The Significance of Recurrent Polyhydramnios

Summary: A study of 30 women who had polyhydramnios in more than 1 pregnancy revealed that 8 of the 36 resultant pregnancies (22.2%) were associated with diabetes mellitus, 14 (37.8%) with fetal macrosomia, and the perinatal mortality rate was 16.2% (6 of 37). The incidence of major fetal malformations or abnormalities was 18.9% (7 of 37); 4 of the 6 deaths resulted from malformations (anencephalus (2), hydrocephalus (1), nonimmune hydrops (1)), and the other 2 deaths were from hyaline membrane disease associated with prematurity. Recurrent polyhydramnios occurred in 1 in 1,720 pregnancies. The onset was acute in 3, subacute in 2 and chronic in 31, the perinatal deaths in these categories being 2, 1 and 3 respectively. The risk of recurrent polyhydramnios is the risk of fetal malformation and premature delivery. The latter may be preventable by prompt therapy with indomethacin, and serial amniocentesis if this therapy fails.     

Acute Polyhydramnios in Twin Pregnancies

This paper reports the experience with acute polyhydramnios complicating twin pregnancies at the Mercy Maternity Hospital for the 10-year and 2-month period from January, 1979 to February, 1989 during which time there were 13 such cases, an incidence of 1 in 4,044 pregnancies. Acute polyhydramnios complicated 1.7% of all twin pregnancies. The perinatal mortality rate was 88.5% and accounted for 16.7% of the perinatal deaths in twins. No major fetal malformations were found. One case of acute polyhydramnios was successfully managed with ultrasonographically guided serial amniocenteses. The management of this rare condition is considered.     

Polyhydramnios and associated maternal and fetal complications in singleton pregnancies

During the 10-year period 1 January 1979 to 31 December 1988, polyhydramnios occurred in 537 patients with singleton pregnancies delivered at the Mercy Maternity Hospital. Associated maternal and fetal complications and the perinatal outcome of these pregnancies with polyhydramnios were analysed. In 248 of the 537 pregnancies (46%) in this group there were no maternal complications or fetal malformations and the perinatal mortality (PNM) rate was 2.4%. The PNM rate increased significantly to 13.1% when there was associated pre-eclampsia, 10% with gestational diabetes, and to 7.6% with miscellaneous complications. When polyhydramnios was associated with a fetal or placental malformation the PNM rate was 61.4%. The commonest malformations were central nervous system (31%), musculoskeletal (12%) and gastrointestinal system anomalies (10%). Placental chorioangioma occurred in two patients (0.4%) and both babies died. In women with low oestriol excretion (18% of the 455 tested) the PNM rate increased five times to 22.7%.     

Polyhydramnios and associated maternal and fetal complications in singleton pregnancies

Summary. During the 10-year period 1 January 1979 to 31 December 1988, polyhydramnios occurred in 537 patients with singleton pregnancies delivered at the Mercy Maternity Hospital. Associated maternal and fetal complications and the perinatal outcome of these pregnancies with polyhydramnios were analysed. In 248 of the 537 pregnancies (46%) in this group there were no maternal complications or fetal malformations and the perinatal mortality (PNM) rate was 2.4%. The PNM rate increased significantly to 13.1% when there was associated pre-eclampsia, 10% with gestational diabetes, and to 7.6% with miscellaneous complications. When polyhydramnios was associated with a fetal or placental malformation the PNM rate was 61.4%. The commonest malformations were central nervous system (31%), musculoskcletal (12%) and gastrointestinal system anomalies (10%). Placental chorioangioma occurred in two patients (0.4%) and both babies died. In women with low oestriol excretion (18% of the 455 tested) the PNM rate increased five times to 22.7%.     

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.     

Fetal malformations associated with chronic polyhydramnios in singleton pregnancies.

