Blood pressure during pregnancy in a Swedish population; impact of parity.

SUBJECT: Hypertension represents the most commonly encountered complication of pregnancy. Normal levels of blood pressure (BP) need to be established in each pregnant population in order to recognize pathology. A lack of studies from our own country and certain methodological objections to early studies motivated this study. PATIENTS AND METHODS: Six hundred pregnant women were included in a historical cohort. The maternal BP had been measured with a mercury sphygmomanometer and standardized routines at each antenatal visit. Data regarding age, baseline BMI, weight gain and smoking habits as well as parity had been recorded. RESULTS: BP values were overall somewhat higher than in international studies, the SBP increasing slightly towards term. The diastolic blood pressure (DBP) decreased slightly until 25-28 weeks of gestation. A steady increase thereafter led to values at term 7.3% above initial values. In nulliparae the increase was significantly greater, 9.9% versus 5.4% in multiparae. Primigravidae showed mean DBP levels significantly higher than all multigravidae towards term. The DBP was correlated with the baseline BMI, but not with age or weight gain. In smoking pregnant women the DBP showed a significantly greater initial decrease and failed to follow the subsequent rise to the same degree as in non-smokers. CONCLUSION: Slightly higher blood pressure levels were found in this study compared to other international studies. Multiple regression analysis showed that parity, baseline BMI and smoking all significantly influenced the DBP at term. Multiparae have significantly lower DBP levels in pregnancy compared to nulliparae. The first pregnancy seems to have the greatest impact in lowering the blood pressure in subsequent pregnancies.

Transient fetal cerebral dysfunction after road traffic accident. A case report.

We present a case at 30 weeks gestation with transient abnormal fetal cerebral function after a road traffic accident, with loss of fetal movements and abnormal FHR tracings for almost 1 week. The pregnancy had after this incident a normal course and a healthy baby boy was born at term. We suggest the mechanism to be related to fetal hypoxia after excessive maternal psychological stress.

Transient fetal cerebral dysfunction after road traffic accident. A case report.

We present a case at 30 weeks gestation with transient abnormal fetal cerebral function after a road traffic accident, with loss of fetal movements and abnormal FHR tracings for almost 1 week. The pregnancy had after this incident a normal course and a healthy baby boy was born at term. We suggest the mechanism to be related to fetal hypoxia after excessive maternal psychological stress.

Long term outcome after umbilical artery acidaemia at term birth: influence of gender and duration of fetal heart rate abnormalities.

OBJECTIVE: To study the outcome after acidaemia at term birth, and the relation to gender and duration of pathological fetal heart rate changes. DESIGN: Population based study of 154 infants with umbilical artery pH < 7.05 at term birth. Neonatal outcome and the result of developmental screening at age four years were compared with a control group with pH > 7.10. Fetal heart rate traces in infants with acidaemia were reviewed, and the relation between duration of fetal heart rate changes and outcome was analysed. RESULTS: Of the 154 newborns with acidaemia at birth, 10 had encephalopathy, of which two died and two developed cerebral palsy. Nine of these 10 infants were boys, and eight had pH < 7.00. Male newborns (n = 39) more often had pronounced acidaemia (pH < 7.00) than females (n = 22). Although few infants had severe impairment, infants born with acidaemia significantly more often had speech problems at follow up than controls (19/102 versus 8/98; P = 0.03). In infants with acidaemia, duration of abnormal fetal heart rate changes was significantly associated with neonatal encephalopathy and speech problems at age four years. CONCLUSIONS: Acidaemia at term birth was associated with neonatal encephalopathy and with speech problems at four years of age. Boys had more often pronounced acidaemia and a complicated course. A protracted abnormal fetal heart rate trace was associated with poor outcome.

Stillbirths and rate of neonatal deaths in 76,761 postterm pregnancies in Sweden, 1982-1991: a register study.

OBJECTIVE: To study stillbirths and neonatal mortality in the postterm period. DESIGN: Register study of information obtained from the Swedish Medical Birth Registry (MBR), National Board of Health and Welfare, Stockholm. METHODS: Singleton pregnancies with deliveries occurring between 1982 and 1991 were selected involving 914,702 women (of whom 76,761 had a postterm pregnancy continuing beyond the 42nd week of amenorrhea). All 2,043 records of dead infants were scrutinized before analysis of neonatal deaths. Stratification was made for year of birth, maternal age, and parity. RESULTS: Generally, the rates of stillbirths and neonatal deaths were low. The stillbirth rate was highest for primiparas at 38 completed weeks (2.72%), lowest at 40 weeks (1.23%), then increasing to 2.26% in the postterm period. The difference vs. multiparas was significant from 41 weeks onwards. Neonatal mortality was increased at 41 completed weeks for primiparas, but for multiparas it changed significantly first in the postterm period. The OR for a primipara to have an intrauterine death increased from 1.50 at 41 weeks (1.0 at 40 weeks) to 1.79 at 42 weeks and beyond. The OR for multiparas showed no sign of increase as gestation progressed. CONCLUSIONS: The results of this study indicate an increased risk of stillbirth with gestational age for primiparas but not for multiparas. The neonatal death rate was increased for both primiparas and multiparas (after 42 completed weeks).

