Abstract

---

Introduction: Advanced abdominal pregnancy is classically defined as a pregnancy that has progressed beyond 20 weeks of gestation in which the fetus is growing and developing in the mother’s abdominal cavity. An advanced abdominal pregnancy resulting in a live birth is rare. Cases of pre-eclampsia occurring with advanced abdominal pregnancy (non-distended uterus) helped to dispel the hypothesis that excessive stretching of the myometrium was involved in pre-eclampsia’s etiology. Thus advanced abdominal pregnancies, in particular those with live births can provide a unique and useful opportunity to understand certain reproductive biologic phenomena.

Methods: PubMed, Scopus and Google Scholar were searched for English language articles that reported a live birth resulting from an advanced abdominal pregnancy from 2008 (the year of the last major review on advanced abdominal pregnancy) to 2013.

Results: 38 cases of an advanced abdominal pregnancy resulting in a live birth were identified from 16 countries. 37.5% males at birth (normal average 51.5%) were observed in this study.

Conclusion: Physiologically males are more vulnerable than females from conception; the presumed hostile extrauterine environment of advanced abdominal pregnancy may cause excess in-utero demise of males compared to females. Live births from advanced abdominal pregnancy serve as a useful model to elucidate certain reproductive biologic mechanisms.

Introduction

---

Advanced abdominal pregnancy (AAP) is classically defined as a pregnancy that has progressed beyond 20 weeks of gestation in which the fetus is growing and developing in the mother’s abdominal cavity, or the fetus shows signs of having been in the mother’s abdominal cavity [1].

Ovarian, broad ligament and tubal pregnancies are excluded from AAPs definition; however this omission has been contested because from a clinical perspective these pregnancies pose similar diagnostic and therapeutic challenges as AAPs [2]. Furthermore, the greater than 20 weeks of gestation cutoff is arbitrary.

An AAP resulting in a live birth is rare. This is because abdominal pregnancy has an incidence of about 1 in 400 to 50 000 deliveries [3]; the variable incidence depends on the characteristics of a particular geographic region. In addition, because the fetus is outside the uterus, AAP has a high maternal and perinatal morbidity and mortality. It is estimated that a woman with an abdominal pregnancy is 90 times more likely to die in comparison to a woman with an intrauterine pregnancy [4]. On average, more than half of AAP babies die [1]. About 20% of AAP infants have malformations or deformations [5].

AAP can be primary or secondary (see Illustration 1). Primary AAP where there is direct implantation of the conceptus into the abdominal cavity is the less common type; certain criteria have to be met for an AAP to be classified as being primary [6]. Secondary AAP due to fimbrial abortion, tubal rupture, ruptured uterus or a ruptured uterine rudimentary horn is the more common type; ruptured tubal pregnancies account for the majority of AAPs.

An over distended uterus (with excessive stretching of the myometrium) for example occurring with twins was at one stage considered to be involved in the etiology of pre-eclampsia [7]. Cases of pre-eclampsia occurring with AAP (non-distended uterus) helped to dispel the hypothesis that excessive stretching of the myometrium was involved in pre-eclampsia’s etiology [7]. Thus AAPs in particular those with live births provide a unique and useful opportunity to understand certain reproductive biologic phenomena. In addition AAP serves as a prototype of pregnancy in males, who lack a uterus, however such a pregnancy would be difficult and dangerous.

Methods

---

PubMed, Scopus and Google Scholar were searched with the term ‘advanced abdominal pregnancy’ from January 1 2008 (the year of the last major review on AAP [1]); the last search date was November 30 2013. The title and abstract of articles was used to select articles that could have a live birth resulting from an AAP (AAP was classically defined). Articles citing these identified articles were also considered. The full text of identified English language articles were read to identify a live birth resulting from an AAP. Articles which had a viable birth resulting from an AAP were included.

A single investigator extracted from the identified articles the variables of year reported, country, maternal age, gestational age at delivery, etc. The full list of extracted variables (33) is available in the data set (see Additional file).

Statistical analysis was done using Stata version 12IC (StataCorp LP College Station, TX). Continuous variables were tested for normality and where they were not normally distributed the median and interquartile range (IQR) were reported.

Results

---

38 cases of an AAP with a live birth were identified from 16 countries (in Africa, Asia, the Caribbean, North America and South America) see Table 1 and Illustration 3.

The median age of women was 29 years, IQR 24 – 34 years. 50.0% of women were having their first pregnancy when they had an AAP.

36.5 weeks was the median gestation at delivery, IQR 33 – 39 weeks. The median birth weight was 2.4kg, IQR 1.35 – 2.85kg.

Of the 32 AAP cases with data on sex of the baby, 12 (37.5%) were males.

