk of adverse maternal and fetal outcome.     

Thrombocytopenia related neonatal outcome in preterms

Objective To investigate the thrombocytopenia and platelet transfusion related outcome in very preterm infants. Methods Cases (n=94) with at least one episode of thrombocytopenia (platelet counts <150X10⁹/L) and controls (n=70) were identified from a database of 1054 neonates with gestational age ≤32 weeks admitted to a level III NICU. Thrombocytopenia and platelet transfusion related morbidity (IVH, sepsis, NEC, and bleeding) and mortality were analyzed with respect to gestational age (<28 weeks and 28–32 weeks), severity of thrombocytopenia (mild if platelet count ≥ 100 and <150X10⁹/L, moderate if count ≥ 50 and <100X10⁹/L, and severe if platelets <50X10⁹/L), age of thrombocytopenia onset (early <72 hours and late ≥72 hours). Results The majority of thrombocytopenia (67.0%) was diagnosed after 72 hours of age, and was mild in 12.8%, moderate in 36.2% and severe in 51.0% of the cases. Neonates with severe and moderate thrombocytopenia were more frequently born at lower gestational age and birth weight. NEC and sepsis especially that caused by Candida infection, were associated with severe thrombocytopenic events. The development of IVH was strongly associated with lower gestational age but not the severity and age of thrombocytopenia onset. Mucocutaneous bleeding complicated 18.4% of cases with severe and late-onset thrombocytopenia (7/38). Platelets were transfused to 85.4% of infants with severe and 64.7% of infants with moderate thrombocytopenia (P<0.02). The gestational age of the majority of the platelet transfused neonates (49/60, 81.7%) was <28 weeks. Mean gestational age and birth weight, and rates of severe thrombocytopenia, IVH, sepsis and mortality were comparable in transfused vs not-transfused infants with gestational age 28–32 weeks. Platelet transfused neonates with gestational age <28 weeks had lower birth weights, were more often severely thrombocytopenic, and died more frequently than infants of a similar gestational age who were not transfused. Conclusion Platelet transfusions did not lower mortality in very premature born infants with moderate and severe thrombocytopenia during the NICU admission.     

Underlying maternal and pregnancy‐related conditions account for a substantial proportion of neonatal morbidity in late preterm infants

Aim

We studied the impact of maternal and pregnancy‐related conditions and the effect of gestational age itself, on the health of infants born late preterm.

Methods

Singletons born in gestational weeks 34 + 0 to 41 + 6 in 1995–2013 in the southern region of Sweden were identified from a perinatal register. We found 14 030 infants born late preterm and 294 814 born at term. A hierarchical system was developed to examine the impact of pregnancy complications. The outcomes studied were as follows: neonatal death, central nervous system (CNS) or respiratory disease, infection, neonatal admission and respiratory support. Odds ratios (OR) and 95% confidence intervals (95% CI) were obtained using logistic regression analyses.

Results

Late preterm infants were at increased risk for all outcomes compared to term infants, with adjusted ORs from 13.1 (95% CI: 12.7–13.6) for neonatal admission to 2.3 (95% CI: 1.8–2.9) for infections. Late preterm birth after preterm prelabour rupture of membranes was associated with an overall lower risk compared to late preterm births due to other causes. Exposure to antepartum haemorrhage or maternal diabetes increased the risk for CNS and respiratory morbidity.

Conclusion

Morbidity decreased in late preterm infants with increasing gestational age. Underlying conditions accounted for a substantial part of the morbidity.     

Neonatal complications of extreme prematurity in mechanically ventilated infants

Previous data have suggested that neonatal complications amongst preterm ventilated infants increase with decreasing gestational age and thus are likely to be greatest among ventilated infants of less than 28 weeks gestational age. The aim of this study was to test that hypothesis, thus we report the neonatal complications of 175 extremely preterm mechanically ventilated infants (gestational age 28 weeks). Of the infants 152 were ventilated because of respiratory distress syndrome (RDS) or respiratory distress of severe prematurity, 41% of these infants died. Amongst infants with RDS or respiratory distress of extreme prematurity, mortality was significantly increased in infants of gestational age 24 weeks and birth weight 1000 g. In this group 20% developed a pneumothorax, and mortality was inversely related to gestational age. In infants with RDS, 43% developed a periventricular haemorrhage and 37% were still oxygen-dependent at 28 days of age; neither of these complications was significantly related to birth weight or gestational age. Of infants with RDS 38% developed a patent ductus arteriosus and 16% developed retinopathy of prematurity. These data suggest that even amongst very immature infants there has been an impressive reduction in the neonatal complications of mechanical ventilation.     