Risk factors for acidemia at birth.

OBJECTIVE: To identify risk factors for acidemia at birth. METHODS: From September 1988 to December 1996, cord arterial blood pH was measured in 23,016 of 27,064 live-born infants (85.0%). Values below 7.05 were observed in 264 newborns (1.1%), of whom 14 born by cesarean delivery before labor and one triplet infant were excluded from the study. The remaining 249 newborns with acidemia and their mothers were compared with 249 unmatched controls with normal pH (the first infant with umbilical arterial pH above 7.10 born after each case). Multivariate logistic regression was used to adjust for potentially confounding variables. RESULTS: Variables significantly and independently associated with acidemia at birth were labor with breech presentation (adjusted odds ratio [OR]2.9), oxytocin administration (OR 2.1), meperidine administration (OR 2.0), cord entanglement (OR 1.7), and male gender of the infant (OR 1.4). Clinical evidence of chorioamnionitis also was associated with acidemia, although after adjustment for prematurity, the association was not statistically significant (OR 3.9, 95% confidence interval 0.8, 19). CONCLUSION: Labor with breech presentation, administration of oxytocin and meperidine, cord entanglement, and male gender are associated with an increased risk for insufficient fetomaternal gas exchange.

Maternal fever in term labour in relation to fetal tachycardia, cord artery acidaemia and neonatal infection.

OBJECTIVE: To determine 1. whether maternal fever during term labour is associated with acidaemia at birth and neonatal infection and 2. whether fetal tachycardia precedes maternal fever and is associated with neonatal infection. DESIGN: Retrospective matched-pair case-control study. SUBJECTS: Two hundred and forty-eight newborn infants whose mothers developed fever during term labour (cases) and 248 control infants. The women were matched for parity and duration of labour. MAIN OUTCOME MEASURES: Cord artery acid-base status, Apgar scores, neonatal infections, and fetal heart rate before maternal fever. RESULTS: Mean pH, as well as the rate of cord artery acidaemia at birth (pH < 7.10) was equal in cases and controls (in both groups 7.24% and 6%, respectively). Signs of septicaemia and/or pneumonia were identified in 17 case newborns (7%) and in one control (0.4%; OR 17.0, P < 0.001). Of 212 pairs with complete heart rate data, fetal tachycardia preceded maternal fever in 39 cases (18%) and in 16 controls (8%) (OR 2.6, P = 0.003). Tachycardia before maternal fever was not associated with increased neonatal infectious morbidity. CONCLUSIONS: Maternal fever during term labour was associated with perinatal infection, but not with acidaemia at birth. Elevated fetal heart rate preceded maternal fever in a minority of cases and was not associated with perinatal infection.

Preeclampsia is associated with a reduced response to activated protein C.

OBJECTIVE: Resistance to activated protein C is an inherited mutation of the coagulation factor V gene, a major factor predisposing to thromboembolic events. The purpose of this study was to investigate the occurrence of heterozygote and homozygote activated protein C resistance in women with preeclampsia. STUDY DESIGN: Activated protein C resistance and protein C and antithrombin III levels were determined in women (n = 50) with a history of preeclampsia and in controls (50 women with a previous normal pregnancy). The mutation of the factor V gene was analyzed. RESULTS: Activated protein C resistance was found in 22% of women with previous preeclampsia compared with 10% among controls. Two women in the previous preeclampsia group had a homozygote mutation of factor V; the others were heterozygous. There was a significant difference in the activated protein C ratio between women with previous preeclampsia and the control group, 2.6 +/- 0.4 versus 3.1 +/- 0.5 (p = 0.04). None of the women had protein C or antithrombin III deficiency. CONCLUSION: The results indicate that activated protein C resistance may be a contributory factor in the pathogenesis of preeclampsia.

Different types of acid-base changes at birth, fetal heart rate patterns, and infant outcome at 4 years of age.

