Fetal age assessment based on 2nd trimester ultrasound in Africa and the effect of ethnicity

<p>Abstract</p> <p>Background</p> <p>The African population is composed of a variety of ethnic groups, which differ considerably from each other. Some studies suggest that ethnic variation may influence dating. The aim of the present study was to establish reference values for fetal age assessment in Cameroon using two different ethnic groups (Fulani and Kirdi).</p> <p>Methods</p> <p>This was a prospective cross sectional study of 200 healthy pregnant women from Cameroon. The participants had regular menstrual periods and singleton uncomplicated pregnancies, and were recruited after informed consent. The head circumference (HC), outer-outer biparietal diameter (BPDoo), outer-inner biparietal diameter and femur length (FL), also called femur diaphysis length, were measured using ultrasound at 12–22 weeks of gestation. Differences in demographic factors and fetal biometry between ethnic groups were assessed by t- and Chi-square tests.</p> <p>Results</p> <p>Compared with Fulani women (N = 96), the Kirdi (N = 104) were 2 years older (p = 0.005), 3 cm taller (p = 0.001), 6 kg heavier (p < 0.0001), had a higher body mass index (BMI) (p = 0.001), but were not different with regard to parity. Ethnicity had no effect on BPDoo (p = 0.82), HC (p = 0.89) or FL (p = 00.24). Weight, height, maternal age and BMI had no effect on HC, BPDoo and FL (p = 0.2–0.58, 0.1–0.83, and 0.17–0.6, respectively).</p> <p>When comparing with relevant European charts based on similar design and statistics, we found overlapping 95% CI for BPD (Norway & UK) and a 0–4 day difference for FL and HC.</p> <p>Conclusion</p> <p>Significant ethnic differences between mothers were not reflected in fetal biometry at second trimester. The results support the recommendation that ultrasound in practical health care can be used to assess gestational age in various populations with little risk of error due to ethnic variation.</p

Risk factors for surgical site infection following cesarean delivery: A hospital-based case–control study

Introduction Cesarean section is the single most important risk factor for postpartum infection. Where the rest of the world shows increasing trends, the cesarean section rates are low in Norway and risk factors for infection after cesarean section may differ in high and low cesarean section settings. The goal of this study was to examine independent risk factors for surgical site infection after cesarean delivery in a setting of low cesarean section rates. Material and methods We conducted a hospital-based case-control study at Haukeland University Hospital. We included women who presented to our hospital with surgical site infection after cesarean section during the years 2014–2016 (n = 75). Controls were selected at a ratio of 2:1 (n = 148). Cases and controls were compared with respect to maternal and pregnancy characteristics using uni- and multivariable logistic regression models. Main outcome measures were anticipated risk factors for surgical site infection. Results The occurrence of surgical site infection was 0.4% and 5.4% after elective and emergency cesarean section, respectively. Compared to women without surgical site infection, women with surgical site infection were almost thrice more obese before pregnancy (OR 2.8, 95% CI 1.2–7.0), four times more likely to have preexisting psychiatric conditions (OR 4.4, 95% CI 1.1–17.6), and five times more likely to receive blood transfusion (OR 5.1, 95% CI 1.4–18.8). Signs of infection during labor was a marginally significant risk factor for surgical site infection (OR 2.0, 95% CI 1.0–5.4). Conclusions Emergency cesarean section was a significant risk factor for surgical site infection. Pregestational obesity, preexisting psychiatric conditions, and blood transfusion during or following delivery, were independent risk factors for surgical site infection. Signs of infection during labor was a marginally significant risk factor. Women with either of these risk factors should be carefully monitored and evaluated for signs of infection in the postpartum period.publishedVersio

Social inequalities in the provision of obstetric services in Norway 1967-2009: A population-based cohort study

