Comparison of risk factors for major obstetric complications between Western countries and Japan: A case-cohort study

Risk factors for cerebral palsy in neonates due to placental abruption

Aim

This study aimed to identify risk factors for the onset of cerebral palsy (CP) in neonates due to placental abruption and investigate their characteristics.

Methods

A retrospective case–control study was conducted using a nationwide registry from Japan. The study population included pregnant women (n = 122) who delivered an infant with CP between 2009 and 2015, where placental abruption was identified as the single cause of CP. The control group consisted of pregnant women with placental abruption, who delivered an infant without CP and were managed from 2013 to 2014. They were randomly identified from the prenatal database of the Japan Society of Obstetrics and Gynecology (JSOG‐DB; n = 1214). Risk factors were investigated using multivariate analysis.

Results

Alcohol consumption (3.38, 2.01–5.68) (odds ratio, 95% confidence interval), smoking during pregnancy (3.50, 1.32–9.25), number of deliveries (1.28, 1.05–1.56), polyhydramnios (5.60, 1.37–22.6), oral administration of ritodrine hydrochloride (2.09, 1.22–3.57) and hypertensive disorders in pregnancy (2.25, 1.27–4.07) were significant risk factors. In contrast, intravenous administration of oxytocin (odds ratio, 95% confidence interval: 0.22, 0.09–0.58) and magnesium sulfate (0.122, 0.02–0.89) attenuated risk.

Conclusion

Alcohol consumption, smoking during pregnancy, number of deliveries, polyhydramnios, oral administration of ritodrine hydrochloride and hypertensive disorders in pregnancy were identified as risk factors for CP following placental abruption. Regarding alcohol consumption and smoking during pregnancy, the results suggest the importance of educational activities targeting pregnant women to increase their awareness of placental abruption.

Trial of labor after cesarean delivery (TOLAC) in Japan: rates and complications

PURPOSE

To determine the rates of trial of labor after cesarean delivery (TOLAC) and complications in Japan.

METHODS

We conducted a descriptive study of pregnant women with one prior cesarean section registered between January 2013 and December 2015 in the perinatal database of the Japan Society of Obstetrics and Gynecology. This database is a nationwide institution-based registry in Japan. This study included women who had undergone one prior cesarean delivery and who delivered a singleton by cephalic presentation between 37 and 41 weeks of gestation. We collected data on delivery method, particularly with regard to the involvement of TOLAC or elective repeated cesarean deliveries (ERCD). Rates of TOLAC were investigated by facility type, and we calculated the rates of maternal and perinatal complications including uterine rupture in TOLAC.

RESULTS

During the study period, 647,098 births were registered. Among the 34,460 women who met the inclusion criteria, 1730 (5.0%) and 32,730 (95.0%) underwent TOLAC and ERCD, respectively. In total, 76.4% of hospitals did not perform TOLAC at all. Generally in perinatal medical centers, which are better equipped with facilities, 58.7% women did not perform TOLAC. With regard to complications, we identified eight cases (0.46%) of uterine rupture with TOLAC. TOLAC births did not include maternal death and perinatal death. Among women attempting TOLAC, 1532 (88.6%) had successful vaginal births.

CONCLUSION

The TOLAC rate in Japan was considerably lower than that reported in other countries, despite comparable complication rates.

Complications and outcomes of pregnant women with adenomyosis in Japan

Purpose

To investigate the impact of adenomyosis on the complications and outcomes of pregnancy in Japan.

Methods

We carried out a multicenter retrospective questionnaire survey. A questionnaire regarding pregnancy complications and the outcomes of pregnancy was sent to 725 facilities.

