Prenatal diagnosis in Sweden 2011 to 2013-a register-based study

Impact of a prenatal screening program on the Down syndrome phenotype: An interrupted time series analysis

INTRODUCTION

We hypothesized that children with Down syndrome who were born after the implementation of first-trimester combined screening for trisomy 13, 18, and 21 and a second-trimester ultrasound scan in Denmark would show a milder syndrome phenotype. We investigated the birth biometry, prevalence of congenital malformations, and early childhood morbidity of children with Down syndrome before and after implementation of this screening program.

MATERIAL AND METHODS

A nationwide register-based study of all live born singletons with Down syndrome in Denmark from 1995 to 2018. In interrupted time series analyses, we studied the temporal developments in birth biometry, prevalence of congenital malformations, and early childhood morbidity related to the implementation of a national prenatal screening program.

RESULTS

We included 602 singletons with Down syndrome born before and 308 after implementation of the screening program. Z-scores of birthweight and head circumference increased over time before screening, but this temporal development changed after implementation by -0.05 (95% confidence interval [CI]: -0.11 to 0.01) and -0.05 (95% CI -0.12 to 0.02), respectively. Just after implementation, the prevalence of non-severe congenital heart disease decreased (relative change in odds 0.48 [95% CI: 0.24-0.94]). For severe congenital heart disease, atrioventricular septal defect, and non-heart malformations, this change was 1.16 (95% CI: 0.56-2.41), 0.95 (95% CI: 0.43-2.03), and 0.98 (95% CI: 0.33-2.76), respectively. For all malformations, pre-existing temporal developments did not change following implementation of screening. The implementation was associated with higher odds of admission to a neonatal intensive care unit (relative change 1.98 [95% CI: 0.76-5.26]) and an increased risk of hearing impairment (risk difference 3.4% [95% CI: -0.4% to 7.1%]). In contrast, the implementation was not associated with the incidence of hospital admissions by 2 years of age or with the probability of a thyroid disorder.

CONCLUSIONS

After implementation of a national prenatal screening program, we did not observe a milder Down syndrome phenotype apart from an apparent reduction in the proportion of children with non-severe congenital heart disease; this result is, however, limited by small numbers.

The Stockholm-Gotland perinatal cohort-A population-based cohort including longitudinal data throughout pregnancy and the postpartum period

BACKGROUND

Register-based reproductive and perinatal databases rarely contain detailed information from medical records or repeated measurements throughout pregnancy and delivery. This lack of enriched pregnancy and birth data led to the initiation of the Swedish Stockholm-Gotland Perinatal Cohort (SGPC).

OBJECTIVES

To describe the strengths of the SGPC, as well as the unique research questions that can be addressed using this cohort.

POPULATION

The SGPC is a prospectively collected, population-based cohort that includes all births (from 22 completed gestational weeks onwards) between 1 January 2008 and 15 June 2020 in the Stockholm and Gotland regions of Sweden (N 335,153 singleton and N 11,025 multiple pregnancies).

DESIGN

Descriptive study.

METHODS

The SGPC is based on the electronic medical records of women and their infants. The medical record system is used for all antenatal clinic visits and admissions, delivery and neonatal admissions, as well as postpartum clinical visits. SGPC has been further enriched with data linkages to 10 Swedish National Health Care and Quality Registers.

PRELIMINARY RESULTS

In contrast to other reproductive and perinatal databases available in Sweden, including the Medical Birth Register and the Pregnancy Register, SGPC contains highly detailed medical record data, including time-varying serial measurements for physiological parameters throughout pregnancy, delivery, and postpartum, for both mother and infant. These strengths have enabled studies that were previously inconceivable; the effects of serial measurements of pregnancy weight gain, changes in haemoglobin counts and blood pressure during pregnancy, fetal weight estimations by ultrasound, duration of stages and phases of labour, cervical dilatation and oxytocin use during delivery, and constructing reference curves for umbilical cord pH.

CONCLUSIONS

The SGPC-with its rich content, repeated measurements and linkages to numerous health care and quality registers-is a unique cohort that enables high-quality perinatal studies that would otherwise not be possible.

