Determinants and outcome of fetal macrosomia in a Nigerian tertiary hospital

Background:

To determine the incidence and risk factors of fetal macrosomia and maternal and perinatal outcome.

Patients and Methods:

This was a 1-year prospective case–control study of singleton pregnancies in a Nigerian tertiary hospital. Only women who gave consent were recruited for the study. The maternal and perinatal outcomes in women who delivered macrosomic infants (birth weight ≥ 4000 g) were compared with the next consecutive delivery of normal birth weight (2500–3999 g) infants.

Results:

The total deliveries for the study period were 2437, of which 135 were macrosomic babies. The incidence of fetal macrosomia was 5.5%. The mean birth weights of macrosomic and nonmacrosomic babies were 4.26 ± 0.29 kg and 3.20 ± 0.38 kg, respectively, P = 0.000. Mothers with macrosomic babies were more likely to be older (P = 0.047), of higher parity (0.001), taller (P = 0.007), and weighed more at delivery (P = 0.000). Previous history of fetal macrosomia (P = 0.000) and maternal diabetes (P = 0.007) were factors strongly associated with the delivery of macrosomic infants. Pregnancies associated with fetal macrosomia had increased duration of labor (P = 0.007), interventional deliveries (P = 0.000), shoulder dystocia, and genital laceration (P = 0.000). There was no significant difference in the incidence of primary postpartum hemorrhage (P = 0.790), birth asphyxia, and perinatal mortality (P = 0.197).

Conclusion:

Fetal macrosomia is associated with maternal and fetal morbidities. The presence of the observed risk factors should elicit the suspicion of a macrosomic fetus and the need for appropriate management to reduce maternal and fetal morbidities.     

2例巨大儿肩难产致新生儿臂丛神经损伤的教训分析

肩难产是产科一种急症,指胎头娩出后,胎儿前肩嵌顿在耻骨联合上方,常规手法不能娩出,如处理不当或贻误时机,可造成母婴的并发症。我院于2001年和2004年先后发生2例肩难产致新生儿臂丛神经损伤,现分析如下。临床资料例1:孕妇25岁,G2P1孕39 4周,因下腹痛4h于2001年11月14日9∶00入院。产检:宫高35cm,腹围105cm,估计胎儿体重3700g,胎方位LOA,胎心140次/min。肛查宫口开指尖。入院诊断G2P1孕39 4周,LOA。于10∶00出现规律性宫缩,持续约25s,间隔4～5min。11∶15肛查宫口开2 cm,宫颈薄松,未破膜。11∶45肛查宫口开4cm,先露头,高位“-1”,宫缩…     

After shoulder dystocia: managing the subsequent pregnancy and delivery

Among risk factors for shoulder dystocia, a prior history of delivery complicated by shoulder dystocia is the single greatest risk factor for shoulder dystocia occurrence, with odds ratios 7 to 10 times that of the general population. Recurrence rates have been reported to be as high as 16%. Whereas prevention of shoulder dystocia in the general population is neither feasible nor cost-effective, intervention efforts directed at the particular subgroup of women with a prior history of shoulder dystocia can concentrate on potentially modifiable risk factors and individualized management strategies that can minimize recurrence and the associated significant morbidities and mortality.     

The risk of shoulder dystocia related permanent fetal injury in relation to birth weight

OBJECTIVE: To examine birth weight related risks of fetal injury in connection with shoulder dystocia. STUDY DESIGN: The investigation was based on a retrospective analysis of 316 fetal neurological injuries associated with deliveries complicated by arrest of the shoulders that occurred across the United States. RESULTS: The study revealed that the distribution of birthweights for the high risk shoulder dystocia population differs from the standard birthweight distribution. The relative difference per birthweight interval is used to adjust an assumed 1:1000 baseline risk of injury due to shoulder dystocia following vaginal deliveries. These adjusted risks show a need to consider new thresholds for elective cesarean delivery. CONCLUSIONS: Current North American and British guidelines, that set 5000 g as minimum estimated fetal weight limit for elective cesarean section in non-diabetic and 4500 g for diabetic gravidas, may expose some macrosomic fetuses to a high risk of permanent neurological damage. The authors present the opinion that the mother, having been informed of the risks of vaginal versus abdominal delivery, should be allowed to play an active role in the critical management decisions.     

