Risk of cesarean section in singleton pregnancies after assisted reproductive techniques

OBJECTIVE: To evaluate the perinatal outcome of singleton pregnancies after assisted reproductive techniques in comparison with that in matched controls from spontaneous pregnancies. STUDY DESIGN: A total of 11,776 deliveries from January 1, 1995, to May 31, 2001, were subjected to retrospective analysis. Data on 259 neonates from singleton pregnancies after ovulation induction (n = 85, 32.8%), intrauterine insemination (n = 17, 6.6%) or in vitro fertilization (n = 157, 60.6%) were evaluated. The pregnancy outcome was compared with that for controls (n = 518) matched for age, gravidity and parity after spontaneous pregnancies. RESULTS: Cesarean section was significantly more frequent in the study group than in the control group (42.1% vs. 27.6%, P < .001, odds ratio [OR] 1.91, 95% confidence interval [CI] 1.39-2.61). The prevalence of preterm deliveries was not significantly higher (P = .40, OR 1.23, 95% CI .78-1.95) in the study group as compared with the controls (12.7% vs. 10.6%). There was no significant difference in intrauterine growth retardation between the two groups (9.3% vs. 6.2%, P = .14, OR 1.55, 95% CI .89-2.69). CONCLUSION: Singleton pregnancies after assisted reproductive techniques are associated with an increased rate of cesarean section, whereas neonatal outcome is not influenced.     

Perinatal outcome of pregnancies after assisted reproduction: a case-control study.

OBJECTIVE: We conducted a case-control study of all pregnancies obtained with assisted reproduction technology in the Dutch-speaking part of Belgium from 1992 until 1997 to investigate differences in peripartum obstetric events and the perinatal outcome. STUDY DESIGN: Three thousand fifty-seven singleton and 1241 twin pregnancies were studied. About 90% of pregnancies resulted from in vitro fertilization; the remainder resulted from intracytoplasmic sperm injection. Control subjects were selected from a regional register and were matched for maternal age, parity, fetal sex, plurality, and date of delivery. The main outcome measures were duration of gestation, birth weight, perinatal death, perinatal morbidity, incidence of congenital malformations, and incidence of cesarean delivery. RESULTS: Odds ratios and 95% confidence intervals were 2.6 (1.4-4.8) for perinatal mortality, 3.5 (2.2-5.7) for birth before 33 weeks of gestation, and 1.7 (1.5-1.9) for cesarean delivery in singleton pregnancies that resulted after in vitro fertilization. Twin pregnancies obtained with in vitro fertilization, on the contrary, were similar for all outcome measures, except for the incidence of cesarean delivery (odds ratio, 1.4; 95% confidence interval, 1.2-1.7) compared with spontaneously conceived twin pregnancies. CONCLUSION: The perinatal outcome of singleton pregnancies obtained with in vitro fertilization is significantly worse than that of spontaneously conceived pregnancies, mainly because of the increased rate of preterm birth. The outcome of twin pregnancies obtained with in vitro fertilization is comparable with that of normally conceived twins. For both singleton and twin pregnancies obtained with in vitro fertilization, the incidence of cesarean delivery is increased.     

Perinatal Outcome of Pregnancies After Assisted Reproduction: A Case–Control Study

Purpose: A matched case–control study of all pregnancies obtained after either IVF or ICSI was conducted to investigate the perinatal outcome. Methods: Three hundred eleven singleton and 115 twin pregnancies obtained after assisted reproduction were studied. Controls were selected from a regional register and were matched for maternal age, parity, singleton or twin pregnancy, and date of delivery. Results: No significant difference was observed for gestational age at delivery, birth weight, incidence of congenital anomalies, and incidence of perinatal mortality between ART (singleton and twin) pregnancies and spontaneous controls. ART twin pregnancies showed a higher incidence of preterm deliveries than control pregnancies (52 vs 42%; P < 0.05) and needed more neonatal intensive care (47 vs 26%; P < 0.05). Conclusions: From this case–control study it is concluded that the perinatal outcome of ART singleton pregnancies is not different from that in matched controls. ART twin pregnancies showed a higher incidence of preterm deliveries than control pregnancies and needed more neonatal intensive care.     

Clinical Assisted Reproduction: Are Singleton Assisted Reproductive Technology Pregnancies at Risk of Prematurity?

