[Abnormal twin pregnancy--early resorption of a single fetus in a twin pregnancy pregnancy].
BACKGROUND
Twin pregnancy presents a condition of development of two fetuses in the uterus and can be monozygotic (single ovum) and dizygotic (two ova). In case of fertilization and segmentation of one ovum monozygotic twins are produced, while in case of fertilization of two ova, which can originate from one or two Graff follicles, dizygotic twins are developed. The ratio of twin and single pregnancies is 1:89 (according to Hellin's law) (1). The incidence of twin and other multiple pregnancies is influenced by: race of parents, age and parity of mother, use of clomid and gonadotrophin to stimulate ovulation, discontinued use of contraceptive pills and certain seasons (exposure to sunlight) (1). Due to occurrence of numerous complications twin pregnancy and parturition are considered to be highly risky. This is supported by clinical data on more frequent spontaneous abortions--especially in monozygotic pregnancies, hypertension in pregnancy, hemorrhage of various etiologies, anemias, early rupture of amniotic membranes, hydramnios, premature deliveries, etc. Nowadays diagnosis of both twin and other multiple pregnancies in the early stage is required, in order to establish normal or pathological development of such pregnancies. As early as 6 gestation week in twin pregnancies it is possible to sonographically visualize two gestation sacs in the uterus, while in 7-8 gestation weeks it is possible to see two embryos with evidence of fetal heart rate. In early pregnancy a differentially-diagnosed uterus may be clinically enlarged due to: hydratidaform mole, uterine mioma or ovarian cyst. In later gestation confirmation of twin pregnancy is possible by clinical and sonographic examination and biochemical analyses (elevated values of HPL and -fetoprotein) and less frequently, by x-ray. Repeated sonographic examinations can reveal the following anomalies of twin pregnancies: one normal pregnancy with one sac containing no embryo, one sac containing no embryo and one sac with a dead fetus, fetuses without vitality in both gestation sacs, two ultrasound echoes from which only one normal fetus and one dead mummified fetus (fetus papiraceus) result within the uterus. One gestation sac may be resorbed during pregnancy, while the undamaged fetus continues to develop normally in the uterus. In certain cases the loss of one fetus is not accompanied by any clinical symptoms, and in others this can be accompanied by light hemorrhage. An initial twin pregnancy after the loss of one twin may end by a birth of one healthy infant.


METHODS
A patient aged 35 years, came for gynecological examination due to missed menstruation. Ananmesis showed that she had a nascent uterine myoma which was removed by myomectomy six months earlier, had one parturition four years earlier, and no abortions. The last menstrual period was on February 12, 1991. Clinical examination showed a somewhat larger uterus than would be normal for amenorrhea of 9-gestation week. By sonographic examination two regular gestation sacs were found in the uterus with fetal echoes present as well as heart rate in both fetuses (Figure 1). Embryo measurements were as follows: Fetus 1-CRL-22.5 mm, NEG-8 + 4, heart rate present. Fetus 2-CRL-23.6 mm, NEG-9, heart rate present (Figure 2). The patient was cautiously informed that two fetuses are visible in the uterus and that this is a sign of twin pregnancy, but for certain diagnosis a control examination was scheduled two weeks later. The sonographic examination after 14 days later showed discord in fetal growth (Figure 3). Embryo measurement in 11-gestation week rendered the following parameters: Fetus 1-CRL-22.8 mm, NEG 8 + 6, no heart rate registered (Figure 4), while the second fetus continued to develop and had the following characteristics: Fetus 2-CRL-50.5 mm, NEG 11 + 4, heart rate and fetal movement registered (Figure 5). During entire pregnancy the patient suffered no pain or any kind of hemorrhage. She took no drugs. (ABST
Petaković
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Sluzba za ginekologiju, akuserstvo i neonatologiju, Zdravstveni centar, Sremska Mitrovica.
Petaković
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Madzić
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D000328:Adult; D005260:Female; D005327:Fetal Resorption / Q000000981:diagnostic imaging*; D006801:Humans; D011247:Pregnancy; D011272:Pregnancy, Multiple; D014427:Twins; D016216:Ultrasonography, Prenatal