Forty-one congenital malformations were found in 28 newborns in a group of 197 cases of chronic polyhydramnios in singleton pregnancies. Of these, a total of 61% (17/28) was antenatally diagnosed ultrasonically. Nine newborns (4.5%) had malformations of the central nervous system (CNS), 9 (4.5%) cardiovascular malformations, 8 (4.1%) musculoskeletal anomalies, 7 (3.6%) malformations of the urinary and reproductive system, 4 (2%) respiratory system anomalies and 3 (1.6%) anomalies of the gastrointestinal system. Chromosomal abnormalities were found in three cases. As the association of polyhydramnios with fetal congenital anomalies is quite high (14.2% in our series), it is imperative to make a major effort to antenatally detect as many cases as possible. This means that in the case of hydramnios the following are required: ultrasound examination by an expert, echo ultrasonography when no other abnormalities are detected, and maybe even a chromosomal analysis.     

Acute polyhydramnios--a complication of monozygous twin pregnancy.

Eight patients with acute polyhydramnios were encountered in 31 103 pregnancies, an incidence of 1 in 3888. All patients with acute polyhydramnios had monozygous twin pregnancies and 14 of the 16 infants were normal. The condition occurred in the second trimester and usually ended in premature delivery within a few days. The perinatal mortality was 100 per cent and accounted for 14.9 per cent of the perinatal mortality in twins.     

The impact of multiple pregnancies and malformations on perinatal mortality

AIM: To evaluate the impact of the rate of multiple pregnancies and congenital malformations on perinatal mortality. METHODS: The study is based on data from the perinatal audit in Vejle County Denmark. Fetal deaths with gestational age > or = 22 weeks and deaths in livebirths within the first 28 days after birth were included in the calculated perinatal mortality. Total number of births was 30,181 and 252 pregnancies and 268 fetuses/infants were evaluated. The study period was 1995-2000. There was no routine ultrasound screening for congenital malformations in the county, though midtrimester ultrasound was used to assess gestational age. RESULTS: Perinatal mortality was 8.9 per 1000 births with no significant change over time. Rate of multiple pregnancies was 1.94% ranging from 1.81% during the first 3 years to 2.06% for the last 3 years (not significant). Fetuses and infants from multiple pregnancies contributed 18% of all deaths. Perinatal mortality for single births was 7.6 per 1000 births and for multiple births 42.2/1000 (P<0.0001). The distribution of gestational age for single and multiple births was highly significant (P<0.0001) with 67% of multiple pregnancies with GA < 28 weeks compared to 26% of single pregnancies. Nineteen percent of all deaths were caused by congenital malformations and the majority of these were potentially detectable by ultrasound investigation. CONCLUSIONS: The increasing rate of multiple pregnancies makes it difficult to see improvements in perinatal mortality. Calculated from the perinatal mortality in single and multiple pregnancies in Vejle County assisted conceptions contribute with an an excess of 45 perinatal deaths per year in Denmark. The difference between countries in rate of multiple pregnancies and in prenatal ultrasound screening recommendations for malformations makes it difficult to compare perinatal mortality.     

The severity of polyhydramnios, estimated fetal weight and preterm delivery are independent risk factors for the presence of congenital malformations.