Purpose: Our purpose was to determine the risk of premature delivery among singleton pregnancies derived from assisted reproduction technology (ART).Methods: Ninety-five singleton ART pregnancies and 190 matched spontaneous pregnancies were assessed for preterm delivery rates, pregnancy complications, and cesarean section rates in a retrospective study at an academic medical center.Results: Among the ART singleton deliveries group (n = 95), 19 (20%) were preterm, which was statistically significantly higher than the 4% (8 of 190) found in the control group. Among the pregnancies achieved by intracytoplasmic sperm injection (ICSI) in the severe male-factor infertility subgroup (n = 22), only one preterm delivery occurred (4.5%).Conclusions: Singleton ART pregnancies are at an increased risk of preterm delivery compared to singleton pregnancies after spontaneous conception. The higher rate may be attributed to various infertility cofactors, such as uterine malformations, previous operative procedures that involved cervical dilatation, and a history of pelvic infection. This is supported by the finding that ICSI-derived pregnancies in couples with strict male-factor infertility are not at an increased risk of preterm delivery.     

Pregnancy complications,obstetric risks,and neonatal outcome in singleton and twin pregnancies after GIFT and IVF

Purpose In vitro fertilization (IVF) and to a lower extent gamete intra-fallopian transfer (GIFT) have become routine infertility treatments in industrialized countries. Our purpose is to compare the obstetric and neonatal characteristics of singleton and twin pregnancies after GIFT and IVF with those conceived spontaneously.Methods This case-control study was conducted in a tertiary care medical center. The 322 singleton and 78 twin pregnancies after GIFT or IVF from 1991 through 1996 were evaluated and compared with each other, and with a control group that conceived spontaneously and matched for parity, maternal and gestational age. Statistical significance of differences was assessed by ² test or two-tailed Fisher exact test. Continuous variables were compared by the paired t-test.Results Pregnancy-induced hypertension (PIH) and vaginal bleeding were significantly more frequent maternal complications in the GIFT/IVF singleton groups compared to controls. In twin pregnancies the rate of cesarean sections, vaginal bleeding and preterm labor were more common after GIFT/IVF but did not reach statistical significance. Assisted reproduction was associated with low birth weight only in twin pregnancies when controlled for confounding variables, however perinatal outcome was comparable. There was no significant difference in the outcome measures between GIFT and IVF pregnancies.Conclusion After controlling for parity, maternal and gestational age, singleton pregnancies conceived by GIFT/IVF are at increased obstetrical risk, however the perinatal outcome is comparable despite a lower average birth weight.     

Obstetric outcome of in vitro fertilization pregnancies compared with normally conceived pregnancies.

OBJECTIVE: To compare the obstetric outcome of in vitro fertilization pregnancies with normally conceived pregnancies. STUDY DESIGN: The obstetric outcome of in vitro fertilization pregnancies achieved in 763 British residents at two in vitro fertilization clinics resulting in the births of 961 babies were compared by means of the relative risk statistic with a control group of naturally conceived primiparous pregnancies matched by maternal age and multiplicity of pregnancy. RESULTS: Twenty-five percent of in vitro fertilization pregnancies were multiple pregnancies. The incidence of singleton term breech presentation was similar to that among controls. As compared with controls there was an increased incidence among in vitro fertilization pregnancies of vaginal bleeding and hypertension requiring hospitalization (p less than 0.001) and cesarean births (p less than 0.001) and, among in vitro fertilization singleton pregnancies, an increased incidence of intrauterine growth retardation (p less than 0.05), placenta previa (p less than 0.05), and preterm delivery (p less than 0.001). The congenital malformation, stillbirth, and perinatal mortality rates were comparable with maternal age-standardized national rates. CONCLUSIONS: Although the majority of in vitro fertilization pregnancies have a satisfactory obstetric outcome, there are a number of increased obstetric risks that may reflect the history of infertility, the relatively high incidence of poor obstetric history, and the lower threshold for obstetric intervention in in vitro fertilization patients.     

Is the obstetric outcome of in vitro fertilized singleton gestations different from natural ones? A controlled study

Objective: To determine whether singleton IVF pregnancies carry adverse maternal or fetal outcome when compared with naturally conceived gestations.

Design: An analysis of the obstetric outcome of singleton IVF pregnancies in comparison with matched, naturally conceived singleton controls. Setting: In vitro fertilization unit and obstetric service at a tertiary medical center.

