Stillbirth: are we making more progress than we think? A retrospective cohort study.

OBJECTIVE: To quantify how the changing stillbirth risk profile of women is affecting the interpretation of the stillbirth rate. DESIGN: A retrospective, population-based cohort study from 1983 to 2018. SETTING: Victoria, Australia. POPULATION: A total of 2 419 923 births at ≥28 weeks of gestation. METHODS: Changes in maternal characteristics over time were assessed. A multivariable logistic regression model was developed for stillbirth, based on maternal characteristics in 1983-1987, and used to calculate individual predictive probabilities of stillbirth from the regression equation. The number of expected stillbirths per year as a result of the change in maternal demographics was then calculated, assuming no changes in care and in the associations between maternal characteristics and stillbirth over time. MAIN OUTCOME MEASURE: Stillbirth. RESULTS: Compared with 1983-1987, there were more women in older age groups giving birth, more nulliparous women, more indigenous women and women born in Oceania, Asia and Africa, more multiple pregnancies and more women with pre-existing diabetes in 2014-2018. Despite this, the rate of stillbirth fell from 5.42 per 1000 births in 1983 to 1.72 per 1000 births in 2018 (P < 0.001). Applying the multivariable logistic regression equation, derived from the 1983-87 data, to each year, had there been no changes in care or in the associations between maternal characteristics and stillbirth, the rate of stillbirth would have increased by 12%, from 4.94 per 1000 in 1983 to 5.54 per 1000 in 2018, as a result of the change in maternal characteristics. CONCLUSIONS: Population rates of stillbirth are falling faster than is generally appreciated. TWEETABLE ABSTRACT: Population reductions in stillbirth have been underestimated as a result of changing maternal characteristics.

Racial Disparities in Fertility Care: an Analysis of 4537 Intrauterine Insemination Cycles.

BACKGROUND: Studies suggest that race may affect access to fertility treatments and their outcomes. We examined whether race affects the following: duration of infertility prior to seeking evaluation, diagnosis, treatment cycle characteristics, and outcomes. MATERIALS AND METHODS: Design: Retrospective cohort. SETTINGS: Academic fertility center. PATIENTS: 4537 intrauterine insemination ± ovulation induction (IUI ± OI) cycles/1495 patients. INTERVENTIONS: IUI following: (i) OI with either clomiphene citrate or gonadotropins and (ii) ultrasound-monitored natural cycles. OUTCOME MEASURES: Duration of infertility prior to seeking treatment, SART diagnosis, treatment cycle characteristics and outcomes (spontaneous abortion (SABR), clinical (CPR) and multiple pregnancy rates (MPR)). RESULTS: Asians and Hispanics compared to Caucasians waited significantly longer prior to seeking fertility evaluation (p < 0.01). The mean age of patients seeking infertility evaluation did not differ between groups nor did the type of treatment initially chosen by the patients. Idiopathic infertility was more common among Caucasians (p < 0.05, compared to all others) while PCOS and tubal factor infertility were more frequent among Hispanics (p < 0.05, compared to Caucasian, Asian, and mixed ancestry women) and decreased ovarian reserve was more common among African-Americans (p < 0.01, compared to Caucasians, Asians, and Hispanics). Gonadotropin cycle characteristics including dosing and duration of treatment, follicular recruitment, peak estradiol levels, and endometrial lining thickness differed between certain groups. However, no difference was found in CPR, MPR, and SABR between groups. CONCLUSION: Race affects timely access to infertility care, diagnosis, and treatment cycle characteristics but not outcomes. Considering the nation's growing multiracial population, understanding the effect of race on fertility care becomes increasingly important.

Ethnic differences in the use of intrapartum epidural analgesia.