BACKGROUND: To study the relationship between different types of acidemia in umbilical artery blood at birth, fetal heart rate (FHR) patterns during labor, and infant long-term outcome. METHODS: Case-control study of 48 infants with pure high base deficit (base deficit (BD) > or = 12 mmol/L and pCO2 < 8.0 kPa), 51 with mixed acidemia (BD > or = 12 mmol/L and pCO2 > or = 8.0 kPa), born at or after term, and controls matched for maternal age, parity, and gestational age at birth. FHR patterns during labor and the results of developmental screening at age 4 were compared between the groups. RESULTS: Late decelerations were associated with pure high base deficit and complicated variable decelerations with mixed acidemia. Both types of acidemia were correlated with Apgar scores below 7 at 1 minute, and mixed acidemia with more admissions to the neonatal intensive care unit. Developmental screening at age 4 years showed no significant differences between infants with mixed acidemia or pure high base deficit and controls. Twelve infants with mixed acidemia and six controls had deficits in language/speech development. CONCLUSIONS: Late decelerations may be an indicator of a metabolic component of acidemia and complicated variable decelerations an indicator of mixed acidemia. The higher rate of admissions to the neonatal intensive care unit in cases with mixed acidemia may suggest that a concomitant hypercapnia (resulting in lower pH) in metabolic acidemia at birth may be of importance for the outcome. A possible relation between acidemia at birth and deficits in speech/language development should be further evaluated.

Fetal monitoring with lactate.

Lactate is a metabolite that can safely and easily can be determined in fetal scalp blood using new microvolume (5-20 microliters) lactate meters. However, new lactate analysing methods need their own reference values. There are factors other than hypoxia that might increase fetal lactate levels, although this does not disqualify this parameter for intrapartum surveillance. Available data on fetal lactate determination give support that it can simplify FBS in labour and is likely to predict fetal tissue hypoxia at least as well as is pH determination. Prospective randomized studies are needed before the method can be introduced into clinical practice. As a predictor of neonatal outcome, lactate can substitute pH in routine assessment of cord artery blood at delivery.

Controversies: premature rupture of membranes at term--no advantage of delaying induction > 24 hours.

Results from randomised trials with formal randomisation indicate no evidence of benefits in terms of cesarean delivery of maternal/neonatal infectious morbidity by awaiting spontaneous onset of labor for more than 24 hours in women with term PROM. An overnight policy of management seems to be an attractive alternative to other management protocols. Women with prelabor rupture of membranes await stimulation of labor with oxytocin till next morning if admitted before midnight. A majority of the women may go into spontaneous labor with an excellent prospect of having a vaginal delivery. Particularly the nulliparous woman with poor cervical score could benefit from such an approach. Although prostaglandins in theory should be an useful adjunct agent to oxytocin, particularly in the nulliparous woman with unripe cervix, convincing evidence of the efficacy of the drug is still lacking. Well-conducted and randomised studies to evaluate the role of prostaglandins in nulliparous women with PROM are required.

Randomised controlled trial of methyldopa and isradipine in preeclampsia--effects on uteroplacental and fetal hemodynamics.

This is a prospective randomised controlled study in 21 women admitted with preeclampsia in the third trimester. The mean arterial blood pressure decreased by 11.1 mmHg (95% confidence interval -14.9 to -7.3 mmHg) in the methyldopa group, and by 9.3 mmHG (95% confidence interval-14.4 to -4.2 mmHG) in the isradipine group. The maternal heart rate decreased by 6.9 beats per min (95% confidence interval -11.6 to -2.2 bpm) during methyldopa treatment, and by 2.5 beats per min (95% confidence interval -9.2 to 4.3) during isradipine treatment. Pulsatility index in maternal and fetal vessels was not affected by either of the two drugs. The birth weight and placental weight and neonatal outcome were similar and uneventful. The hypotensive effect was similar for methyldopa and isradipine. Except reduced maternal heart rate on methyldopa, fetal and uteroplacental hemodynamics were not altered during treatment of preeclampsia with methyldopa or isradipine.

Risk factors for fever in labor.

OBJECTIVE: To identify risk factors for fever in labor. METHODS: A retrospective case-control study was conducted. Maternal sublingual temperature was measured every 2-4 hours during labor in 3109 of 3860 consecutive term parturients presenting from September 1992 through December 1993. Women who had fever (at least one recorded temperature of 38C or more, n = 72) during labor were compared with those who remained afebrile (n = 3037). Furthermore, a matched-pair case-control study was conducted, involving 250 women at term who developed fever in labor and 250 controls matched for parity and duration of labor; all delivered between January 1989 and December 1993. A conditional multiple logistic regression analysis was used to identify independent risk factors for fever during labor. RESULTS: In the case-control study, fever was associated with epidural analgesia, nulliparity, and a long duration of labor. These three variables were also related among themselves. However, multiple regression analysis showed that all three variables were independently associated with maternal temperature. In the matched-pair study, epidural analgesia, rupture of membranes longer than 24 hours, latency phase exceeding 8 hours, and a temperature in the upper normal range (37.5-37.9C) at admission were independent risk factors for developing fever in labor. CONCLUSION: Epidural analgesia, duration of labor, and a long interval from rupture of membranes to delivery were independent risk factors for maternal fever in labor.