Utilisation of supplementary prenatal screening and diagnostics in Germany: cross-sectional study using data from the KUNO Kids Health Study

BACKGROUND

Appropriate health system utilisation during pregnancy is fundamental for maintaining maternal and child's health. To study the use and determinants of supplementary prenatal screening and diagnostics in Germany this study provides comprehensive data.

METHODS

We obtained data from a recently established prospective German birth cohort study, the KUNO Kids Health Study. Analyses are based on Andersen's Behavioural Model of health system use, which distinguishes between predisposing (e.g. country of birth), enabling (e.g. health insurance) and need factors (e.g. at-risk pregnancy). We examined bi- and multivariate association with the use of supplementary prenatal screening and diagnostics using logistic regression.

RESULTS

The study has a sample size of 1886 participating mothers. One fifth of the mothers investigated did not use any supplementary prenatal screening or diagnostics. Notably, the chance of using supplementary prenatal screening and diagnostics more than doubled if the pregnant woman had a private health insurance (OR 2.336; 95% CI 1.527-3.573). Higher maternal age (OR 1.038; 95% CI 1.006-1.071) and environmental tobacco smoke exposure (OR 1.465 95% CI 1.071-2.004) increased the use of supplementary prenatal screening and diagnostics. However, regarding need factors only having an at-risk-pregnancy (OR 1.688; 95% CI 1.271-2.241) showed an independent association.

CONCLUSION

The important role of the type of health insurance and the relatively small influence of need factors was surprising. Especially with respect to equity in accessing health care, this needs further attention.

Associations of ultrasound estimated early mid pregnancy visceral and subcutaneous fat depths and early pregnancy BMI with adverse neonatal outcomes

This study investigated whether maternal central adiposity and body mass index (BMI) were associated with neonatal hypoglycemia and adverse neonatal outcomes. A cohort study was performed at Uppsala University Hospital, Sweden, between 2015 and 2018. Visceral and subcutaneous fat depths were measured by ultrasound at the early second-trimester anomaly scan in 2771 women giving birth to singleton infants. Body mass index was assessed in early pregnancy. Logistic regression models were performed. Adjustments were made for age, BMI (not in model with BMI as exposure), smoking, maternal country of birth, and parity. Outcomes were neonatal hypoglycemia (blood glucose concentration < 2.6 mmol/l), a composite of adverse neonatal outcomes (Apgar < 7 at 5 min of age, or umbilical artery pH ≤ 7.0, or admission to neonatal intensive care unit), and the components of the composite outcome. Visceral and subcutaneous fat depths measured by ultrasound in early mid pregnancy were not associated with any of the outcomes in adjusted analyses. For every unit increase in BMI, the likelihood of neonatal hypoglycemia increased by 5% (aOR 1.05, 95% CI 1.01–1.10), the composite outcome by 5% (aOR 1.05, 95% CI 1.01–1.08), and admission to neonatal intensive care unit by 6% (aOR 1.06, 95% CI 1.02–1.10).

Uptake of fetal aneuploidy screening after the introduction of the non-invasive prenatal test: A national population-based register study

INTRODUCTION

The introduction of the non-invasive prenatal test (NIPT) has shifted the prenatal screening landscape. Countries are exploring ways to integrate NIPT in their national prenatal screening programs, either as a first- or second-tier test. This study aimed to describe how the uptake of fetal aneuploidy screening changed after the introduction of NIPT as a second-tier and as a first-tier test within the national prenatal screening program of the Netherlands.

MATERIAL AND METHODS

A population-based register study in the Netherlands, recording uptake of fetal aneuploidy screening. Data from all pregnant women choosing to have the first-trimester combined test (FCT) or first-tier NIPT between January 2007 and March 2019 were retrospectively collected using national registration systems. Uptake percentages for fetal aneuploidy screening (FCT and NIPT) were calculated and stratified by region and maternal age. Statistical significance was determined using trend analysis and chi-squared tests.

RESULTS

Between 2007 and 2013 FCT uptake increased from 14.8% to 29.5% (P = .004). In April 2014 NIPT was introduced as a second-tier test for high-risk women after FCT (TRIDENT-1 study). FCT uptake rose from 29.5% in 2013 to 34.2% in 2015 (P < .0001). After the introduction of NIPT as a first-tier test for all women in April 2017 (TRIDENT-2 study), FCT uptake declined significantly from 35.8% in 2016 to 2.6% in 2018 (P < .0001). NIPT uptake increased to 43.4% in 2018. Regionally, NIPT uptake ranged from 31.8% to 67.9%. Total uptake (FCT and NIPT) between 2007 and 2018 increased significantly from 14.8% to 45.9% (P < .0001). However, total uptake stabilized at 46% for both years of TRIDENT-2 (April 2017-March 2019).