Results

Data were obtained on the cases of 272 pregnant women with adenomyosis from 65 facilities. The complications of pregnancy included miscarriage before 12 weeks of pregnancy (14.8%), miscarriage after 12 weeks of pregnancy (9.9%), preterm delivery (24.4%), fetal growth restriction (11.8%), pregnancy‐induced hypertension (9.9%), intrauterine infection (7.3%), and cervical incompetency (5.3%). The rates of pregnancy complications in the three groups classified according to pretreatment for adenomyosis (no pretreatment, medication, surgery) did not differ to a statistically significant extent. The rates of miscarriage (>12 weeks) and cervical incompetency increased according to the size of the adenomyosis. The rates of pregnancy‐induced hypertension and uterine infection in patients with diffuse‐type adenomyosis were higher than that in patients with focal‐type adenomyosis.

Conclusions

Our results show that the increased size and diffuse type of adenomyosis are associated with adverse pregnancy outcome. We should be aware of the higher incidence of pregnancy‐induced hypertension and uterine infection in patients with diffuse‐type adenomyosis.

Pre-pregnancy BMI-specific optimal gestational weight gain for women in Japan

Background

The Institute of Medicine (IOM) guidelines are the most widely used guidelines on gestational weight gain; however, accumulation of evidence that body composition in Asians differs from other races has brought concern regarding whether their direct application is appropriate. We aimed to study to what extent optimal gestational weight gain among women in Japan differs by pre-pregnancy body mass index (BMI) and to compare estimated optimal gestational weight gain to current Japanese and Institute of Medicine (IOM) recommendations.

Methods

We retrospectively studied 104,070 singleton pregnancies among nulliparous women in 2005–2011 using the Japanese national perinatal network database. In five pre-pregnancy BMI sub-groups (17.0–18.4, 18.5–19.9, 20–22.9, 23–24.9, and 25–27.4 kg/m²), we estimated the association of the rate of gestational weight gain with pregnancy outcomes (fetal growth, preterm delivery, and delivery complications) using multivariate regression.

Results

Weight gain rate associated with the lowest risk of adverse outcomes decreased with increasing BMI (12.2 kg, 10.9 kg, 9.9 kg, 7.7 kg, and 4.3 kg/40 weeks) for the five BMI categories as described above, respectively. Current Japanese guidelines were lower than optimal gains, with the lowest risk of adverse outcomes for women with BMI below 18.5 kg/m², and current IOM recommendations were higher than optimal gains for women with BMI over 23 kg/m².

Conclusion

Optimal weight gain during pregnancy varies largely by pre-pregnancy BMI, and defining those with BMI over 23 kg/m² as overweight, as proposed by the World Health Organization, may be useful when applying current IOM recommendations to Japanese guidelines.

•

We estimated gestational weight gain that optimizes pregnancy outcomes in Japanese.

•

Optimal gain was 12.2 kg/40 weeks for pre-pregnancy BMI 17.0–18.4 kg/m².

•

Optimal gain was 4.3 kg/40 weeks for pre-pregnancy BMI 25.0–27.4 kg/m².

•

Current national guidelines are too low for women with pre-pregnancy BMI < 18.5 kg/m².

•

BMI > 23 kg/m² should be defined as overweight if applying IOM recommendations.

Impact of risk factors for perinatal events in Japan: Introduction of a newly created perinatal event score

AIM

A cohort study was performed to clarify the influence of risk factors on perinatal events (obstetric complications and/or perinatal deaths).

METHODS

This cohort study reviewed 395 785 births from 2011 to 2013. Women with singleton pregnancies delivered after 22 weeks of gestation were included. The OR were determined on multivariate analysis. The perinatal event score (PES) for risk factors, which is the product of the OR of risk factors for obstetric complications, OR of risk factors for perinatal death, and OR of obstetric complications for perinatal death, was introduced to clarify the impact of each risk combination.

RESULTS

There were 20 risk factors such as maternal age and medical complications relating to the 11 obstetric complications, including pregnancy-induced hypertension and preterm labor. As a result, 77 combinations of risk factors and obstetric complications were found to be significant. Six obstetric complications such as preterm labor and cervical insufficiency were found to be related to perinatal death. Two factors were found to be directly related to perinatal death: age >40 years old (OR, 1.24; 95%CI: 1.11-1.39) and essential hypertension (OR, 1.56; 95%CI: 1.19-2.05). As a result, PES ranged from 1.07 (primipara for premature rupture of membrane) to 40.1 (essential hypertension for placental abruption), and high PES (≥8) was identified in 21 combinations of risk factors and obstetric complications.