Background: Socioeconomic (SE) inequalities have been observed in a number of adverse outcomes of pregnancy and many of the risk factors for such outcomes are associated with a low SE level. However, SE inequalities persist even after adjustment for these risk factors. Less well-off women are more vulnerable, but may also get less adequate health services. The objective of the present study was to assess possible associations between SE conditions in terms of maternal education as well as ethnic background and obstetric care. Methods: A population-based national cohort study from the Medical Birth Registry of Norway. The study population comprised 2 305 780 births from the observation period 1967–2009. Multilevel analysis was used because of the hierarchical structure of the data. Outcome variables included induction of labour, epidural analgesia, caesarean section, neonatal intensive care and perinatal death. Results: While medical interventions in the 1970s were employed less frequently in women of short education and non-western immigrants, this difference was eliminated or even reversed towards the end of the observation period. However, an excess perinatal mortality in both the short-educated [adjusted relative risk (aRR) ¼ 2.49] and the non-western immigrant groups (aRR ¼ 1.75) remained and may indicate increasing health problems in these groups. Conclusion: Even though our study suggests a fair and favourable development during the last decades in the distribution across SE groups of obstetric health services, the results suggest that the needs for obstetric care have increased in vulnerable groups, requiring a closer follow-up.publishedVersio

Sex-specific reference ranges of cerebroplacental and umbilicocerebral ratios: A longitudinal study

This is the peer reviewed version of the following article: Acharya, G., Ebbing, C., Karlsen, H., Kiserud, T. & Rasmussen, S. (2019). Sex-specific reference ranges of cerebroplacental and umbilicocerebral ratios: A longitudinal study. Ultrasound in Obstetrics and Gynecology, 2019, which has been published in final form at https://doi.org/10.1002/uog.21870. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Objectives - The ratio of middle cerebral artery (MCA) pulsatility index (PI) to umbilical artery (UA) PI, i.e. cerebro‐placental ratio (CPR), has been suggested as a measure of fetal “brain sparing” phenomenon reflecting redistribution of fetal cardiac output as a response to placental insufficiency. Observational studies have shown that low CPR values predict increased risk of adverse perinatal outcomes although evidence from randomized clinical trials is lacking. The inverse ratio, i.e. umbilico‐cerebral ratio (UCR), is preferred by some as it increases with increasing degree of fetal compromise. Monitoring fetal wellbeing requires serial assessment, and for this purpose, appropriate reference values should be based on data from longitudinal studies. However, longitudinal reference ranges for the UCR have not been established. Furthermore, the sex of the fetus influences its growth velocity, cord properties, in utero circadian rhythm, behavioral states and placental function, but whether gestational age‐dependent changes in CPR or UCR differ between male and female fetuses has not been studied. Thus, our objective was to investigate sex‐specific, gestational age‐associated serial changes in CPR and UCR during the second half of pregnancy and establish longitudinal reference ranges. Methods - This was a dual‐center prospective longitudinal study of singleton low risk pregnancies. Doppler blood flow velocity waveforms were obtained serially from the UA and MCA during 19‐41 weeks of gestation, and PIs were determined. CPR and UCR were calculated as the ratios, MCA PI/ UA PI and UA PI/ MCA PI, respectively. The course and outcome of pregnancies was recorded. Sex of the fetus was determined after delivery. Reference intervals were constructed using multilevel modelling and gestational age‐specific Z‐scores of male and female fetuses were compared. Results - Of a total of 299 pregnancies enrolled, 284 women and their fetuses (148 male and 136 female) were included in the final analysis, and 979 paired measurements of UA and MCA PIs were used to construct sex‐specific longitudinal reference intervals. Both CPR and UCR had U‐shaped curves of development during pregnancy, but with opposite directions. There was a small but significant (P=0.007) difference in z‐scores of CPR and UCR between male and female fetuses throughout the second half of pregnancy. Conclusions - We have established longitudinal reference ranges for CPR and UCR suitable for serial monitoring with possibilities to refine the assessment by fetal sex‐specific ranges and the conditioning by a previous measurement. The clinical significance of such refinements needs further evaluation

Pregnancy outcome in women before and after cervical conisation: population based cohort study

Objectives To examine the consequences of cervical conisation in terms of adverse outcome in subsequent pregnancies

Recurrence of postpartum hemorrhage, maternal and paternal contribution, and the effect of offspring birthweight and sex: a population-based cohort study