CONCLUSIONS

An increase in total fetal aneuploidy screening uptake up to 45.9% was observed after the introduction of NIPT. Uptake appears to have stabilized within a year after introducing first-tier NIPT.

Rates and risk factors for preterm birth and low birthweight in the global network sites in six low- and low middle-income countries

Background

Preterm birth continues to be a major public health problem contributing to 75% of the neonatal mortality worldwide. Low birth weight (LBW) is an important but imperfect surrogate for prematurity when accurate assessment of gestational age is not possible. While there is overlap between preterm birth and LBW newborns, those that are both premature and LBW are at the highest risk of adverse neonatal outcomes. Understanding the epidemiology of preterm birth and LBW is important for prevention and improved care for at risk newborns, but in many countries, data are sparse and incomplete.

Methods

We conducted data analyses using the Global Network’s (GN) population-based registry of pregnant women and their babies in rural communities in six low- and middle-income countries (Democratic Republic of Congo, Kenya, Zambia, Guatemala, India and Pakistan). We analyzed data from January 2014 to December 2018. Trained study staff enrolled all pregnant women in the study catchment area as early as possible during pregnancy and conducted follow-up visits shortly after delivery and at 42 days after delivery. We analyzed the rates of preterm birth, LBW and the combination of preterm birth and LBW and studied risk factors associated with these outcomes across the GN sites.

Results

A total of 272,192 live births were included in the analysis. The overall preterm birth rate was 12.6% (ranging from 8.6% in Belagavi, India to 21.8% in the Pakistani site). The overall LBW rate was 13.6% (ranging from 2.7% in the Kenyan site to 21.4% in the Pakistani site). The overall rate of both preterm birth and LBW was 5.5% (ranging from 1.2% in the Kenyan site to 11.0% in the Pakistani site). Risk factors associated with preterm birth, LBW and the combination were similar across sites and included nulliparity [RR − 1.27 (95% CI 1.21–1.33)], maternal age under 20 [RR 1.41 (95% CI 1.32–1.49)] years, severe antenatal hemorrhage [RR 5.18 95% CI 4.44–6.04)], hypertensive disorders [RR 2.74 (95% CI − 1.21–1.33], and 1–3 antenatal visits versus four or more [RR 1.68 (95% CI 1.55–1.83)].

Conclusions

Preterm birth, LBW and their combination continue to be common public health problems at some of the GN sites, particularly among young, nulliparous women who have received limited antenatal care services.

Trial registration The identifier of the Maternal and Newborn Health Registry at ClinicalTrials.gov is NCT01073475.Trial registration: The identifier of the Maternal and Newborn Health Registry at ClinicalTrials.gov is NCT01073475.

Association of maternal central adiposity measured by ultrasound in early mid pregnancy with infant birth size

We sought to investigate whether early mid pregnancy visceral and subcutaneous fat depths measured by ultrasound were associated with infant birth size, independent of early pregnancy BMI. A cohort study was performed at Uppsala University Hospital, Sweden, between 2015–2018. Visceral and subcutaneous fat depths were measured at the early second-trimester anomaly scan in 2498 women, giving birth to singleton, term infants. Primary outcomes were birthweight and LGA (birthweight standard deviation score > 90th percentile in the cohort). Linear and logistic regression models were used, adjusted for BMI, age, smoking, parity, maternal country of birth, gestational age and infant sex. A 5-mm increase in visceral fat depth was associated with an increase in birthweight of 8.3 g [95% confidence interval (CI) 2.5 − 14.1 g], after adjustments, and a 6% increase in the adjusted odds of having an infant born LGA (OR 1.06, CI 1.02–1.11). There was no association between subcutaneous fat depth and birthweight or LGA after covariate adjustments. Hence, visceral fat depth measured by ultrasound in early mid pregnancy was associated with excessive fetal growth, independent of early pregnancy BMI, and may be useful in models for predicting LGA infants.

