103:
This leaves unprotected vessels running over the cervix and in the lower uterine segment. This has been demonstrated using serial ultrasound. Oyelese et al. found that 2/3 of patient with vasa previa at delivery had a low-lying placenta or placenta previa that resolved prior to the time of delivery. There are three types of vasa previa. Types 1 and 2 were described by
Catanzarite et al. In Type 1, there is a velamentous insertion with vessels running over the cervix. In Type 2, unprotected vessels run between lobes of a bilobed or succenturiate lobed placenta. In Type 3, a portion of the placenta overlying the cervix undergoes atrophy. In this type, there is a normal placental cord insertion and the placenta has only one lobe. However, vessels at a margin of the placenta are exposed.
155:
evidence of a velamentous cord insertion with rupture of the vessels. However, with almost universal use of ultrasound in the developed world, many cases are now detected during pregnancy, giving the opportunity to deliver the baby before this catastrophic rupture of the membranes occurs. Vasa previa is diagnosed with ultrasound when echolucent linear or tubular structures are found overlying the cervix or in close proximity to it. Transvaginal ultrasound is the preferred modality. Color, power and pulsed wave
Doppler should be used to confirm that the structures are fetal vessels. The vessels will demonstrate a fetal arterial or venous waveform.
40:
172:
risk of death and that of prematurity. Several authorities have recommended hospital admission about 32 weeks. This is to give the patient proximity to the operating room for emergency delivery should the membranes rupture. Because these patients are at risk for preterm delivery, it is recommended that steroids should be given to promote fetal lung maturation. When bleeding occurs, the patient goes into labor, or if the membranes rupture, immediate treatment with an emergency
1288:
171:
It is recommended that women with vasa previa should deliver through elective cesarean prior to rupture of the membranes. Given the timing of membrane rupture is difficult to predict, elective cesarean delivery at 35–36 weeks is recommended. This gestational age gives a reasonable balance between the
158:
Alkali denaturation test detects the presence of fetal hemoglobin in vaginal blood, as fetal hemoglobin is resistant to denaturation in presence of 1% NaOH. Tests such as the Ogita Test, Apt test or
Londersloot test were previously used to attempt to detect fetal blood in the vaginal blood, to help
102:
will rapidly occur, leading to fetal death. It is thought that vasa previa arises from an early placenta previa. As the pregnancy progresses, the placenta tissue surrounding the vessels over the cervix undergoes atrophy, and the placenta grows preferentially toward the upper portion of the uterus.
154:
Prior to the advent of ultrasound, this diagnosis was most often made after a stillbirth or neonatal death in which the mother had ruptured her membranes, had some bleeding, and delivered an exsanguinated baby. In these cases, examination of the placenta and membranes after delivery would show
85:
Vasa praevia occurs in about 0.6 per 1,000 pregnancies. The term "vasa previa" is derived from the Latin; "vasa" means vessels and "previa" comes from "pre" meaning "before" and "via" meaning "way". In other words, vessels lie before the fetus in the birth canal and in the way.
596:
489:
474:
98:
or may be joining an accessory (succenturiate) placental lobe to the main disk of the placenta. If these fetal vessels rupture the bleeding is from the fetoplacental circulation, and fetal
589:
582:
1293:
130:
pregnancy. In IVF pregnancies, incidence as high as one in 300 has been reported. The reasons for this association are not clear, but disturbed orientation of the
213:
Ruiter, L; Kok, N; Limpens, J; Derks, JB; de Graaf, IM; Mol, B; Pajkrt, E (July 2016). "Incidence of and risk indicators for vasa praevia: a systematic review".
847:
116:
135:
1189:
94:
Vasa previa is present when unprotected fetal vessels traverse the fetal membranes over the internal cervical os. These vessels may be from either a
1315:
326:
Lee W, Lee V, Kirk J, Sloan C, Smith R, Comstock C (2000). "Vasa previa: prenatal diagnosis, natural evolution, and clinical outcome".
827:
794:
159:
make the diagnosis. These tests are no longer widely used in the US, but are sometimes used in other parts of the world.
842:
1245:
1100:
1027:
722:
1272:
893:
631:
774:
138:
and the increased frequency of placental morphological variations in IVF pregnancies have all been postulated.