OBJECTIVE: To evaluate maternal and fetal factors associated with congenital malformations in patients with polyhydramnios. STUDY DESIGN: The study group consisted of 275 singleton pregnancies with an amniotic fluid index (AFI) >25.0 cm. An equal number of controls were matched for maternal age, gravidity, parity and gestational age. The proportion of cases and controls with malformations was compared. Polyhydramnios cases were categorized into three groups by severity: mild (AFI 25-30 cm), moderate (AFI: 30.1-35.0 cm) and severe (AFI >35.1 cm). Among cases, logistic regression analysis was utilized to estimate the risk for fetal congenital malformations in relation to severity of polyhydramnios, estimated fetal weight, maternal diabetic status and gestational age at delivery. RESULTS: Congenital malformations were detected in 40 of 275 cases (14.5%) with polyhydramnios and in 9 cases (3.3%) of the control group (p < 0.01). The relative risks of congenital malformations increased with the severity of polyhydramnios: 3.2 (95% CI 1.5-6.8), 5.7 (95% CI 2. 4-13.3) and 13.1 (95% CI 5.8-29.5) for mild, moderate and severe polyhydramnios, respectively. Congenital malformations among polyhydramnios cases were present in 54.5% of small-for-gestational age fetuses, in contrast to 12.7% for average-for-gestational age fetuses and 10.8% for large-for-gestational age fetuses (p < 0.001). Maternal diabetic status did not significantly affect the fetal anomaly rate once polyhydramnios was detected. Premature newborns in the polyhydramnios group had a higher malformation rate (24%) than did term newborns (11.3%) (p < 0.02). In the study group, multiple logistic analysis confirmed the significance of severe polyhydramnios, small-for-gestational age status and preterm delivery as independent contributors to the malformation risk. CONCLUSIONS: Polyhydramnios (AFI >35 cm), small-for-gestational age fetus and preterm delivery are independent risk factors for congenital malformations.     

Contribution of congenital malformation to perinatal mortality in Lagos, Nigeria

Over a 17-month period we prospectively recorded identifiable congenital malformations at delivery in singleton births in our hospital. Despite the prevailing religious and cultural belief we carried out autopsies in 41% of the perinatal deaths that occurred during the study period. Out of a total of 63 (21/1000 singleton births) congenital malformations discovered, 21 (33%) were identified at autopsy only. About 16% of total perinatal deaths were due to congenital malformation. Cardiovascular malformations accounted for about 40% of perinatal deaths from congenital malformations followed by central nervous system malformation (23.3%), gastrointestinal malformations (20%), musculo-skeletal malformations (6.7%); renal malformations (3.3%) and others (6.7%). No relationship between maternal age, parity and congenital malformation was found. The results from this study suggest that with the use of autopsy, teratology may contribute significantly to the prevailing high perinatal mortality in Lagos more than was previously thought.     

Perinatal Outcome with Sonographically Thin Placentas

In order to determine the incidence and significance of sonographically thin placentas, we reviewed the computerized records of 18,937 viable, singleton pregnancies. Of these, 0.6% had thin placentas diagnosed by ultrasound examination with a mean thickness of 16 ± 4 mm in the second and 20 ± 3 mm in the third trimester. At the time of the first ultrasound diagnosis of a thin placenta, 22.2% had polyhydramnios, and 1.8% had oligohydramnios. When the thin placenta cohort without polyhydramnios was compared to controls, there was a significantly increased incidence of perinatal mortality, odds ratio = 2.9, 95% confidence limits (CL) = 1.2 to 7.3; neonatal intensive care unit admissions, odds ratio = 2.2, CL = 1.3 to 3.7; and birth weight below the 10th percentile, odds ratio = 2.8, CL = 1.7 to 4.7. The finding of a thin placenta by ultrasound should alert the clinician to the possibility of compromised perinatal outcome.     

Congenital abnormalities in newborns of consanguineous and nonconsanguineous parents

The aim of this study was to determine the types, patterns, and frequencies of congenital anomalies among newborns of both consanguineous and nonconsanguineous parents in southern Iran. From 9526 consecutive pregnancies observed, 9623 newborns resulted (9431 singleton and 95 sets of multiple gestation). There were 7261 newborns from nonconsanguineous parents and 2362 (24.5%) babies from consanguineous marriages. Of the total pregnancies, 1.54% resulted in malformed children (1.53% of singleton and 2.1% of multiple gestations). The incidence of congenital abnormalities in newborns of nonconsanguineous parents was 1.66% as compared to 4.02% for newborns of the consanguineous group. Major and multiple malformations were found to be slightly more common in the consanguinous group. Prematurity, prenatal mortality rate, and congenital abnormalities were more common in the consanguineous group. Probably the closer the familial relationship of the parents, the greater the chances of congenital abnormalities.     