Discordant dating of pregnancy by LMP and ultrasound and its implications in perinatal statistics

Context

High perinatal mortality in India may be caused by inaccurate dating of pregnancy resulting from suboptimal uptake of antenatal care and ultrasound services during pregnancy.

Aim

To determine the discrepancy in the last menstrual period (LMP) assigned expected date of delivery (EDD) and ultrasound assigned EDD in pregnant women in a rural district of central India.

Methods

Data from an ongoing cross-sectional screening program providing fetal radiology imaging in Guna district of Madhya Pradesh from 2012-2019 was analyzed for recall of LMP and discordance between LMP and ultrasound assigned EDD. The discrepancy was present when EDD assigned by ultrasound differed by 3 or more days at gestational ages less than 8⁺⁶ weeks, 5-7 days at gestational ages 8⁺⁶ weeks till 14 weeks, and 7-10 days at gestational ages 14-20 weeks.

Results

The program screened 14,701 pregnant women of which 4,683 (31.86%, 95% CI: 31.11, 32.61) could not recall LMP. EDD assigned by LMP and ultrasound matched in 7,035 (70.22%, 95% CI: 69.32, 71.12) of the remaining 10,018 pregnant women. EDD was overestimated by LMP for 26.06% (95% CI: 25.21, 26.93) women; these foetuses were at risk of being misclassified as a term fetus. In 2018, the project had no maternal deaths, infant mortality rate of 24.7, low birth weight rate of 9.69%, and 100% antenatal coverage.

Conclusion

Accurate dating of pregnancy and systematic follow-up integrating radiology imaging and obstetrics care for appropriate risk-based management of pregnant women can significantly improve perinatal statistics of India.

Proton Pump Inhibitors and Preeclampsia Risk Among 157 720 Women

Preeclampsia is a hypertensive disorder of pregnancy with a high rate of maternal and neonatal morbidity and mortality. The only definite treatment is delivery. Preclinical investigations have identified proton pump inhibitors (PPIs), which are commonly used to treat reflux during pregnancy, as a potential treatment for preeclampsia. The aim of this study was to determine the association between PPI use during pregnancy and preeclampsia risk in a population-based register cohort. Using the Swedish Pregnancy Register, we conducted a cohort study of nulliparous pregnant women delivering from January 2013 to July 2017. Associations between PPI use and preeclampsia were investigated using logistic regression analyses with risk estimates presented as crude and adjusted odds ratios (aOR) with 95% CI. Of 157 720 nulliparous pregnant women, 6051 (3.8%) reported PPI use during pregnancy. PPI use during any point of pregnancy was associated with an increased risk of overall preeclampsia (aOR of 1.17; 95% CI, 1.04-1.32) and preeclampsia at term (aOR of 1.20; 95% CI, 1.04-1.39). However, PPI use recorded after 28 gestational weeks was associated with a reduced risk of preterm (delivery <37 weeks) preeclampsia (aOR of 0.63; 95% CI, 0.41-0.96) and early (delivery <34 weeks) preeclampsia (aOR of 0.41; 95% CI, 0.20-0.82). These findings highlight the heterogeneity of this disease, with a potential role PPIs for preventing preterm preeclampsia when used in close proximity to disease onset. Targeting PPI use to women at greatest risk of preterm preeclampsia may help prevent this severe form of disease.

Neighborhood deprivation and adverse perinatal outcomes in Sweden: A population-based register study

INTRODUCTION

Neighborhood deprivation has been associated with adverse perinatal outcomes but it is unclear to what extent maternal and social risk factors explain the association and how a stressful environment per se contributes.

MATERIAL AND METHODS

A population-based register study including 218 030 deliveries in Sweden between January 2013 and July 2017 was conducted. Exposure was living in a deprived or severely deprived area defined by the National Operations Department of the Swedish Police Authority. Adverse perinatal outcomes included preterm births, small-for-gestational-age births and stillbirths. A propensity score-based method was used to control for individual baseline characteristics. Associations were investigated with logistic regression analyses and risk estimates are presented as crude (OR) and adjusted odds ratio (aOR) with 95% confidence interval (CI).