111:
Vasa previa is seen more commonly with velamentous insertion of the umbilical cord, accessory placental lobes (
64:
267:
976:
67:. These vessels are at risk of rupture when the supporting membranes rupture, as they are unsupported by the
1260:
1043:
888:
1056:
574:
1167:
966:
940:
676:
622:
95:
1204:
1194:
1112:
1012:
730:
504:
1129:
1051:
809:
185:
147:
The classic triad of the vasa praevia is: membrane rupture, painless vaginal bleeding and fetal
1250:
1224:
1002:
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817:
789:
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666:
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121:
112:
79:
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1209:
661:
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983:
804:
779:
255:
16:
Condition in which fetal blood vessels cross or run near the internal opening of the uterus
8:
1255:
1199:
1093:
1022:
1007:
988:
837:
651:
493:
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Bhide A, Thilaganathan B (2004). "Recent advances in the management of placenta previa".
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1184:
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425:
394:
351:
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Yasmine
Derbala, MD; Frantisek Grochal, MD; Philippe Jeanty, MD (2007). "Vasa previa".
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303:
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173:
47:
441:
398:
355:
242:
39:
1017:
956:
688:
555:
421:
412:
Oyelese Y, Smulian J (2006). "Placenta previa, placenta accreta, and vasa previa".
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335:
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1139:
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913:
693:
509:
313:
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1177:
1073:
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862:
740:
520:
99:
68:
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1119:
852:
735:
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1078:
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234:
604:
1083:
832:
784:
717:
698:
683:
148:
466:
703:
610:
131:
52:
747:
606:
550:
526:
162:
Also detection of fetal hemoglobin in vaginal bleeding is diagnostic.
641:
72:
63:
is a condition in which fetal blood vessels cross or run near the
946:
531:
950:
478:
909:
880:
713:
848:
Pruritic urticarial papules and plaques of pregnancy (PUPPP)
215:
569:
212:
456:
368:
1190:Childbirth-related post-traumatic stress disorder
1307:
325:
411:
590:
96:velamentous insertion of the umbilical cord
597:
583:
279:
38:
297:
78:Risk factors include low-lying placenta,
208:
206:
1308:
282:"Vasa previa diagnosis and management"
828:Intrahepatic cholestasis of pregnancy
795:Intrahepatic cholestasis of pregnancy
578:
203:
1316:Complications of labour and delivery
894:Pregnancy-induced hypercoagulability
570:International Vasa Previa Foundation
13:
843:Pruritic folliculitis of pregnancy
426:10.1097/01.AOG.0000207559.15715.98
14:
1327:
1101:Pain management during childbirth
1028:Twin-to-twin transfusion syndrome
452:
258:Journal of Prenatal Medicine 2007
1287:
1286:
1273:Sexual activity during pregnancy
383:10.1097/00001703-200412000-00002
106:
775:Acute fatty liver of pregnancy
405:
362:
319:
273:
249:
65:internal opening of the uterus
1:
977:Prelabor rupture of membranes
340:10.1016/S0029-7844(99)00600-6
196:
1256:Systemic lupus erythematosus
907:Maternal care related to the
889:Gestational thrombocytopenia
166:
141:
7:
1057:Cephalopelvic disproportion
179:
126:), multiple gestation, and
10:
1332:
1168:Breastfeeding difficulties
967:Constriction ring syndrome
941:Braxton Hicks contractions
1281:
1238:
1205:Peripartum cardiomyopathy
1195:Pubic symphysis diastasis
1158:
1042:
906:
879:
861:
803:
765:
756:
712:
630:
621:
541:
460:
280:Lijoi A, Brady J (2003).
46:
37:
29:
24:
731:Gestational hypertension
371:Curr Opin Obstet Gynecol
89:
1130:Umbilical cord prolapse
1052:Amniotic fluid embolism
810:dermatoses of pregnancy
227:10.1111/1471-0528.13829
186:Single umbilical artery
1246:Concomitant conditions
1225:Postpartum thyroiditis
1003:Circumvallate placenta
823:Impetigo herpetiformis
818:Gestational pemphigoid
790:Hyperemesis gravidarum
723:hypertensive disorders
299:10.3122/jabfm.16.6.543
176:is usually indicated.