CONCLUSION

This newly created score for perinatal events, PES, can be used as an indicator of the impact of risk factors on perinatal events.

Cohort study of the incidence of spontaneous preterm birth and septic abortion referred by pathological examination in Gifu prefecture in Japan

AIMS

To clarify the incidence of spontaneous preterm birth (PB) and septic abortion (sab) in Gifu prefecture in Japan.

STUDY DESIGN

This prospective, population-based cohort study was approved by our hospital's Institutional Review Board. All 36 hospitals (100%) in Gifu prefecture offering obstetrical services participated in the study. Patient enrollment criteria were: sab and PB from 22 to <37weeks gestation (WG), excluding for maternal and fetal indications. Pathological examinations before 36 WG and associated factors for both PB and chorioamnionitis (CAM) stage 3 were analyzed by multiple logistic regression analysis judging from minimum daily clinical information in Gifu prefecture.

RESULTS

The sab rate per all deliveries was 29/16871 (0.17%) at 16.9±2.9 WG. The total spontaneous PB rate was 615/16871 (3.65%) at 34.5±2.7 WG, with birth weight (BW) 2267±557g. There were 26 (0.15%) PBs from 22+0 to 27+6 WG (weeks+days) at 25.2±1.5 WG, with BW 745±199g. Among 214 pathological examinations, CAM was detected in 80% (sab) and 63% (PB<36 WG), respectively. Funisitis were 14% and 17% respectively. Episodes of serial genital bleeding and/or hematoma at <12 WG were more frequent in sab and earlier PB (<28 WG) associated with CAM stage 3 (odds 1.9, P<0.0001). Combined factors such as bleeding and past history of CAM correlated with earlier delivery at 23.4±5.9 WG (P=0.0032).

CONCLUSION

In Gifu prefecture, the incidence of sab was 0.17% (per all deliveries) and 3.65% of spontaneous PB. The combined risk of past CAM history and bleeding was associated with earlier delivery among total preterm birth.

Factors affecting maternal confidence and satisfaction in older Japanese primiparae during postpartum hospital stay

The purpose of this study was to identify factors affecting maternal confidence and satisfaction in older Japanese primiparae during their postpartum hospital stay. Participants were Japanese primiparae (age ≥ 35) who delivered live singleton infants (n = 479). Questionnaires completed 1 day before discharge from hospital included the Postpartum Maternal Confidence Scale and the Postpartum Maternal Satisfaction Scale. Data were analysed using stepwise multiple regression for maternal confidence and stepwise logistic regression for maternal satisfaction, after controlling for delivery mode. Maternal confidence was negatively affected by feeling overwhelmed by postpartum routines, needing a longer time for feeding, and a pregnancy with complications. Satisfaction with the birth experience and a longer rooming-in period were related to greater maternal satisfaction. Lack of prior experiences with caring for babies and lack of communication with their partner about parenting role were also associated with lower confidence and satisfaction. These findings provide an important framework for nurses to teach and counsel older first-time mothers.

Relevant Obstetric Factors for Cerebral Palsy: From the Nationwide Obstetric Compensation System in Japan

Objective

The aim of this study was to identify the relevant obstetric factors for cerebral palsy (CP) after 33 weeks’ gestation in Japan.

Study design

This retrospective case cohort study (1:100 cases and controls) used a Japanese national CP registry. Obstetric characteristics and clinical course were compared between CP cases in the Japan Obstetric Compensation System for Cerebral Palsy database and controls in the perinatal database of the Japan Society of Obstetrics and Gynecology born as live singleton infants between 2009 and 2011 with a birth weight ≥ 2,000 g and gestation ≥ 33 weeks.