RESULTS

Living in a deprived neighborhood in Sweden was associated with extremely preterm births (deprived area OR 1.50, 95% CI 1.07-2.11, severely deprived OR 1.90, 95% CI 1.40-2.58), small-for-gestational-age birth (deprived OR 1.45, 95% CI 1.31-1.60, severely deprived OR 1.85, 95% CI 1.69-2.03) and stillbirth (deprived OR 1.62, 95% CI 1.17-2.26, severely deprived OR 1.56, 95% CI 1.11-2.19). After accounting for individual maternal and social risk factors, the risk of small for gestational age in severely deprived areas remained (aOR 1.45, 95% CI, 1.19-1.75).

CONCLUSIONS

The contextual effect of living in a deprived neighborhood on the risk of extremely preterm births, small-for-gestational-age births and stillbirths was to a high extent explained by individual factors of women residing in exposed areas, yet remained for small-for-gestational-age births in severely deprived areas after adjustment for maternal and social risk factors.

Use of pregnancy ultrasound before the 19th week scan: an analytical study based on the Icelandic Childbirth and Health Cohort

Background and aim

Use of ultrasound scans early in pregnancy is increasing, but we have limited knowledge about the actual prevalence, associated decision-making and impact on expectant women/couples in a general population. The aim of this study was to document the use of, and experiences related to, foetal scanning before the recommended 19th week scan among pregnant women in Iceland.

Population and methods

The data come from the Icelandic Childbirth and Health Cohort Study 2009–11. A total of 1111 women attending prenatal care at primary care health centres answered questionnaires before mid-pregnancy and after birth, including questions about the number of scanning procedures during pregnancy. These might include consumer-initiated ‘pregnancy confirmation scans,’ scans for clinical reasons, and screening for foetal anomalies in week 11–14 which is optional in Iceland. The questionnaires also addressed parental decision-making associated with the 11–14 week screening, perception of the pre-screening information, reasons for attending or declining, and whether/how early foetal screening affected the women’s concerns related to the unborn child.

Results

A total of 95% of the women reported some kind of foetal ultrasound scanning before the 19th week scan, and 64% reported two or more scans in this period. 78% of the women chose to participate in screening for foetal anomalies in week 11–14. Decision-making in relation to this screening was mainly informed by sources outside the healthcare system, and many women characterized participation as ‘self-evident’. Most women felt they got sufficient information about the scope of screening, whilst information regarding potential downsides and risks was frequently perceived as insufficient. Most women who chose the 11–14 week screening reported a reassuring or neutral effect, whilst 10% of the women reported that it increased their concerns related to their unborn child.

Conclusions

Ultrasound scans in the first half of pregnancy are in high use in Iceland and have apparently become part of a broader pregnancy culture, encompassing both high- and low-risk pregnancies. Whether this is a favourable development or to some extent represents unwarranted medicalization, can be debated. More balanced information might be provided prior to early screening for foetal anomalies.

Reasons for non-participation in malformation scans in Denmark: a cohort study

Background

The aim of the study was to estimate the proportion of women giving birth in two hospitals in the Region of Southern Denmark who did not attend the malformation scan and to elucidate the reasons for not participating.

Methods

In this register-based descriptive study, we used patient administration systems to identify women who had given birth at two Danish hospitals between March 2013 and January 2015. We then linked this information with the hospital database for fetal medicine (Astraia) to identify women who did not attend the malformation scan at week 18–20. We reviewed the medical records of these women to validate the data and to identify the reason for non-participation.

Results

Of 7690 births, 153 (2%) women did not attend the malformation scan. The main reason for non-participation was a passive deselection (81%). Most of these women were not present in Denmark at the time of the malformation scan (61%) and few women declined (8%).

Conclusions

Less than 2% of a birth cohort in two major hospitals in Denmark did not attend the free offer of a malformation scan. Most of these women (81%) did not actively decide against the malformation scan. Very few (0.2%) declined the malformation scan. Non-attendance is not always due to an active decision made by the pregnant woman.

Electronic supplementary material

The online version of this article (10.1186/s12884-018-1877-z) contains supplementary material, which is available to authorized users.

