The author (1)
Dr. Abdelrahman H. Al Harazi, PhD
Assistant professor in Obstetrics & Gynaecology Department
Thamar University, Faculty of medicine
Yemen Republic

The author (2)
Dr. Kaima A Frass, PhD
Assistant professor, in Obstetrics & Gynaecology Department
Sana'a University, Faculty of medicine
Al- Thawra General Hospital
Sana'a - Yemen

Correspondence:
P.O BOX 25244
Yemen Republic
Tel: 009671541840
Mobile: 00967771843083
E-mail: yem008@yahoo.com

INTRODUCTION

Khat plant (catha edulis forsk) is a stimulant leaf, widespread in several countries of the Africa and Arabian peninsula region, including Yemen. It is also called Qat, chat, catha and other names. It has a pleasure-inducing effect, increasing intellectual efficiency and hyper alertness¹. It is chewed daily by a high percentage of the adult population in Yemen. It has been estimated that about 80% of Yemeni men and 60% of women chew Khat².

Several studies demonstrated that the leaves of the Khat plant contain many alkaloids such as cathine and cathinone, the latter structurally related and pharmacologically similar to amphetamine and this is considered to be the main active ingredient in fresh Khat leaves³. However, more than 40 alkaloids, glycosides, tannis and terpenoides have been reported1. The pharmacological effects of the plant are largely due to its symphathomimetic ingredients cathine as (+) Norpseudoephedrine and other alkaloid fractions⁴.

Khat use during pregnancy has many clinical implications like intrauterine growth restriction, decreasing milk production after delivery, and it causes failure to thrive during childhood with its likely long-term consequences⁵. A study on pregnancy outcome and khat showed that it is associated with significantly increased incidence of LBW of full term infants compared to those non-chewers during pregnancy⁶.

In pregnant women, khat consumption may have detrimental effects on utero- placental blood flow and as a consequence, on fetal growth and development⁷. Lower mean birth weights have been reported in khat-chewing mothers compared to non-using mothers indicating an association between khat chewing and decreased birth weight⁶.

Recently, a significant number of young males and females have been involved in the daily chewing habit, and many pregnant women continue chewing Khat during pregnancy. Unfortunately, "Khat chewing during pregnancy is highly prevalent in Yemen2". The purpose of this study was to evaluate the relationship between Khat chewing during pregnancy and the possible low birth weight in unaffected low-risk pregnancies.

It was a prospective controlled study carried out in Al Thawra General Hospital, Sana'a through a year from 1st January to December 31st 2006, to study the effect of khat chewing during pregnancy on neonatal birth weight. For the purpose of this study, we considered a woman as a khat user, if she had chewed khat at least twice a week, regularly for at least one year including the time of index pregnancy. All pregnant women who attended delivery room with labor pain or pregnancy complications (preeclampsia, antepartum hemorrhage, etc), 37 week gestational age or more, were initially surveyed for chewing khat.

However, for those women who were considered khat chewers (n = 1154 women) a complete assessment of maternal and fetal risk factors for low birth weight (LBW) was undertaken. This includes past medical and obstetric history, medication use, recent infections, history of congenital anomalies, occupational or toxic exposure, pre-pregnancy body weight, smoking and other factors.

The gestational ages were estimated either by the last menstrual period (LMP) and/or early ultrasonography. Antenatal cards were reviewed when available. On physical examination, any sign of malnutrition or chronic illnesses were noted. Those presenting with chronic illness, namely, chronic hypertension, anemia, renal disease, prior history of poor pregnancy outcome and other risk factors likely to cause intrauterine growth restriction were excluded from the study. Multiple pregnancy as well as delivery before 37 week gestational age, were also excluded.

1154 women were enrolled in the study and control group (n = 400); women were chosen by simple random sampling and for each case enrolled, the 5th next case, of term pregnant woman who was not a khat chewer, was selected as a control. Consent was obtained from each participant after explaining the study objectives and procedures to the respondents.

In this study we used WHO criteria for low birth weight as less than 2500g.
Standing height was measured before and after delivery with a wall-mounted ruler, and the body weight was estimated either from clinical record or obtained at the time of admission.