Patient(s): Two hundred sixty consecutive singleton IVF pregnancies and 260 naturally conceived singleton controls matched 1:1 for maternal age, parity, ethnic origin, and location and date of delivery.

Intervention(s): In vitro fertilization-ET.

Main Outcome Measure(s): The rate of antenatal obstetric complications, nonvertex presentation, cesarean section, preterm labor, low birth weight, small and very small for gestational age, neonatal intensive care unit admissions, and perinatal mortality.

Result(s): The rates of most antenatal complications were similar in both groups. Urinary tract infection was the only complication diagnosed significantly more frequently after IVF (7.3% versus 1.2%); however, the rates of severe urinary tract infection necessitating hospitalization were similar. The incidence of nonvertex presentation was also similar. The cesarean section rate was significantly higher among IVF patients (41.9% versus 15.5%). The rates of preterm labor, low birth weight, small and very small for gestational age, neonatal intensive care unit admissions, and perinatal mortality were comparable.

Conclusion(s): When controlling for maternal age, parity, ethnic origin, and location and date of delivery, singleton IVF pregnancies do not carry an increased risk for prematurity, low birth weight, or maternal or fetal complications. Still, these pregnancies are associated with a high rate of cesarean sections.     

Association between second-trimester isolated high maternal serum maternal serum human chorionic gonadotropin levels and obstetric complications in singleton and twin pregnancies

OBJECTIVE: The purpose of this study was to examine the clinical significance of high maternal serum human chorionic gonadotropin levels in the second trimester in singleton and twin pregnancies within the Ontario maternal serum screening program. STUDY DESIGN: The study group comprised 564 women with singleton pregnancies with total maternal serum human chorionic gonadotropin levels of > or =4.0 multiples of the median (MoM) and serum marker alpha-fetoprotein levels of <2.0 MoM. The cases were matched with 1692 control subjects who had both serum marker alpha-fetoprotein levels and maternal serum human chorionic gonadotropin levels of <2.0 MoM. The second part of the study comprised 93 twin pregnancies with maternal serum human chorionic gonadotropin levels of > or =5.0 MoM and serum marker alpha-fetoprotein levels of <4.0 MoM; the control group (n = 1496) had serum marker alpha-fetoprotein levels of <4.0 MoM and maternal serum human chorionic gonadotropin levels of <5.0 MoM. The final part of the study included 25 women with extremely high maternal serum human chorionic gonadotropin levels (> or = 14;10 MoM). RESULTS: Of the singleton pregnancies with maternal serum human chorionic gonadotropin levels of > or = 14;4.0 MoM, 22.5% had severe adverse obstetric outcomes, compared with only 10.9% of the matched control population (P =.001). Women with markedly elevated maternal serum human chorionic gonadotropin levels had significantly increased risks of having spontaneous miscarriage, small-for-gestational-age infants, pregnancy-associated hypertensive disorder, and preterm delivery. Of the women with twin pregnancies with high maternal serum human chorionic gonadotropin levels (> or =5.0 MoM), 71% had at least one complication (such as miscarriage and preterm delivery) compared with 55.3% in the control group. Finally, 23 of 25 women with extremely high maternal serum human chorionic gonadotropin levels (> or = 14;10 MoM) had serious adverse outcomes (such as fetal abnormalities, pregnancy-associated hypertensive disorder, premature separation of placenta, intrauterine growth restriction, neonatal respiratory distress syndrome, and neonatal jaundice). CONCLUSION: Pregnancies with an elevated maternal serum human chorionic gonadotropin level are associated with adverse obstetric outcomes. Increased maternal and fetal surveillance is warranted in these pregnancies.     

Maternal risks and perinatal outcome in a Danish national cohort of 1005 twin pregnancies: the role of in vitro fertilization