In 10 (26.3%) cases, the placenta was not removed, in four of these cases a re-laparatomy had to be done because of complications resulting from the retained placenta. In the remaining 28 (73.7%) cases, the placenta was either removed completely or partially.

18 (47.4%) of women received blood or blood product transfusion, but it is important to note that in some of the other cases it was not mentioned whether blood or blood products were administered.

In 18 (47.4%) of cases the diagnosis of AAP was made before delivery, in 15 (39.5%) cases the diagnosis was not made before delivery and in 5 (13.2%) cases it was not mentioned or unclear if the diagnosis was made before delivery.

30 (79.0%) of women had sonography before delivery, the remainder of the women either did not have sonography or this information was not mentioned in the articles.

19 (50.0%) cases had an abnormal lie; the lie was unknown in 16 (42.1%) cases; 10 (26.3%) of the cases had a breech presentation.

Discussion

---

As has been previously noted with AAP, the following features were also present in this study; symptoms and signs of AAP are generally non specific, an abnormal lie or presentation is common, it is difficult to diagnose AAP despite the widespread use of sonography and there is frequent need for transfusion of blood or blood products [1].

On average, the sex ratio at birth is 51.5% males [39]. The 37.5% male births seen in this study can be attributed to the fact that physiologically males are more vulnerable than females from conception [40]; the presumed hostile extrauterine environment of AAP may cause excess in-utero demise of males compared to females. Although in this study some data on the sex of the newborn baby was missing, the sex ratio at birth would still be in favor of fewer males compared to females even if all the missing cases were males.

The median gestation and birth weight at delivery were pre-term (<37 completed weeks) and of low birth weight (<2.5kg) respectively; this is not unusual for a pregnancy in an unnatural location.

A case of bilateral [19] and unilateral talipes equinovarus [38] were observed in this study, both cases seemed to be non-syndromic. Crudely, this would yield a congenital talipes equinovarus (CTEV) birth prevalence of 52.6 per 1 000 live AAP births, which far exceeds the estimated CTEV prevalence of 1 to 4.5 per 1000 live births [41]. The etiology and mechanism of development of idiopathic CTEV is unknown [41] ; one can only speculate about the role of AAP in the development of CTEV. One infant had bronchopulmonary dysplasia [37] which was likely related to pre-maturity among other factors [42]. Another infant [27] had patent ductus arteriosus, inguinal hernia, undescended testes and phimosis which were very likely related to pre-maturity [43].

“The two key components in successful embryo implantation are the competent embryo and the receptive endometrium that together undertake intimate bilateral communication” [44] . Live births from AAP render this preceding statement debatable because the endometrium does not seem to be invariably essential for successful pregnancy. This has important implications.

It is worth noting that live births from AAP have been described in the setting of HIV infection [16,20], described with twins [36] and one case of abdominal pregnancy diagnosed at 14 weeks of gestation was managed expectantly until delivery at 32 weeks gestation [10].

The key controversy in the management of abdominal pregnancy has been whether to remove or not remove the placenta after delivery [16,19,32]. In this study, in the majority of cases, the placenta was removed successfully after delivery. Ultimately, removal of the placenta seems best done on a case by case basis.

Including only English language articles is a limitation, it is unclear what the impact of this limitation is. The quality of the reported cases differed, for example some articles lacked information on hemoglobin, the APGAR score and other variables which precluded analysis of these variables. Some full texts of articles meeting the inclusion criteria could not be accessed, namely these reports from Ethiopia, Greece and India [45–47]. Publication bias is possible where only well managed cases were reported. None of the cases mention information about the male partner (father of the newborn); the biologic father is increasingly recognized to play a pivotal role in pregnancy related conditions [48].

Conclusion(s)

---

Live births from advanced abdominal pregnancy serve as a useful model to elucidate certain reproductive biologic mechanisms.