After delivery the infants were weighed at birth to the nearest 100gm on ordinary scales by the nursing attendants. Head circumference and height were examined by neonatologists within the first hour after delivery. Neonatal resuscitation and subsequent care of the growth-restricted infants were followed in the same manner as used with other newborns. Also the placentae (appearance, weight and size) were noted.

All statistical analyses were conducted using SPSS for Windows version 16.0. Mean and standard deviations (SD) were calculated for continuous variables, and proportions were calculated for categorical variables. To test the difference in means, we used Student's t test (2-tailed) because data were distributed normally. We used Pearson's x² test to analyze differences in proportions. Statistical significance was defined at the 5% level.

Table 1 gives the general characteristics of the study population. 361 out of 1154 (31.3%) of khat chewing women had delivered babies of less than 2500g body weight. The mean birth weight (MBW) in this group was 2243.5±127.2 g. In the control group 63 women out of 400 (15.75%) had delivered babies of less than 2500g. The MBW was 2861±339g. The difference between the two groups was statistically significant (P < 0.0001). (See Table 2).

Values are expressed in mean±SD, n (%)

Values are expressed in mean±SD, n (%)
*Extremely significant

The age of both groups was statistically similar, (P = 0.791). There were no differences in the gravidity, maternal weight, height, gestational age, mode of delivery, and neonatal gender between the two groups (P > 0.05). The prevalence of placental abnormalities among LBW infants in our study was 49% in the case group versus 32% in control group. No stillborn or congenital anomalies were detected in this study.

Worldwide, 15.5 percent of all births, are born with low birth weight, 95.6 percent of them in developing countries⁸. However, the incidence of LBW varies from as low as 3% in industrialized countries to as high as 30% in some developing countries in Asia and Africa⁹.

Our study showed that the consumption of khat during pregnancy was associated with LBW (< 2500g) in 31.3%, in comparison to the rate of 15.75% in the control group. Recent evidence indicates that the neonates of mothers who chewed khat during pregnancy had a significant decrease in all neonatal parameters such as birth weight, length, head circumference and Apgar score at 1 and 5 minutes compared to non-chewer mothers¹⁰.

LBW could be attributed to many factors. Decrease of daily food intake is a feature of khat chewers that has been proved among pregnant women and female guinea pigs^2,11, which therefore, could explain the low maternal weight gain during pregnancy. Placental insufficiency has been demonstrated through animal data. Jansoon and Colleagues (1987) found that the (+) norpseudoephedrine causes vasconstriction in the utero-placental vascular bed of guinea pigs, which may in turn impair fetal growth through the reduction of placental blood flow¹². Also moderate elevation in blood pressure during and immediately after chewing is reported¹³ that might have a role in placental insufficiency. An experimental study in rats has recently proved that khat consumption can effect intrauterine fetal growth by reducing total fetal fat and weight through some changes in the chemical composition of fetal organs, particularly the liver, heart and kidneys due to depletion of carbohydrate materials and suppression of DNA and protein synthesis in the fetal organs¹⁴.

A large study on pregnant mothers conducted in Yemen (1991), showed that the Khat chewing mothers had more low birth weight babies than the control, but there was no difference between the groups in stillbirth or congenital anomalies6. Our results, however, are in agreement with these findings as there were no congenital anomalies, observed in both groups. A possible explanation is that the teratogenic properties of khat chewing were found to be dose-related¹⁵ whereas the women in fact consume much smaller quantities of khat than men.

During the chewing sessions, the users have more desire to smoke tobacco as both habits are mostly associated, and this further potentiates the adverse effects on fetal weight. Recently, chemical pesticides have been used on Khat by farmers and the residual pesticide could be ingested by Khat users. Although, the causal relationship cannot yet be determined, nevertheless these combined intoxications may expand the list of the possible adverse health effects on pregnant women.

The recorded LBW in control group of 15.75% ia consistent with the finding of the other studies. Makki A.M (2002) found in a study conducted at four main hospitals in Sana'a city that the mean birthweight of a newborn was 2812g and 22% of them had weights between 700 - 2499g⁶.

