Spontaneous preterm birth: prevention, management and outcome

The risk of low birth weight and associated factors in West Bengal, India: a community based cross-sectional study

Background

Low birth weight (LBW) is a challenging multifaceted public health problem as it associated with infant mortality. Present study was undertaken to assess magnitude and risk factors associated with LBW in West Bengal, India. A community-based cross-sectional study was carried out among 2611 birth episodes in different districts of West Bengal using multi-stage stratified cluster sampling, followed by systematic random sampling methodology. Participants were interviewed by semi-structured questionnaires containing socio-demographic, pregnancy, and mothers’ health-related variables.

Results

This study revealed that 21.49% infants were born LBW. The risk of LBW was higher among women those age < 20 years and BMI < 18.5 kg/m2. The odd of giving LBW baby were higher among women having weight < 45 kg and height < 150 cm. Anemic (AOR 3.33) and hypertensive (AOR 1.69) women were more likely to give LBW baby. Preterm delivery (AOR 1.93) and history of chronic illness (AOR 2.09) were the determinants of LBW. The odd of LBW was higher among women who never followed ANC visit (AOR 1.35). The likelihood of giving LBW baby was higher among women who did not consume iron folic acid tablet and additional diet during pregnancy. More LBWs were observed among women who were from low socioeconomic family, rural residence, and illiterate.

Conclusions

This study provided scientific recommendations during preconception period which will help to target women who may potentially benefit from lifestyle and dietary interventions. To reduce LBW community specific strategies such as improving awareness of the community and utilization of existing maternal health services is essential.

Bacterial vaginosis diagnosed at the first antenatal visit better predicts preterm labour than diagnosis later in pregnancy

This study was conducted as part of a double-blind randomised placebo-controlled trial, the aim of which was to determine whether vitamin C could reduce the recurrence risk of pre-term labour. In this study, women with a history of pre-term labour in a preceding pregnancy were randomised to receive either 250 mg vitamin C or a matching placebo twice daily until 34 weeks' gestation. They attended a dedicated pre-term labour clinic every 2 weeks. All women were screened for bacterial vaginosis (BV) at each visit. It was first determined that vitamin C did not have any effect on the presence of BV. Women who were diagnosed with BV before 20 weeks' gestation were at higher risk of delivering pre-term than those who developed BV after 20 weeks.

Low preconception body mass index is associated with birth outcome in a prospective cohort of Chinese women

Low maternal prepregnancy BMI is associated with adverse birth outcomes, but the BMI at which risk increases is not well defined. We assessed whether the relationship between prepregnancy BMI and birth outcomes is influenced by the extent to which mothers were underweight in a prospective study in Anhui, China. The women (n = 575) were 20-34 y old, married, nulliparous and nonsmokers. All measures of infant growth increased with increasing maternal BMI until a plateau was reached at a BMI of 22-23 kg/m2. Infants born to the 27% of women who were severely underweight before pregnancy (BMI < or = 18.5 kg/m2) were at increased risk for fetal growth deficits associated with infant morbidity. Compared with a normal BMI, being severely underweight was associated with mean (+/- SEM) reductions of 219 +/- 40 g in infant birthweight and 6.7 +/- 1.3% in the birthweight ratio and an 80% increase in risk of intrauterine growth restriction [odds ratio (OR) 1.8; 95% CI: 1.0, 3.3; P = 0.05]. Being severely underweight was also associated with smaller infant head circumference and lower ponderal index. Being moderately underweight (18.5 < BMI < 19.8 kg/m2) was not significantly associated with adverse pregnancy outcomes. Gestational age and risk of preterm birth were not associated with maternal BMI. More than half of the women in this study were underweight before pregnancy. Although being moderately underweight was not associated with increased risk of adverse pregnancy outcomes, being severely underweight was an important risk factor for reduced fetal growth.

Changes in perinatal care and survival in very preterm and extremely preterm infants in The Netherlands between 1983 and 1995

OBJECTIVE

To evaluate changes in obstetrical and neonatal care for very preterm and extremely preterm infants between 1983 and 1995 in The Netherlands and to evaluate the effect of those changes.

STUDY DESIGN

Data on all very preterm or VLBW infants from the linked national obstetrical and neonatal databases of 1995 (N=2066) were compared to data on similar infants from a nation-wide study of very preterm infants born in 1983 (N=1338).