BACKGROUND: Twin pregnancies constitute 25% of all in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) pregnancies. There is a lack of knowledge on maternal risks and perinatal outcome of IVF/ICSI twin pregnancies. METHODS: National survey by questionnaire (n = 1769). The study population consisted of all IVF/ICSI twin mothers (n = 266) and the two control groups of all IVF/ICSI singleton mothers (n = 764) and non-IVF/ICSI twin mothers (n = 739) who delivered in Denmark in 1997. The response rate was 89% among IVF twin mothers and overall 81%. RESULTS: In terms of maternal risks and perinatal outcome no significant differences were observed between IVF/ICSI twin and non-IVF/ICSI twin pregnancies after stratification for maternal age and parity. Nevertheless, IVF/ICSI twin mothers were more frequently on sick leave (OR 2.5, 95% CI 1.5-4.0) and hospitalized (OR 1.9, 95% CI 1.3-2.8) during pregnancy. Compared with IVF/ICSI singleton pregnancies, IVF/ICSI twin pregnancies were characterized by a higher incidence of preeclampsia (OR 2.4, 95% CI 1.5-4.2) and a higher frequency of sick leave (OR 6.8, 95% CI 4.4-10.5) and hospitalizations during pregnancy (OR 3.5, (95% CI 2.5-4.9); moreover, mean birthweight (p < 0.001) and gestational age (p < 0.001) were lower. No differences were observed in the incidence of pregnancy-induced hypertension and gestational diabetes between IVF/ICSI twin and singleton pregnancies. CONCLUSION: Although this population study indicates that maternal risks in IVF/ICSI twin pregnancies are comparable with non-IVF/ICSI twin pregnancies, the IVF/ICSI twin mothers were more likely to be on sick leave or hospitalized during pregnancy. Furthermore, maternal risks were higher and obstetric outcome poorer in IVF/ICSI twin vs. IVF/ICSI singleton pregnancies.     

First trimester screening with free beta-hCG,PAPP-A and nuchal translucency in pregnancies conceived with assisted reproduction

OBJECTIVE: To evaluate the effect of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) on free beta-human chorionic gonadotrophin (beta-hCG), pregnancy-associated plasma protein A (PAPP-A) and nuchal translucency (NT). METHODS: First trimester maternal dried whole blood specimens from 74 singleton pregnancies (32 by IVF and 42 by ICSI) and 30 twin pregnancies (16 by IVF and 14 by ICSI) in which conception was achieved with assisted reproduction techniques were matched with five controls resulting in 370 singleton controls and 150 twin controls. NT was measured using the Fetal Medicine Foundation protocol. Free beta-hCG, PAPP-A and NT levels were compared between the IVF and control groups and between the ICSI and control groups using the Mann-Whitney U test. RESULTS: In singleton pregnancies, the only significant difference was a 21% (95% CI: -35%--7%) reduction in PAPP-A in IVF cases. In twin pregnancies, the only significant difference was a 12% (95% CI: -34%--3%) reduction in NT in IVF cases. In singleton pregnancies, the false-positive rate for Down syndrome screening was 1.4% and 1.9% greater for the IVF and ICSI groups, respectively, compared to controls for a general screening population. CONCLUSIONS: Patients undergoing assisted reproduction techniques should be counseled about the possibility of increased false-positive rates. Larger studies are needed to confirm this observation and to develop appropriate adjustment factors to reduce false-positive rates.     

Maternal and neonatal outcome of twin pregnancies complicated by single fetal death.

OBJECTIVE: To study the maternal and neonatal outcome of twin pregnancies complicated by the intrauterine death of one fetus after 20 weeks of gestation. DESIGN: Retrospective, observational study of 7 twin pregnancies out of 185 twin pregnancies with the diagnosis of a single intrauterine death over a 5-years period in a university hospital. RESULTS: The incidence of single fetal death in twin gestation after 20 weeks was 3.8% in the study population with a high incidence of intrauterine growth retardation (IUGR) of the remaining fetus and preeclampsia in the further course of pregnancy. The incidence of preterm delivery was 71% with a mean gestational age of 33.0 +/- 1.0 weeks. The median interval from diagnosis of single fetal death to delivery was 10.2 +/- 4.1 days (range 1-28 days). 5 of 7 (71%) cases were delivered by cesarean section for standard obstetrical reasons. Neither perinatal nor neonatal death of the remaining twin were observed. Two cases of neurologic injury were diagnosed after delivery by ultrasound and MRI. No maternal coagulopathy related to single fetal death occurred. CONCLUSION: Expectant management of single fetal death in twin pregnancies might be advisible under close surveillance of both, mother and the surviving fetus.     