The thrombopoietin level in the cord blood in premature infants born to mothers with pregnancy-induced hypertension

OBJECTIVE: To investigate the level of thrombopoietin in the cord blood of preterm infants, and its relationship with neonatal platelet count and pregnancy-induced hypertension. STUDY METHOD: Thrombopoietin levels in the cord blood of preterm neonates, with or without maternal pregnancy-induced hypertension, were measured by enzmye-linked immunosorbent assay. RESULTS: The platelet count was significantly lower in very low birth weight infants, infants with maternal pregnancy-induced hypertension, and infants with maternal thrombocytopenia. Neonatal thrombocytopenia was associated with maternal pregnancy-induced hypertension and very low birth weight. The neonatal platelet count was correlated significantly with the birth weight and the maternal platelet count. There was no difference in the cord blood level of thrombopoietin between infants born to mothers with pregnancy-induced hypertension and those without. No correlation was found between the thrombopoietin level and the neonatal platelet count. A positive correlation between the cord blood thrombopoietin and the maternal platelet count was identified. CONCLUSIONS: Maternal pregnancy-induced hypertension and very low birth weight were significantly associated with thrombocytopenia in premature infants, which cannot be explained by decreased thrombopoietin level.     

Association of Neonatal Thrombocytopenia and Maternal Anti-HLA Antibodies

In order to evaluate the influence of maternal anti-HLA antibody on neonatal thrombocytopenia, clinical features and maternal anti-HLA antibody of three groups of infants (19 thrombocytopenic and low birth weight, 27 nonthrombocytopenic and low birth weight, and 80 healthy full-term) were investigated. The incidence of positive maternal anti-HLA antibodies in the three groups was 73.7%, 29.6% and 27.5%, respectively. Thrombocytopenia in small-for-gestational-age (SGA) infants was closely related to the presence of maternal anti-HLA antibodies. Among 20 SGA infants (11 thrombocytopenic, 9 non-thrombocytopenic), anti-HLA antibody was detected in 10 mothers (90.9%) of thrombocytopenic SGA infants, while it was positive in only one mother (11.1%) of nonthrombocytopenic SGA infants. Investigation of the SGA infants revealed that in those whose mothers were sensitized to HLA antigen, not only the platelet count but also the leukocyte and lymphocyte counts in the first week of life were significantly lower than in infants whose mothers were not sensitized. The results suggest that the presence of maternal anti-HLA antibody is a cause of neonatal thrombocytopenia especially in SGA infants.     

Necrotizing enterocolitis in very low birth weight infants: biodemographic and clinical correlates. National Institute of Child Health and Human Development Neonatal Research Network

We studied the occurrence of necrotizing enterocolitis in 2681 very low birth weight infants during an 18-month period to characterize the biodemographic and clinical correlates. Proven necrotizing enterocolitis (Bell stage II and beyond) occurred in 10.1% of study infants; necrotizing enterocolitis was suspected in 17.2% of study infants. Positivity of blood cultures was related to necrotizing enterocolitis staging. The mortality rate increased only for stage III necrotizing enterocolitis (54% died). Logistic regression identified medical center of birth, race, gender, birth weight, maternal hemorrhage, duration of ruptured membranes, and cesarean section as significant risk factors. For one center the odds ratio was 3.7, whereas for another center it was only 0.3. For black boys, the odds ratio was 2.3 relative to nonblack boys; for girls, race did not affect prevalence of necrotizing enterocolitis. Age at onset was related to birth weight and gestational age. Intercenter differences in necrotizing enterocolitis prevalence were related to time required to regain birth weight and other indicators of fluid management. Gram-positive organisms predominated in positive blood cultures for stage I and II necrotizing enterocolitis; enteric bacteria were isolated more frequently in infants with stage III disease. We conclude that necrotizing enterocolitis prevalence varies greatly among centers; this may be related to early clinical practices of neonatal care.     

Randomized double blind trial of Ambroxol for the treatment of respiratory distress syndrome

In order to test the ability of Ambroxol to improve the clinical course of respiratory distress syndrome and to reduce the incidence of complications a multicentre, randomized, placebo-controlled double-blind trial was conducted. Entry was limited to infants with a birth weight below 1500g. A total of 179 neonates were enrolled, but 31 were later excluded because they had other diseases. Of the remaining 148 babies, 74 received Ambroxol (birth weight 1190±216g; gestational age 29.1±1.9 weeks) and 74 placebo (birth weight 1168±216g; gestational age 28.9±1.9 weeks). In the Ambroxol group 23 (31%) and in the placebo group 27 (37%) infants died during the first 5 months of life. In 28 day-survivors Ambroxol was able to significantly improve the P_aO₂/FiO₂ ratio, mean airway pressure, phospholipid profile of tracheal effluent and pulmonary mechanics of spontaneously breathing infants. In addition, the incidences of bronchopulmonary dysplasia (29% vs 54%), intraventricular haemorrhage (25% vs 44%) and postnatally acquired pneumonia (15% vs 36%) were significantly reduced in the Ambroxol group as compared to the control group. No adverse events attributed to the Ambroxol treatment were reported.     