BACKGROUND: Obstetric epidural analgesia (EA) is widely applied, but studies have reported that its use may be less extensive among immigrant women or those from minority ethnic groups. Our aim was to examine whether this was the case in our geographic area, which contains an important immigrant population, and if so, to describe the different components of this phenomenon. METHODS: Cross-sectional observational study. SETTING: general acute care hospital, located in Marbella, southern Spain. Analysis of computer records of deliveries performed from 2004 to 2010. Comparison of characteristics of deliveries according to the mothers' geographic origins and of vaginal deliveries noting whether EA was received, using univariate and bivariate statistical analysis and multiple logistic regression (MLR). RESULTS: A total of 21,034 deliveries were recorded, and 37.4% of these corresponded to immigrant women. EA was provided to 61.1% of the Spanish women and to 51.5% of the immigrants, with important variations according to geographic origin: over 52% of women from other European countries and South America received EA, compared with around 45% of the African women and 37% of the Asian women. These differences persisted in the MLR model after adjusting for the mother's age, type of labor initiation, the weight of the neonate and for single or multiple gestation. With the Spanish patients as the reference category, all the other countries of origin presented lower probabilities of EA use. This was particularly apparent for the patients from Asia (OR 0.38; 95%CI 0.31-0.46), Morocco (OR 0.49; 95%CI 0.43-0.54) and other Africa (OR 0.55; 95%CI 0.37-0.81). CONCLUSIONS: We observed a different use of EA in vaginal deliveries, according to the geographic origin of the women. The explanation for this involves a complex set of factors, depending both on the patient and on the healthcare staff.

Normal ranges of fetal nasal bone length during the second trimester in an Iranian population.

OBJECTIVE: To provide a normal reference range for nasal bone length (NBL) during the second trimester of pregnancy in an Iranian population. METHODS: This cross-sectional study was performed on 3201 fetuses at 15 to 28 weeks of gestational age (GA). Both singleton and twin fetuses were evaluated. The relationship between NBL and GA was determined and percentile values for each gestational week were provided. RESULTS: NBL measurement was obtained in 98% of singleton and 96% of twin fetuses. There was a linear relationship between GA and NBL both in singleton (R(2) = 0.62) and in twin (R(2) = 0.74) fetuses. There was no significant difference between twins regarding NBL (p = 0.18). CONCLUSION: We have provided the normal reference range for NBL during the second trimester in an Iranian population. NBL in singleton and twin fetuses is similar and there is no significant difference between twins regarding NBL.

The contribution of maternal race/ethnicity and fetal sex to prematurity in twins.

OBJECTIVE: The contribution of male fetal sex to twin preterm birth (PTB) rates was evaluated in the United States. STUDY DESIGN: The 2002 National Center for Health Statistics Natality database was analyzed for fetal sex and twin gestations based on birth sex for MM and FF pairs (M, male; F, female). Multivariable Cox proportional hazards regression was applied to estimate the hazard ratio for PTB with adjustments for known risks. RESULTS: Thirty-three thousand nine hundred twenty-six pairs were analyzed. PTBs between 20-36 completed weeks occurred in 59.1% MM pairs and 57.5% FF pairs. MM sex was an independent risk factor for PTB. This effect was greatest for deliveries between 20-29 weeks (hazard ratio, 1.224; 95% CI, 1.113-1.346). The effect was most pronounced in non-Hispanic white MM pairs. CONCLUSION: In the United States, MM pairs are at greater risk for PTB. Race and ethnicity modulate sex effects. Further studies are needed to understand potential mechanisms.

Lived experiences of Taiwanese women with multifetal pregnancies who receive fetal reduction.

This study explores lived experiences of Taiwanese women with multifetal pregnancies who receive fetal reduction. This qualitative study adopted a field method with observer-as-participant approach to collect data. Six subjects were recruited from a medical center using purposive sampling. Most of the subjects were contacted nine times. The total time of observation was 8-10 weeks. The collected data was analyzed by content analysis, and forming themes. The findings are as follows: (1) difficulty in accepting unexpected multiple pregnancies; (2) worry over danger/risk of multiple pregnancies and concern about fetal reduction; (3) decision to take fetal reduction for the safe delivery and health of two babies; (4) anxiety about the techniques of fetal reduction; (5) growing emotion of attachment to the fetus and guilty feeling; (6) unbearable physical/mental stress when facing the intrusion of fetal reduction; (7) being enmeshed in fear of unstable pregnancy and guilt; and (8) cloud of uncertainty diminished, return to normal pregnancy. The results indicated that the women with multifetal pregnancies, who received fetal reduction, encountered a difficult decision. They were exposed to tremendous emotional responses. The findings of this study can help nurses to gain a deeper understanding of those women's experiences. More sensitive, precise recognition, as well as suitable nursing intervention can be provided, in order to promote better acceptance of and adjustment to the fetal reduction.