Purpose: This study examines individual aggregation of postpartum hemorrhage (PPH), paternal contribution and how offspring birthweight and sex influence recurrence of PPH. Further, we wanted to estimate the proportion of PPH cases attributable to a history of PPH or current birthweight. Methods: We studied all singleton births in Norway from 1967 to 2017 using data from Norwegian medical and administrational registries. Subsequent births in the parents were linked. Multilevel logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CI) for PPH defined as blood loss > 500 ml, blood loss > 1500 ml, or the need for blood transfusion in parous women. Main exposures were previous PPH, high birthweight, and fetal sex. We calculated adjusted population attributable fractions for previous PPH and current high birthweight. Results: Mothers with a history of PPH had three- and sixfold higher risks of PPH in their second and third deliveries, respectively (adjusted OR 2.9; 95% CI 2.9–3.0 and 6.0; 5.5–6.6). Severe PPH (> 1500 ml) had the highest risk of recurrence. The paternal contribution to recurrence of PPH in deliveries with two different mothers was weak, but significant. If the neonate was male, the risk of PPH was reduced. A history of PPH or birthweight ≥ 4000 g each accounted for 15% of the total number of PPH cases. Conclusion: A history of PPH and current birthweight exerted strong effects at both the individual and population levels. Recurrence risk was highest for severe PPH. Occurrence and recurrence were lower in male fetuses, and the paternal influence was weak.publishedVersio

Paternal and maternal birthweight and offspring risk of macrosomia at term gestations: A nationwide population study

Background There is a paucity of data on whether parents' macrosomia (birthweight ≥4500 g) status influences the risk of macrosomia in the offspring. The role of maternal overweight in the generational effect of macrosomia is not known. Objective To estimate the risk of macrosomia by parental birthweight at term and evaluate if this risk varied with maternal body mass index (BMI, kg/m2) early in pregnancy. Methods We used data from the Medical Birth Registry of Norway on all singleton term births (37–42 gestational weeks) during 1967–2017. The primary exposure was parental macrosomia, and the outcome was macrosomia in the second generation. The secondary exposure was maternal BMI. We used binomial regression to calculate relative risk (RR) with a 95% confidence interval. We assessed potential unmeasured confounding and selection bias using a probabilistic bias analysis and performed analyses with and without imputation for variables with missing values. Results The data included 647,957 singleton parent-offspring trios born at term. The prevalence of macrosomia was 3.2% (n = 41,396) in the parental generation and 4.0% (n = 25,673) in the offspring generation. Macrosomia in parents was associated with an increased risk of macrosomia in offspring, with the RR for both parents were born macrosomic being 6.53 (95% confidence interval [CI] 5.31, 8.05), only mother macrosomic 3.37 (95% CI 3.17, 3.57) and only father macrosomic RR 2.22 (95% CI 2.12, 2.33). These risks increased by maternal BMI in early pregnancy: if both parents were born macrosomic, 17% of infants were macrosomic among mothers with normal BMI. If both parents were macrosomic and the mothers were obese, 31% of offspring were macrosomic. Macrosomia-related adverse outcomes did not differ with parental macrosomia status. Conclusions Parents' weight at birth and maternal BMI appear to be strongly associated with macrosomia in the offspring delivered at term gestations.publishedVersio

Recurrence of postpartum hemorrhage in relatives: A population-based cohort study

Introduction Studies on the family aggregation of postpartum hemorrhage (PPH) are scarce and with inconsistent results, and to what extent current birthweight influences recurrence between relatives remains to be studied. Further, family aggregation of PPH has been studied from an individual, but not from a public heath perspective. We aimed to investigate family aggregation of PPH in Norway, how birthweight influences these effects, and to estimate the proportion of PPH cases attributable to a family history of PPH and current birthweight. Material and methods Using data from the Medical Birth Registry of Norway, Statistics Norway, and Central Population Registry of Norway we identified individuals as newborns, parents, grandparents, and full and half-siblings, and studied 1 002 687 mother–offspring, 841 164 father–offspring, and 761 011 both-parents–offspring pairs. We used multilevel logistic regression to calculate odds ratios (OR) with 95% CI. Results If the birth of the mother but not of the father involved PPH, then the OR of PPH (>500 mL) in the next generation was 1.44 (95% CI 1.39–1.49). If the birth of the father but not of the mother involved PPH, then OR was 1.12 (95% CI 1.08–1.16). These effects were stronger in severe PPH. Recurrence between siblings was highest between full sisters (OR 1.47, 95% CI 1.41–1.52), followed by maternal half-sisters, paternal half-sisters, and partners of full brothers. A family history of PPH or birthweight of 4000 g or more accounted for ≤5% and 15% of the total number of PPH cases, respectively. Conclusions A history of PPH in relatives influenced the recurrence risk of PPH in a dose–response pattern consistent with the anticipated proportion of shared genes. The recurrence was highest through the maternal line.publishedVersio