吸毒孕妇所生新生儿临床结局分析

目的 分析吸毒孕妇围生儿的临床结局.方法 回顾性分析105例吸毒孕妇所生新生儿的临床资料,包括早产儿、低体重儿、新生儿窒息、新生儿呼吸窘迫综合征(neonatal respiratory distress syndrome,NRDS)、颅内出血、先天畸形及死亡,并与50例健康孕妇所生的新生儿(对照组)进行比较,同时观察新生儿戒断综合征的发生情况.结果 105例吸毒孕妇中,自然分娩80例,剖宫产25例.早产56例(53.3％),平均出生体重(2 534±1 234)g,新生儿窒息25例(23.8％),NRDS 18例(17.1％),颅内出血16例(15.2％),先天畸形3例(2.9％).吸毒孕妇所生新生儿胎龄及出生体重低于对照组,吸毒孕妇围生儿发生早产、低体重儿、新生儿窒息、NRDS及颅内出血的比例高于对照组,差异有统计学意义(P＜0.05).与吸毒时间≤2年者比较,吸毒时间＞2年者所生新生儿早产、低体重儿、新生儿窒息、NRDS的比例更高,差异有统计学意义(P＜0.05).静脉注射吸毒孕妇发生早产、低体重儿、新生儿窒息、NRDS的比例高于口服吸毒者,差异有统计学意义(P＜0.05).吸毒组新生儿红细胞、白细胞、天门冬氨酸氨基转移酶、丙氨酸转氨酶高于对照组,血小板及白蛋白低于对照组,差异有统计学意义(P＜0.05).共30例新生儿出现新生儿戒断综合征表现.105例新生儿中治愈99例,死亡6例,死亡原因包括3例NRDS合并肺部感染,1例严重颅内出血,1例窒息,1例多器官功能衰竭.结论 吸毒会导致新生儿早产增加,窒息及NRDS的比例升高.妊娠晚期吸毒会导致新生儿戒断综合征.     

胎龄≤32周早产儿低血糖的危险因素分析

目的 探讨胎龄≤32周早产儿出生后发生低血糖的危险因素。方法 回顾性纳入2017年1月至2020年6月入住新生儿重症监护病房的86例胎龄≤32周低血糖早产儿作为低血糖组,随机选取同期住院监测血糖正常的早产儿172例为对照组。采用单因素分析与多因素logistic回归分析筛选早产儿低血糖的危险因素。结果 研究期间早产儿共计515例,其中低血糖86例（16.7%）。低血糖组小于胎龄儿（SGA）、剖宫产出生、孕母高血压、产前使用激素的比例均高于对照组（P < 0.05）,而出生体重及血糖检测前已静脉使用葡萄糖的比例均低于对照组（P < 0.05）。SGA（OR=4.311,95% CI：1.285~14.462）、孕母高血压（OR=2.469,95% CI：1.310~4.652）和产前使用激素（OR=6.337,95% CI：1.430~28.095）为早产儿低血糖的危险因素（P < 0.05）,静脉使用葡萄糖（OR=0.318,95% CI：0.171~0.591）为早产儿低血糖的保护因素（P < 0.05）。结论 SGA、孕母高血压和产前使用激素可增加胎龄≤32周早产儿早期发生低血糖的风险;对胎龄≤32周早产儿,建议生后尽早静脉使用葡萄糖,以减少低血糖的发生。     

Incidence of thrombocytopenia in infants born to mothers with idiopathic thrombocytopenic purpura

Abstract Neonatal thrombocytopenia related to maternal idiopathic thrombocytopenic purpura (ITP) is reportedly uncommon but may have severe complications. The present report reviews records of 15 infants born to mothers with ITP during a 10-year period, and the incidence of neonatal thrombocytopenia and the risk of hematological complications is examined. Severe thrombocytopenia (platelets < 50 000/μL) was seen in three infants despite successful therapy with high-dose gamma globulin prior to delivery, which elevated maternal platelet counts. Although the platelet counts of these three infants fell to < 10 000/μL, none had severe complications. Moreover, no infants required treatment such as adrenocorticosteroids, platelets transfusion, or high doses of gamma globulin. No maternal markers predicted the degree of neonatal thrombocytopenia. The risk of complications arising from neonatal thrombocytopenia is low, but careful observation is required for the thrombocytopenic newborn of ITP mothers even when the infant has no bleeding complications at delivery.     

Safety of term birth and cesarean birth rates

This was a parallel of the rate of caesarean section and neurological morbidity of the term newborn. This study was performed on all infants born at a gestational age of 37 weeks or greater in 1981 and 1982 at the Baudelocque Maternity Hospital. The results show a stable caesarean section rate during these two years: 21% in 1981, 20% in 1982; as for the safety of term birth there was only one case of perinatal insult during a vaginal birth responsible for cerebral dysfunction of moderate degree. There was a 18% operative maternal morbidity and there were no deaths. We concluded that a caesarean section rate of 20% in a University Hospital is justified by the virtual absence of neonatal morbidity with an acceptable maternal risk. This rate should not increase. The possible ways of decreasing this rate, while maintaining neonatal safety, must be studied. The original aspect of this work concerns the monitoring of the caesarean section rate by the incidence of neurological complications of all term births during a fixed period of time.