Population‐Based Study of Cesarean Section After In Vitro Fertilization in Australia

Abstract: Background: Decisions about method of birth should be evidence based. In Australia, the rising rate of cesarean section has not been limited to births after spontaneous conception. This study aimed to investigate cesarean section among women giving birth after in vitro fertilization (IVF). Methods: Retrospective population‐based study was conducted using national registry data on IVF treatment. The study included 17,019 women who underwent IVF treatment during 2003 to 2005 and a national comparison population of women who gave birth in Australia. The outcome measure was cesarean section. Results: Crude rate of cesarean section was 50.1 percent versus 28.9 percent for all other births. Single embryo transfer was associated with the lowest (40.7%) rate of cesarean section. Donor status and twin gestation were associated with significantly higher rates of cesarean section (autologous, 49.0% vs donor, 74.9%; AOR: 2.20, 95% CI: 1.80, 2.69) and (singleton, 45.0% vs twin gestations, 75.7%; AOR: 3.81, 95% CI: 3.46, 4.20). The gestation‐specific rate (60.1%) of cesarean section peaked at 38 weeks for singleton term pregnancies. Compared with other women, cesarean section rates for assisted reproductive technology term singletons (27.8% vs 43.8%, OR: 2.02 [95% CI: 1.95–2.10]) and twins (62.0% vs 75.7%, OR: 1.92 [95% CI: 1.74–2.11]) were significantly higher. Conclusions: Rates for cesarean section appear to be disproportionately high in term singleton births after assisted reproductive technology. Vaginal birth should be supported and the indications for cesarean section evidence based. (BIRTH 37:3 September 2010)     

Analysis of 104 twin pregnancies conceived with assisted reproductive technologies and 193 spontaneously conceived twin pregnancies

OBJECTIVE: To evaluate pregnancy outcome of assisted reproductive technology (ART)-conceived twin pregnancies. DESIGN: Retrospective study. SETTING: A tertiary obstetric care center. PATIENT(S): All twin pregnancies delivered > or = 24 weeks of gestation from January 1, 1996, to December 31, 1997. INTERVENTION(S): Maternal and neonatal record review. MAIN OUTCOME MEASURE(S): Pregnancy and perinatal outcome. RESULT(S): The study group comprised 104 ART-conceived twin pregnancies, and 193 non-ART-conceived pregnancies served as controls. Mean maternal age, the proportion of nulliparae, and the percentage of women who delivered before 34 weeks' gestation was higher among the study women, whereas mean gestational age was younger. The incidences of pregnancy-induced hypertension, uterine bleeding, premature contractions, intrauterine growth retardation, fetal death, discordance, and cesarean section were significantly higher in the study group. Correspondingly, in the study group, the mean birth weight of both twins was lower; more neonates weighed < 1, 500 g, more had Apgar scores of < 7 at 5 minutes, more were admitted to the intensive care unit, and more second twin neonates died. The outcome of twin pregnancies conceived spontaneously was comparable with those conceived by ovulation induction. CONCLUSION(S): Assisted reproductive technology-conceived twin pregnancies are at greater risk than non-ART-conceived ones for pregnancy complications and adverse perinatal outcome.     

Does assisted reproduction technology, per se, increase the risk of preterm birth?

There is little doubt that all methods of assisted reproduction increase the likelihood of multiple pregnancy and, as a result, increase the likelihood of preterm birth. Data from the East Flanders Prospective Twin Study clearly show that the proportion of spontaneous to iatrogenic twins has changed from 25:1 to 1:1 over the past two decades. Data from the very low birthweight (VLBW) Infant Database of the Israel Neonatal Network showed that 10% of VLBW singletons were a result of assisted reproduction compared with 60% of the VLBW twins and 90% of the VLBW triplets. Irrespective of plurality, an association between preterm birth and assisted reproduction has long been suspected and was related to causes such as iatrogenic preterm birth (in the so-called 'premium' pregnancies), fertility history, past obstetric performance and to underlying medical conditions of the female partner. With more data available, a clearer picture is defined. Two different, recent meta-analyses showed that singleton pregnancies resulting from in vitro fertilisation (IVF) have increased rates of preterm birth at <33 weeks of gestation (OR 2.99; 95% CI 1.54–5.80), at <37 weeks of gestation (OR 1.93; 95% CI 1.36–2.74) and a relative risk of 1.98 (95% CI 1.77–2.22) for preterm birth in singleton pregnancies resulting from in vitro fertilisation embryo transfer/gamete intra fallopian transfer (IVF-ET/GIFT) compared with naturally conceived pregnancies. Since there is no way to predict which pregnant woman is at increased risk of preterm birth, it may be advisable to consider all pregnancies after assisted reproduction as being at risk. In any case, the most appropriate endpoint after assisted reproduction should also include preterm or term birth as measure of success.     