There are certain limitations in our study. First, it is a result obtained in one referral hospital, therefore, the results may not be generalized to the other hospitals.

In fact the khat chewing habit is increasing among the young group of both sexes and becoming popular in all segments of the female population, which could be attributed to the modern life and gradual disappearance of what was socially deemed unacceptable. For this reason, more surveys and population-based studies are needed.

The other limitation of this study is that, it was carried out in the labour room where admission is restricted to those pregnant women already having labor pain .The future studies are needed to cover, in addition, all durations of gestation through evaluating other variables such as head and abdominal circumferences, femur length, and some of the Doppler measurements in utero during the antenatal check-up.

Despite the limitations in the research methods, the study provides the basic information on the national level and could excite further researchers to address this important issue.

Our results support the proposition that the women who continue their khat chewing habits during pregnancy may result in delivery of neonates with a reduced birth weight in a large proportion ofbirths. However, the issue of possible impact of khat chewing on birth weight warrants further evaluation.

1. Dalu, A. Impact of long term consumption of Khat on public health. The Sudama Concern 2000; 5: 15-16.
   
2. Marwan K, Mohannad A. Khat (Catha edulis) chewing during pregnancy in Yemen: Findings from a national population survey. Matern Child Health J (2008) 12: 308-312.
   
3. Nezar N. AL- Hebshi & Niisskaug. Khat (catha edulis) - an updated review. Addiction Biology 2005, 10, 299 - 307.
   
4. Ali AA, Al-Sharabi AK, Aguirre JM, Nahas R. A study of 342 oral keratotic white lesions induced by Khat chewing among 2500 Yemeni. J Oral Pathol Med. 2004; 33: 368-372.
   
5. Abdul, G. A, Eriksson, M., Kristiansson, B. Qirbi, A. The influence of Khat chewing on birth-weight in full term infants. Soc. Sci. Med. 1987; 24: 625-627.
   
6. Eriksson M, Ghani NA, Kristiansson B; khat-chewing during pregnancy-effect upon the off-spring and some characteristics of the chewers. East Afr. Med. J 1991; 68: 106 - 111.
   
7. el Shoura SM, Abdel AM, Ali ME, el Said MM, Ali KZ, Kemeir MA, Raoof AM, Allam M, Elmalik EM. Deleterious effects of Khat addiction on semen parameters and sperm ultrastructure. Hum Repord 1995; 10: 2295-2300.
   
8. UNICEF and WHO. LBW, country, regional and global estimates. UNICEF, New York, 2004.
   
9. Wannous, S S Arous, Incidence and determinants of low birth weight in Syrian government hospitals. Eastern Med. Health J. 7 (6) November, 2001, 966-974.
   
10. Gamal, S.A., Khalid, A. Neonatal parameters and placental weight in Khat-chewing mothers in Jimma. Ethiopian J of health sci. 1998; 8(1): 39-45.
    
11. Jansson, T. Kristiansson B, Al-Qirbi AA. (1988). Effects of khat on maternal food intake, maternal weight gain and fetal growth in late pregnant guinea pig. J Ethnopharmacol 23: 11-17.
    
12. Jansson, T., Kristian, B., Qirbi, A. Effect of Khat alkaloid (+) norpseudoephedrine on utero placental blood flow in guinea pig. pharmacol. 1987; 34: 95-98.
    
13. Hassan NA, Gunaid AA, Abdo-Rabbo AA, Abdel-Kader ZY, al mansoob MA, Awad AY, Murray-Lyon IM. The effects of Qat chewing on blood pressure and heart rate in healthy volunteers. Trop Doct 2000; 30: 107-108.
    
14. Abd-El-Aziz GS. Effect of Khat extract (catha edulis Forsk) administration on the intrauterine growth in the rat. Egyptian J of anatomy, 1996; 19: 251-277.
    
15. Mwend, J.M et al, Effects of khat (Catha edulis) consumption on reproductive functions: Review. East Africa Med J (2003); 80(6): 318-323.
    
16. Makki, A.M. Risk factors for low birth weight in Sana'a city, Yemen. Annals of Saudi Medicine, 2002, Vol 22, Nos 5 - 6.