128:in vitro fertilisation
80:in vitro fertilization
1215:Postpartum infections
1210:Postpartum depression
1220:Postpartum psychosis
1089:Obstetrical bleeding
984:Obstetrical bleeding
805:Integumentary system
780:Gestational diabetes
759:related to pregnancy
757:Other, predominantly
286:J Am Board Fam Pract
1200:Postpartum bleeding
1023:Placental abruption
1008:Monochorionic twins
838:Prurigo gestationis
1230:Puerperal mastitis
1185:Breast engorgement
972:Monoamniotic twins
962:Chorionic hematoma
542:External resources
174:caesarean delivery
1303:
1302:
1261:Thyroid disorders
1251:Diabetes mellitus
1135:Uterine inversion
1067:Shoulder dystocia
1062:Obstructed labour
1038:
1037:
902:
901:
871:Chorea gravidarum
647:Ectopic pregnancy
565:
564:
136:vanishing embryos
134:at implantation,
117:bilobate placenta
58:
57:
19:Medical condition
1323:
1290:
1289:
1125:Postmature birth
1113:Placenta accreta
1018:Placenta praevia
1013:Placenta accreta
957:Chorioamnionitis
767:Digestive system
763:
762:
689:Fetal resorption
677:Rudimentary horn
634:abortive outcome
628:
627:
599:
592:
585:
576:
575:
458:
457:
446:
445:
409:
403:
402:
366:
360:
359:
323:
317:
311:
301:
277:
271:
265:
253:
247:
246:
210:
191:Placenta praevia
125:
73:placental tissue
42:
22:
21:
1331:
1330:
1326:
1325:
1324:
1322:
1321:
1320:
1306:
1305:
1304:
1299:
1277:
1234:
1178:Cracked nipples
1173:Low milk supply
1154:
1140:Uterine rupture
1034:
929:Oligohydramnios
914:amniotic cavity
908:
898:
875:
857:
808:
799:
758:
752:
721:
708:
694:Molar pregnancy
633:
617:
603:
566:
561:
560:
537:
536:
469:
455:
450:
449:
410:
406:
367:
363:
324:
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254:
250:
211:
204:
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151:or fetal death.
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119:
109:
92:
20:
17:
12:
11:
5:
1329:
1319:
1318:
1301:
1300:
1298:
1297:
1282:
1279:
1278:
1276:
1275:
1270:
1268:Maternal death
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1264:
1263:
1258:
1253:
1242:
1240:
1236:
1235:
1233:
1232:
1227:
1222:
1217:
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1207:
1202:
1197:
1192:
1187:
1182:
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1180:
1175:
1164:
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1127:
1122:
1117:
1116:
1115:
1103:
1098:
1097:
1096:
1086:
1081:
1076:
1074:Fetal distress
1071:
1070:
1069:
1059:
1054:
1048:
1046:
1040:
1039:
1036:
1035:
1033:
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1020:
1015:
1010:
1005:
993:
992:
991:
981:
980:
979:
974:
969:
964:
959:
943:
938:
937:
936:
934:Polyhydramnios
931:
923:amniotic fluid
918:
916:
904:
903:
900:
899:
897:
896:
891:
885:
883:
877:
876:
874:
873:
867:
865:
863:Nervous system
859:
858:
856:
855:
850:
845:
840:
835:
830:
825:
820:
814:
812:
801:
800:
798:
797:
792:
787:
782:
777:
771:
769:
760:
754:
753:
751:
750:
745:
744:
743:
741:HELLP syndrome
733:
727:
725:
710:
709:
707:
706:
701:
696:
691:
686:
681:
680:
679:
674:
669:
664:
659:
654:
644:
638:
636:
632:Pregnancy with
625:
619:
618:
602:
601:
594:
587:
579:
573:
572:
563:
562:
559:
558:
546:
545:
543:
539:
538:
535:
534:
523:
512:
501:
486:
470:
465:
464:
462:
461:Classification
454:
453:External links
451:
448:
447:
414:Obstet Gynecol
404:
361:
328:Obstet Gynecol
318:
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248:
221:(8): 1278–87.