Teen twin pregnancies: differences in fetal growth outcomes among blacks and whites.

We set out to determine the magnitude of black-white disparity in intrauterine fetal growth inhibition among twin births to teenagers (age 15 to 19) in the United States using a retrospective cohort study design. We compared the risk for low and very low birthweight, preterm and very preterm, and small for gestational age between black and white twins born to teen mothers during the period 1995 through 1998. The methodology of generalized estimating equations was used to adjust for the presence of intracluster correlation within twin pairs. A total of 29,307 individual twins were analyzed. For all fetal growth indices examined, infants born to black mothers remained disadvantaged except for preterm birth, for which the risk was comparable to that of whites (adjusted OR, 1.03; 95% confidence interval [CI] 0.95 to 1.11). The racial gap was most marked for low birthweight (OR, 1.27; 95% CI, 1.19, 1.37]) and very low birthweight (OR, 1.30; 95% CI, 1.19 to 1.42). Black twins had an equal level of elevated risk for very preterm and small for gestational age (OR, 1.17; 95% CI, 1.07 to 1.27 and OR, 1.17; 95% CI, 1.07 to 1.28, respectively). In conclusion, we found significant differences in fetal growth parameters between black and white twins born to teen gravidas. Our findings confirm similar black disadvantage reported for singletons. Current prevention strategies aimed at reducing adverse fetal outcomes among teenagers in the United States need to consider the heightened risk among neonates born to black mothers.

Twinning and birth weight in the Israeli Jewish versus Muslim maternities.

Ethnicity differences account for genetic, environmental, lifestyle, and reproductive variables, influencing the rate of twinning (Nylander, 1981). Frequently, ethnic differences correlate with variable perinatal care leading to differences in outcome. Free access to antenatal care, and to facilities for delivery and neonatal care is available for the entire population in Israel, and therefore differences attributed to levels of medical care are practically negligible. We previously evaluated the overall relationship between ethnicity and outcome in a population-based cohort of mothers of twins (Goldman et al., 2001). However, the overall comparison may have masked some differences that could be present. The purpose of this study was to evaluate whether ethnicity is associated with differences in perinatal outcome in randomly selected, matched-controlled Israeli Jewish and Muslim mothers of twins.

The epidemiology of multiple births.

On the basis of MEDLINE and manual searches, we examined the main papers in the English literature regarding risk factors for spontaneous (i.e. not related to fertility drug use) multiple births. The constant frequency of monozygotic (MZ) pregnancies over time and in different geographical areas suggests that the determination of MZ twins is largely unchanged over time, and that a genetic mechanism may have a role. In contrast, temporal and geographical trends observed in dizygotic (DZ) pregnancies suggest that environmental factors play a role in determining this condition. At present, maternal age and hereditary components are the best-defined determinants for spontaneous multiple births.

The danger of overmatching in studies of the perinatal mortality and birthweight of infants born after assisted conception.

OBJECTIVE: To examine the impact of gestation length and plurality on short-term outcome of in vitro fertilization (IVF)-children. STUDY DESIGN: A register study using the Finnish Medical Birth Register for 1991-1993 (N = 194 383 newborns, of which 1335 were IVF-newborns). RESULTS: For IVF-newborns, a high proportion of multiple births (27%, odds ratio (OR) 19.67 compared with non-IVF births), low birth weight infants (30%, OR 7.94), and perinatal deaths (2.9%, OR 4.17) was found. The mothers' background did not explain the increased risks. After adjusting for gestation length and/or plurality, the odds ratios decreased significantly. CONCLUSION: Because of the high risk of plurality and premature births, matching the control group by gestation length and/or the number of multiples births may yield misleading results on the total health impact of IVF, and therefore it should be avoided.

Increasing trends in plural births in the United States.

OBJECTIVE: To determine the nature and possible reasons for the increasing trend in plural births in the United States during the 1980s. METHODS: We performed a descriptive analysis of births in the United States for five racial and ethnic groups from 1980-1989, using the United States vital records natality files. RESULTS: The rates of twin and triplet births rose 19 and 100%, respectively, during the 1980s. Approximately one-fourth of the observed increases can be attributed to rising maternal age. The increases in twin and triplet births occurred mainly among more educated and older white women. CONCLUSION: The association of high education status with rising rates of plural births, independent of maternal age, suggests that the observed increase is the result of increasing use of fertility-stimulating therapy among a subset of the childbearing population.

