This study aimed to investigate the association between maternal birth weight (MBW) with preterm delivery (PTD) in the Japanese population. To this end, a total of 78,972 Japanese pregnant women were included in a prospective birth cohort study. Multiple logistic regression and multinominal logistic regression models were applied to investigate the associations of MBW with PTD (delivery from 22 to < 37 weeks of gestation), early PTD (delivery from 22 to < 34 weeks), and late PTD (delivery from 34 to < 37 weeks). The results showed that MBW was inversely associated with PTD, early PTD, and late PTD (p-for-trend < 0.0001, 0.0014, and < 0.0001, respectively). The adjusted odds ratios per each 500 g of MBW decrease were 1.167 (95% confidence interval [CI]: 1.118–1.218) for PTD, 1.174 (95% CI: 1.070–1.287) for early PTD and 1.151 (95% CI: 1.098–1.206) for late PTD. The effect size of the association of MBW with early PTD was similar to that with late PTD. This study demonstrated for the first time an association of a low MBW with PTD, early PTD, and late PTD in a Japanese nationwide cohort.

According to the World Health Organization, smoking is the most important risk factor for adverse pregnancy outcomes in industrialized nations. We aimed to establish how fetal gender and smoking interact with regard to perinatal outcomes, especially preterm delivery. Data from 220,339 singleton pregnancies, obtained from the German Perinatal Survey in Schleswig-Holstein and registered between 2004 and 2017 were analyzed in regard to smoking behavior, fetal gender, and preterm delivery. The rate of preterm births was directly proportional to the women’s consumption of nicotine. The rate of preterm deliveries was 6.8% among nonsmokers, and 13.2% in women who were very heavy smokers (≥22 cigarettes/day). Very heavy smoking (≥22 cigarettes/day) had a marked impact on extremely preterm births (<28 weeks of gestation) and very preterm births (28–31 weeks of gestation). Preterm births increased by 1.2% from heavy smokers to very heavy smokers; the differences between the other groups ranged between 0.1% and 0.4%. Fetal gender also had an impact on preterm birth: male infants were predominant in nearly all groups of women who delivered preterm infants. Smoking during pregnancy and male gender are both risk factors for preterm delivery. Fetal gender should be given greater attention as one of the several risk factors of preterm birth. Due to the high rate of morbidity among preterm infants and enormous costs for the healthcare system, women should be encouraged to cease or at least reduce smoking during pregnancy.

The first positive genome-wide association study on gestational length and preterm delivery showed the involvement of an Se metabolism gene. In the present study, we examine the association between maternal intake of Se and Se status with gestational length and preterm delivery in 72 025 women with singleton live births from the population-based, prospective Norwegian Mother, Father and Child Cohort Study (MoBa). A self-reported, semi-quantitative FFQ answered in pregnancy week 22 was used to estimate Se intake during the first half of pregnancy. Associations were analysed with adjusted linear and Cox regressions. Se status was assessed in whole blood collected in gestational week 17 (n 2637). Median dietary Se intake was 53 (interquartile range (IQR) 44–62) µg/d, supplements provided additionally 50 (IQR 30–75) µg/d for supplement users (n 23 409). Maternal dietary Se intake was significantly associated with prolonged gestational length (β per sd = 0·25, 95 % CI, 0·07, 0·43) and decreased risk of preterm delivery (n 3618, hazard ratio per sd = 0·92, 95 % CI, 0·87, 0·98). Neither Se intake from supplements nor maternal blood Se status was associated with gestational length or preterm delivery. Hence, the present study showed that maternal dietary Se intake but not intake of Se-containing supplements, during the first half of pregnancy was significantly associated with decreased risk of preterm delivery. Further investigations, preferably in the form of a large randomised controlled trial, are needed to elucidate the impact of Se on pregnancy duration.