Results

One hundred and seventy-five CP cases and 17,475 controls were assessed. Major relevant single factors for CP were placental abnormalities (31%), umbilical cord abnormalities (15%), maternal complications (10%), and neonatal complications (1%). A multivariate regression model demonstrated that obstetric variables associated with CP were acute delivery due to non-reassuring fetal status (relative risk [RR]: 37.182, 95% confidence interval [CI]: 20.028–69.032), uterine rupture (RR: 24.770, 95% CI: 6.006–102.160), placental abruption (RR: 20.891, 95% CI: 11.817–36.934), and preterm labor (RR: 3.153, 95% CI: 2.024–4.911), whereas protective factors were head presentation (RR: 0.199, 95% CI: 0.088–0.450) and elective cesarean section (RR: 0.236, 95% CI: 0.067–0.828).

Conclusion

CP after 33 weeks’ gestation in the recently reported cases in Japan was strongly associated with acute delivery due to non-reassuring fetal status, uterine rupture, and placental abruption.

Pregnancy outcomes after living donor liver transplantation: results from a Japanese survey

A national survey of pregnancy outcomes after living donor liver transplantation (LDLT) was performed in Japan. Thirty-eight pregnancies in 30 recipients resulted in 31 live births (25 recipients), 3 artificial abortions in the first trimester (3 recipients), 1 spontaneous abortion (1 recipient), and 3 fetal deaths (3 recipients). After the exclusion of the 3 artificial abortions, there were 35 pregnancies in 27 recipients: pregnancy-induced hypertension developed during 6 pregnancies (5 recipients), fetal growth restriction developed during 7 pregnancies (6 recipients), acute rejection developed during 2 pregnancies (2 recipients), and ileus developed during 1 pregnancy (1 recipient). Preterm delivery (<37 weeks) occurred for 10 pregnancies (10 recipients), and cesarean delivery was performed for 12 pregnancies (12 recipients). After delivery, acute rejection developed in 3 recipients. Twelve neonates were born with low birth weights (<2500 g), and 4 of these 12 neonates had extremely low birth weights (<1500 g). Two neonates had congenital malformations. The pregnancy outcomes after LDLT were similar to those reported for cadaveric liver transplantation (LT). The incidence of pregnancy-induced hypertension in recipients who were 33 years old or older at the diagnosis of pregnancy was significantly higher than the incidence in recipients who were less than 33 years old at the diagnosis of pregnancy. The incidences of fetal growth restriction, pregnancy-induced hypertension, and extremely low birth weight were significantly higher in the early group (<3 years after transplantation) versus the late group (≥3 years after transplantation). In conclusion, it is necessary to pay careful attention to complications during pregnancy in recipients who become pregnant within 3 years of LT, particularly if the age at the diagnosis of pregnancy is ≥33 years.

Multiple pregnancy, short cervix, part-time worker, steroid use, low educational level and male fetus are risk factors for preterm birth in Japan: a multicenter, prospective study

AIM

To examine the relationship between preterm birth and socioeconomic factors, past history, cervical length, cervical interleukin-8, bacterial vaginosis, underlying diseases, use of medication, employment status, sex of the fetus and multiple pregnancy.

METHODS

In a multicenter, prospective, observational study, 1810 Japanese women registering their future delivery were enrolled at 8⁺⁰ to 12⁺⁶ weeks of gestation. Data on cervical length and delivery were obtained from 1365 pregnant women. Multivariate logistic regression analysis was performed.

RESULTS

Short cervical length, steroid use, multiple pregnancy and male fetus were risk factors for preterm birth before 34 weeks of gestation. Multiple pregnancy, low educational level, short cervical length and part-timer were risk factors for preterm birth before 37 weeks of gestation.

CONCLUSION

Multiple pregnancy and cervical shortening at 20-24 weeks of gestation was a stronger risk factor for preterm birth. Any pregnant woman being part-time employee or low educational level, having a male fetus and requiring steroid treatment should be watched for the development of preterm birth.