Shoulder dystocia related fetal neurological injuries: the predisposing roles of forceps and ventouse extractions

On the basis of 333 documented cases of permanent perinatal neurological damage, associated with arrest of the shoulders at birth, the authors conducted a retrospective study in order to evaluate the predisposing role, if any, of the utilization of extraction instruments. The investigation revealed that 35% of all injuries occurred in neonates delivered by forceps, ventouse or sequential ventouse–forceps procedures. This frequency was several-fold higher than the prevailing instrument use in the practices of American obstetricians during the same years. A high rate of forceps and ventouse extractions was demonstrable in all birth weight categories. Average weight and moderately large for gestational age fetuses underwent instrumental extractions more often than grossly macrosomic ones. This circumstance indicates that forceps and ventouse are independent risk factors, unrelated to fetal size. Their use entailed central nervous system injuries significantly more often than did spontaneous deliveries. The findings suggest that extraction procedures may be as important as macrosomia among the factors that lead to neurological damage in the child in connection with shoulder dystocia. Because they augment the intrinsic dangers of excessive fetal size exponentially, the authors consider their use in case of ≥4,000 g estimated fetal weight inadvisable. Sequential forceps–ventouse utilization further doubles the risks and is, therefore, to be avoided in all circumstances.     

A review of factors associated with dystocia and cesarean section in nulliparous women

The primary indication for cesarean section in nulliparous women continues to be clinical diagnoses that fall under the rubric of dystocia. These diagnoses account for approximately two-thirds of all cesareans experienced by otherwise healthy nulliparous women. Contemporary research evidence suggests that this clinical phenomenon is complex and multifactorial. This review explores factors associated with the phenomenon of dystocia in the context of a conceptual model that considers women's physical and psychological characteristics, fetal factors, intrapartum care and interventions, assessments and clinical decision-making of health care providers, the sociopolitical environment, and the social and physical environment of childbirth. Clinical recommendations include emphasis on the maintenance of normal weight and weight gain during pregnancy, delaying the admission of nulliparous women to the hospital until active labor is established, avoiding elective induction for nulliparous women, keeping women well-hydrated and well-fed during labor, providing high-quality supportive care during labor, staying the course with effective treatment when dystocia is encountered, and a renewed emphasis on the psychobehavioral preparation of nulliparous women for the realities of labor.     

浅谈头位难产剖宫产的时机选择

目的总结头位难产剖宫产的最佳时机。方法对2003年1月～2005年12月产妇480例,随机分成剖宫产组和阴道分娩组各240例,对剖宫产的时机进行回顾性分析。结果剖宫产组和阴道分娩组在新生儿出生体重有显著性差异(P<0.05);两组胎位异常发生率有显著性差异(P<0.05)。结论新生儿出生体重偏大和胎位异常是头位难产的主要因素,准确地掌握剖宫产的时机是治疗的关键。     

肩难产21例回顾性分析

目的　了解肩难产的发生率 ,并发症及处理方法 ,分析肩难产的高危因素 ,探讨其临床价值。方法　回顾性分析 1997年 1月至 2 0 0 1年 12月 5年间的肩难产病例 ,并随机抽取同期阴道分娩病例作为对照 ,比较两组间孕妇在产前、产时指标和胎儿径线等方面有无差别。分析巨大儿、糖尿病、阴道助产、产程异常等高危因素在肩难产中的比率。评价松解胎肩的方法。结果　 5年间分娩总数为 6 4 0 0例 ,肩难产 2 4例 ,其中巨大儿 12例 ,占5 7 10 %。有 6例并发新生儿损伤 ,占 30 0 0 %。肩难产组和对照组在新生儿体重、身长、头围、胸围有显著差异 ,两组孕妇的宫高和腹围有显著差异。结论　肩难产是产科少见的并发症 ,巨大儿发生肩难产的比例最高 ,但根据高危因素仍很难预测肩难产。正确处理肩难产是降低围生儿并发症的重要措施。