Placenta previa in singleton and twin births in the United States, 1989 through 1998: a comparison of risk factor profiles and associated conditions

OBJECTIVE: The purpose of this study was to compare risk factor profiles for placenta previa between singleton and twin live births. STUDY DESIGN: This cohort study was based on United States natality data files (1989 through 1998) and comprised 37,956,020 singleton births and 961,578 twin births. Women who were diagnosed with placenta previa were included only if they were delivered by cesarean delivery. Risk factors for placenta previa that were examined included sociodemographic (age, gravidity, education, marital status, and race), behavioral (prenatal care, smoking, and alcohol use), previous preterm birth, and medical and obstetric factors. Effect modification between maternal age and gravidity and the dose-response relationship with number of cigarettes smoked/day on placenta previa risk were also evaluated. RESULTS: The rate of placenta previa was 40% higher among twin births (3.9 per 1,000 live births, n = 3,793 births) than among singleton births (2.8 per 1,000 live births, n = 104,754 births). Comparison of risk factors for placenta previa between the singleton and twin births revealed fairly similar risk factor profiles. Compared with primigravid women <20 years old, the risk for placenta previa increased by advancing age and by increasing number of pregnancies among both singleton and twin births. The number of cigarettes smoked per day also showed a dose-response trend for placenta previa risk in the two groups. CONCLUSION: The increased rate of placenta previa among twin births underscores the need to monitor carefully such pregnancies with heightened suspicion and awareness for the development of this condition.     

Predicting Preterm Birth in Twin Pregnancy: Was the Previous Birth Preterm? A Canadian Experience

ObjectiveMost studies determining risk of preterm birth in a twin pregnancy subsequent to a previous preterm birth are based on linkage studies or small sample size. We wished to identify recurrent risk factors in a cohort of mothers with a twin pregnancy, eliminating all known confounders.MethodsWe conducted a retrospective cohort study of twin births at a tertiary care centre in Montreal, Quebec, between 1994 and 2008, extracting information, including chorionicity, from patient charts.To avoid the effect of confounding factors, we included only women with a preceding singleton pregnancy and excluded twin-to-twin transfusion syndrome, fetal chromosomal/structural anomalies, fetal demise, and preterm iatrogenic delivery for reasons not encountered in both pregnancies. We used multiple regression and sensitivity analyses to determine recurrent risk factors.ResultsOf 1474 twin pregnancies, 576 met the inclusion criteria. Of these, 309 (53.6%) delivered before 37 weeks. Preterm birth in twins was strongly associated with preterm birth of the preceding singleton (adjusted OR 3.23; 95% CI 1.75 to 5.98). The only other risk factors were monochorionic twins (adjusted OR 1.82; 95% CI 1.21 to 2.73) and oldest or youngest maternal ages. Chronic or gestational hypertension, preeclampsia, and insulin-dependent diabetes during the singleton pregnancy did not significantly affect risk.ConclusionPreterm birth in a previous singleton pregnancy was confirmed as an independent risk factor for preterm birth in a subsequent twin pregnancy. This three-fold increase in risk remained stable regardless of year of birth, inclusion/exclusion of pregnancies following assisted reproduction, or defining preterm birth as < 34 or < 37 weeks’ gestational age. Until the advent of optimal preventive strategies, close obstetric surveillance of twin pregnancies is warranted.     

Maternal and fetal atrial natriuretic peptide levels at delivery from normal and growth retarded pregnancies.

OBJECTIVE: To determine whether circulating fetal levels of the vasodilator atrial natriuretic peptide (ANP) are reduced in pregnancies complicated by intrauterine growth retardation (IUGR). DESIGN: Prospective observational study. SETTING: University teaching hospital and research laboratory. SUBJECTS: 25 normal singleton pregnancies delivered at term by spontaneous vertex delivery (n = 16) or by elective caesarean section (n = 9), and a series of 14 singleton pregnancies complicated by IUGR. INTERVENTION: Measurement of ANP by radio-immunoassay in maternal venous, umbilical artery, and umbilical vein plasma from a series of normal, and IUGR pregnancies. MAIN OUTCOME MEASURES: Comparison of plasma ANP levels between the three groups; relation between fetal ANP, PO2 and pH. RESULTS: Mode of delivery did not influence either maternal, umbilical artery or umbilical vein plasma ANP levels in normal term singleton pregnancies. Umbilical vein ANP levels were significantly higher in the IUGR group when compared with normal pregnancies at term (mean 66 95%, CI 36-122 vs mean 37, 95% CI 29-47 pg/ml, P = 0.03) and were inversely related to umbilical artery pH (R2 = 65%; P = 0.003). CONCLUSIONS: These data suggest that umbilical vein ANP levels are elevated in pregnancies complicated by IUGR, and rise appropriately in response to the stress of acidosis. In the absence of any receptor or second messenger defect within feto-placental vascular smooth muscle, these data suggest that ANP is not directly implicated in the vascular pathophysiology of IUGR.     