201:
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188:
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178:
168:
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164:
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160:
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108:
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100:exsanguination
91:
88:
69:umbilical cord
56:
55:
50:
44:
43:
35:
34:
31:
27:
26:
18:
15:
9:
6:
4:
3:
2:
1328:
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1183:
1179:
1176:
1174:
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1166:
1165:
1163:
1161:
1157:
1151:
1150:Uterine atony
1148:
1146:
1143:
1141:
1138:
1136:
1133:
1131:
1128:
1126:
1123:
1121:
1120:Preterm birth
1118:
1114:
1111:
1110:
1109:
1108:
1104:
1102:
1099:
1095:
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1016:
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1001:
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994:
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987:
986:
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978:
975:
973:
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968:
965:
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932:
930:
927:
926:
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920:
919:
917:
915:
911:
905:
895:
892:
890:
887:
886:
884:
882:
878:
872:
869:
868:
866:
864:
860:
854:
853:Stretch marks
851:
849:
846:
844:
841:
839:
836:
834:
831:
829:
826:
824:
821:
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773:
772:
770:
768:
764:
761:
755:
749:
746:
742:
739:
738:
737:
736:Pre-eclampsia
734:
732:
729:
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724:
719:
715:
711:
705:
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697:
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678:
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663:
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648:
645:
643:
640:
639:
637:
635:
629:
626:
624:
620:
616:
612:
608:
605:Pathology of
600:
595:
593:
588:
586:
581:
580:
577:
571:
568:
567:
557:
553:
552:
548:
547:
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528:
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517:
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507:
506:
502:
500:
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491:
487:
485:
481:
480:
476:
472:
471:
468:
463:
459:
443:
439:
435:
431:
427:
423:
420:(4): 927–41.
419:
415:
408:
400:
396:
392:
388:
384:
380:
377:(6): 447–51.
376:
372:
365:
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353:
349:
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333:
329:
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316:
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309:
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129:
123:
118:
114:
113:succenturiate
104:
101:
97:
87:
83:
81:
76:
74:
70:
66:
62:
54:
51:
49:
45:
41:
36:
32:
28:
23:
1292:
1285:
1145:Vasa praevia
1144:
1105:
1079:Locked twins
995:
945:
921:
667:Interstitial
549:
525:
514:
503:
488:
473:
417:
413:
407:
374:
370:
364:
334:(4): 572–6.
331:
327:
321:
312:
292:(6): 543–8.
289:
285:
275:
266:
261:
257:
251:
218:
214:
170:
110:
107:Risk factors
93:
84:
77:
61:Vasa praevia
60:
59:
25:Vasa praevia
1084:Nuchal cord
833:Linea nigra
785:Hepatitis E
718:proteinuria
699:Miscarriage
684:Embryo loss
662:Heterotopic
149:bradycardia
120: [
33:Vasa previa
30:Other names
1094:Postpartum
989:Antepartum
704:Stillbirth
615:puerperium
613:, and the
611:childbirth
516:DiseasesDB
264:(1): 2–13.
197:References
132:blastocyst
53:Obstetrics
1160:Puerperal
748:Eclampsia
652:Abdominal
623:Pregnancy
607:pregnancy
551:eMedicine
527:SNOMED CT
314:Full text
268:Full text
167:Treatment
142:Diagnosis
48:Specialty
1310:Category
1294:Category
1107:placenta
997:placenta
657:Cervical
642:Abortion
556:med/3276
532:79668009
442:22774083
434:16582134
399:24710500
391:15534438
356:19815088
348:10725492
308:14963081
243:43666201
235:26694639
180:See also
947:chorion
672:Ovarian
510:D055949
951:amnion
440:
432:
397:
389:
354:
346:
306:
241:
233:
1239:Other
1044:Labor
910:fetus
881:Blood
720:, and
714:Edema
521:13743
499:663.5
484:O69.4
438:S2CID
395:S2CID
352:S2CID
239:S2CID
124:]
90:Cause
912:and
505:MeSH
494:9-CM
430:PMID
387:PMID
344:PMID
304:PMID
231:PMID
490:ICD
475:ICD
422:doi
418:107
379:doi
336:doi
294:doi
223:doi
219:123
115:or
71:or
1312::
949:/
716:,
609:,
554::
530::
519::
508::
497::
482::
479:10
436:.
428:.
416:.
393:.
385:.
375:16
373:.
350:.
342:.
332:95
330:.
302:.
290:16
288:.
284:.
260:.
237:.
229:.
217:.
205:^
122:fr
82:.
75:.
807:/
598:e
591:t
584:v
492:-
477:-
467:D
444:.
424::
401:.
381::
358:.
338::
310:.
296::
262:1
245:.
225::
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