Maternal height and risk of caesarean section in singleton births in Sweden-A population-based study using data from the Swedish Pregnancy Register 2011 to 2016

Caesarean section (CS) has short and long term adverse health consequences, and should therefore only be undertaken when necessary. Risk factors such as maternal age, maternal body mass index (BMI) and fetal weight have been extensively investigated in relation to CS, but the significance of maternal height has been less explored in Sweden. The aim was to investigate the significance of maternal height on risk of CS in a representative, population-based sample from Sweden, also taking into account confounders. Data on singleton births in the Swedish Pregnancy Register 2011 to 2016 were collected, including women with heights of 140 cm and above, constituting a sample of 581,844 women. Data were analysed with epidemiological and biostatistical methods. Mean height was 166.1 cm. Women born outside Sweden were significantly shorter than women born in Sweden (162.8 cm vs. 167.1 cm, p<0.001). There was a decreasing risk of CS with increasing maternal height. This effect remained after adjustment for other risk factors for CS such as maternal age, BMI, gestational age, parity, high birth weight and country of birth. Frequency of CS was higher among women born outside Sweden compared with Swedish-born women (17.3% vs. 16.0%), however, in a multiple regression model country of birth outside Sweden diminished as a risk factor for CS. Maternal height of 178-179 cm was associated with the lowest risk of CS (OR = 0.76, CI95% 0.71-0.81), whereas height below 160 cm explained 7% of CS cases. BMI and maternal age are established factors involved in clinical assessments related to birth, and maternal height should increasingly enjoy a similar status in these considerations. Moreover, when healthcare professionals are counselling pregnant women, taller stature should be more emphasized as a positive indicator for successful vaginal birth to increase pregnant women's confidence in giving birth vaginally, with possible positive impacts for lowering CS rates.

Norwegian obstetricians' experiences of the use of ultrasound in pregnancy management. A qualitative study

OBJECTIVE

To explore obstetricians' experiences and views of the use of obstetric ultrasound in clinical management of pregnancy.

METHODS

A qualitative interview study was undertaken in 2015 with obstetricians (N = 20) in Norway as part of the CROss Country Ultrasound Study (CROCUS).

RESULTS

Three categories developed during analyses. 'Differing opinions about ultrasound and prenatal diagnosis policies' revealed divergent views in relation to Norwegian policies for ultrasound screening and prenatal diagnosis. Down syndrome screening was portrayed as a delicate and frequently debated issue, with increasing ethical challenges due to developments in prenatal diagnosis. 'Ultrasound's influence on the view of the fetus' illuminated how ultrasound influenced obstetricians' views of the fetus as a 'patient' and a 'person'. They also saw ultrasound as strongly influencing expectant parents' views of the fetus, and described how ultrasound was sometimes used as a means of comforting women when complications occurred. 'The complexity of information and counselling' revealed how obstetricians balanced the medical and social aspects of the ultrasound examination, and the difficulties of 'delivering bad news' and counselling in situations of uncertain findings.

CONCLUSION

This study highlights obstetricians' experiences and views of ultrasound and prenatal diagnosis in Norwegian maternity care and the challenges associated with the provision of these services, including counselling dilemmas and perceived differences in expectations between caregivers and expectant parents. There was notable diversity among these obstetricians in relation to their support of, and adherence to Norwegian regulations about the use of ultrasound, which indicates that the care pregnant women receive may vary accordingly.

Do pregnant women want to know the sex of the expected child at routine ultrasound and are they interested in sex selection?

BACKGROUND

The aim of the study was to investigate if expecting parents wanted to know the sex of the fetus during ultrasound examination and if they had discussed it with the midwife. Another aim was to explore any interest in sex selection.

METHODS

A longitudinal survey in early and late pregnancy among 2393 women in Sweden.

RESULTS

Almost all (95.8%, n = 2289) women had discussed sex determination with the partner before the ultrasound scan, and 57% (n = 1356) of women and their partners wanted to find out the fetal sex. The expecting parents mostly initiated a discussion with the midwife (46%, n = 1088), but 10% (n = 229) stated that the midwives initiated the discussion. Few (5%, n = 118) expressed a potential interest in selecting sex of a baby. Women who were interested in sex determination did not differ from those who were not, with respect to age, origin, education, parity, level of pregnancy planning, or importance of religion, but women who had chosen another fetal diagnostic method were more interested in sex determination and in potential sex selection.

CONCLUSIONS

Half of women and their partners wanted to know the fetal sex, and 5% were interested in sex selection. This high interest in sex determination is a challenge, since present national guidelines do not include sex determination as an option.