Green Amniotic Fluid in a Term Neonate

AFFILIATIONS:
¹Stritch School of Medicine, Loyola University Chicago, Maywood, IL
²Assistant Professor, Department of Pediatrics, Stritch School of Medicine, Loyola Univeristy Chicago, Maywood, IL

CITATION:
Green amniotic fluid in a term neonate. Consultant. 2023;63(5):e8. doi:10.25270/con.2023.04.000003

Received September 29, 2022. Accepted January 11, 2023. Published online April 24, 2023.

DISCLOSURES:
The authors report no relevant financial relationships.

ACKOWLEDGEMENTS:
Consent was provided by the parent of the infant followed in this report.

CORRESPONDENCE:
Veena Bhamre, MD, MacNeal Hospital/Loyola Medicine, 3249 S. Oak Park Ave, Berwyn, IL 60402  (veena.bhamre@lumc.edu)

Introduction. A neonate was born to a 29-year-old gravida 3 para 2 woman at 37 weeks and 3 days. Rupture of membranes occurred 13 hours prior to birth and was initially described as “meconium-stained” by the obstetric team.  

History. At delivery, the infant’s abdomen was noted to be distended and hard with normoactive bowel sounds. The infant was appropriate for gestational age, and the neonatal team was present at delivery. The physical examination was otherwise unremarkable.

Initial vitals were stable; 98.06^o F, 86/53 mmHg, 148 beats/min, 36 breaths/min. During neonatal resuscitation, an orogastric (OG) tube was temporarily placed for suctioning. Following initial suctioning during resuscitation, the neonatal team noticed 175 cc of thick, green fluid in the suction canister. After suctioning, the infant’s abdomen was noted to be soft and non-distended. The infant was otherwise stable.

There was increased abdominal distension shortly after initial suctioning, and an additional 50 cc of thick, green fluid was suctioned from the abdomen. Due to the repeated abdominal distension and large volume of aspirate, the infant was started on intravenous fluids, placed on nothing-by-mouth orders, and a nasogastric tube was placed and started on continuous wall suction to prevent further distension.

Diagnostic Testing. Initial chest and abdomen x-ray showed a lack of gastrointestinal air with no observable pneumoperitoneum or pneumatosis (Figure 1). Initial laboratory work revealed no leukocytosis (white blood cell count 13.0 K/uL) and a neutrophil percentage that was slightly elevated at 69%. Hemoglobin was within normal limits. Creatinine was very mildly elevated at 0.8 mg/dL. Electrolytes (sodium, potassium, and chloride) were within normal limits. The blood culture did not show any growth. The infant was found to have O-positive blood type and was Coombs negative. Neonatology specialists were consulted, and the infant was transferred to the neonatal intensive care unit (NICU). A kidney, ureter, and bladder X-ray was ordered due to concern for obstruction. Repeat X-ray revealed dilated loops of bowel filled with air, suggestive of a distal bowel obstruction (Figure 2).

Figure 1. Limited bowel gas was observed on initial abdominal X-ray.

Figure 2. Repeat abdominal X-ray showed evidence of dilated loops of bowel, suggestive of a distal bowel obstruction.

Differential Diagnoses. The presence of green-stained amniotic fluid during labor was suggestive of either in utero biliary emesis or meconium passage. Upon birth, the neonate had a large volume of gastric aspirate suctioned via OG tube. The gastric aspirate volume, 225 mL, far exceeded the reported mean gastric aspirate volume in neonates with intestinal obstruction, 58.6 ± 6.1 mL.^1,2 Furthermore, notable abdominal distension was observed on physical examination, suggestive of buildup of gastric air in the intestines. Abdominal distension relieved by gastric decompression, green-pigmented amniotic fluid, and the large volume of gastric aspirate were suggestive of biliary emesis secondary to possible small bowel obstruction as opposed to meconium-stained amniotic fluid.

Differential diagnosis of the neonate’s biliary emesis included Hirschsprung disease, intestinal malrotation, and meconium ileus. Hirschsprung disease commonly occurs with abdominal distension and biliary emesis and may also present with a tight anus on digital rectal exam. Difficulty passing stool is an additional finding often found in neonates with Hirschsprung disease.³ Intestinal malrotation also presents most often with the combination of bilious emesis during the first month of life and abdominal distension. Rectal bleeding may also occur later in the presentation. Intestinal atresia, most commonly jejunoileal, often presents concurrently with intestinal malrotation or intestinal volvulus and may occur secondary to these forms of small bowel obstruction.⁴ A previous report identified a neonate with abdominal distension and suctioning of bilious content that was found to have meconium ileus with no other signs of small bowel obstruction upon surgical exploration.⁵ Meconium ileus was less likely given the infant's passage of meconium, however, meconium ileus could not be completely ruled out without further imaging. Per chart review, the infant was noted to have a patent anus, further suggestive of small bowel obstruction as opposed to Hirshsprung disease.

Treatment and management. Further radiographic investigation was required to distinguish the various causes of bowel obstruction. A lower gastrointestinal barium enema revealed an intestinal pattern consistent with intestinal malrotation and showed evidence of microcolon, further suggestive of intestinal obstruction (Figure 3). An upper gastrointestinal series revealed lower positioning of the suspensory muscle of the duodenum and a duodenojejunal junction that did not cross the midline, suggestive of malrotation. Corkscrew sign was also observed, suggestive of possible partial volvulus (Figure 4).

Figure 3. Cecum is abnormally positioned in the midline as opposed to the right lower quadrant. Small colon caliber; colon does not appear to cross the midline.