Routine measurements of umbilical artery lactate levels in the prediction of perinatal outcome.

OBJECTIVE: Our purpose was to compare lactate levels with acid-base balance in the umbilical artery with respect to the prediction of pregnancy outcome. STUDY DESIGN: A prospective study of 4045 cord samples was performed. Lactate was measured with a new method that requires 5 microliters of blood and provides the result within 1 minute. RESULTS: The umbilical artery lactate concentrations were significantly elevated in instrumental deliveries (2.65 +/- 1.2 mmol/L) and in emergency cesarean sections (2.44 +/- 1.7 mmol/L) compared with spontaneous vaginal delivery (1.87 +/- 0.94 mmol/L) (p < 0.001, p < 0.001). Lactate correlated significantly to fetal pH, hemoglobin, base deficit, PCO2, and HCO3-. Lactate was comparable to pH and base deficit in sensitivity, specificity, and positive and negative predictive values in relation to morbidity and mortality. CONCLUSION: Umbilical artery lactate concentration and acid-base balance predicted perinatal outcomes with similar efficacies; however, its simplicity makes lactate analysis an interesting alternative in obstetric care.

Scalp blood lactate: a new test strip method for monitoring fetal wellbeing in labour.

OBJECTIVE: To determine fetal scalp blood lactate with a new test strip method in parturients with normal and abnormal cardiotocograms during labour and to describe the relation to maternal lactate, fetal scalp blood pH, cord artery lactate and acid-base balance. SETTING: Labour wards at the University Hospitals of Huddinge and Lund and at the County Hospital of Ostersund, Sweden. MATERIALS AND METHOD: Fetal scalp blood was sampled for lactate (n = 269) and pH (n = 285) determination in 177 parturients with abnormal intrapartum CTG. Lactate and pH were also analysed in a group of 64 women with normal pregnancies and with a reactive fetal heart rate tracing prior to sampling of fetal scalp blood. At fetal blood sampling lactate was also determined in maternal capillary blood, while at birth lactate and acid-base balance in cord artery blood was performed in almost all cases. MAIN OUTCOME MEASUREMENTS: Medians and percentiles (lactate and acid-base balance). Correlation between fetal scalp blood lactate (dependent) and scalp blood pH, cord artery blood lactate and acid-base parameters and labour time prior to fetal blood sampling. RESULTS: In the group with abnormal cardiotocograms, fetal scalp and umbilical artery blood lactate and acid-base parameters differed significantly from the same parameters in the normal group. The fetal-maternal lactate gradient changed from negative in the normal group to positive in the fetal distress group. Multiple regression analysis, with scalp lactate as the dependent parameter, revealed a significant correlation with fetal scalp blood pH (P < 0.001) and umbilical artery lactate (P < 0.01). CONCLUSIONS: Intrapartum scalp blood lactate was significantly correlated with pH and cord artery lactate. The results indicate that increased lactate levels in fetal blood sampling describes fetal lactacidosis. The new disposable test strip requiring only 5 microliters of blood for lactate determination may be better than traditional methods for monitoring fetal wellbeing in labour.

Calcium channel blockade (isradipine) in treatment of hypertension in pregnancy: a randomized placebo-controlled study.

OBJECTIVE: Our purpose was to study the effects of isradipine, a dihydropyridine calcium channel blocker, on mother and fetus in the treatment of hypertensive disorders of pregnancy. STUDY DESIGN: The investigation was performed as a two-group, parallel, double-blind multicenter study of isradipine versus placebo. Fifty-four women were randomized to treatment with isradipine slow-release capsules given orally 5 mg twice a day and 57 to a placebo group. RESULTS: Isradipine lowered the maternal mean arterial blood pressure effectively in women with nonproteinuric hypertension but did not do so in women with proteinuria at recruitment or appearing during treatment. Blood flow in the umbilical artery and maternal renal and liver function were not influenced by treatment. Isradipine had few side effects and was well tolerated. CONCLUSION: Calcium channel blockade with isradipine is effective for treatment of nonproteinuric hypertension but not in preeclampsia.