RESULTS

Obstetrical and neonatal management changed over time, with an increased number of deliveries in tertiary centres (35.7-60.7%), an increase in C-sections (43.7-56.8%) and prolonged artificial ventilation (3.4-9.5%). Survival until discharge increased from 75 to 90% and neonatal morbidity decreased in relative terms.

CONCLUSIONS

The short-term outcome for these very preterm and extremely preterm infants has improved. Long-term follow-up through to school age and adulthood of preterm infants is needed to investigate the changes in the sequelae of intensive obstetrical and neonatal care.

Preterm delivery: an overview

Preterm delivery is the leading factor causing neonatal mortality and morbidity. We have conducted a PubMed literature search to obtain an update on the etiology, diagnostic problems and therapeutic considerations of preterm delivery. Approximately 5-10% of all births are premature. Preterm labor is associated with preterm rupture of membranes, cervical incompetence, polyhydramnion, fetal and uterine anomalies, infections, social factors, stress, smoking, heavy work and other risk factors. The diagnosis is made on the patients presenting symptoms, clinical findings and of progressive effacement and dilatation of the cervix. Biochemical markers of preterm delivery are of minor importance in daily clinical work. Measurement of the cervix, however, is a practical and valuable tool to predict preterm delivery. Cervical cerclage can be useful in selected cases. Antibiotics may help to prevent preterm labor in cases of known etiologic agents (e.g. preterm rupture of membranes and urinary infection). The use of tocolytic agents such as beta-sympathetic receptor stimulators can be advocated for a few days. There is evidence that their long-term use is not beneficial and could even be harmful to the fetus. Calcium channel blockers (nifedipine) and a new selective oxytocin receptor antagonist, atosiban, appear to be as effective as beta-sympathomimetic drugs on uterine contractions with fewer side-effects. Prostaglandin synthetase inhibitors such as indomethacin may prevent uterine contractions and can be used prior to the 32nd week of pregnancy. A single course of corticosteroid treatment in two doses of 12 mg betamethasone or 6 mg of dexamethasone is important for the prevention of respiratory distress between the 24th and 34th weeks of pregnancy. Multiple doses may be harmful and should be avoided. In these cases management should depend on gestation age (fetal maturity). Uterine contractions after 34 weeks' gestation are not an indication for tocolytic treatment.

Preconception homocysteine and B vitamin status and birth outcomes in Chinese women

BACKGROUND

The associations between homocysteine, B vitamin status, and pregnancy outcomes have not been examined prospectively.

OBJECTIVE

We assessed the associations of preconception homocysteine and B vitamin status with preterm birth and birth of low-birth-weight (LBW) and small-for-gestational-age (SGA) infants in Chinese women.

DESIGN

This was a case-control study of women aged 21-34 y. Preterm cases (n = 29) delivered living infants at <37 wk gestation; term controls (n = 405) delivered infants at > or =37 wk. LBW cases (n = 33) had infants weighing <2500 g; normal-birth-weight controls (n = 390) had infants weighing > or =2500 g. SGA cases (n = 65) had infants below the 10th percentile of weight-for-gestational-age; appropriate-for-gestational-age controls (n = 358) had infants above this cutoff. Nonfasting plasma concentrations of homocysteine, folate, and vitamins B-6 and B-12 were measured before conception.

RESULTS

Elevated homocysteine (> or =12.4 micro mol/L) was associated with a nearly 4-fold higher risk of preterm birth (OR: 3.6; 95% CI: 1.3, 10.0; P < 0.05). The risk of preterm birth was 60% lower among women with vitamin B-12 > or =258 pmol/L than among vitamin B-12-deficient women (OR: 0.4; 95% CI: 0.2, 0.9; P < 0.05) and was 50% lower among women with vitamin B-6 > or =30 nmol/L than among vitamin B-6-deficient women (OR: 0.5; 95% CI: 0.2, 1.2; NS). Folate status was not associated with preterm birth, and homocysteine and B vitamin status were not associated with LBW or SGA status.

CONCLUSIONS

Elevated homocysteine and suboptimal vitamin B-12 and B-6 status may increase the risk of preterm birth. These results need to be confirmed in larger prospective studies.