Figure 4. Duodenojejunal juncture is lower and more right-sided than expected. Duodenojejunal juncture is expected at the level of L2 (black triangle). Corkscrew configuration of distal duodenum and proximal jejunum observed. Barium enema was conducted prior to the upper gastrointestinal series. Hence, residual signal from the barium enema is observed in bowel loops distal to the duodenojejunal juncture and corkscrew sign (white bracket). Signal from upper gastrointestinal series is more dense in comparison to residual signal from the barium enema.

The patient underwent an exploratory laparotomy in which she was found to have malrotation, a type 1 jejunal atresia, and a type 2 atresia. She underwent a Ladd procedure, appendectomy, and small bowel resection with jejunal atresia repair and tapering enteroplasty.

Outcome and follow-up. Following her initial surgery, the infant remained in the NICU for 58 days due to feeding intolerance, persistent bilious emesis, and intermittent abdominal distension. She was followed by pediatric gastroenterology and pediatric surgery specialists. She was noted to have dilated small bowel loops on a follow-up upper gastrointestinal series, and due to her clinical presentation, it was suspected that she may have had a persistent distal small bowel obstruction. Therefore, she underwent another exploratory laparotomy with proximal bowel resection. After her second surgery, enteral feeding was initiated which she tolerated.

She was noted to have an atrial septal defect vs a patent foramen ovale during her time in the NICU, so she was briefly followed by pediatric cardiology specialists as an outpatient. This defect was noted to have closed, requiring no further follow-up.

Discussion. Several reports have described incidences of green-stained amniotic fluid prior to or during delivery. Meconium-stained amniotic fluid has been estimated to occur in about 12-15% of deliveries and is typically identified by the green pigment noted in maternal amniotic fluid.⁶ Bile-stained amniotic fluid also presents with a green pigment, but it is reported in the literature to a lesser extent. Appendicitis,⁷ Hirschsprung disease, small bowel atresia,^1,8 intestinal malrotation, meconium ileus, meconium plug, and colonic atresia⁹ have been reported as causes of bilious emesis in neonates. Intestinal obstruction occurs in 1 out of 1500 live births, and presenting signs include abdominal distension, maternal polyhydramnios, bilious emesis, and failure to pass meconium within 24 hours.¹⁰

The work of Puvabanditsin and colleagues¹ summarizes 13 studies that present examples of neonates exhibiting biliary emesis with their subsequent diagnoses. Among these studies, intestinal obstruction was the most common. Intestinal atresia has been cited as the cause of intestinal obstruction in neonates in one-third of cases.^11,12 Jejunoileal atresia has been said to occur in 1 in 330 live births in the United States.¹³ Bile-stained amniotic fluid is often mistaken for meconium-stained amniotic fluid, and previous reports have highlighted the importance of considering bile-related causes of green amniotic fluid.¹ If green-pigmented amniotic fluid is present, it is important to examine the patient carefully for signs of bowel obstruction regardless of meconium passage. Abdominal distension, as seen in this infant, was the initial sign suggestive of bowel obstruction. Importantly, this presentation on physical examination led providers to reevaluate whether the green-stained amniotic fluid was the result of biliary emesis in utero rather than meconium-stained fluid that had been initially presumed. Some studies suggest the importance of rectal examination for presence of meconium to differentiate between meconium-stained vs bile-stained amniotic fluid.

Malrotation in conjunction with intestinal atresia is a rare finding^3,14 and has been reported to occur in about 19-20% of cases of jejunoileal atresia.^4,15 Another study cited malrotation in 7 out of 38 patients with jejunal atresia.¹⁶ Type 1 jejunal atresia occurs when there is a membranous occlusion or web within the intestinal lumen. The serosa and mesentery are not disrupted in type 1 jejunal atresia.^17,18 Type 2 jejunal atresia occurs when a narrow cord forms between the proximal and distal intestine while disrupting the serosa. Both are considered minimal risk compared with types 3 and 4.^18,19

Laparoscopic surgery has been shown to be an effective method of repairing small bowel obstruction in neonates with minimal complications.²⁰ Complications of intestinal atresia surgical repair include infection, leakage from anastomosis sites, short bowel syndrome, and adhesion-related small bowel obstruction and typically present within 1 month of repair.¹⁵ The survival rate of jejunoileal atresia has increased to 90% with a mortality rate of less than 1% post-operatively. In a study retrospectively examining 63 infants with jejunoileal atresia, 56 infants were found to have survived at the time of follow-up, which ranged from 6 months to 11 years. Mortality occurred in infants with associated congenital anomalies or severe stages of jejunoileal atresia.¹⁸

Our infant exhibited both jejunal atresia and malrotation. Complications from repair of malrotation include recurrence of malrotation, volvulus, anastomotic leak, and post-operative adhesive small bowel obstruction.^21,22 In a study examining 45 infants who underwent laparoscopic repair of malrotation, these complications were found to occur in 19% of the infants.²³ Prognosis after surgical repair appears to have improved in recent years due to improvements in surgical repair methods and better management of post-operative nutritional management.²⁴

Although the infant did not present with biliary emesis upon delivery and initial X-ray was not suggestive of a bowel obstruction, bilious fluid noted on gastric aspiration warranted further workup for possible bowel obstruction. It is important for clinicians to distinguish the different causes of pigmented amniotic fluid in order to identify concerning gastrointestinal pathologies in time, especially if emergency surgery is required. If green-pigmented amniotic fluid is present, clinicians must examine the patient carefully for signs of bowel obstruction regardless of meconium passage as this fluid color may be indicative of biliary emesis in utero.