References

---

1. Nkusu Nunyalulendho D, Einterz EM. Advanced abdominal pregnancy: case report and review of 163 cases reported since 1946. Rural Remote Health. 2008; 8(4):1087.
2. Worley KC, Hnat MD, Cunningham FG. Advanced extrauterine pregnancy: diagnostic and therapeutic challenges. Am J Obstet Gynecol. 2008; 198(3):297.e1-7.
3. Naim NM, Ahmad S, Siraj HH, Ng P, Mahdy ZA, Razi ZR. Advanced abdominal pregnancy resulting from late uterine rupture. Obstet Gynecol. 2008; 111(2 Pt 2):502-4.
4. Atrash HK, Friede A, Hogue CJ. Abdominal pregnancy in the United States: frequency and maternal mortality. Obstet Gynecol. 1987; 69(3 Pt 1):333-7.
5. Stevens CA. Malformations and deformations in abdominal pregnancy. Am J Med Genet. 1993; 47(8):1189-95.
6. Friedrich EG Jr, Rankin CA Jr. Primary pelvic peritoneal pregnancy. Obstet Gynecol. 1968 31(5):649-53.
7. Moodley J, Subrayen KT, Sankar D, Pitsoe SB. Advanced extra-uterine pregnancy associated with eclampsia. A report of 2 cases. S Afr Med J. 1987; 4;71(7):460-1.
8. Isah AY, Ahmed Y, Nwobodo EI, Ekele BA. Abdominal pregnancy with a full term live fetus: case report. Ann Afr Med. 2008; 7(4):198-9.
9. Zhang J, Li F, Sheng Q. Full-term abdominal pregnancy: a case report and review of the literature. Gynecol Obstet Invest. 2008; 65(2):139-41.
10. Gomez E, Vergara L, Weber C, Wong AE, Sepulveda W. Successful expectant management of an abdominal pregnancy diagnosed at 14 weeks. J Matern Fetal Neonatal Med. 2008; 21(12):917-20.
11. Amritha B, Sumangali T, Priya B, Deepak S, Sharadha R. A rare case of term viable secondary abdominal pregnancy following rupture of a rudimentary horn: a case report. J Med Case Rep. 2009; 29(3):38.
12. Ramphal SR, Moodley J. Antepartum uterine rupture in previous caesarean sections presenting as advanced extrauterine pregnancies: lessons learnt. Eur J Obstet Gynecol Reprod Biol. 2009; 143(1):3-8.
13. Adesiyun AG, Audu AI. Term extrauterine pregnancy in a Nigerian mother: a complication of uterine dehiscence. Arch Gynecol Obstet. 2009; 279(1):75-7.
14. Kshirsagar AY, Pujari Sharvari, Tamhankar HP, Shinde SL, Langade YB, Shekhar Gayatri N. A live intra abdominal pregnancy: A case report. J Obstet Gynaecol India. 2010; 60(2): 157–159.
15. Paul AK, Latif ZA, Amin AH, Prasad I, Hoque WMM, Shefin SM. Advanced abdominal pregnancy with alive fetus : A case report and review. The ORION Medical Journal. 2010; 33(1):733-734.
16. Oneko O, Petru E, Masenga G, Ulrich D, Obure J, Zeck W. Management of the placenta in advanced abdominal pregnancies at an East african tertiary referral center. J Womens Health (Larchmt). 2010; 19(7):1369-75.
17. Dahab AA, Aburass R, Shawkat W, Babgi R, Essa O, Mujallid RH. Full-term extrauterine abdominal pregnancy: a case report. J Med Case Rep. 2011; 5:531.
18. Baffoe P, Fofie C, Gandau BN. Term abdominal pregnancy with healthy newborn: a case report. Ghana Med J. 2011; 45(2):81-3.
19. Brewster EM Sr, Braithwaite EA, Brewster EM Jr. Advanced abdominal pregnancy: a case report of good maternal and perinatal outcome. West Indian Med J. 2011; 60(5):587-9.
20. Leyva WR, Nigussie ET, Nonkwelo R, Novikova N, Hofmeyr GJ. Advanced abdominal pregnancy in HIV-infected women: A case series. S Afr J OG. 2011; 17(3):80-81.
21. Farooq S. Abdomial pregnancy a case report. Journal of Postgraduate Medical Institute (Peshawar - Pakistan), North America, 25, oct. 2011. Available at: 22. Kawthalkar AS, Gawande MS, Jain SH, Joshi SA, Ghike SD, Bhalerao AV. Rare case of live birth in a ruptured rudimentary horn pregnancy. J Obstet Gynaecol Res. 2011; 37(8):1169-72.
23. Sunday-Adeoye I, Twomey D, Egwuatu EV, Okonta PI. A 30-year review of advanced abdominal pregnancy at the Mater Misericordiae Hospital, Afikpo, southeastern Nigeria (1976-2006). Arch Gynecol Obstet. 2011; 283(1):19-24.
24. Ashraf F, Choudhury FR, Yesmin N, Islam ZA, Yusuf MA. A Secondary Abdominal Pregnancy – Threat to Maternal Life. J Shaheed Suhrawardy Med Coll. 2011; 3(1):24-26.
25. Nwosu B, Igwegbe A, Eleje G, Ugboaja J, Etoniru I, Egwuonwu O, et al. Full term secondary abdominal pregnancy in a Jehovah’s witness: A case report. Case Reports in Clinical Medicine. 2012; (1)19-22.