Incidence,obstetric risk factors and pregnancy outcome of preterm placental abruption: a retrospective analysis

Objective: To determine obstetric risk factors for the occurrence of preterm placental abruption and to investigate its subsequent perinatal outcome. Study design: A retrospective comparison of all singleton preterm deliveries complicated with placental abruption, between the years 1990-1998, to all singleton preterm deliveries without placental abruption, in the Soroka University Medical Center. Results: Placental abruption complicated 300 (5.1%) of all preterm deliveries (n = 5934). A back-step multivariable analysis found the following factors to be independently correlated with the occurrence of preterm placental abruption: grandmultiparity (more than five deliveries), early gestational age, severe pregnancy-induced hypertension, previous second-trimester bleeding and non-vertex presentation. These pregnancies had a significantly lower rate of preterm premature rupture of membranes than preterm pregnancies without placental abruption. Pregnancies complicated with preterm placental abruption had significantly higher rates of cord prolapse, non-reassuring fetal heart rate patterns, congenital malformations, Cesarean deliveries, perinatal mortality, Apgar scores lower than 7 at 5 min, postpartum anemia and delayed discharge from the hospital than did preterm deliveries without placental abruption. In order to assess whether the increased risk for perinatal mortality was due to the placental abruption, or due to its significant association with other risk factors, a multivariable analysis was constructed with perinatal mortality as the outcome variable. Placental abruption (OR 3.0, 95% CI 2.1-4.1) as well as cord prolapse, previous perinatal death, low birth weight and congenital malformations were found to be independent risk factors for perinatal mortality. Conclusion: Preterm placental abruption is an unpredictable severe complication associated with significant perinatal morbidity and mortality. Factors found to be independently associated with placental abruption were grandmultiparity, severe pregnancy-induced hypertension, malpresentation, earlier gestational age and a history of second-trimester vaginal bleeding.     

Study of 156 cases of polyhydramnios and congenital malformations in a series of 118,265 consecutive births

Polyhydramnios associated with congenital anomalies was studied over nine years in 118,265 consecutive pregnancies. The prevalence of this association was 1.32% (156 cases). A case-control study allowed the examination of genetic and environmental factors for the origin of polyhydramnios associated with congenital malformations. Diagnosis of polyhydramnios associated with congenital malformations was performed prenatally in 41% of the cases; 16% of the infants were stillborn. Fifty-five percent of the cases had more than one malformation, 13.4% of them had a chromosomal aberration, and 32% had multiple malformations that do not constitute a syndrome. There was an increase of consanguinity in the parents of our patients. The incidence of polyhydramnios and congenital anomalies in first-degree relatives was 3.8%, and first-degree relatives had more malformations than the controls had (8.3% vs 3.2%). Our study demonstrated the low capacity of a general prenatal screening program because the diagnosis of malformations associated with polyhydramnios was made in only 41% of the cases and only six of 21 chromosomal abnormalities were diagnosed prenatally. We recommend the use of fetal chromosome analysis and careful ultrasonographic examination in every pregnancy complicated by polyhydramnios.     

The association of in vitro fertilization and perinatal morbidity

In recent years, there has been increasing concern regarding the safety of in vitro fertilization (IVF) because of the potential health impact on these infants. Multiple pregnancy contributes the vast majority of morbidity associated with IVF and, initially, many thought that adverse outcomes after IVF were solely attributable to the high incidence of twin pregnancies. More recently, multiple studies have suggested that IVF singleton pregnancies may be at increased risk for preterm birth, low birth weight, congenital anomalies, perinatal mortality, and several other pregnancy-related complications compared with unassisted singleton pregnancies. We have focused this review on the increased risk of adverse outcomes in IVF singleton conceptions compared with that of unassisted conceptions. The available evidence evaluating the association between IVF and low birth weight, preterm delivery, placental abruption, preeclampsia, congenital anomalies, and perinatal mortality in singleton pregnancies is summarized. In addition, data reporting an increased risk of congenital and chromosomal anomalies after IVF are presented.     