Trends in multiple births.

Since the early 1970s, the number and rate of multiple births have increased fairly steadily. Of the 4,110,907 babies born in the United States in 1991, 98,125 (2.4 percent) were twins, triplets or other higher order plural births. The 1991 rate of 23.9 multiple births per 1,000 live births--the highest recorded in this country in the last 50 years--was 1.3 percent higher than that in 1990, and 14 percent higher than the rate in 1985. The twins proportion of all multiple births has been slowly decreasing--97.6 percent in 1985, 96.9 percent in 1990 and 96.6 percent in 1991. Rates of multiple births continue to be higher among black women than white (2.8 and 2.3 per 1,000 live births, respectively, in 1991) and are more prevalent among older women. In 1991 the rates were higher through each age group to a high of 3.4 for white and 3.6 for black mothers aged 35-39 before dropping to 1.9 and 0.5, respectively, among 45- to 49-year-olds. Incidence of low birthweight (< 2,500 grams) and of very low birthweight (< 1,500 grams) babies were more frequent among multiple births than singletons and were more common among black than white infants. The median weight for white singleton births was 3,420 grams versus 2,260 grams for black plural births. The District of Columbia, Michigan and Massachusetts registered the highest percentage of multiple births in 1991 (2.9 to 2.7 percent) and the lowest rates were recorded in New Mexico and Wyoming (1.9 percent).

High ovarian response in Yoruba African women during ovulation induction for assisted conception.

Fertile Yoruba women from western Nigeria have a much higher incidence of naturally conceived multizygotic twin and triplet pregnancies than Caucasians. The objective of the present study was to determine whether there are differences between infertile Yoruba and Caucasian women in terms of ovarian response in stimulate cycles for assisted conception. A total of 11 Yoruba women were scheduled for 14 in-vitro fertilization (IVF) and one gamete intra-Fallopian transfer (GIFT) cycles from 1990 to 1992. The Caucasian group consisted of 209 women scheduled for 213 IVF and 22 GIFT cycles during the same period. Buserelin, 500 micrograms subcutaneously daily, was started in the mid-luteal phase to achieve pituitary desensitization. Ovarian stimulation was with variable amounts of menopausal gonadotrophins. Human chorionic gonadotrophin (HCG) was given to trigger the ovulatory process. The Yoruba and Caucasian groups were similar in age and body weight, but significantly more Yorubas (45 versus 11%; P < 0.005) had ultrasound features of polycystic ovary syndrome (PCOS). The serum oestradiol concentration (3024 versus 2058 pg/ml; P < 0.05) and number of follicles > 14 mm in diameter (15.5 versus 9.5; P < 0.05) on the day of HCG were higher in the Yoruba group. The ovarian hyperstimulation syndrome (OHSS) was also more prevalent in the Yoruba group (20 versus 5%; P < 0.05). No difference was found in clinical pregnancy or embryo implantation rates. These results show a higher tendency toward exaggerated ovarian response in infertile Yoruba than Caucasian women, associated with a higher prevalence of PCOS. The risk of developing symptomatic OHSS is higher in Yoruba women.

Low twinning rate and seasonal effects on twinning in a fertile population, the Hutterites.

This paper analyzes from the mid 18th century to 1987 the birth records of the "Dariusleut," one of the three subgroups of the Hutterite population. The aim of this study is to describe several aspects of the twinning rate in a fertile population. The overall rate of twinning was 0.90%: 103 twins among all 11,492 maternities. The rate peaked at the 7th birth order and at the maternal age of 40 years and over. Until the mid 19th century when the Hutterites lived in Russia, the twinning rate was higher (1.5%), and it decreased during the migration period in the second half of the 19th century (0.7%). After the group had settled in the USA and Canada, the population maintained a twinning rate of 1.0% until 1965. After 1965 the rate decreased to 0.7%, partly due to a decline in fertility among women aged 30 years and over. There was a significant seasonal variation: the twinning rate decreased to 0.5% in May-July compared to 1.2% for the other three seasons during the years up to 1965 (P < 0.01), while more recent mothers did not show such a seasonal variation. The incidence of twin births in this population seems to have been influenced by environmental factors, which would change their effect seasonally and secularly.