26. Sharma R, Puri M, Madan M, Trivedi SS. Advanced live intra-abdominal pregnancy with good fetomaternal outcome: A case report. International Journal of Case Reports and Images 2012; 3(11):5–8.
27. Pieh-Holder KL, Scardo JA, Costello DH. Lactogenesis failure following successful delivery of advanced abdominal pregnancy. Breastfeed Med. 2012; 7(6):543-6.
28. Kalava A, Mardakh S, Weinberg J, Yarmush J, Schianodicola J, Ahmed K. Anesthetic management of an undiagnosed advanced extrauterine pregnancy under combined spinal-epidural anesthesia. Journal of Anesthesiology and Clinical Science. 2012; 1:13.
29. Tungsagunwattana S, Poolsavatkitikool R. Term Advanced Abdominal Pregnancy. Royal Thai Airforce Medical Gazette. 2012; 58(1):18-22.
30. Kim MJ, Bae JY, Seong WJ, Lee YS. Sonographic diagnosis of a viable abdominal pregnancy with planned delivery after fetal lung maturation. J Clin Ultrasound. 2012.
31. Smrtka MP, Gunatilake R, Miller MJ, Heine RP, Brown HL. Improving the management of an advanced extrauterine pregnancy using pelvic arteriography in a hybrid operating suite. AJP Rep. 2012; 2(1):63-6.
32. Masukume G, Sengurayi E, Muchara A, Mucheni E, Ndebele W, Ngwenya S. Full-term abdominal extrauterine pregnancy complicated by post-operative ascites with successful outcome: a case report. J Med Case Rep. 2013; 7(1):10.
33. Aliyu LD, Ashimi AO. A multicentre study of advanced abdominal pregnancy: a review of six cases in low resource settings. Eur J Obstet Gynecol Reprod Biol. 2013; pii: S0301-2115(13)00253-4.
34. Abdullahi HM, Yakasai IA, Zakari M, Shuaibu SD. Late presentation of advanced abdominal pregnancy with live baby: A case report and literature review. Niger J Basic Clin Sci. 2013; 10:25-8.
35. Pednekar G, Dweep J, Surve S. Successful outcome in a near term Secondary Abdominal pregnancy presenting as Diagnostic Dilemma. IOSR Journal of Dental and Medical Sciences. 2013; 8(6):83-86.
36. Mpogoro F, Gumodoka B, Kihunrwa A, Massinde A. Managing a live advanced abdominal twin pregnancy. Ann Med Health Sci Res. 2013; 3(1):113-5.
37. Renfroe S, Dajani NK, Pandey T, Magann EF. Role of serial MRI assessment in the management of an abdominal pregnancy. BMJ Case Rep. 2013; 14;2013.
38. Mahbuba, Fatema K, Saha RK. Advanced Abdominal Pregnancy with a Full-Term Live Fetus: Case Report. Faridpur Med. Coll. J. 2013; 8(1): 40-43.
39. Navara KJ. Humans at tropical latitudes produce more females. Biol Lett. 2009; 5(4):524-7.
40. Grant VJ, Irwin RJ. A simple model for adaptive variation in the sex ratios of mammalian offspring. J Theor Biol. 2009; 258(1):38-42.
41. Cardy AH, Barker S, Chesney D, Sharp L, Maffulli N, Miedzybrodzka Z. Pedigree analysis and epidemiological features of idiopathic congenital talipes equinovarus in the United Kingdom: a case-control study. BMC Musculoskelet Disord. 2007; 8:62.
42. Ali Z, Schmidt P, Dodd J, Jeppesen DL. Bronchopulmonary dysplasia: a review. Arch Gynecol Obstet. 2013; 288(2):325-33.
43. Taneja B, Srivastava V, Saxena KN. Physiological and anaesthetic considerations for the preterm neonate undergoing surgery. J Neonat Surg. 2012;1:14
44. Weimar CH, Post Uiterweer ED, Teklenburg G, Heijnen CJ, Macklon NS. Reprint of: In-vitro model systems for the study of human embryo-endometrium interactions. Reprod Biomed Online. 2013; 27(6):673-88.
45. Teklu S, Terefe Y. Advanced abdominal pregnancy. Ethiop Med J. 2008; 46(1):99-103.
46. Thomakos N, Kallianidis K, Voulgaris Z, Drakakis P, Arefetz N, Antsaklis A. Extrauterine pregnancy resulting from late spontaneous rupture of an unscarred gravid uterus: case report. Clin Exp Obstet Gynecol. 2009; 36(3):192-3.
47. Tripathi JB, Patel BS, Rawal SA, Garg S. Undiagnosed case of term heterotopic pregnancy with ectopic abdominal pregnancy. J Indian Med Assoc. 2011; 109(10):764-5.
48. Dekker G, Robillard PY, Roberts C. The etiology of preeclampsia: the role of the father. J Reprod Immunol. 2011; 89(2):126-32.

Source(s) of Funding

---

None

Competing Interests

---

None