Neonatal outcomes with placenta previa

OBJECTIVE: To identify neonatal complications associated with placenta previa. METHODS: This was a population-based, retrospective cohort study involving all singleton deliveries in Nova Scotia from 1988 to 1995. The study group consisted of all completed singleton pregnancies complicated by placenta previa; all other singleton pregnancies were considered controls. Patient information was collected from the Nova Scotia Atlee perinatal database. Neonatal complications were evaluated while controlling for potential confounders. The data were analyzed using chi2, Fisher exact test, and multiple logistic regression. RESULTS: Among 92,983 pregnancies delivered during the study period, 305 cases of placenta previa were identified (0.33%). After controlling for potential confounders, neonatal complications significantly associated with placenta previa included major congenital anomalies (odds ratio [OR] 2.48), respiratory distress syndrome (OR 4.94), and anemia (OR 2.65). The perinatal mortality rate associated with placenta previa was 2.30% (compared with 0.78% in controls) and was explained by gestational age at delivery, occurrence of congenital anomalies, and maternal age. Although there was a higher rate of preterm births in the placenta previa group (46.56% versus 7.27%), there was no difference in birth weights between groups after controlling for gestational age at delivery. CONCLUSION: Neonatal complications of placenta previa included preterm birth, congenital anomalies, respiratory distress syndrome, and anemia. There was no increased occurrence of fetal growth restriction.     

Incidence of fetal malformations in pregnancies complicated by oligo- and polyhydramnios

Oligo- and polyhydramnios could be observed in 1%-7% of all pregnancies and are associated with an increased risk of fetal anomalies. We evaluated the fetal outcomes of 840 pregnancies with oligo- and polyhydramnios on the basis of ultrasonographic findings (oligohydramnios: single deepest pocket <2 cm, polyhydramnios: single deepest pocket >8 cm) between 12 and 42 weeks of gestation. We observed 734 pregnancies (752 fetuses) with oligohydramnios and 106 pregnancies (108 fetuses) with polyhydramnios. Of the 752 fetuses with oligohydramnios, 81% survived and 19% died in utero. Among the 108 fetuses of pregnancies with polyhydramnios, 72% of the babies survived and 28% died in utero. In polyhydramnios, 48% (52 of 108) of the fetuses had severe malformations, which is significant compared to the rate of 11.8% (89 of 752) of fetal malformations in oligohydramnios ( P-value<0.001). Oligohydramnios is predominantly associated with malformations of the urinary tract, whereas polyhydramnios is associated with anomalies of the gastrointestinal tract. In conclusion, measurement of single deepest pocket is a valuable screening method to evaluate pregnancies showing the complications of oligo- and polyhydramnios. Pregnancies with severe polyhydramnios have a poorer outcome and fetuses have a significantly higher risk of congenital malformations compared to pregnancies with oligohydramnios.     

Relation of mild idiopathic polyhydramnios to perinatal outcome.

The relation between clinically obvious polyhydramnios and poor perinatal outcome has been described. Much less is known about mild, unexplained polyhydramnios, which usually is initially suggested by sonographic examination late in gestation. The purpose of the present investigation was to relate mild idiopathic polyhydramnios to perinatal outcome. Mild polyhydramnios was defined sonographically as an amniotic fluid index of 24.1-39.9 during fetal biophysical testing. All subjects had singleton gestations not complicated by conditions known to predispose to polyhydramnios. We diagnosed mild polyhydramnios in 97 of 1177 patients (8.2%) undergoing fetal testing at 26-42 gestational weeks. Premature delivery, intrapartum complications, and neonatal depression were no more frequent in the pregnancies complicated by mild, unexplained polyhydramnios than in a comparable control group with normal fluid volume. The mild polyhydramnios group showed a significantly higher incidence of birth weight greater than 4000 g than did the control group (18.6 versus 8.6%; P less than .05). We conclude that mild idiopathic polyhydramnios in late gestation is relatively common. Except for a higher incidence of large for gestational age fetuses, this condition by itself is not associated with an increased risk of adverse perinatal outcomes.     