Anaemia during pregnancy, characterised by Hb <110 g/l, is a specific risk factor for adverse maternal and perinatal outcomes in developing countries. The objective of this study was to determine the effectiveness of daily antenatal supplementation with multiple micronutrients (MMN) compared with folic acid (FA) on the occurrence of anaemia among pregnant women and their infants’ health in a high-altitude area. A prospective cohort study was carried out in two rural counties in Tibet from 2007 to 2012. A total of 1149 eligible pregnant women were allocated daily supplementation with FA in one county and MMN containing a recommended allowance of twenty-three vitamins and minerals in another county starting ≤24 weeks of gestation and continuing until delivery. Compared with the FA group, prenatal supplementation with MMN was significantly associated with reduced odds of anaemia in the third trimester. This was demonstrated in the primary outcome, with an adjusted OR (AOR) of 0·63; 95 % CI 0·45, 0·88 and P=0·007 and also reduced odds of preterm delivery (AOR: 0·31; 95 % CI 0·15, 0·61; P=0·001). There was no difference between MMN and FA groups in mean birth weight (adjusted mean difference: 36·78; 95 % CI −19·42, 92·98 g; P=0·200), whereas MMN supplementation significantly reduced the odds of low-birth weight (LBW) babies (AOR: 0·58; 95 % CI 0·36, 0·91; P=0·019). In conclusion, the antenatal MMN supplementation in rural Tibet is associated with a reduction of maternal anaemia in the third trimester, and may potentially decrease the risk of preterm delivery and LBW babies.

The primary study objective was to investigate three decades from 1985 to 2014 of changes in pregnancies among HIV-infected women. The secondary objective was to assess risk factors associated with preterm delivery and severe small-for-gestational-age (SGA) infants in HIV-infected women. A retrospective review of deliveries among pregnant HIV-infected women at the University of Genoa and IRCCS San Martino-IST in Genoa between 1985 and 2014 was performed. Univariate and multivariable analyses were used to study the variables associated with neonatal outcomes. Overall, 262 deliveries were included in the study. An increase in median age (26 years in 1985–1994 vs. 34 years in 2005–2014), in the proportion of foreigners (none in 1985–1994 vs. 27/70 (38·6%) in 2005–2014), and a decrease in intravenous drug use (75·2% (91/121) in 1985–1994 vs. 12·9% (9/70) in 2005–2014) among pregnant HIV-infected women was observed. Progressively, HIV infections were diagnosed sooner (prior to pregnancy in 80% (56/70) of women in the last decade). An increase in combined antiretroviral therapy (cART) prescription during pregnancy (50% (27/54) in 1995–2004 vs. 92·2% (59/64) in 2005–2014) and in HIV-RNA <50 copies/ml at delivery (19·2% (5/26) in 1995–2004 vs. 82·3% (53/64) in 2005–2014) was observed. The rate of elective caesarean section from 1985 to 1994 was 9·1%, which increased to 92·3% from 2004 to 2015. Twelve (10·1%) mother-to-child transmissions (MTCT) occurred in the first decade, and six (8·3%) cases occurred in the second decade, the last of which was in 2000. Preterm delivery (<37 weeks gestation) was 5% (6/121) from 1985 to 1994 and increased to 17·1% (12/70) from 2005 to 2014. In univariate and multivariable logistic regression analyses, advancing maternal age and previous pregnancies were associated with preterm delivery (odds ratio (OR) 2·7; 95% confidence intervals (CI) 1–7·8 and OR 2·6; 95% CI 1·1–6·7, respectively). In the logistic regression analysis, use of heroin or methadone was found to be the only risk factor for severe SGA (OR 3·1; 95% CI 1·4–6·8). In conclusion, significant changes in demographic, clinical and therapeutic characteristics of HIV-infected pregnant women have occurred over the last 30 years. Since 2000, MTCT has decreased to zero. An increased risk of preterm delivery was found to be associated with advancing maternal age and previous pregnancies but not with cART. The use of heroin or methadone has been confirmed as a risk factor associated with severe SGA.

The study aimed at investigating the impact of late prematurity (LPT) on neonatal outcome in twins and neonatal morbidity and mortality within LPT with regard to the completed weeks of gestation. The study was conducted in six tertiary obstetric departments from different provinces of Poland (Warsaw, Lublin, Poznan, Wroclaw, Bytom). It included 465 twin deliveries in the above centers in 2012. A comparative analysis of maternal factors, the course of pregnancy and delivery and neonatal outcome between LPT (34 + 0–36 + 6 weeks of gestation) and term groups (completed 37 weeks) was performed. The neonatal outcome included short-term morbidities. The analysis of neonatal complication rates according to completed gestational weeks was carried out. Out of 465 twin deliveries 213 (44.8%) were LPT and 156 (33.55%) were term. There were no neonatal deaths among LPT and term twins. One-third of LPT newborns suffered from respiratory disorders or required antibiotics, 40% had jaundice requiring phototherapy, and 30% were admitted to NICU. The analysis of neonatal morbidity with regard to each gestational week at delivery showed that most analyzed complications occurred less frequently with the advancing gestational age, especially respiratory disorders and NICU admissions. The only two factors with significant influence on neonatal morbidity rate were neonatal birth weight (OR = 0.43, 95% CI = 0.2–0.9, p = .02) and gestational age at delivery (OR = 0.62, 95% CI = 0.5–0.8, p < .01). LPT have a higher risk of neonatal morbidity than term twins. Gestational age and neonatal birth weight seem to play a crucial role in neonatal outcome in twins.