Post-delivery oxidative stress in women with preeclampsia or IUGR

AIM: To compare oxidative stress in patients with preeclampsia (PE) or intrauterine growth restriction (IUGR) vs. normal pregnancy (controls) during 48 h after delivery. STUDY DESIGN: Women with singleton pregnancies were recruited immediately after delivery (gestational age >26.0 weeks). Women with PE or IUGR were matched with healthy controls by age, BMI, gestational age and delivery mode. Venous blood samples and urine samples were tested for oxidative stress products 24 h and 48 h after delivery. RESULTS: Plasma malondialdehyde (MDA) concentration 24 h after delivery was significantly higher in subjects with PE or IUGR (3.41+/-1.14 micromol/L, n=20) than in controls (2.91+/-0.82 micromol/L, n=38) (P=0.04). Urine iPF(2alpha)-VI declined from 24 to 48 h after delivery significantly in controls (P=0.006) and not in subjects with PE or IUGR (P=0.71). CONCLUSION: Of the markers tested only MDA is indicating higher oxidative stress in women with PE/IUGR than in normal pregnancy and only at 24 h after delivery. No consistent pattern of change in the oxidative stress markers exists between 24-48 h after delivery.     

Pregnancy, obstetric and neonatal outcome after assisted reproduction in Nigerians.

PURPOSE: To evaluate the pregnancy, obstetric and neonatal outcome after assisted reproduction in Nigerians. METHODS: Case control study of all confirmed pregnancies following assisted reproduction managed at the Havana Specialist Hospital (HSH), Lagos over a 7 year period. RESULTS: Adverse obstetric and neonatal outcome occurred in 30.8% of pregnancy following assisted reproduction compared to 12.6% in spontaneously conceived pregnancy (p = 0.0003). Multiple pregnancy (<0.001), preterm delivery (p < 0.000), placenta praevia (0.00002), antenatal admission (0.02), early pregnancy bleeding (0.04), miscarriage (0.001) and caesarean delivery (<0.001) were significantly commoner in the assisted reproduction group. After adjustment for confounding variables, preterm delivery (OR: 5.95), miscarriage (OR: 5.84), multiple pregnancy (OR: 4.58), placenta praevia (OR: 4.13), caesarean delivery (OR: 3.57), early pregnancy bleeding (OR: 2.18) and antenatal admission (OR: 2.01) retained their significance. CONCLUSION: This study has provided the first evidence from our part of the world showing that assisted pregnancy is associated with poorer obstetric outcome when compared with spontaneously conceived pregnancy.     

Cause and risk of stillbirth in twin pregnancies: a retrospective audit

BACKGROUND: The epidemiology of twin pregnancies complicated by stillbirth of one or both fetuses is a scarcely examined area. The risk of perinatal death in twin pregnancies is increased 2-5 times compared to singletons, and the identification of preventable risk factors becomes increasingly important as the number of multiple pregnancies is rising. We report the causes of death in twin pregnancies and their respective risk factors. METHODS: Twin pregnancies (n = 54) complicated by antepartum or intrapartum stillbirth of one or both twins (n = 68) and twin pregnancies with normal outcome (n = 103) in the counties of Oslo and Akershus, Norway, from 1986 to 1995 were included. The cases were classified and compared to the controls in multiple logistic regression analyses with regard to risk factors. RESULTS: The risk of stillbirth increased with monochorionicity, non-Western origin and assisted reproduction techniques (ART). The cases could be divided into eight different groups according to the primary diagnosis. The groups did not fit any of the existing cause-of-death classifications used on singleton stillbirths. CONCLUSIONS: The identification of monochorionic gestation should be made early in pregnancy to designate the level of risk. Assisted reproduction techniques leading to a high incidence of twins should be avoided. Health care professionals in the immigrant population should address the detrimental effects of consanguinity on reproductive outcome. We emphasize the need of a new cause-of-death classification for twin stillbirths.