Birth-weight-specific perinatal mortality in Japan, 1989-1993: singleton versus multifetal pregnancies.

OBJECTIVE: To investigate the relation between birth weight and perinatal mortality in multifetal pregnancies, which is more than 5 times higher than for singleton infants. METHODS: We assessed the incidence of perinatal deaths based on birth weight in 89,566 infants of multifetal pregnancies and 6,025,199 infants of singleton pregnancies in Japan. Perinatal death was defined as stillbirth and early neonatal death (death <1 week of age). RESULTS: The incidence of perinatal death was consistently lower for infants of multifetal pregnancies than for infants of singleton pregnancies at birth weights of 500-2,499 g. However, the incidence of infants of multifetal pregnancies with birth weights >/=2,500 g consistently exceeded that in singleton infants weighing >/=2,500 g. The relative risk (95% CI) of perinatal death among infants of multifetal pregnancies compared with singleton infants in the same category of birth weight was 0.88 (0.84-0.93) at 500 g. The relative risk decreased to 0.31 (0.25-0.39) at 1,900 g, increased to >1.0 at 2,500 g, to 3.7 (2.2-6.1) at 3,000 g, and to 14.9 (7.8-28.4) at >/=3,500 g. CONCLUSIONS: Japanese infants of multifetal pregnancies reaching >/=2,500 g in body weight have a significantly higher risk of perinatal death than singleton infants in the same category of body weight. Increased monitoring of fetuses of multifetal pregnancies who weigh >/=2,500 g may be helpful in reducing the incidence of perinatal mortality.     

Outcome of fetuses in women with pregestational diabetes mellitus

OBJECTIVE: To investigate the effects of pregestational diabetes on pregnancy outcome. METHODS: Data of 126 women with pregestational diabetes prospectively collected and controlled in a single tertiary center. HbA(1C) levels at early pregnancy were registered. Adverse pregnancy outcome was defined as spontaneous abortion, congenital defect, stillbirth, or neonatal death. RESULTS: There were 10 spontaneous abortions (7.9%) and 17 fetuses with congenital anomalies (13.4%), including 8 major malformations (6.3%). Compared with pregnancies with a favorable outcome, a higher HbA(1C) concentration in early pregnancy was observed in pregnancies with adverse perinatal outcome [mean (SD): 6.3 (1.6) vs. 7.2 (1.7), P=0.001]. A positive correlation between increased maternal HbA(1C) levels and the rate of fetal malformations was observed, and the group of women with poor metabolic control (early maternal HbA(1c) concentration >7%) showed a 3 to 5-fold increase in the major malformation rate. Cardiovascular and genitourinary defects accounted for 58.8% of the anomalies, and the ultrasound examinations detected seven of them (41.2%). For major malformations, the detection rate was 50% (4/8). Perinatal mortality rate was 26 per thousand (3/116). There was almost 5-fold increase in the total pregnancy loss rate in the poor control group compared with the group with fair control [22.2% vs. 5.3%, OR (95% CI): 5.1 (1.4-17.1)]. Only 11.9% of mothers used a preconception care program. CONCLUSIONS: Pregestational diabetes mellitus is a significant risk factor for the developing fetus. Spontaneous abortions and congenital defects are more common when a poor metabolic control is present in early pregnancy. It is most important to improve access to preconception care programs for achieving a good metabolic control in early pregnancy. Ultrasound examinations have a low performance for detecting congenital defects in diabetic pregnancies.