A preterm 29-week gestation baby was delivered because of gross foetal hydrops secondary to congenital complete heart block. Despite a poor prognosis, she survived stabilisation and received emergency epicardial pacing followed by permanent pacemaker insertion on day 13, weighing 1.2 kg.

The objective of our study was to evaluate the correlation of the cervical length at 20–25 weeks of gestation with the incidence of spontaneous preterm delivery in twins in a country with a high incidence of preterm delivery compared to other European countries. Cervical length was measured in 262 consecutive patients. Previous preterm delivery before 34 weeks of gestation, chorionicity, maternal age, body-mass-index, smoking habit and parity were recorded as risk factors for preterm delivery. Women who were symptomatic at 20–25 weeks and who delivered because of other reasons than spontaneous labour and preterm rupture of membranes or at term were excluded. The primary outcome was incidence of preterm birth before 34 weeks. Two hundred and twenty-three patients were analyzed. Thirty-two (14%) delivered before 34 weeks. There was a significant correlation between cervical length of less than 25 mm and spontaneous delivery before 34 weeks (50% vs. 13%, p = .007). In addition, logistic regression analysis found cervical length to be the only significant predictor of spontaneous delivery before 34 weeks (OR 1.084; 95% CI 1.015; 1.159; p = .017). We conclude that the risk of severe preterm delivery in twins is high. Cervical length at mid-gestation was the only predictor of delivery before 34 weeks.

The increasing number of twin (and higher order) births is a matter of national concern for two reasons: First, the differential rates of preterm (< 37 weeks) delivery and low birthweight (< 2,500g) among twins compared to singletons; and second, the inordinate contribution of these infants to overall infant mortality, morbidity and long-term handicap. Data from all births in the U.S. during 1987 and 1988 was used to calculate distribution frequencies for gestational age at delivery, and birthweight, as well as mortality and handicap rates and the corresponding relative risks of these latter events for twins compared to singletons. A suggestion for improvement in the mortality and handicap rates and reduced costs among survivors is presented. This proposal is based upon data from the singleton and twin literature and the use of the prenatal invervention of adequate maternal nutrition during the pregnancy.

Nineteen women attending a special multiple pregnancy antenatal clinic with a triplet pregnancy were randomly allocated to either bed rest in hospital from 24 weeks gestation onwards until delivery, or to continue conventional outpatient management. Conclusions are limited by the trial size, but the study suggests that routine hospitalization for bed rest decreases the incidence of preterm delivery and light-for-gestational age infants and reduces the need for intensive neonatal care. Although still compatible with change variation, the observations, if confirmed in a larger randomized study, would have considerable implications for clinical practice. The policy needs further evaluation in a large multicentred collaborative study.

As an extension of previous work on the risk of prematurity in singletons and on the social cost of twin births, an analysis has been carried out into the cost effectiveness of preventing premature delivery in twin pregnancies. The cost of prevention is assessed in terms of early diagnosis through ultrasound screening and of an extra 11 weeks of work leave to expectant mothers. When this cost is compared to the social cost involved in the transfer of newborns to neonatal intensity care units and in supporting handicapped children, it is concluded that the total cost of prevention corresponds to one-third of the long-term costs associated to lack of prevention.

We investigated if it is possible to use the data collected in twins to identify areas with high rates of operative deliveries, preterm deliveries and low birthweight infants in singletons. Our data correspond to all deliveries registered in Belgium in 1983. A significant correlation was found between the rates of cesarean sections in twins and in singletons. A significant correlation was also found between the rate of deliveries at a gestational age of less than 32 weeks in twins and the rate of deliveries at less than 37 weeks in singletons. However, correlations between other preterm rates, low birthweight rates and vacuum extraction or forceps rates, were nonsignificant. We conclude that the use of twins as tracers of the quality of care in singletons is of limited value.